Therefore, an acetylide anion is produced. A mild acid workup will quench the acetylide anion and the 3-aminopropylamine anion.
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M12O40 cage in metatungstate. In chemistry, metatungstate refers to the anion with the formula [W12O40]8- and salts derived from this anion. The term also refers to protonated derivatives of this anion, including [H2W12O40]6-. The unprotonated anion [W12O40]12- has Td symmetry.
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Mixed anion compounds, heteroanionic materials or mixed anion materials are chemical compounds containing cations and more than one kind of anion. The compounds contain a single phase, rather than just a mixture.
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Lithium tetrakis(pentafluorophenyl)borate, containing the BARF-20 anion, is used similarly to the BARF-24 anion.
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The anion is generated by dissolving in hot concentrated HNO3. The salt consists of the anion and a pair of NH4+ counter ions. The ammonium ions are not involved in the oxidising reactions of this salt. In the anion each nitrate group is chelated to the cerium atom in a bidentate manner as shown below: :Hexanitratocerate anion The anion has Th (idealized Oh) molecular symmetry.
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At least two major types of anion channels have been characterized in the plasma membrane: S-type anion channels and R-type anion channels.Linder B & Raschke K (1992) A slow anion channel in guard cells, activation at large hyperpolarization, may be principal for stomatal closing. FEBS Lett. 131:27-30.
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Trithiophosphate is the anion [POS3]3−, which has C3v symmetry. Tetrathiophosphate is the anion [PS4]3−, which has Td symmetry.
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Another large class of non-coordinating anions are derived from carborane anion . Using this anion, the first example of a three-coordinate silicon compound, the salt [(mesityl)3Si][HCB11Me5Br6] contains a non-coordinating anion derived from a carborane.
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Hyperchloremic acidosis is a form of metabolic acidosis associated with a normal anion gap, a decrease in plasma bicarbonate concentration, and an increase in plasma chloride concentration (see anion gap for a fuller explanation). Although plasma anion gap is normal, this condition is often associated with an increased urine anion gap, due to the kidney's inability to secrete ammonia.
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The urine anion gap is calculated using measured ions found in the urine. It is used to aid in the differential diagnosis of metabolic acidosis. The term "anion gap" without qualification usually implies serum anion gap. The "urine anion gap" is a different measure, principally used to determine whether the kidneys are capable of appropriately acidifying urine.
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For example, methane, CH4, obeys the conditions for the ionic model with carbon as the cation and hydrogen as the anion (or vice versa, since carbon and hydrogen have the same electronegativity). For compounds that contain cation-cation or anion-anion bonds it is usually possible to transform these homoionic bonds into cation-anion bonds either by treating the atoms linked by the homoionic bond as a single complex cation (e.g., Hg22+), or by treating the bonding electrons in the homoionic bond as a pseudo-anion to transform a cation-cation bond into two cation - pseudo-anion bonds, e.g., Hg2+-e2−-Hg2+.
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The phosphaethynolate anion is the phosphorus-containing analogue of the cyanate anion with the chemical formula [PCO]− or [OCP]−. The anion has a linear geometry and is commonly isolated as a salt. When used as a ligand, the phosphaethynolate anion is ambidentate in nature meaning it forms complexes by coordinating via either the phosphorus or oxygen atoms. This versatile character of the anion has allowed it to be incorporated into many transition metal and actinide complexes but now the focus of the research around phosphaethynolate has turned to utilising the anion as a synthetic building block to organophosphanes.
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Chemical structure of the dimethyldithiocarbamate anion Dimethyldithiocarbamate is the organosulfur anion with the formula (CH3)2NCS2−. It is one of the simplest organic dithiocarbamate.
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Delta ratio, or "delta-delta", is a formula that can be used to assess elevated anion gap metabolic acidosis and to evaluate whether a mixed acid- base disorder (metabolic acidosis) is present. The anion gap (AG) without potassium is calculated first and if a metabolic acidosis is present, results in either a high anion gap metabolic acidosis (HAGMA) or a normal anion gap acidosis (NAGMA). A low anion gap is usually an oddity of measurement, rather than a clinical concern.
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Proposed mechanism for CO2 reduction to CO in non-aqueous media involves single electron reduction of CO2 to CO2●− radical anion and adsorption of radical anion to surface followed by disproportionate reaction between unreduced CO2 and CO2●− radical anion to form CO32− and CO.
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Space-filling model of the cyanate anion. Cyanate is an anion with the structural formula [O=C=N]−, usually written [OCN]− or [NCO]−; or any salt containing it, such as ammonium cyanate. It is the same as the isocyanate anion and an isomer of the much less stable fulminate anion [C−≡N+O]−. It can take up a proton to form isocyanic acid, H−N=C=O.
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Structure of the anion In chemistry, orthosilicate is the anion , or any of its salts and esters. It is one of the silicate anions. It is occasionally called the silicon tetroxide anion or group.C. A. Kumins, and A. E. Gessler (1953), "Short-Cycle Syntheses of Ultramarine Blue".
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Ammonium hexafluorophosphate is the inorganic compound with the formula NH4PF6. It is a white water-soluble, hygroscopic solid. The compound is a salt consisting of the ammonium cation and hexafluorophosphate anion. It is commonly used as a source of the hexafluorophosphate anion, a weakly coordinating anion.
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Hydrogenacetylenedicarboxylate (often abbreviated as Hadc or HADC) is a monovalent anion of acetylenedicarboxylic acid with the formula or . The anion can be derived from acetylenedicarboxylic acid by removal of a single proton or from the acetylenedicarboxylate dianion by addition of a proton. The name is also used for any salt of this anion. Salts of this anion are of interest in crystallography because they contain unusually short and strong hydrogen bonds.
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Structural formula of the mesylate anion Ball-and-stick model of the mesylate anion In chemistry, a mesylate is any salt or ester of methanesulfonic acid (CH3SO3H). In salts, the mesylate is present as the CH3SO3− anion. When modifying the International Nonproprietary Name of a pharmaceutical substance containing the group or anion, the correct spelling is mesilate (as in imatinib mesilate, the mesylate salt of imatinib). Retrieved 5 December 2008.
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The Vilsmeier reagent is an organic compound with the formula [(CH3)2NCHCl]Cl. It is a salt consisting of the N,N-dimethyliminium cation ([(CH3)2N=CHCl]+) and chloride anion. Depending on the particular reaction, the anion can vary. In typical POCl3-based reactions, the anion is PO2Cl2−.
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Lazurite contains . Although is elusive under ordinary conditions, the radical anion is abundant. It exhibits an intense blue colour. Sometimes called thiozonide, by analogy with the ozonide anion, .
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Skeletal formula of the bistriflimide anion Ball-and-stick model of the bistriflimide anion Bistriflimide, systematically known as bis(trifluoromethane)sulfonimide (or 'imidate', see below) and colloquially as TFSI, is a non-coordinating anion with the chemical formula [(CF3SO2)2N]−. Its salts are typically referred to as being metal triflimidates.
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Because this bond is fragile, the dithionite anion dissociates in solution into the [SO2]− radical anion, as has been confirmed by EPR spectroscopy. It is also observed that 35S undergoes rapid exchange between S2O42− and SO2 in neutral or acidic solution, consistent with the weak S-S bond in the anion.
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Tributylammonium TRISPHAT is an organic salt with the formula . The anion features phosphorus(V) bonded to three tetrachlorocatecholate () ligands. This anion can be resolved into the enantiomers, which are optically stable (the picture shows the Δ enantiomer). The TRISPHAT anion has been used as a chiral shift reagent for cations.
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Solute carrier organic anion transporter family member 2B1 also known as organic anion-transporting polypeptide 2B1 (OATP2B1) is a protein that in humans is encoded by the gene SLCO2B1.
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The position adjacent to a double bond is acidic because the resulting allyl anion is stabilized by resonance. This effect becomes more pronounced as more alkenes are involved to create greater stability. For example, deprotonation at position 3 of a 1,4-diene or position 5 of a 1,3-diene give a pentadienyl anion. An even greater effect is seen if the anion is aromatic, for example, deprotonation of cyclopentadiene to give the cyclopentadienyl anion.
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The anion from the corresponding silver salt is then added by nucleophilic substitution to the iodinium ion. center In the Prévost reaction, the iodinium ion undergoes nucleophilic attack by benzoate anion. The benzoate anion acts as a nucleophile again to displace iodide through a neighboring-group participation mechanism. A second benzoate anion reacts with the intermediate to produce the anti-substituted dibenzoate product, which can then undergo hydrolysis to yield trans-diols.
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In organometallic chemistry, the pentadienyl anion is a ligand, the acyclic analogue of the more-common cyclopentadienyl anion. The pentadienyl anion is generated by deprotonation of pentadiene. A number of complexes are known, including bis(pentadienyl) iron, Fe(C5H7)2, the "open" analog of ferrocene. Only few pentadienyl complexes feature simple C5H7 ligands.
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Dr. James F. Keggin, the discoverer of the Keggin Structure. The first example of a polyoxometalate compound was ammonium phosphomolybdate, containing the anion, discovered in 1826. This anion has the same structure as the phosphotungstate anion, whose structure was reported in 1934. This structure is called the Keggin structure after its discoverer.
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Anion attachment can also lead to the formation of negative ions for some molecules, for example, (M + Cl)−. Thermal desorption usually produces anion (A−) and cluster ion (e.g. CA2−) for salts.
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Other types of semipermeable membranes are cation exchange membrane (CEM), charge mosaic membrane (CMM), bipolar membrane (BPM), anion exchange membrane (AEM) alkali anion exchange membrane (AAEM) and proton exchange membrane (PEM).
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Structure of . A distinctive derivative of rhenium is nonahydridorhenate, originally thought to be the rhenide anion, Re−, but actually containing the anion in which the oxidation state of rhenium is +7.
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Result 2: if the delta ratio is somewhere between low (<0.4) and high (1–2), then it is usually due to a combination of high anion gap metabolic acidosis and normal anion gap acidosis. For example, a person with cholera may have a normal anion gap acidosis due to diarrhea, but becomes progressively dehydrated and develops a lactic acidosis from shock, and proceeds to develop a high anion gap metabolic acidosis – i.e. a mixed acid-base disorder.
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In analogy with the Lieb Limiger model of \delta function bose gas, the quantum Kundu-Ekchaus model in the N-particle sector therefore corresponds to a one-dimensional (1D) anion gas interacting via a \delta function interaction. This model of interacting anion gas was proposed and exactly solved by the Bethe ansatz in and this basic anion model is studied further for investigating various aspects of the 1D anion gas as well as extended in different directions.
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An analog of the deltate anion can be obtained by replacing the three oxygen atoms (=O or −O−) by cyanoimino groups (=N−C≡N or −N=C=N−) to yield the symmetric anion . Replacement of the three oxygen atoms by dicyanomethylene (=C(CN)2) provides an oxidizing species that is readily reduced to a stable radical anion and dianion.
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The di-anion has its two negative charges in one ring, converting that ring into a 10-pi electron aromatic system similar to the di-anion of cyclooctatetraene. In the 18-pi electron tetra-anion, both rings effectively have access to 10 pi electrons, leading to a planar, bicyclic aromatic structure analogous to that of naphthalene.
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Serum glucose levels are measured to document the degree of hypoglycemia. Serum electrolytes calculate the anion gap to determine presence of metabolic acidosis; typically, patients with glycogen-storage disease type 0 (GSD-0) have an anion gap in the reference range and no acidosis. See the Anion Gap calculator. Serum lipids (including triglyceride and total cholesterol) may be measured.
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The iodate anion, Space-filling model of the iodate anion An iodate is a conjugate base of iodic acid.Merriam-Webster definition In the iodate anion, iodine is bonded to three oxygen atoms and the molecular formula is . The molecular geometry of iodate is trigonal pyramidal. Iodate can be obtained by reducing a periodate with a sulfide.
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A commercially important heptafluoride anion is the heptafluorotantalate anion, TaF72−. It is an intermediate in the purification of tantalum. Many dimeric and oligomeric heptafluorides have been observed or proposed. One example is B2F7−.
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The final glucose oxidation products besides sodium gluconate have been identified as D-arabino-hexos-2-ulose (glucosone), the anion of D-arabinonate after splitting off of a formate anion and arabinonic acid.
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Sodium molybdate, Na2MoO4, is useful as a source of molybdenum. It is often found as the dihydrate, Na2MoO4·2H2O. The molybdate(VI) anion is tetrahedral. Two sodium cations coordinate with every one anion.
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The tetramethylborate anion (CH3)4B− only has one boron atom.
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The hydrogen anion is written as "H–" and called hydride.
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The anion is prepared by treatment of phosphorus pentachloride with tetrachlorocatechol followed by a tertiary amine gives the anion: :PCl5 \+ 3 C6Cl4(OH)2 → H[P(O2C6Cl4)3] + 5 HCl H[P(O2C6Cl4)3] + Bu3N Bu3NH+ [P(O2C6Cl4)3]− Using a chiral amine, the anion can be readily resolved.F. Favarger, C. Goujon-Ginglinger, D. Monchaud, J. Lacour "Large-Scale Synthesis and Resolution of TRISPHAT [Tris(tetrachlorobenzenediolato) Phosphate(V)] Anion" Journal of Organic Chemistry, 2004, volume 69, pp. 8521–8524, 2004. .
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Tantalate is an tantalum-containing anion or a salt of such an anion. A commercially important example is heptafluorotantalate (TaF72−) and its potassium salt (K2TaF7). :Potassium heptafluorotantalate. Many oxides of tantalum are called tantalates.
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Inorganic ozonidesF. A. Cotton and G. Wilkinson "Advanced Inorganic Chemistry", 5th edition (1988), p.462 are dark red ionic compounds containing the reactive anion. The anion has the bent shape of the ozone molecule.
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The sum of the cation and anion transport numbers equals 1.
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The bifluoride ion is an inorganic anion with the chemical formula .
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Layered double hydroxides are well known for their anion exchange properties.
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Anion-stabilizing group will prefer the endo orientation in transition state.
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Phenalene is deprotonated by potassium methoxide to give the phenalenyl anion.
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The malate anion is an intermediate in the citric acid cycle.
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The proposed mechanism for cationic photopolymerization begins with the photoexcitation of the initiator. Once excited, both homolytic cleavage and dissociation of a counter anion takes place, generating a cationic radical (R), an aryl radical (R') and an unaltered counter anion (X). The abstraction of a lewis acid by the cationic radical produces a very weakly bound hydrogen and a free radical. The acid is further deprotonated by the anion (X) in solution, generating a lewis acid with the starting anion (X) as a counter ion.
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High anion gap metabolic acidosis is a form of metabolic acidosis characterized by a high anion gap (a medical value based on the concentrations of ions in a patient's serum). Metabolic acidosis occurs when the body produces too much acid, or when the kidneys are not removing enough acid from the body. Several types of metabolic acidosis occur, grouped by their influence on the anion gap. The anion gap can be increased due to relatively low levels of cations other than sodium and potassium (e.g.
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For this reason, this equation is also called the constant selectivity relationship. In the original publication the data were obtained by reactions of selected nucleophiles with selected electrophilic carbocations such as tropylium or diazonium cations: :Ritchie equation diazonium ion reactions or (not displayed) ions based on malachite green. Many other reaction types have since been described. Typical Ritchie N+ values (in methanol) are: 0.5 for methanol, 5.9 for the cyanide anion, 7.5 for the methoxide anion, 8.5 for the azide anion, and 10.7 for the thiophenol anion.
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There are two types of ion exchange chromatography: Cation-Exchange and Anion- Exchange. In the Cation-Exchange Chromatography the stationary phase has negative charge and the exchangeable ion is a cation, whereas, in the Anion- Exchange Chromatography the stationary phase has positive charge and the exchangeable ion is an anion. Ion exchange chromatography is commonly used to purify proteins using FPLC.
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If the substance lacks the ability to dissolve in water, the molecules form a precipitate. Reactions in aqueous solutions are usually metathesis reactions. Metathesis reactions are another term for double-displacement; that is, when a cation displaces to form an ionic bond with the other anion. The cation bonded with the latter anion will dissociate and bond with the other anion.
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In chemistry, paratungstate refers to the anion with the formula [W12O42]12- and salts derived from this anion. The term also refers to protonated derivatives of this anion, including [H2W12O42]10-. Ammonium paratungstate (or APT), (NH4)10[H2W12O42] is a key intermediate in the purification of tungsten from its ores. Structure of the paratungstate [H2W12O42]10-, highlighting its relatively low symmetry.
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The Chloroplast Envelope Anion Channel-forming Tic110 (Tic110) Family (TC#1.A.18) consists of proteins of the inner chloroplast envelope membrane. This family consists of the inner membrane protein import apparatus, and appears to be a protein import-related anion-selective channel. It has also been designated (1) IEP110, (2) IAP100 and (3) protein import-related anion channel (PIRAC).
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The anion can also be obtained by electrolysis of a saturated solution of rubidium carbonate in water. In addition, the peroxodicarbonate anion can be obtained by electrosynthesis on boron doped diamond (BDD) electrodes. The formal oxidation of two carbonate ions takes place at the anode. Due to the high oxidation potential of the peroxodicarbonate anion, a high anodic overpotential is necessary.
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Scheme 2. Anion relay chemistry, Ph stands for phenyl The anion relay chemistry tactic has been applied elegantly in the total synthesis of complex molecules of significant biological activity, such as spongistatin 2 and mandelalide A.
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Sodium phosphide is the inorganic compound with the formula Na3P. It is a black solid. It is often described as Na+ salt of the P3− anion. Na3P is a source of the highly reactive phosphide anion.
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A counterion will be more commonly referred to as an anion or a cation, depending on whether it is negatively or positively charged. Thus, the counterion to an anion will be a cation, and vice versa.
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The cyanate anion is isoelectronic with carbon dioxide and with the azide anion, being linear. The C-N distance is 121 pm, about 5 pm longer than for cyanide.Jursík, F. (2001). Anorganická chemie nekovů (1. vydání).
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The anion is known in high pH solutions of Al(OH)3.
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It is a mixed anion compound that also contains carbonate and chloride.
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The conjugate anion of a heteropoly acid is known as a polyoxometalate.
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In inorganic chemistry disulfide usually refers to the corresponding anion (−S−S−).
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The trichloride anion, , has also been characterised; it is analogous to triiodide.
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Called Rongalite, this anion is also commercially useful as a reducing agent.
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Lithium monoxide anion (LiO−) is a superbase existing in the gas phase. It was the strongest known base until 2008, when the isomeric diethynylbenzene dianions were determined to have a higher proton affinity. Ortho- diethynylbenzene dianion is the strongest base, followed by meta- diethynylbenzene dianion and para-diethynylbenzene dianion. The methyl anion CH3− was the strongest known base before lithium monoxide anion was discovered.
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Hydrogenoxalate or hydrogen oxalate is an anion with chemical formula or , derived from oxalic acid by the loss of a single proton; or, alternatively, from the oxalate anion by addition of a proton. The name is also used for any salt containing this anion, such as NaHC2O4, KHC2O4, or NH3HC2O4. Hydrogenoxalates may also be called (especially in older literature) bioxalates, acid oxalates, or monobasic oxalates.
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A ball-and-stick model of the peroxodisulfate anion The structure of the peroxodisulfate anion The peroxydisulfate ion, , is an oxyanion. It is commonly referred to as the persulfate ion or peroxodisulfate anions, but this term also refers to the peroxomonosulfate ion, . Approximately 500,000 tons of salts containing this anion are produced annually. Important salts include sodium persulfate (Na2S2O8), potassium persulfate (K2S2O8), and ammonium persulfate ((NH4)2S2O8).
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Lithium tetrakis(pentafluorophenyl)borate is the lithium salt of the weakly coordinating anion (B(C6F5)4)−. Because of its weakly coordinating abilities, lithium tetrakis(pentafluorophenyl)borate makes it commercially valuable in the salt form in the catalyst composition for olefin polymerization reactions and in electrochemistry. It is a water-soluble compound. Its anion is closely related to the non-coordinating anion known as BARF.
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Protein DRA is a membrane protein in intestinal cells. It is an anion exchanger and a member of the sulfate anion transporter (SAT) family. It mediates chloride and bicarbonate exchange and additionally transports sulfate and other anions at the apical membrane, part of the plasma membrane of enterocytes. It is different from the anion exchanger that present in erythrocytes, renal tubule, and several other tissues.
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The salt contains the tetrahedral [MoS4]2− anion. The compound is prepared by treating solutions of molybdate, [MoO4]2− with hydrogen sulfide in the presence of ammonia: :(NH4)2MoO4 \+ 4 H2S -> (NH4)2MoS4 \+ 4 H2O The [MoS4]2− anion.
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Crystal structure of sodium tellurite, highlighting the pyramidal structure of the anion. Tellurite dianion is pyramidal, like selenite and sulfite. The anion has C3v symmetry. Tellurites can be reduced to elemental tellurium by electrolysis or a strong reducing agent.
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Chromate salts contain the chromate anion, . Dichromate salts contain the dichromate anion, . They are oxoanions of chromium in the 6+ oxidation state and are moderately strong oxidizing agents. In an aqueous solution, chromate and dichromate ions can be interconvertible.
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Barium tungstate is an inorganic chemical compound of barium and the tungstate anion.
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The ion chromatogram shows a typical chromatogram obtained with an anion exchange column.
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The perrhenate ion is the anion with the formula , or a compound containing this ion. The perrhenate anion is tetrahedral, being similar in size and shape to perchlorate and the valence isoelectronic permanganate. The perrhenate anion is stable over a broad pH range and can be precipitated from solutions with the use of organic cations. At normal pH, perrhenate exists as metaperrhenate (), but at high pH mesoperrhenate () forms.
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Initiation of styrene polymerization with sodium naphthalene proceeds by electron transfer from the naphthalene radical anion to the monomer. The resulting radical dimerizes to give a dilithio compound, which then functions as the initiator. Polar solvents are necessary for this type of initiation both for stability of the anion-radical and to solvate the cation species formed. The anion-radical can then transfer an electron to the monomer.
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Band 3 anion transport protein, also known as anion exchanger 1 (AE1) or band 3 or solute carrier family 4 member 1 (SLC4A1), is a protein that is encoded by the SLC4A1 gene in humans. Band 3 anion transport protein is a phylogenetically-preserved transport protein responsible for mediating the exchange of chloride (Cl−) with bicarbonate (HCO3−) across plasma membranes. Functionally similar members of the AE clade are AE2 and AE3.
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Hypoalbuminemia can mask a mild elevation of the anion gap, resulting in failure to detect an accumulation of unmeasured anions. Therefore, it is important to correct the calculated value of the anion gap for the concentration of albumin, particularly in critically ill patients. Corrections can be made for the albumin concentration using the Figge-Jabor-Kazda-Fencl equation to give an accurate anion gap calculation as exemplified below.
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The ascorbate anion forms salts, such as sodium ascorbate, calcium ascorbate, and potassium ascorbate.
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The triflide anion has also been employed as the anionic component of ionic liquids.
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Hydrogen-bond catalysts can also accelerate reactions by assisting in the formation of electrophilic species through abstracting and/or coordinating an anion such as a halide. Urea and thiourea catalysts are the most common donors in anion-binding catalysis, and their ability to bind halides and other anions has been well established in the literature. The use of chiral anion-binding catalysts can create an asymmetric ion pair and induce remarkable stereoselectivity. One of the first reactions proposed to proceed through anion-binding catalysis is the Pictet-Spengler- type cyclization of hydroxylactams with TMSCl under thiourea catalysis.
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Sodium perborate undergoes hydrolysis in contact with water, producing hydrogen peroxide and borate. More precisely, in solution the cyclic anion hydrolizes into two anions , which then enter in equilibrium with boric acid , hydrogen peroxide , the hydroperoxyl anion , and the tetrahydroxyborate anion : \+ 2 H2O <=> 2 [B(OH)3(OOH)]- [B(OH)3(OOH)]- <=> B(OH)3 + HOO- B(OH)3 + HOO- + H2O <=> [B(OH)4]- + H2O2 As the concentration of the solution increases, other peroxoborate species become significant. With excess , the anions , , and eventually appear. At high borate concentrations, the sodium perborate with dimeric anion crystallizes out, due to its relatively low solubility.
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Often, a polyatomic ion can be considered as the conjugate acid or base of a neutral molecule. For example, the conjugate base of sulfuric acid (H2SO4) is the polyatomic hydrogen sulfate anion (). The removal of another hydrogen ion produces the sulfate anion ().
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The naphthalene anion initiate polymerization by reducing styrene to its radical anion, which dimerizes to the dilithiodiphenylbutane, which then initiates the polymerization. These experiments relied on Szwarc's ability to control the levels of impurities which would destroy the highly reactive organometallic intermediates.
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Structure of formate Formate (IUPAC name: methanoate) is the anion derived from formic acid. Its formula is represented in various equivalent ways: HCOO− or CHOO− or HCO2−. It is the product of deprotonation of formic acid. It is the simplest carboxylate anion.
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Anion exchange transporter is a protein that in humans is encoded by the SLC26A7 gene.
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NADH, in contrast, is a doubly charged anion, because of its two bridging phosphate groups.
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Anion exchange sorbents are derivatized with positively charged functional groups that interact and retain negatively charged anions, such as acids. Strong anion exchange sorbents contain quaternary ammonium groups that have a permanent positive charge in aqueous solutions, and weak anion exchange sorbents use amine groups which are charged when the pH is below about 9. Strong anion exchange sorbents are useful because any strongly acidic impurities in the sample will bind to the sorbent and usually will not be eluted with the analyte of interest; to recover a strong acid a weak anion exchange cartridge should be used. To elute the analyte from either the strong or weak sorbent, the stationary phase is washed with a solvent that neutralizes the charge of either the analyte, the stationary phase, or both.
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With a formula weight of 86.8, BF is also conveniently the smallest weakly coordinating anion from the point of view of equivalent weight, often making it the anion of choice for preparing cationic reagents or catalysts for use in synthesis, in the absence of other substantial differences in chemical or physical factors. The anion is less nucleophilic and basic (and therefore more weakly coordinating) than nitrates, halides or even triflates. Thus, when using salts of , one can usually assume that the cation is the reactive agent and this tetrahedral anion is inert. owes its inertness to two factors: (i) it is symmetrical so that the negative charge is distributed equally over four atoms, and (ii) it is composed of highly electronegative fluorine atoms, which diminish the basicity of the anion.
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Some silicon centers may be replaced by atoms of other elements, still bound to the four corner oxygen corners. If the substituted atom is not normally tetravalent, it usually contributes extra charge to the anion, which then requires extra cations. For example, in the mineral orthoclase , the anion is a tridimensional network of tetrahedra in which all oxygen corners are shared. If all tetrahedra had silicon centers, the anion would be just neutral silica .
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A low anion gap is frequently caused by hypoalbuminemia. Albumin is a negatively charged protein and its loss from the serum results in the retention of other negatively charged ions such as chloride and bicarbonate. As bicarbonate and chloride anions are used to calculate the anion gap, there is a subsequent decrease in the gap. The anion gap is sometimes reduced in multiple myeloma, where there is an increase in plasma IgG (paraproteinaemia).
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The structure of the tetrafluoroborate anion, Tetrafluoroborate is the anion . This tetrahedral species is isoelectronic with tetrafluoroberyllate (), tetrafluoromethane (CF4), and tetrafluoroammonium () and is valence isoelectronic with many stable and important species including the perchlorate anion, , which is used in similar ways in the laboratory. It arises by the reaction of fluoride salts with the Lewis acid BF3, treatment of tetrafluoroboric acid with base, or by treatment of boric acid with hydrofluoric acid.
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In chemistry, plumbite is the oxyanion or hydrated forms, or any salt containing this anion. In these salts, lead is in the oxidation state +2. It is the traditional term for the IUPAC name plumbate(II). For example, lead(II) oxide (PbO) dissolves in alkali to form salts containing the anion: :PbO + → Lead(II) hydroxide also dissolves in excess alkali to form the anion: : + 4 → The plumbite ion is a weak reducing agent.
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Gabriel-Colman Rearrangement Mechanism The reaction mechanism starts with an attack on the carbonyl group by a strong base, such as methoxide ion. The ring is then opened, forming an imide anion. This is then followed by a rapid isomerization of the imide anion to the carbanion. This is facilitated by the electron withdrawing effect of the substituent, which allows for greater stabilization of the adjacent carbanion with respect to the imide anion.
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When the phosphate anion is replaced by the larger vanadate anion, the tetragonal crystal system preferentially accommodates the larger light rare- earth elements.Miyawaki R., and I. Nakai. (1996). "Crystal Chemical Aspects of Rare Earth Minerals". Ed. Andrian P. Jones, Frances Wall, and C. Terry Williams.
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In inorganic chemistry, perrhenate anion is also used as a weakly coordinating anion. It is a weaker base than or but stronger than or . Unlike the related permanganate, perrhenate is nonoxidising. Silver perrhenate reacts with trimethylsilyl chloride to give the silyl "ester" (CH3)3SiOReO3.
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Ferricyanide is the anion [Fe(CN)6]3−. It is also called hexacyanoferrate(III) and in rare, but systematic nomenclature, hexacyanidoferrate(III). The most common salt of this anion is potassium ferricyanide, a red crystalline material that is used as an oxidant in organic chemistry.
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The chlorate anion has the formula . In this case, the chlorine atom is in the +5 oxidation state. "Chlorate" can also refer to chemical compounds containing this anion; chlorates are the salts of chloric acid. "Chlorate", when followed by a Roman numeral in parentheses, e.g.
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In other substitution reactions, it undergoes halogenation. Polychlorinated biphenyls were once popular pesticides. Lithium biphenyl contains the radical anion, which is highly reducing (-3.1 V vs Fc+/0). Several solvates of alkali metal salts of biphenyl anion have been characterized by X-ray crystallography.
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Hyponitrous acid is a chemical compound with formula or HON=NOH. It is an isomer tautomer of nitramide, H2N−NO2. Hyponitrous acid forms two series of salts, the hyponitrites containing the [ON=NO]2− anion, and the "acid hyponitrites" containing the [HON=NO]− anion.
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Testis anion transporter 1 is a protein that in humans is encoded by the SLC26A8 gene.
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A hypobromite is a compound that contains this anion. Examples include sodium hypobromite and potassium hypobromite.
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To simplify the presentation, the image in the table depicts the acid form of this anion.
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There is some evidence that the anion, which obeys the 4n+2 Hückel rule, is aromatic.
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Anion gap can be classified as either high, normal or, in rare cases, low. Laboratory errors need to be ruled out whenever anion gap calculations lead to results that do not fit the clinical picture. Methods used to determine the concentrations of some of the ions used to calculate the anion gap may be susceptible to very specific errors. For example, if the blood sample is not processed immediately after it is collected, continued cellular metabolism by leukocytes (also known as white blood cells) may result in an increase in the HCO concentration, and result in a corresponding mild reduction in the anion gap.
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This ambidentate character of the anion means that it is able to bind via both the phosphorus and oxygen atoms depending on the nature of the centre being coordinated. Computational studies carried out on the anion such as Natural Bond Orbital (NBO) and Natural Resonance Theory (NRT) analyses can go part way to explain why PCO can react in such a manner (see Figure 1). The two dominant resonance forms of the phosphaethynolate anion localise negative charge on either the phosphorus or oxygen atoms meaning both are sites of nucleophilicity. The same applies for the cyanate anion hence why PCO is observed to have similar pseudo-halogenic behaviour.
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Hence, synthetic chemists have developed various acyl anion synthetic equivalents, such as dithianes, as surrogates. However, as a partial exception, hindered dialkylformamides (e.g., HCONiPr2) can undergo deprotonation at low temperature (−78 °C) with lithium diisopropylamide as the base to form a carbamoyl anion stable at these temperatures.
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Miyazawa found mitochondrial superoxide anion production can lead to organ atrophy and dysfunction via mitochondrial- mediated apoptosis. In addition, they suggest mitochondrial superoxide anion plays an essential part in aging.Miyazawa M, Ishii T, Yasuda K, Noda S, Onouchi H, Hartman PS, et al. Lund et al.
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Because we know that plasma is electro-neutral (uncharged), we can conclude that the anion gap calculation represents the concentration of unmeasured anions. The anion gap varies in response to changes in the concentrations of the above-mentioned serum components that contribute to the acid-base balance.
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The structure shown is a composite of five resonance contributors in which each carbon atom carries part of the negative charge. Salts of the cyclopentadienyl anion can be stable, e.g., sodium cyclopentadienide. Coordination compounds of the cyclopentadienyl anion (not the cyclopentadienyl radical) are known as cyclopentadienyl complexes.
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Structure of (Me4N+)2[Fe(C2B9H11)2]+, showing only one Me4N+. In organometallic chemistry, a dicarbollide is an anion of the formula [C2B9H11]2-. Various isomers exist, but most common is 1,2-dicarbollide derived from ortho-carborane. These dianions function as ligands, related to the cyclopentadienyl anion.
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Anion-exchange chromatography is a process that separates substances based on their charges using an ion-exchange resin containing positively charged groups, such as diethyl-aminoethyl groups (DEAE). In solution, the resin is coated with positively charged counter-ions (cations). Anion exchange resins will bind to negatively charged molecules, displacing the counter-ion. Anion exchange chromatography is commonly used to purify proteins, amino acids, sugars/carbohydrates and other acidic substances with a negative charge at higher pH levels.
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Rhodizonic acid is a member of a chain of oxidation products: benzenehexol , tetrahydroxybenzoquinone (THBQ) , rhodizonic acid , and cyclohexanehexone . Lithium rhodizonate, together with salts of THBQ and benzenehexol, has been considered for possible use in rechargeable electrical batteries. The monovalent anion has been detected in mass spectrometry experiments. Rhodizonic acid and the rhodizonate anion can lose one of the CO units to yield croconic acid and the croconate anion , respectively, by mechanisms that are still imperfectly known.
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It can be produced on heterotrophic growth media and purified via anion exchangeand size exclusion chromatography matrices.
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A Ball-and-stick model of the peroxomonosulfate anion The structure of the peroxomonosulfate anion The peroxomonosulfate ion, , is a sulfur oxoanion. It is sometimes referred to as the persulfate ion, but this term also refers to the peroxydisulfate ion, . Its other IUPAC names are sulfuroperoxoate and trioxidoperoxidosulfate(2−).
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DEAE-C is a weak anion exchanger. This exchange is utilized to separate proteins that have faintly differing charges. Like all anion exchangers, the resin carries a positive charge that interacts favorably with negative charges. The positive charge of DEAE cellulose is due to a protonated amine group.
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Two related products have been crystallized from HF-SbF5 mixtures, and both have been analyzed by single crystal X-ray crystallography. These salts have the formulas and . In both salts, the anion is . As mentioned above, is weakly basic; the larger anion is expected to be still weaker.
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Manganate(V) is a tetrahedral oxyanion structurally similar to sulfate, manganate, and permanganate. As expected for a tetrahedral complex with a d2 configuration, the anion has a triplet ground state. The anion is a bright blue species. with a visible absorption maximum at wavelength λmax = 670 nm (ε = )..
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In chemistry, perxenates are salts of the yellow xenon-containing anion . This anion has octahedral molecular geometry, as determined by Raman spectroscopy, having O–Xe–O bond angles varying between 87° and 93°. The Xe–O bond length was determined by X-ray crystallography to be 1.875 Å.
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Channelrhodopsin-2. Anion-conducting channelrhodopsins are light-gated ion channels that open in response to light and let negatively charged ions (such as chloride) enter a cell. All channelrhodopsins use retinal as light- sensitive pigment, but they differ in their ion selectivity. Anion-conducting channelrhodopsins are used as tools to manipulate brain activity in mice and fruit flies (Optogenetics). Neurons expressing anion-conducting channelrhodopsins are silenced when illuminated with light, an effect that has been used to investigate information processing in the brain.
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Ferrioxalate or trisoxalatoferrate(III) is a trivalent anion with formula . It is a transition metal complex consisting of an iron atom in the +3 oxidation state and three bidentate oxalate ions anions acting as ligands. The ferrioxalate anion gives a lime green color to salts, and in solution it is fluorescent. The anion is sensitive to light and higher-energy electromagnetic radiation, which causes the decomposition of one oxalate to carbon dioxide and reduction of the iron(III) atom to iron(II).
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If the anion name ends in -ide then as a ligand its name is changed to end in -o. For example the chloride anion, Cl− becomes chlorido. This is a difference from organic compound naming and substitutive naming where chlorine is treated as neutral and it becomes chloro, as in PCl3, which can be named as either substitutively or additively as trichlorophosphane or trichloridophosphorus respectively. Similarly if the anion names end in -ite, -ate then the ligand names are -ito, -ato.
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Compounds containing the tetrathionate anion include sodium tetrathionate, Na2S4O6, potassium tetrathionate, K2S4O6, and barium tetrathionate dihydrate, BaS4O6·2H2O.
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The anion has been observed in the gas phase. It may adopt a trigonal shape akin to SO3.
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In the second part, the HSO4− anion is a nucleophile in a nucleophilic aromatic substitution followed by hydrolysis.
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BiF5 also reacts with alkali metal fluorides, MF, to form hexafluorobismuthates, M[BiF6], containing the hexafluorobismuthate anion, [BiF6]−.
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Canalicular multispecific organic anion transporter 2 is a protein that in humans is encoded by the ABCC3 gene.
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Removal of a single proton would result in the monovalent anion hydrogendioxosuccinate, or HO−(C=O)4−O−.
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The ion reacts and then forms another ion, which is then transferred back to the aqueous phase. For instance, the 31.1 kJ mol−1 is required to transfer an acetate anion into nitrobenzene, while the energy required to transfer a chloride anion from an aqueous phase to nitrobenzene is 43.8 kJ mol−1. Hence, if the aqueous phase in a reaction is a solution of sodium acetate while the organic phase is a nitrobenzene solution of benzyl chloride, then, when a phase transfer catalyst, the acetate anions can be transferred from the aqueous layer where they react with the benzyl chloride to form benzyl acetate and a chloride anion. The chloride anion is then transferred to the aqueous phase.
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The reaction of polonium dioxide with potassium hydroxide or potassium nitrate in air gives the colourless potassium polonite (K2PoO3): :PoO2 \+ 2 KOH → K2PoO3 \+ H2O :PoO2 \+ 2 KNO3 → K2PoO3 \+ 2 NO Polonium dioxide is closely related to the polonite anion (), similar to the relationship between polonium trioxide and the polonate anion ().
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Alkaline hydroxide solutions dissolve gallium, forming gallate salts (not to be confused with identically-named gallic acid salts) containing the anion. Gallium hydroxide, which is amphoteric, also dissolves in alkali to form gallate salts. Although earlier work suggested as another possible gallate anion, it was not found in later work.
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Tetraperchloratoaluminates are salts of the tetraperchloratoaluminate anion, [Al(ClO4)4]−. The anion contains aluminium tetrahedrally surrounded by four perchlorate groups. The perchlorate is covalently bonded to the aluminium, but perchlorate is much more well known as an ion. The covalent bond to aluminium distorts the perchlorate and renders it unstable.
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On heating to its melting point, sodium tetrafluoroborate decomposes to sodium fluoride and boron trifluoride: :NaBF4 → NaF + BF3 It is a source of tetrafluoroborate anion, which is used in organic chemistry for the preparation of salts. Sodium tetrafluoroborate can be used for synthesis of ionic liquids, where tetrafluoroborate is the anion.
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This requires that the rate-limiting step be the conversion of radical anion B to the cyclohexadienyl radical C.
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Mixed anion compounds exist that contain hydride with other anions. These include boride hydrides, carbohydrides, hydridonitrides, oxyhydrides and others.
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It may be considered the conjugate acid of the azide anion, and is similarly analogous to the hydrohalic acids.
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The salt consists of a protonated tryptammonium cation and a 3-carboxyacrylate (hydrogen fumarate) anion in the asymmetric unit.
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They are competitive to or better than comparable bifurcated anion binding structural motifs such as (thio)urea and squaramide.
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An amidate/imidate anion is formed upon deprotonation of an amide or imidic acid. Since amides and imidic acids are tautomers, they form the same anion upon deprotonation. The two names are thus synonyms describing the same anion, although arguably, imidate refers to the resonance contributor on the left, while amidate refers to the resonance contributor on the right. However, they are distinguished when they act as ligands for transition metals, with O-bound species referred to as imidates and N-bound species referred to as amidates.
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If the pH is above the pI, the protein will have a negative charge and bind to the matrix in an anion exchange column. The stability of the protein at values above or below the pI, will determine if an anion exchange column or cation exchange column should be used. If it is stable at pH values below the pI, the cation exchange column be used. If it is stable at pH values above the pI then the anion exchange column can be used.
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Moreover, the resulting phenolate anion can stabilize the resulting carbocation through cation-π interactions, which would be particularly strong due to the highly electron-rich nature of the phenolate anion. The allylic cation generated is then attacked by the olefin of a second molecule of FPP, affording a tertiary carbocation. The phenolate anion generated previously then serves as a base to abstract a proton from this adduct to form a cyclopropane product, presqualene pyrophosphate (PSPP). The PSPP created remains associated with SQS for the second reaction.
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The anion is prepared in a mass spectrometer by successive decarboxylation and decarbonylation of lithium oxalate anion under collision induced dissociation (CID) conditions: LiO(C=O)(CO) → LiOCO− \+ CO2, LiOCO− → LiO− \+ CO. The above method to synthesize the lithium monoxide anion is inefficient and difficult to carry out. The required ion rapidly reacts with traces of moisture and molecular oxygen present in the air. The reaction is further intensified by the high pressure argon that is introduced into the instrument to carry out the CID step.
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The structure of the sulfite anion Sulfite is a ligand in coordination chemistry. The structure of Co(ethylenediamine)2(SO3)N3. The structure of the sulfite anion can be described with three equivalent resonance structures. In each resonance structure, the sulfur atom is double-bonded to one oxygen atom with a formal charge of zero (neutral), and sulfur is singly bonded to the other two oxygen atoms, which each carry a formal charge of −1, together accounting for the −2 charge on the anion.
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Heterolytic bond cleavage is a process where the electron pair that comprised a bond moves to one of the atoms that was formerly joined by a bond. The bond breaks, forming a negatively charged species (an anion) and a positively charged species (a cation). The anion is the species that retains the electrons from the bond while the cation is stripped of the electrons from the bond. The anion usually forms on the most electronegative atom, in this example atom A. :Heterolytic bond cleavage.
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Squaric acid, also called quadratic acid because its four carbon atoms approximately form a square, is a dibasic organic acid with the chemical formula 4O2(OH)2. The conjugate base of squaric acid is the hydrogensquarate anion ; and the conjugate base of the hydrogensquarate anion is the divalent squarate anion . This is one of the oxocarbon anions, which consist only of carbon and oxygen. Squaric acid is a reagent for chemical synthesis, used for instance to make photosensitive squaraine dyes and inhibitors of protein tyrosine phosphatases.
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ChemFETs can be utilized in either liquid or gas phase to detect target analyte, requiring reversible binding of analyte with a receptor located in the gate electrode membrane. There is a wide range of applications of ChemFETs, including most notably anion or cation selective sensing. More work has been done with cation-sensing ChemFETs than anion- sensing ChemFETs. Anion-sensing is more complicated than cation-sensing in ChemFETs due to many factors, including the size, shape, geometry, polarity, and pH of the species of interest.
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A large part of the research involving PCO is now looking into utilising the anion as a synthetic building block to derive phosphorus containing analogues of small molecules. The first major breakthrough in this area came from Goicoechea et al. in 2013; they published the reaction between the PCO anion and ammonium salts which yielded the phosphorus containing analogue of urea in which phosphorus replaces a nitrogen atom. The group predict that this heavier congener could have applications in new materials, anion sensing and coordination chemistry.
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Urine anion gap is calculated by subtracting the urine concentration of chloride (anions) from the concentrations of sodium plus potassium (cations): : = Na+ \+ K+ − Cl− where the concentrations are expressed in units of milliequivalents/liter (mEq/L). In contrast to the serum anion gap equation, the bicarbonate is excluded. This is because urine is acidic, so the bicarbonate level would be negligible.Batlle DC, Hizon M, Cohen E, Gutterman C, Gupta R. The use of the urinary anion gap in the diagnosis of hyperchloremic metabolic acidosis.
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In chemistry, triiodide usually refers to the triiodide ion, . This anion, one of the polyhalogen ions, is composed of three iodine atoms. It is formed by combining aqueous solutions of iodide salts and iodine. Some salts of the anion have been isolated, including thallium(I) triiodide (Tl+[I3]−) and ammonium triiodide ([NH4]+[I3]−).
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Octalene can be readily reduced by lithium to a di-anion C14H122- and, unusually for such a small molecule, a tetra-anion C14H124-Müllen, K., Oth, J. F. M., Engels, H.-W. and Vogel, E. (1979), Dianion and Tetraanion Octalene. Angew. Chem. Int. Ed. Engl., 18: 229–231. doi:10.1002/anie.197902291.
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The tetrabromonickelate anion contains a doubly-charged nickel atom (Ni2+) surrounded by four bromide ions in a tetrahedral arrangement. The formula is [NiBr4]2−. The anion combines with cations to form a series of salts called tetrabromonickelates. Strongly-coordinating solvents will displace one or more of the bromido ligands from the complex.
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Most fluoride salts dissolve to give the bifluoride (HF2-) anion. Sources of true F- anions are rare because the highly basic fluoride anion abstracts protons from many, even adventitious, sources. Relative unsolvated fluoride, which does exist in aprotic solvents, is called "naked". Naked fluoride is a strong Lewis base, and a powerful nucleophile.
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Carbon monoxide dissolved in pentane reacted with a uranium coordination compound yielding a deltate anion bound to two uranium atoms.
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Solute carrier organic anion transporter family member 3A1 is a protein that in humans is encoded by the SLCO3A1 gene.
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This adjacent anion binding site structure accommodates a complex of cyanate and bicarbonate, allowing the carbamate producing reaction to proceed.
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Tetramethylpyrazine (also known as ligustrazine) is reported to scavenge superoxide anion and decrease nitric oxide production in human polymorphonuclear leukocytes.
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Solute carrier organic anion transporter family member 4A1 is a protein that in humans is encoded by the SLCO4A1 gene.
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DEAE-Sepharose is a tradename for the anion-exchange reactive group, diethylaminoethanol (DEAE) covalently linked to Sepharose (a polysaccharide polymer).
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The simplest anion which can be a conjugate base is the solvated electron whose conjugate acid is the atomic hydrogen.
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When dissolved in water, the persalt releases hydrogen peroxide (e.g. from sodium percarbonate): :2Na2CO3∙3H2O2 → 2Na2CO3 \+ 3H2O2 In a basic wash solution, hydrogen peroxide loses a proton and is converted to the perhydroxyl anion: :H2O2 H+ \+ HO2− The perhydroxyl anion then attacks the activator, forming a peroxy acid: :HO2− \+ RC(O)X → X− \+ RC(O)O2H The overall reaction of TAED (1) with 2 equivalents of hydrogen peroxide gives diacetylethylenediamine (2) and 2 equivalents of peracetic acid (3): center Only the perhydroxyl anion, and not the hydrogen peroxide molecule, reacts with the bleach activator. In aqueous solutions, the hydroxide ion is also present, but owing to the greater nucleophilicity of the perhydroxyl anion, it will react preferentially. Once formed, the peroxy acid can act as a bleach.
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Potassium bifluoride, as its name indicates, contains a bifluoride, or hydrogen(difluoride) anion: HF2−. This centrosymmetric triatomic anion features the strongest known hydrogen bond, with a F−H length of 114 pm, and a bond energy greater than 155 kJ mol−1.Emsley, J. (1980) Very strong hydrogen bonds, Chemical Society Reviews, 9, 91-124.
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Crystallization from an aqueous solution containing NaF produces compounds containing polynuclear anions, e.g. NaSn2F5 or Na4Sn3F10 depending on the reaction conditions, rather than NaSnF3. The compound NaSnF3, containing the pyramidal SnF3− anion, can be produced from a pyridine–water solution. Other compounds containing the pyramidal SnF3− anion are known, such as Ca(SnF3)2.
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Space-filling model of the perbromate anion, In chemistry, the perbromate ion is the anion having the chemical formula . It is an oxyanion of bromine, the conjugate base of perbromic acid, in which bromine has the oxidation state +7. Unlike its chlorine () and iodine () analogs, it is difficult to synthesize. It has tetrahedral molecular geometry.
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Amavadin is a vanadium-containing anion found in three species of poisonous Amanita mushrooms: A. muscaria, A. regalis, and A. velatipes. Amavadin was first isolated and identified in 1972 by Kneifel and Bayer.Kneifel, H.; Bayer, E. “Stereochemistry and total synthesis of amavadin, the naturally occurring vanadium anion of Amanita muscaria.” J. Am. Chem. Soc.
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In coordination chemistry, anation is the "replacement of the ligand water by an anion in a coordination entity." The term is however used more loosely to include displacement of any neutral ligand by an anion. The reaction is pervasive in coordination chemistry. The reverse reaction, displacement of an anionic ligand by water, is called aquation.
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This would be one of the oxocarbon anions, which consist solely of carbon and oxygen. The name would also used for salts containing that anion, and for esters with the [−O−(C=O)5−O−] moiety. Removal of a single proton would result in the monovalent anion hydrogentrioxoglutarate, or HO−(C=O)5−O−.
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Potassium pyrosulfate contains the pyrosulfate anion which has a dichromate like structure. The geometry can be visualized as a tetrahedron with two corners sharing the SO4 anion's configuration and a centrally bridged oxygen atom. A semi-structural formula for the pyrosulfate anion is O3SOSO32−. The oxidation state of sulfur in this compound is +6.
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The pertechnetate anion is similar to the permanganate anion but is a weaker oxidizing agent. It is tetrahedral and diamagnetic. The standard electrode potential for TcO4−/TcO2 is only +0.738 V in acidic solution, as compared to +1.695 V for MnO4−/MnO2. Because of its diminished oxidizing power, [TcO4]− is stable in alkaline solution.
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Mixing sodium chlorite solution with a weak food-grade acid solution (commonly citric acid), both stable, produces short-lived acidified sodium chlorite (ASC) which has potent decontaminating properties. Upon mixing the main active ingredient, chlorous acid is produced in equilibrium with chlorite anion. The proportion varies with pH, temperature, and other factors, ranging from approximately 5–35% chlorous acid with 65–95% chlorite; more acidic solutions result in a higher proportion of chlorous acid. Chlorous acid breaks down to chlorine dioxide which in turn breaks down to chlorite anion and ultimately chloride anion.
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Radical-nucleophilic aromatic substitution mechanism In this radical substitution the aryl halide 1 accepts an electron from a radical initiator forming a radical anion 2. This intermediate collapses into an aryl radical 3 and a halide anion. The aryl radical reacts with the nucleophile 4 to a new radical anion 5 which goes on to form the substituted product by transferring its electron to new aryl halide in the chain propagation. Alternatively the phenyl radical can abstract any loose proton from 7 forming the arene 8 in a chain termination reaction.
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Anion exchange separation methods are widely used in the purification of actinides and actinide bearing materials through the use of resin columns. The anionic actinide complexes are retained by anion exchange sites that are on the resin and neutral species pass through the column unretained. Then the retained species can be eluted from the column by conversion to a neutral complex, typically by changing the mobile phase passed through the resin bed. Anion exchange-based separations of actinides, while valued for there simplicity and widely used, tend to be time-consuming and are infrequently automated.
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These "unmeasured" ions are mostly anions, which is why the value is called the "anion gap." By definition, only the cations sodium (Na+) and potassium (K+) and the anions chloride (Cl−) and bicarbonate (HCO) are used to calculate the anion gap. (As discussed above, potassium may or may not be used, depending on the specific lab.) The cations calcium (Ca2+) and magnesium (Mg2+) are also commonly measured, but they aren't used to calculate the anion gap. Anions that are generally considered "unmeasured" include a few normally occurring serum proteins, and some pathological proteins (e.g.
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In many situations, alterations in renal function (even if mild, e.g., as that caused by dehydration in a patient with diarrhea) may modify the anion gap that may be expected to arise in a particular pathological condition. A high anion gap indicates that, usually due to disease or intoxication, there are elevated concentrations of anions like lactate, beta-hydroxybutyrate, acetoacetate, PO, and SO in the blood. These anions are not part of the anion-gap calculation and there is a secondary loss of HCO (a buffer) without a concurrent increase in Cl−.
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An alkaline anion exchange membrane fuel cell (AAEMFC), also known as anion- exchange membrane fuel cells (AEMFCs), alkaline membrane fuel cells (AMFCs), hydroxide exchange membrane fuel cells (HEMFCs), or solid alkaline fuel cells (SAFCs) is a type of alkaline fuel cell that uses an anion exchange membrane to separate the anode and cathode compartments. Alkaline fuel cells (AFCs) are based on the transport of alkaline anions, usually hydroxide , between the electrodes. Original AFCs used aqueous potassium hydroxide (KOH) as an electrolyte. The AAEMFCs use instead a polymer membrane that transports hydroxide anions.
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The crystal lattice of an antiperovskite structure is the same as that of the perovskite structure, but the anion and cation positions are switched. The typical perovskite structure is represented by the general formula ABX3, where A and B are cations and X is an anion. When the anion is the (divalent) oxide ion, A and B cations can have charges 1 and 5, respectively, 2 and 4, respectively, or 3 and 3, respectively. In antiperovskite compounds, the general formula is reversed, so that the X sites are occupied by an electropositive ion, i.e.
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The [BArF4]− anion with four fluorinated aryl groups distributed tetrahedrally about a central boron atom Tetrakis[3,5-bis(trifluoromethyl)phenyl]borate is an anion with chemical formula [{3,5-(CF3)2C6H3}4B]−, which is commonly abbreviated as [BArF4]−, indicating the presence of fluorinated aryl (ArF) groups. It is sometimes referred to as Kobayashi's anion in honour of Hiroshi Kobayashi who led the team that first synthesised it. More commonly it is affectionately nicknamed "BARF." The BARF ion is also abbreviated BArF24−, to distinguish it from the closely related BArF20−, [(C6F5)4B]−.
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Although previously thought to be absent, anion transport has also been shown to be an important aspect of prestin's ability to drive electromotility of hair cells. This mechanism is independent of prestin's voltage-sensing capabilities based upon mutagenesis experiments showing that different mutations lead to effects in either anion-uptake or NLC, but not both. It is suggested that prestin contains an intrinsic anion-uptake mechanism based upon research showing concentration dependent [14C]formate uptake in Chinese hamster ovary (CHO) cells. These results could not be reproduced in oocytes.
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Every oxocarbon anion can be matched in principle to the electrically neutral (or oxidized) variant CxOy, an oxocarbon (oxide of carbon) with the same composition and structure except for the negative charge. As a rule, however, these neutral oxocarbons are less stable than the corresponding anions. Thus, for example, the stable carbonate anion corresponds to the extremely unstable neutral carbon trioxide CO3; oxalate correspond to the even less stable 1,2-dioxetanedione C2O4; and the stable croconate anion corresponds to the neutral cyclopentanepentone C5O5, which has been detected only in trace amounts.
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In chemistry, methanetetracarboxylate is a tetravalent anion with formula or C(COO−)4. It has four carboxylate groups attached to a central carbon atom; so it has the same carbon backbone as neopentane. It is an oxocarbon anion, that is, consists only of carbon and oxygen. The term is also used for any salt with that anion; or for any ester with the C(COO)4 moiety.Backer, H. J.; Lolkema, J. (1939), Methanetetracarboxylic esters. Recueil des Travaux Chimiques des Pays-Bas et de la Belgique, volume 58, pages 23–33.
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Vahisalu T, Kollist H, Wang YF, Nishimura N, Chan WY, Valerio G, Lamminmaki A, Brosche M, Moldau H, Desikan R, Schroeder JI, & Kangasjarvi J (2008) SLAC1 is required for plant guard cell S-type anion channel function in stomatal signalling. Nature 452:487-491. Anion channels have several major functions in controlling stomatal closing: (a) They allow release of anions, such as chloride and malate from guard cells, which is needed for stomatal closing. (b) Anion channels are activated by signals that cause stomatal closing, for example by intracellular calcium and ABA.
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It is popularly used as a precursor to the cyclopentadienyl anion (Cp−), an important ligand in cyclopentadienyl complexes in organometallic chemistry.
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Acetylene is the most specific inhibitor of nitrous-oxide reductase. Other inhibitors include azide anion, thiocyanate, carbon monoxide, iodide, and cyanide.
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Solute carrier family 17 (organic anion transporter), member 3 is a protein that in humans is encoded by the SLC17A3 gene.
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The salt (NH4)10(W12O42)·4H2O has been characterized by X-ray crystallography. The unprotonated anion [W12O42]12- has C2h symmetry.
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Hexafluorosilicate is an octahedral anion; the Si–F bond distances are 1.71 Å. Hexafluorosilicic acid is only available commercially as solution.
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Similarly, positively charged sites on colloids can attract and release anions in the soil giving the soil anion exchange capacity (AEC).
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Coupling of sodium pentacyanocyclopentadiene (NaC5(CN)5) with transition metal halide salts generates metal complexes containing the anion. Because the anion binds to metals through the cyanide group it can act as a pentagonal node. Thus it can form fullerene-like structures with large voids containing solvent. This has important implications for gas storage and separation.
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The stability of the Keggin structure allows the metals in the anion to be readily reduced. Depending on the solvent, acidity of the solution and the charge on the α-Keggin anion, it can be reversibly reduced in one- or multiple-electron steps.T. Okuhara; N. Mizuno; M. Misono. Advances in Cayalysis, Vol 41: Catalytic Chemistry of Heteropoly Compounds.
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The compound is unusually acidic (pKa = 16) for a hydrocarbon, a fact explained by the high stability of the aromatic cyclopentadienyl anion, . Deprotonation can be achieved with a variety of bases, typically sodium hydride, sodium metal, and butyl lithium. Salts of this anion are commercially available, including sodium cyclopentadienide and lithium cyclopentadienide. They are used to prepare cyclopentadienyl complexes.
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19–20 of the Guide Book This anion is also responsible for the savory flavor (umami) of certain foods, and used in glutamate flavorings such as MSG. In Europe it is classified as food additive E620. In highly alkaline solutions the doubly negative anion −OOC-CH()-()2-COO− prevails. The radical corresponding to glutamate is called glutamyl.
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Structure of OsO3(N-t- Bu) (multiple bonds are not drawn explicitly), illustrating the type of osmium(VIII)-oxo-imide that adds alkenes en route to the amino alcohol.OsO4 is a Lewis acid and a mild oxidant. It reacts with alkaline aqueous solution to give the perosmate anion . This species is easily reduced to osmate anion, .
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The dissociation of protons from oxalic acid proceeds in a stepwise manner as for other polyprotic acids. Loss of a single proton results in the monovalent hydrogenoxalate anion . A salt with this anion is sometimes called an acid oxalate, monobasic oxalate, or hydrogen oxalate. The equilibrium constant (Ka) for loss of the first proton is (pKa = 1.27).
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Dihydroxyacetone phosphate (DHAP, also glycerone phosphate in older texts) is the anion with the formula HOCH2C(O)CH2OPO32-. This anion is involved in many metabolic pathways, including the Calvin cycle in plants and glycolysis.Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. . It is the phosphate ester of dihydroxyacetone.
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Acetylenedicarboxylic acid or butynedioic acid is an organic compound (a dicarboxylic acid) with the formula C4H2O4 or . It is a crystalline solid that is soluble in diethyl ether. The removal of two protons yields the acetylenedicarboxylate dianion , which consists only of carbon and oxygen, making it an oxocarbon anion. Partial ionization yields the monovalent hydrogenacetylenedicarboxylate anion .
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Solute carrier organic anion transporter family member 1B3 (SLCO1B3) also known as organic anion-transporting polypeptide 1B3 (OATP1B3) is a protein that in humans is encoded by the SLCO1B3 gene. OATP1B3 is a 12-transmembrane domain influx transporter. Normally expressed in the liver, the transporter functions to uptake large, non-polar drugs and hormones from the portal vein.
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The α-hydroxy alkylphosphonates produced by this method can be used for additional transformations. The original carbonyl carbon is acidified by its proximity to the phosphonate group. Deprotonation at this position generates a masked acyl anion, as the phosphonate functionality can be removed after the anion reacts. Phosphonate anions can undergo alkylation and olefination (the Horner- Wadsworth-Emmons reaction).
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The superoxide anion is formed directly from the one-electron reduction of molecular oxygen. Hydrogen peroxide is then formed from the disproportionation of the superoxide anion. This reaction occurs very quickly in seawater. Next, the reduction of hydrogen peroxide yields the hydroxyl radical, H2O2↔2OH•, which can then get reduced to the hydroxyl ion and water.
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Tetrachloroaluminate [AlCl4]− is an anion formed from aluminium and chlorine. The anion has a tetrahedral shape, similar to carbon tetrachloride where carbon is replaced with aluminium. Some tetrachloroaluminates are soluble in organic solvents, creating an ionic non-aqueous solution, making them suitable as component of electrolytes for batteries. E.g. lithium tetrachloroaluminate is used in some lithium batteries.
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Amavadin is a C2-symmetric anion with a 2− charge. The twofold axis bisects the vanadium atom perpendicular to the two NO ligands. The anion features five chiral centers, one at vanadium and the four carbon atoms having S stereochemistry. There are two possible diastereomers for the ligands, (S,S)-(S,S)-Δ and (S,S)-(S,S)-Λ.
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Arsenite minerals are very rare oxygen-bearing arsenic minerals. Classical world localities where such minerals occur include the complex skarn manganese deposit at Långban (Sweden) and the polymetallic Tsumeb deposit (Namibia). The most often reported arsenite anion in minerals is the AsO33− anion, present for example in reinerite Zn3(AsO3)2. Unique diarsenite anions occur i. e.
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The Delta Ratio is a formula that can be used to assess elevated anion gap metabolic acidosis and to evaluate whether mixed acid base disorder (metabolic acidosis) is present. The list of agents that cause high anion gap metabolic acidosis is similar to but broader than the list of agents that cause a serum osmolal gap.
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Ammonium lauryl sulfate (ALS) is the common name for ammonium dodecyl sulfate (CH3(CH2)10CH2OSO3NH4). The anion consists of a nonpolar hydrocarbon chain and a polar sulfate end group. The combination of nonpolar and polar groups confers surfactant properties to the anion: it facilitates dissolution of both polar and non-polar materials. ALS is classified as a sulfate ester.
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For a list of the common causes of this change in bicarbonate or chloride, see normal anion gap acidosis. Results 2–4 all involve HAGMAs. A high anion gap metabolic acidosis usually occurs because of an increase in anions. So in the equation: : AG = [Na⁺] – ([Cl¯] + [HCO3¯] + [A¯]) it is the [A¯] that is the cause.
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For a list of the common anions responsible, see high anion gap metabolic acidosis. KULT is probably the easiest of the mnemonics to use [ Ketones, Uremia, Lactate, Toxins ]. Toxins are an uncommon cause of high anion gap metabolic acidosis – a list of the commonest toxins is ACE GIFTs [ibid]. Metformin as a pure toxicological cause is vanishingly rare.
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Structure of dicyanamide Dicyanamide, also known as dicyanamine, is an anion having the formula . It contains two cyanide groups bound to a central nitrogen anion. The chemical is formed by decomposition of 2-cyanoguanidine. It is used extensively as a counterion of organic and inorganic salts, and also as a reactant for the synthesis of various covalent organic structures.
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This reaction type is also called a dissolving metal reduction. Alkyne reduction to an alkene in the liquid ammonia/sodium system follows the same theme. The first radical anion intermediate abstracts a proton from ammonia to the free radical. A second one-electron transfer leads to the anion, which also abstracts a proton to the neutral alkene.
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Degradation of ethiofencarb illustrating the presence of a stable anion due to resonance between the amide functional group and the carbonyl group.
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Ammonium thiocyanate is an inorganic compound with the formula NH4SCN. It is the salt of the ammonium cation and the thiocyanate anion.
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In chemistry, pentadienyl refers to the organic radical, anion, or cation with the formula [CH2CHCHCHCH2]z, where z = 0, −1, +1, respectively.
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Hexanitratoaluminate is an anion of aluminium and six nitrate groups with formula [Al(NO3)6]3− that can form salts called hexanitratoaluminates.
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The anion has eight valence electrons, the radical seven and the cation six. All three forms are highly reactive and rarely observed.
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4,4'-Diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) is an anion exchange inhibitor, blocking reversibly, and later irreversibly, exchangers such as chloride-bicarbonate exchanger.
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Sodium rhodizonate has the same structure, with slightly more distorted anions (0.113 Å rms) In solution, the rhodizonate anion is not hydrated.
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Hedrich R, Busch H, & Raschke K (1990) Ca2+ and nucleotide dependent regulation of voltage dependent anion channels in the plasma membrane of guard cells. EMBO J. 9:3889-3892.Schroeder JI & Keller BU (1992) Two types of anion channel currents in guard cells with distinct voltage regulation. Proc. Natl. Acad. Sci. USA 89:5025-5029.Pei Z-M, Kuchitsu K, Ward JM, Schwarz M, & Schroeder JI (1997) Differential abscisic acid regulation of guard cell slow anion channels in Arabdiopsis wild-type and abi1 and abi2 mutants. Plant Cell 9:409-423.Negi J, Matsuda O, Nagasawa T, Oba Y, Takahashi H, Kawai-Yamada M, Uchimiya H, Hashimoto M, & Iba K (2008) CO2 regulator SLAC1 and its homologues are essential for anion homeostasis in plant cells. Nature 452:483-486.
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Thus, the presence of a high anion gap should result in a search for conditions that lead to an excess of these anions.
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Stearates are the salts or esters of stearic acid. The conjugate base of stearic acid, C17H35COO−, is also known as the stearate anion.
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In this conformation, instead of synthesizing NO, eNOS produces superoxide anion, a highly reactive free radical with deleterious consequences to the cardiovascular system.
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5b00407 This yellow-orange solid is a salt of the superoxide anion. It is an intermediate in the oxidation of sodium by oxygen.
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The stabilities of the alkali-ion pairs as function of the anion charge z by can be described by a more detailed equation.
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More often, a bent geometry is still preferred for substituted alkenyl anions, though the linear geometry is only slightly less stable, resulting in facile equilibration between the (E) and (Z) isomers of the (bent) anion through a linear transition state. For instance, calculations indicate that the parent vinyl anion, H2C=CH⊖, has an inversion barrier of 27 kcal/mol, while allenyl anion, H2C=C=CH⊖ (↔ H2C⊖–C≡CH), whose negative charge is stabilized by delocalization, has an inversion barrier of only 4 kcal/mol, reflecting stabilization of the linear transition state by better π delocalization.
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Superexchange, or Kramers–Anderson superexchange, is the strong (usually) antiferromagnetic coupling between two next-to-nearest neighbour cations through a non-magnetic anion. In this way, it differs from direct exchange in which there is coupling between nearest neighbor cations not involving an intermediary anion. Superexchange is a result of the electrons having come from the same donor atom and being coupled with the receiving ions' spins. If the two next-to-nearest neighbor positive ions are connected at 90 degrees to the bridging non-magnetic anion, then the interaction can be a ferromagnetic interaction. Fig.
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The final step of the Wolff–Kishner reduction is the collapse of the diimide anion 2 in the presence of a proton source to give the hydrocarbon via loss of dinitrogen to afford an alkyl anion 3, which undergoes rapid and irreversible acid-base reaction with solvent to give the alkane. Evidence for this high-energy intermediate was obtained by Taber via intramolecular trapping. The stereochemical outcome of this experiment was more consistent with an alkyl anion intermediate than the alternative possibility of an alkyl radical. The overall driving force of the reaction is the evolution of nitrogen gas from the reaction mixture.
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For example, suppressing dendritic calcium spikes in specific neurons with light reduced the ability of mice to perceive a light touch to a whisker. Studying how the behavior of an animal changes when specific neurons are silenced allows scientists to determine the role of these neurons in the complex circuits controlling behavior. The first anion-conducting channelrhodopsins were engineered from the cation-conducting light-gated channel Channelrhodopsin-2 by removing negatively charged amino acids from the channel pore (Fig. 1). As the main anion of extracellular fluid is chloride (Cl−), anion-conducting channelrhodopsins are also known as “chloride-conducting channelrhodopsins” (ChloCs).
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An anion exchange membrane (AEM) is a semipermeable membrane generally made from ionomers and designed to conduct anions while being impermeable to gases such as oxygen or hydrogen. Anion exchange membranes are used in electrolytic cells and fuel cells to separate reactants present around the two electrodes while transporting the anions essential for the cell operation. An important example is the hydroxide anion exchange membrane used to separate the electrodes of a direct methanol fuel cell (DMFC)Comparison of PVDF and FEP based radiation-grafted alkaline anionexchange membranes for use in low temperature portable DMFCs or direct-ethanol fuel cell (DEFC).
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This was shown in a single crystal X-ray diffraction study revealing shortened bond lengths in the heterocyclic portion of the ring suggesting electronic delocalization. The chlorinated carba-closo- dodecaborate anion is an outstandingly stable anion with what has previously been described as “substitutionally inert” B–Cl vertices. While the C-vertex of the boron-based anion can de deprotonated and furthermore react with electrophiles, the B–Cl vertices remain substantially inert. The descriptor closo indicates that the molecule is formally derived (by B-to-C+ replacement) from a borane of stoichiometry and charge [BnHn]2– (n = 12 for known carborane acids).
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BARF has a tetrahedral geometry around the central boron atom but each of the four surrounding aryl groups is aromatic and planar. The motivation for its preparation was the search for an anion that coordinates more weakly than the then-available ions hexafluorophosphate, tetrafluoroborate, or perchlorate. Salts of this anion are known as solids and in both aqueous and non-aqueous solutions. BARF can be used in catalytic systems where the active site requires an anion which will not coordinate to the metal centre and interfere with the catalytic cycle, such as in the preparation of polyketones.
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Chemical structure of the disulfate anion In chemistry, disulfate or pyrosulfate is the anion with the molecular formula . Disulfate is the IUPAC name. It has a dichromate-like structure and can be visualised as two corner- sharing SO4 tetrahedra, with a bridging oxygen atom."The crystal structure determinations and refinements of K2S2O7, KNaS2O7 and Na2S2O7 from X-ray powder and single crystal diffraction data", Ståhl K, Balic-Zunic T, da Silva F, Eriksen K M, Berg R W, Fehrmann R Journal of Solid State Chemistry 178, 1697–1704, (2005) In this anion, sulfur has an oxidation state of +6.
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She discovered the Si4− butterfly anion in Ba3Si4 during her work on her dissertation. Furthermore, she and Herbert Schäfer extended the definition of Zintl phases: In their definition, Zintl phases are intermetallic compounds with a pronounced heteropolar bonding contribution. Furthermore, their anion partial lattices should obey the (8-N) rule. The latter was newly introduced to the definition of Zintl phases.
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Here, n-butyllithium is used to perform lithium-halogen exchange with bromide. The nucleophilic carbanion center quickly undergoes carbolithiation to the double bond, generating an anion stabilized by the adjacent sulfone group. An intramolecular SN2 reaction by the anion forms the cyclic backbone of morphine. synthesis of morphine lithium halogen exchange Lithium halogen exchange is a crucial part of Parham cyclization.
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Quadrupole moments of benzene and hexafluorobenzene. The polarity is inverted due to differences in electronegativity for hydrogen and fluorine relative to carbon; the inverted quadrupole moment of hexafluorobenzene is necessary for anion-pi interactions. In many respects, anion–π interaction is the opposite of cation–π interaction, although the underlying principles are identical. Significantly fewer examples are known to date.
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Ammonium bifluoride, as its name indicates, contains an ammonium cation (NH4+) and a bifluoride, or hydrogen(difluoride), anion (HF2−). The centrosymmetric triatomic bifluoride anion features the strongest known hydrogen bond, with a F−H length of 114 pm. and a bond energy greater than 155 kJ mol−1.Emsley, J. (1980) Very strong hydrogen bonds, Chemical Society Reviews, 9, 91–124.
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Electrical conductivity variations include cation and anion conductivity. Chromatography such as ion chromatography or HPLC often tests the output stream continuously by measuring electrical conductivity, particularly cation or anion conductivity, refractive index, colorimetry or ultraviolet/visible absorbance at a certain wavelength. InlineOnline and offline analysers are available for other types of analytes. Many of these add reagents to the samples or sample streams.
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Ball-and-stick model of the borohydride anion, Borohydride refers to the anion and its salts. Borohydride is also the term used for compounds containing , for example cyanoborohydride () and triethylborohydride (B(C2H5)3H−). Borohydrides find wide use as reducing agents in organic synthesis. The most important borohydrides are lithium borohydride and sodium borohydride, but other salts are well known (see Table).
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Xenic acid has been used as an oxidizing agent in organic chemistry. Salts of xenic acid are called xenates, containing the anion. They tend to disproportionate into xenon gas and perxenates: :2 + 2 → + Xe + + 2 The energy given off is sufficient to form ozone from diatomic oxygen: :3 (g) → 2 (g) Salts containing the completely deprotonated anion are presently unknown.
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The salt is also soluble in benzene. In crystals grown from a benzene solution the solvent co-crystallizes and a cation is completely separated from the anion. In the cation three benzene molecules surround hydronium forming pi-cation interactions with the hydrogen atoms. The closest (non-bonding) approach of the anion at chlorine to the cation at oxygen is 348 pm.
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Californium(III) oxyfluoride molecule Californium(III) oxyfluoride is a radioactive inorganic compound with a chemical formula CfOF, synthesized in the 1960s. This salt crystallizes with the cubic fluorite structure, with the oxide and fluoride anions randomly distributed in anion sites. Californium(III) oxyfluoride is an oxyfluoride and a mixed anion compound. It can be prepared by the hydrolysis of CfF3 at high temperature.
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This was explained as being due to the greater relative basicity of the deuterated hydroxide anion compared to the normal hydroxide anion, and was used to indicate that hydrogen migration did not occur in the rate determining step of the reaction. This ruled out a concerted mechanism for the reaction, as hydrogen transfer would occur in the rate determining step.
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Sodium pertechnetate is the inorganic compound with the formula NaTcO4. This colourless salt contains the pertechnetate anion, [TcO4]−. The radioactive 99mTcO4− anion is an important radiopharmaceutical for diagnostic use. The advantages to 99mTc include its short half-life of 6 hours and the low radiation exposure to the patient, which allow a patient to be injected with activities of more than 30 millicuries.
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The object was to examine the selectivity with respect to the saccharides. An example of the use of supramolecular complexes in the development of chemosensors is provided by the use of transition-metal ensembles to sense for ATP. Anion complexation can be achieved by encapsulating the anion in a suitable cage. Selectivity can be engineered by designing the shape of the cage.
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This occurs during hydration of metal ions, so colourless anhydrous ionic compounds with an anion absorbing in the infrared can become colourful in solution.
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A Life of Magic Chemistry: Autobiographical Reflections Including Post-Nobel Prize Years and the Methanol Economy, 159p Its conjugate base is the borohydride anion.
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Replacement of one in every four silicon atoms by an aluminum atom results in the anion , whose charge is neutralized by the potassium cations .
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Tetraphenylborate (IUPAC name: Tetraphenylboranuide) is an organoboron anion consisting of a central boron atom with four phenyl groups. Salts of tetraphenylborate uncouple oxidative phosphorylation.
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Solute carrier family 22 member 8, or organic anion transporter 3 (OAT3), is a protein that in humans is encoded by the SLC22A8 gene.
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As a result, they may display either high CEC in an acid soil solution, or high anion exchange capacity in a basic soil solution.
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Perchloratoborates are analogous to perchloratoaluminates ([Al(ClO4)4]−). Another related anion is the chloroperchloratoborate, Cl3B(ClO4). Boron perchlorate itself is unstable above −5 °C.
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Chloride anion exchanger, also known as down-regulated in adenoma (protein DRA), is a protein that in humans is encoded by the SLC26A3 gene.
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When the blood pH is below normal (7.35), this is called acidemia. The metabolic acidosis caused by RTA is a normal anion gap acidosis.
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The bond valence model can be reduced to the traditional ionic model if certain conditions are satisfied. These conditions require that atoms be divided into cations and anions in such a way that (a) the electronegativity of every anion is equal to, or greater than, the electronegativity of any of the cations, (b) that the structure is electroneutral when the ions carry charges equal to their valence, and (c) that all the bonds have a cation at one end and an anion at the other. If these conditions are satisfied, as they are in many ionic and covalent compounds, the electrons forming a bond can all be formally assigned to the anion. The anion thus acquires a formal negative charge and the cation a formal positive charge, which is the picture on which the ionic model is based.
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Hydrazine is used to cleave N-alkylated phthalimide derivatives. This scission reaction allows phthalimide anion to be used as amine precursor in the Gabriel synthesis.
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The nitronickelates are related compounds where more nitro groups are attached to nickel to yield an anion. They could be described as nickel double nitrites.
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Once reduced to the dianion, the borolediide complex gains aromaticity and can then participate in similar reactions as the Cp− anion, including forming sandwich complexes.
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Ammonium azide is ionic. Ammonium azide contains about 93% nitrogen by weight as ammonium cation and azide anion. It is a structural isomer of tetrazene.
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Ball-and-stick model of the pyrophosphate anion, P2O74− Diphosphotransferase are phosphotransferase enzymes which act upon pyrophosphate groups. They are classified under EC number 2.7.6.
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Only the "same" alkoxide anion as the one that one used to alkylate the deprotonated active methylenic site will prevent both base hydrolysis and transesterification.
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Three consecutive amino acid residues form an anion-binding concavity. ; Niche: Extremely common. Three or four consecutive amino acid residues form a cation-binding feature.
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Bicalicene is prepared by treatment of 1,2-bis(tert-butylthio)-3,3-dichlorocyclopropene with cyclopentadiene anion, followed by desulfurizing stannylation with tributyltin hydride and silica gel.
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It is common for samples of iodide-containing compounds to become discolored due to the facile aerobic oxidation of the iodide anion to molecular iodine.
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Due to the high basicity of the fluoride anion, the salt reacts slowly with acetonitrile, inducing its dimerization to CH3C(NH2)=CHCN, which co-crystallizes.
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In organometallic chemistry, a transition metal indenyl complex is a coordination compound that contains one or more indenyl ligands. The indenyl ligand is formally the anion derived from deprotonation of indene. The η5-indenyl ligand is related to the η5cyclopentadienyl anion (Cp), thus indenyl analogues of many cyclopentadienyl complexes are known. Indenyl ligands lack the 5-fold symmetry of Cp, so they exhibit more complicated geometries.
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Beundantite, segnitite and plumbojarosite form solid solutions with each other; conditions that form these minerals are similar. The space group Rm was determined for segnitite as the best fit based on the space group of beudantite, R3m as there is no well observed crystal structure. The difference between segnitite and beundantite is the replacement of the sulfate anion in beundantite with an arsenate anion to form segnitite.
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First, a base abstracts the relatively acidic proton to generate a stabilized anion. The lone pair of electrons on the anion then moves to the neighboring atom, thus expelling the leaving group and forming double or triple bond. The name of the mechanism - E1cB - stands for Elimination Unimolecular conjugate Base. Elimination refers to the fact that the mechanism is an elimination reaction and will lose two substituents.
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Nucleophilic alkylating agents deliver the equivalent of an alkyl anion (carbanion). The formal "alkyl anion" attacks an electrophile, forming a new covalent bond between the alkyl group and the electrophile. The counterion, which is a cation such as lithium, can be removed and washed away in the work-up. Examples include the use of organometallic compounds such as Grignard (organomagnesium), organolithium, organocopper, and organosodium reagents.
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Rotor syndrome has an autosomal recessive pattern of inheritance. Rotor syndrome is inherited in an autosomal recessive manner. The SLCO1B1 and SLCO1B3 genes are involved in Rotor syndrome. Mutations in both genes are required for the condition to occur. The SLCO1B1 and SLCO1B3 genes provide instructions for making similar proteins, called organic anion transporting polypeptide 1B1 (OATP1B1) and organic anion transporting polypeptide 1B3 (OATP1B3), respectively.
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Uronium-based peptide coupling reagents Some coupling reagents omit the carbodiimide completely and incorporate the HOAt/HOBt moiety as an aminium/uronium or phosphonium salt of a non-nucleophilic anion (tetrafluoroborate or hexafluorophosphate). Examples of aminium/uronium reagents include HATU (HOAt), HBTU/TBTU (HOBt) and HCTU (6-ClHOBt). HBTU and TBTU differ only in the choice of anion. Phosphonium reagents include PyBOP (HOBt) and PyAOP (HOAt).
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The anion gap is a calculated measure. This means that it is not directly measured by a specific lab test; rather, it is computed with a formula that uses the results of several individual lab tests, each of which measures the concentration of a specific anion or cation. The concentrations are expressed in units of milliequivalents/liter (mEq/L) or in millimoles/litre (mmol/L).
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Acid salt is an ionic compound consisted of an anion, contributed from a weak parent acid, and a cation, contributed from a strong parent base. Research says that ics + ics= 2ics and between the anion and cation ics, the result gives guys. An example, for instance, is tetraoxidosulfate(2-). We write it as 2- because we do not know how to write in math.
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Phenyl-2-nitropropene is a chemical compound with the chemical formula is C9H9NO2. It can be produced by the reaction of benzaldehyde and nitroethane in the presence of a basic catalyst. In this reaction, the base deprotonates nitroethane to form a resonance stabilized anion. This anion nucleophilically adds to the aldehyde forming a beta nitro alcohol, which is subsequently dehydrated to yield the nitroalkene.
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Cyclononatetraenyl anion is a 10π aromatic system. Two isomers of the cyclononatetraenyl anion are known: the trans,cis,cis,cis isomer ("Pac- Man"-shaped) and the all-cis isomer (a convex enneagon). The former is less stable and isomerizes to the latter upon warming from –40 °C to room temperature. The all-cis isomer of C9H9− can be prepared by treatment of 9-chlorobicyclo[6.1.
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Ammonium permanganate is the chemical compound NH4MnO4, or NH3·HMnO4. It is soluble in water. It is a strong oxidizer, owing to its permanganate anion, and it is a moderately strong explosive, owing to the combination of oxidizer permanganate anion and reducing ammonium cation. Dry ammonium permanganate can detonate by heat, shock, or friction, and it may explode at temperatures above 140 °F (60 °C).
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They hydrolyse only very slowly to give ammonia or nitrogen. The nitride anion (N3−) is the strongest π donor known amongst ligands (the second-strongest is O2−). Nitrido complexes are generally made by thermal decomposition of azides or by deprotonating ammonia, and they usually involve a terminal {≡N}3− group. The linear azide anion (), being isoelectronic with nitrous oxide, carbon dioxide, and cyanate, forms many coordination complexes.
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As a result of having non-paired electrons in both spin states coupled together, this compound exhibits antiferromagnetism. Though similar ground states are observed in molecules containing transition metal atoms, it is unprecedented in organic molecules. The 5-dehydro-m-xylylene anion (DMX−) has also been studied extensively. It has a triplet ground state consisting of a phenyl anion and a m-xylylene biradical.
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H and N. Both are relatively unreactive colourless diatomic gases, with comparably high ionization energies (1312.0 and 1402.3 kJ/mol), each having half-valence subshells, 1s and 2p respectively. Like the reactive azide N3− anion, inter- electron repulsions in the H− hydride anion (with its single nuclear charge) make ionic hydrides highly reactive. Unusually for nonmetals, the two elements are known in cationic forms.
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Another advantage of these anions is that their salts are more soluble in non-polar organic solvents such as dichloromethane, toluene, and, in some cases, even alkanes. Polar solvents, such as acetonitrile, THF, and water tend to bind to electrophilic centers, in which cases, the use of a non-coordinating anion is pointless. Salts of the anion were first reported by Kobayashi and co-workers.
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It is used widely as an acidifier, as a flavoring and a chelating agent. A citrate is a derivative of citric acid; that is, the salts, esters, and the polyatomic anion found in solution. An example of the former, a salt is trisodium citrate; an ester is triethyl citrate. When part of a salt, the formula of the citrate anion is written as or .
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The C9-H sites of the fluorene ring are weakly acidic (pKa = 22.6 in DMSO.) Deprotonation gives the stable fluorenyl anion, nominally C13H9−, which is aromatic and has an intense orange colour. The anion is a nucleophile. Electrophiles react with it by adding to the 9-position. The purification of fluorene exploits its acidity and the low solubility of its sodium derivative in hydrocarbon solvents.
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Suspicion next falls on Anion ap Griffri, a lay servant recovering from a broken leg. Prestcote had ordered his half-brother to be hanged for his part in a fatal brawl, providing motive. Anion flees. Hugh Beringar takes half of his armed men to join forces with Owain Gwynedd to deal with raids by Ranulf of Chester in the northern part of the county.
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Therefore, according to the new classification system, a high anion gap is anything above 11 mEq/L and a normal anion gap is often defined as being within the prediction interval of 3–11 mEq/L, with an average estimated at 6 mEq/L. In the past, methods for the measurement of the anion gap consisted of colorimetry for [HCO] and [Cl−] as well as flame photometry for [Na+] and [K+]. Thus normal reference values ranged from 8 to 16 mEq/L plasma when not including [K+] and from 10 to 20 mEq/L plasma when including [K+]. Some specific sources use 15 and 8–16 mEq/L.
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The conjugate base of pyrithione is an anion containing two donor atoms, a sulfur atom and an oxygen atom each bearing a negative formal charge; the nitrogen atom remains formally positively charged. The thiolate anion can be formed by reaction with sodium carbonate, and zinc pyrithione is formed when zinc chloride is added. The anion can act as either a monodentate or bidentate ligand and forms a 1:2 complex with a zinc(II) metal centre. Zinc pyrithione has been used since the 1930s though its preparation was not disclosed until a 1955 British patent in which pyrithione was reacted directly with hydrated zinc sulfate in ethanol.
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In the oxidative half of the mechanism, Cys63 nucleophilically attacks the nearest sulfide unit in the GSSG molecule (promoted by His467), which creates a mixed disulfide bond (GS-Cys58) and a GS− anion. His467 of GSR then protonates the GS- anion to release the first molecule of GSH. Next, Cys63 nucleophilically attacks the sulfide of Cys58, releasing a GS− anion, which, in turn, picks up a solvent proton and is released from the enzyme, thereby creating the second GSH. So, for every GSSG and NADPH, two reduced GSH molecules are gained, which can again act as antioxidants scavenging reactive oxygen species in the cell.
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Non-coordinating anions are anions that interact only weakly with cations, a useful property when studying highly electrophilic cations. In coordination chemistry, the term can also be used to refer to anions which are unlikely to bind directly to the metal centre of a complex. Hexafluorophosphate is a non-coordinating anion in both senses of the term. Three widely used non-coordinating anions are hexafluorophosphate, tetrafluoroborate , and perchlorate ; of these, the hexafluorophosphate ion has the least coordinating ability and it is deliberately used for this property. BARF was developed as a new non-coordinating anion in the 1990s, and is far less coordinating than even the hexafluorophosphate anion.
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Academic Press Inc., 1996, pp 191-193 For example, silicotungstate anion can be reduced to 20th state.M.T. Pope. Inorganic Chemistry Concepts 8: Heteropoly and Isopoly oxometalates.
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The salt consists of a protonated tryptammonium cation and a 3-carboxyacrylate (hydrogen fumarate) anion in the asymmetric unit along with a water molecule of crystallization.
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One significant difference of the bidentate receptor was that there was no anion-arene stabilizing influence, and operated through purely chalcogen bonding, unlike the monodentate receptor.
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Solute carrier family 22 member 25 (SLC22A25), also known as organic anion transporter UST6, is a protein that in humans is encoded by the SLC22A25 gene.
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Pyrrolidine dithiocarbamate is jargon for various salts containing the pyrrolidine dithiocarbamate anion C4H8NS2−. Dithiocarbamic acids are rarely stable. Typical salts are ammonium and the sodium derivatives.
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This activated catalyst is an ion pair between a cationic catalyst and an weakly basic MAO-derived anion. MAO also functions as scavenger for protic impurities.
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The Iodite ion, or iodine dioxide anion, is the halite with the chemical formula . Within the ion the Iodine exists in the oxidation state of +3.
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Selenium or selenate alums are also known that contain selenium in place of sulfur in the sulfate anion, making selenate () instead. They are strong oxidizing agents.
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One example of a salt of this anion is the well-known sodium chlorite. This and related salts are sometimes used in the production of chlorine dioxide.
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The conjugate base is hypoiodite (IO−). Salts of this anion can be prepared by treating I2 with alkali hydroxides. They rapidly disproportionate to form iodides and iodates.
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Complications include incisional hernia, neobladder-intestinal and neobladder- cutaneous fistulas, ureteroenteric anastomosis stricture, neobladder rupture and mucous formation. Ureteral diversion can lead to normal anion gap acidosis.
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A number of hydrated forms are known which are actually cyclic metaphosphates, Ba2(P4O12)·3.5H2O, Ba3(P3O9)2·6H2O. Structure of a subunit of linear polyphosphate anion.
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Selectivity of crystalline membranes can be for both cation and anion of the membrane-forming substance. An example is the fluoride selective electrode based on LaF3 crystals.
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Scandium(III) fluoride, ScF3, is an ionic compound. It is slightly soluble in water but dissolves in the presence of excess fluoride to form the ScF63− anion.
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Solute carrier family 22 member 10 (SLC22A10), also known as organic anion transporter 5 (OAT5), is a protein that in humans is encoded by the SLC22A10 gene.
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This reaction can suffer from anion availability problems and, therefore, can benefit from the addition of phase transfer catalysts or highly polar aprotic solvents such as DMF.
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Furthermore, part of antioxidants properties of NO is attributable to up-regulation of heme- oxygenase-I and ferritin expression, which reduce superoxide anion concentrations in blood vessels.
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Structure of the hexafluorophosphate anion, PF6−. Many elements form anionic hexafluorides. Members of commercial interest are hexafluorophosphate (PF6−) and hexafluorosilicate (SiF62−). Many transition metals form hexafluoride anions.
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In this case, an anion sits atop an electron-poor π-system, usually established by the placement of electron-withdrawing substituents on the conjugated molecule Figure 5.
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Examples of oxygen nucleophiles are water (H2O), hydroxide anion, alcohols, alkoxide anions, hydrogen peroxide, and carboxylate anions. Nucleophilic attack does not take place during intermolecular hydrogen bonding.
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Pentacyanocyclopentadiene is a derivative of cyclopentadiene with five cyano groups with the molecular formula C5H(CN)5. The corresponding anion, pentacyanocyclopentadienide, is a ligand with the molecular formula . In contrast to other anions based on a C5 ring unit it binds to metals through the pendant cyano groups rather than the C5 ring. The anion was first synthesised by Webster in the 1960s and its conjugate acid much later on.
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Voltage-dependent anion-selective channel protein 2 is a protein that in humans is encoded by the VDAC2 gene on chromosome 10. This protein is a voltage-dependent anion channel and shares high structural homology with the other VDAC isoforms. VDACs are generally involved in the regulation of cell metabolism, mitochondrial apoptosis, and spermatogenesis. Additionally, VDAC2 participates in cardiac contractions and pulmonary circulation, which implicate it in cardiopulmonary diseases.
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Reduction of this compound at low temperature with caesium metal leads first to the radical anion and then to the dianion. The chemical shift for the internal protons in this compound is with +0.2 ppm much more modest than in the tri-trans isomer. :[12]annulene synthesis Heating the radical ion solution to room temperature leads to loss of one equivalent of hydrogen and formation of the heptalene radical anion.
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The anion can be derived from acetylenedicarboxylic acid by the loss of two protons. It is one of several oxocarbon anions which, like carbonate and oxalate , consist solely of carbon and oxygen. The ADC anion can at as a ligand in organometallic complexes, such as the blue polymeric complex with copper(II) and 2,2′-bipyridine, . Thallium(I) acetylenedicarboxylate (Tl2C4O4) decomposes at 195 °C, leaving a residue of pyrophoric thallium powder.
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In a similar manner, the weak unstable carbonic acid can lose one proton to form bicarbonate anion and lose a second to form carbonate anion (CO). Both Ka values are small, but Ka1 > Ka2 . A triprotic acid (H3A) can undergo one, two, or three dissociations and has three dissociation constants, where Ka1 > Ka2 > Ka3. : : : An inorganic example of a triprotic acid is orthophosphoric acid (H3PO4), usually just called phosphoric acid.
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Disodium pyrophosphate or sodium acid pyrophosphate (SAPP) is an inorganic compound consisting of sodium cations and pyrophosphate anion. It is a white, water-soluble solid that serves as a buffering and chelating agent, with many applications in the food industry. When crystallized from water, it forms a hexahydrate, but it dehydrates above room temperature. Pyrophosphate is a polyvalent anion with a high affinity for polyvalent cations, e.g. Ca2+.
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In the migratory insertion, a ligand that is viewed as an anion (X) ligand in and a ligand that is viewed as neutral couple, generating a new anionic ligand. The anion and neutral ligands that react are adjacent. If the precursor complex is coordinatively saturated, migratory insertion often result in a coordinatively unsaturated product. A new (neutral) ligand can then react with the metal leading to a further insertion.
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Further acidification produces the very soluble metatungstate anion, , after which equilibrium is reached. The metatungstate ion exists as a symmetric cluster of twelve tungsten-oxygen octahedra known as the Keggin anion. Many other polyoxometalate anions exist as metastable species. The inclusion of a different atom such as phosphorus in place of the two central hydrogens in metatungstate produces a wide variety of heteropoly acids, such as phosphotungstic acid H3PW12O40.
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With fully solvated and solvent-shared ion pairs the interaction is primarily electrostatic, but in a contact ion pair some covalent character in the bond between cation and anion is also present. An ion triplet may be formed from one cation and two anions or from one anion and two cations. Higher aggregates, such as a tetramer (AB)4, may be formed. Ternary ion associates involve the association of three species.
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Dioxosuccinic acid or dioxobutanedioic acid is an organic compound with formula C4H2O6 or HO−(C=O)4−OH. Removal of two protons from the molecule would yield the dioxosuccinate anion, or −O−(C=O)4−O−. This is one of the oxocarbon anions, which consist solely of carbon and oxygen. The name is also used for salts containing that anion, and for esters with the [−O−(C=O)4−O−] moiety.
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An arsenide mineral is a mineral that contains arsenide as its main anion. Arsenides are grouped with the sulfides in both the Dana and Strunz mineral classification systems.
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Solute carrier family 22 (organic anion/cation transporter), member 12, also known as SLC22A12 and URAT1, is a protein which in humans is encoded by the SLC22A12 gene.
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Perchlorate is the anion resulting from the dissociation of perchloric acid and its salts upon their dissolution in water. Many perchlorate salts are soluble in non-aqueous solutions.
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Weakly coordinating anions often are based on tetraarylborates, with electronegative substituents. Examples include B(C6F5)4− and Brookhart's acid containing the tetrakis[3,5-bis(trifluoromethyl)phenyl]borate anion.
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Urate oxidase is known to be inhibited by both cyanide and chloride ions. This occurs because of anion-π interactions between the inhibitor and the uric acid substrate.
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Such compounds can be viewed as salts and esters of respectively hyponitrous acid or HON=NOH. An acid hyponitrite is an ionic compound with the anion ([HON=NO]−).
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In a prelude to the actual Shapiro reaction, a ketone or an aldehyde (1) is reacted with p-toluenesulfonylhydrazide(2) to form a p-toluenesulfonylhydrazone (or tosylhydrazone) which is a hydrazone (3). Two equivalents of strong base such as n-butyllithium abstract the proton from the hydrazone (4) followed by the less acidic proton α to the hydrazone carbon (5), forming a carbanion. The carbanion then undergoes an elimination reaction producing a carbon–carbon double bond and ejecting the tosyl anion, forming a diazonium anion (6). This diazonium anion is then lost as molecular nitrogen resulting in a vinyllithium species (7), which can then be reacted with various electrophiles, including simple neutralization with water or an acid (8).
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The closing of the actin-binding cleft during the association reaction is structurally coupled with the opening of the nucleotide-binding pocket on the myosin active site. Notably, the final steps of ATP hydrolysis include the fast release of phosphate and the slow release of ADP. The release of a phosphate anion from bound ADP anion into water solution may be considered as an exergonic reaction because the phosphate anion has low molecular mass. Thus, we arrive at the conclusion that the primary release of the inorganic phosphate H2PO4− leads to transformation of a significant part of the free energy of ATP hydrolysis into the kinetic energy of the solvated phosphate, producing active streaming.
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The poly-leucine strands demonstrate enzyme-like kinetics with a first-order dependence on and eventual saturation with both the hydroperoxide anion (KM= 30 mM) and the olefin substrate (KM=110 mM.) Kinetic study suggests that the reaction proceeds by random steady-state formation of a ternary (polyleucine+hydroperoxide anion+olefin) complex. Both substrates must bind prior to reaction, and while either may bind first, initial hydroperoxide binding is kinetically preferred. The rapid equilibrium enabling complex formation is followed by the rate- limiting formation of the peroxide enolate (Figure 3).Carrea, G.; Colonna, S.; Meek, A. D.; Ottolina, G.; Roberts, S. M., "Kinetics of chalcone oxidation by peroxide anion catalysed by poly-L-leucine". Chem. Comm.
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When using Kröger–Vink notation for both intrinsic and extrinsic defects, it is imperative to keep all masses, sites, and charges balanced in each reaction. If any piece is unbalanced, the reactants and the products do not equal the same entity and therefore all quantities are not conserved as they should be. The first step in this process is determining the correct type of defect and reaction that comes along with it; Schottky and Frenkel defects begin with a null reactant (∅) and produce either cation and anion vacancies (Schottky) or cation/anion vacancies and interstitials (Frenkel). Otherwise, a compound is broken down into its respective cation and anion parts for the process to begin on each lattice.
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An oxocarbon anion can be seen as the result of removing all protons from a corresponding acid CxHnOy. Carbonate , for example, can be seen as the anion of carbonic acid H2CO3. Sometimes the "acid" is actually an alcohol or other species; this is the case, for example, of acetylenediolate that would yield acetylenediol C2H2O2. However, the anion is often more stable than the acid (as is the case for carbonate);"Infrared and mass spectral studies of proton irradiated H2O + CO2 ice: evidence for carbonic acid", by Moore, M. H.; Khanna, R. K. and sometimes the acid is unknown or is expected to be extremely unstable (as is the case of methanetetracarboxylate C(COO−)4).
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TlI3 is no exception as it is possible to stabilise thallium(III) with excess I− forming the TlI4− ion (isoelectronic with the tetraiodomercurate anion and with lead(IV) iodide).
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Ascorbic acid Mineral ascorbates are a group of salts of ascorbic acid (vitamin C). They are composed of a mineral cation bonded to ascorbate (the anion of ascorbic acid).
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The anion was optimized at the UB3LYP/6-311++G(d,p) theoretical level and the atomic connectivity modified by the human optimizer to reflect the probable electronic structure.
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Glemser, O. (1963) "Ammonium Perrhenate" in Handbook of Preparative Inorganic Chemistry, 2nd ed., G. Brauer (ed.), Academic Press, NY., Vol. 1, pp. 1476–85. Tetrathioperrhenate anion [ReS4]- is possible.
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An alkali anion exchange membrane (AAEM) is a semipermeable membrane generally made from ionomers and designed to conduct anions while being impermeable to gases such as oxygen or hydrogen.
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Electromotile function of mammalian prestin is blocked by the amphiphilic anion salicylate at millimolar concentrations. Application of salicylate blocks prestin function in a dose-dependent and readily reversible manner.
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The fluorosulfates or fluorosulfonates are a set of salts of fluorosulfuric acid with an ion formula SO3F−. The fluorosulfate anion can be treated as though it were a hydrogen sulfate anion with hydroxyl substituted by fluorine. The fluorosulfate ion has a low propensity to form complexes with the metal cation. Since fluorine is similar in size to oxygen, the fluorosulfate ion is roughly tetrahedral and forms salts similar to those of perchlorate.
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The positively charged species (e.g., sodium) in the D stream migrate toward the negatively charged cathode and pass through the negatively charged cation exchange membrane. These cations also stay in the C stream, prevented from further migration toward the cathode by the positively charged anion exchange membrane.AWWA, Electrodialysis and Electrodialysis Reversal, American Water Works Association, Denver (1995) As a result of the anion and cation migration, electric current flows between the cathode and anode.
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Thus, every chlorine is in the middle of a cube formed by caesium atoms and every caesium is in the middle of a cube formed by chlorine. Most caesium compounds contain the element as the cation , which binds ionically to a wide variety of anions. One noteworthy exception is the caeside anion (), and others are the several suboxides (see section on oxides below). Salts of Cs+ are usually colourless unless the anion itself is coloured.
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Hydride delivery occurs to give intermediate 5, followed by elimination of the metal sulfinate to give azo intermediate 6. This intermediate then decomposes, with loss of nitrogen gas, to give the reduced compound. When strongly basic hydride donors are used such as lithium aluminium hydride, then deprotonation of the tosyl hydrazone can occur before hydride delivery. Intermediate anion 7 can undergo hydride attack, eliminating a metal sulfinate to give azo anion 8.
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Without the mineralizer, higher temperatures are required to solubilize silica. Hydroxides and carbonates make silica more soluble by forming water-soluble sodium silicates. Simplified equations can be represented as :SiO2 \+ 2 NaOH → Na2SiO3 \+ H2O :SiO2 \+ Na2CO3 → Na2SiO3 \+ CO2 Anhydrous sodium silicate is a chain polymeric anion composed of corner shared SiO4 tetrahedra. Hydrates form with the formula Na2SiO3•nH2O which contain the discrete, approximately tetrahedral anion SiO2(OH)22− with waters of hydration.
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Monohalo ketones are reduced by both one-electron and two-electron reducing agents to afford the parent ketones, derivatives functionalized with electrophiles, or products of dimerization. The mechanism of reduction itself depends on the nature of the reducing agent. One-electron reducing agents, such as d6 or d1 transition metal complexes, initially donate a single electron to the halo ketone. Fragmentation of the resulting radical anion yields an organic radical and halide anion.
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The anion is widely used in ionic liquids (e.g.trioctylmethylammonium bis(trifluoromethylsulfonyl)imide), since it is less toxic and more stable than more "traditional" counterions such as tetrafluoroborate. This anion is also of importance in lithium-ion and lithium metal batteries (LiTFSI) because of its high dissociation and conductivity. It has the added advantage of suppressing crystallinity in poly(ethylene oxide), which increases the conductivity of that polymer below its melting point at 50 °C.
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The structure of the tetrathionate anion The tetrathionate anion,, is a sulfur oxoanion derived from the compound tetrathionic acid, H2S4O6. Two of the sulfur atoms present in the ion are in oxidation state 0 and two are in oxidation state +5. Alternatively, the compound can be viewed as the adduct resulting from the binding of to SO3. Tetrathionate is one of the polythionates, a family of anions with the formula [Sn(SO3)2]2−.
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Phytic acid is a six-fold dihydrogenphosphate ester of inositol (specifically, of the myo isomer), also called inositol hexakisphosphate (IP6) or inositol polyphosphate. At physiological pH, the phosphates are partially ionized, resulting in the phytate anion. The (myo) phytate anion is a colorless species that has significant nutritional role as the principal storage form of phosphorus in many plant tissues, especially bran and seeds. It is also present in many legumes, cereals, and grains.
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The anion gap (AG or AGAP) is a value calculated from the results of multiple individual medical lab tests. It may be reported with the results of an electrolyte panel, which is often performed as part of a comprehensive metabolic panel. The anion gap is the difference between certain measured cations (positively charged ions) and the measured anions (negatively charged ions) in serum, plasma, or urine. The magnitude of this difference (i.e.
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For example, of the four currently recognized KCl transporters, KCC1 and KCC4 both recognize KCl with similar affinities, but KCC1 exhibits anion selectivity: Cl− > SCN− = Br− > PO > I−, while KCl4 exhibits anion selectivity: Cl− > Br− > PO = I− > SCN−. Both are activated by cell swelling under hypotonic conditions. These proteins may cotransport water (H2O). CCCs share a conserved structural scaffold that consists of a transmembrane transport domain followed by a cytoplasmic regulatory domain.
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Electrodeionization installation scheme The typical RW-EDI installation has the following components: anode and cathode, anion exchange membrane, cation exchange membrane and the resin. The most simplified configuration consist in 3 compartments, to increase the production these number can be increased. The cations flow towards the cathode and the anions flows toward the anode. Only anions can go through the anion exchange membrane and only cations can go through the cation exchange membrane.
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Alternately, one could view this structure as a face- centered cubic structure with secondary atoms in its octahedral holes. Examples of compounds with this structure include sodium chloride itself, along with almost all other alkali halides, and "many divalent metal oxides, sulfides, selenides, and tellurides". More generally, this structure is more likely to be formed if the cation is somewhat smaller than the anion (a cation/anion radius ratio of 0.414 to 0.732).
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Tungsten carbides (W2C and WC) are produced by heating powdered tungsten with carbon. W2C is resistant to chemical attack, although it reacts strongly with chlorine to form tungsten hexachloride (WCl6). In aqueous solution, tungstate gives the heteropoly acids and polyoxometalate anions under neutral and acidic conditions. As tungstate is progressively treated with acid, it first yields the soluble, metastable "paratungstate A" anion, , which over time converts to the less soluble "paratungstate B" anion, .
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Two polymorphs are known of the pentahydrate. The anhydrous salt exists in several polymorphs. In the solid state, the thiosulfate anion is tetrahedral in shape and is notionally derived by replacing one of the oxygen atoms by a sulfur atom in a sulfate anion. The S-S distance indicates a single bond, implying that the terminal sulfur holds a significant negative charge and the S-O interactions have more double-bond character.
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Both Kohlrausch's law and the Debye-Hückel-Onsager equation break down as the concentration of the electrolyte increases above a certain value. The reason for this is that as concentration increases the average distance between cation and anion decreases, so that there is more inter-ionic interaction. Whether this constitutes ion association is a moot point. However, it has often been assumed that cation and anion interact to form an ion pair.
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This acidification is attributed to (i) the electron-withdrawing quality of the formyl center and (ii) the fact that the conjugate base, an enolate anion, delocalizes its negative charge. Related to (i), the aldehyde group is somewhat polar. The formyl proton itself does not readily undergo deprotonation. The anionic species formally derived from deprotonation of an aldehyde proton, known as an acyl anion, is highly unstable and must be kept at low temperatures.
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Docusate is the common chemical and pharmaceutical name of the anion bis(2-ethylhexyl) sulfosuccinate, also commonly called dioctyl sulfosuccinate (DOSS). Salts of this anion, especially docusate sodium, are widely used in medicine as laxatives and as stool softeners, by mouth or rectally. Docusate sodium is on the WHO List of Essential Medicines. It is a widely available and relatively inexpensive generic medication, with more than six million prescriptions in the US in 2017.
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In this article Faraday coins the words electrode, anode, cathode, anion, cation, electrolyte, and electrolyze. Whewell died in Cambridge in 1866 as a result of a fall from his horse.
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Higher the anion electrokinetic migration rate, higher the rate of pitting corrosion. Electrokinetic transport of ions inside the pit can be the rate-limiting step in the pit growth rate.
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It is a colorless liquid that is a precursor to acetylacetonate anion (commonly abbreviated acac−), a bidentate ligand. It is also a building block for the synthesis of heterocyclic compounds.
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Naturally occurring anion-conducting channelrhodopsins (ACRs) were subsequently identified in cryptophyte algae. The crystal structure of the natural GtACR1 has recently been solved, paving the way for further protein engineering.
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J Virol glucose consumption and plasma lactate concentration increase, glucose 6 phosphate dehydrogenase activity increases, and triglyceride concentration decreases. The voltage- dependent anion channel of the mitochondrion is also upregulated.
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Several vanadium(IV) phosphates are known. These materials are typically blue. In these species, the phosphate anion is singly or doubly protonated. Examples include the hydrogenphosphates, VOHPO4.4H2O and VO(HPO4).
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Ozonide is the unstable, reactive polyatomic anion analog of ozone or any of several classes of organic peroxide compounds similarly formed by the reaction of ozone with an unsaturated compound.
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However, the anion deviates somewhat from a planar, regular pentagon, with C–C bond lengths ranging from 138.0 -140.1 pm and C–C–C bond angles ranging from 107.5-108.8°.
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In chemistry, cyclopentadienyl is a radical with the formula C5H5. The cyclopentadienyl anion (formally related to the cyclopentadienyl radical by one-electron oxidation) is aromatic, and forms salts and coordination compounds.
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When attacked by the perhydroxyl anion (from hydrogen peroxide), NOBS forms the peroxy acid peroxynonanoic acid and releases the leaving group sodium 4-hydroxybenzene sulfonate, which is an inert by-product.
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Oxidation of thienyllithium gives 2,2'-dithienyl, (C4H3S)2. Thienyl lithium is employed in the preparation of higher order mixed cuprates. Coupling of thienyl anion equivalents gives dithienyl, an analogue of biphenyl.
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Bagnall 1957, p. 62; Fernelius 1982, p. 741 Many metal polonides, obtained by heating the elements together at 500–1,000 °C, and containing the Po2− anion, are also known.Bagnall 1966, p.
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The tellurite anion is a weak base. Sodium tellurite would be similar to sodium selenite and sodium sulfite. Sodium tellurite is both a weak oxidizing agent and a weak reducing agent.
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Resonance structures of an enolate anion. Enolates are organic anions derived from the deprotonation of carbonyl compounds. Rarely isolated, they are widely used as reagents in the synthesis of organic compounds.
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This malyl-CoA intermediate then undergoes hydrolysis at the acyl-CoA portion, replacing it with a carboxylate anion. The enzyme is free to release the malate and the coenzyme A molecules.
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Nitrate is a polyatomic ion with the chemical formula . Salts containing this anion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all nitrates are soluble in water.
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This is RbCl's highest possible coordination number. Therefore, according to the radius ratio rule, cations in this polymorph will reach their largest apparent radius because the anion-cation distances are greatest.
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A variety of complexes are known with bidentate ligands. Hexafluorophosphoric acid (HPF6) is derived from phosphorus pentafluoride and hydrogen fluoride. Its conjugate base, hexafluorophosphate (PF6–), is a useful non-coordinating anion.
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The CA IX enzyme, along with the CA II enzyme, binds to Anion Exchanger 2 (AE2) which increases bicarbonate transport and maximizes the rate of acid secretion by gastric parietal cells.
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Prior to final filtration may be treated with a strongly acid cation exchange resin in the sodium ion form, or a weakly basic anion exchange resin in the hydroxyl ion form.
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Potassium sulfite is the inorganic compound with the formula K2SO3. It is the salt of potassium cation and sulfite anion. It is a white solid that is highly soluble in water.
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For example, when targeting anions, quaternary ammonium salts (such as tetraoctylammonium bromide) are used to provide cationic nature to the membrane, facilitating anion mobility through the substrate to the receptor moieties.
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Complex bicyclic and tricyclic oxonium ions have been proposed as key intermediates in the biosynthesis of a series of natural products by the red algae of the genus Laurencia. 900x900px Several members of these elusive species have been prepared explicitly by total synthesis, demonstrating the possibility of their existence. The key to their successful generation was the use of a weakly coordinating anion (Krossing's anion, [Al(pftb)4]−, pftb = perfluoro-tert- butoxy) as the counteranion. As shown in the example below, this was executed by a transannular halide abstraction strategy through the reaction of the oxonium ion precursor (an organic halide) with the silver salt of the Krossing's anion Ag[Al(pftb)4]•CH2Cl2, generating the desired oxonium ion with simultaneous precipitation of inorganic silver halides.
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Graphite is mixed with the polymer to increase the conductivity.Nishide, H.; Suga, T. The Electrochemical Society Interface 2005, No. Winter, 32–36 The negative electrode uses the nitroxide - hydroxylamine anion redox pair to create an electrochemical potential, i.e. when the battery discharges the nitroxide radical is reduced to the hydroxylamine anion and when the battery charges the hydroxylamine anion is oxidized back to the nitroxide. This half-reaction has an oxidation potential of -0.11 V. Since this half-reaction is not readily reversible as the half-reaction at the positive electrode, several research groups have steered away from using pure organic radical batteries and instead use metal/ORB hybrid batteries usually consist of a radical polymer cathode and the same anode found in rechargeable Li-ion batteries.
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Aside from their synthetic utility, P450 enzymes have also been engineered to better understand their biochemistry. Based on the proposed catalytic cycle, an axially ligated thiolate moiety (cysteine) donates electron density to the metal center aiding in protonation of a ferric-peroxo anion intermediate (−O-O-Fe3+) which upon water lose generates a C-H bond reactive iron-oxo species (O=Fe4+). Alternatively, if the ferric-peroxo anion remains un-protonated, this reactive species can mediate C-C bond cleavage in aldehyde-containing substrates (deformylation). In order to better understand intermediate dichotomy between the ferric-peroxo anion and iron-oxo species, CYP125 (which is responsible various metabolic processes including cholesterol degradation) was engineered to replace the axial ligated cysteine residue with selenocysteine (SeCYP125).
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Assume that the cation C has +1 charge and anion A has −1 charge. #Schottky defect – forming a vacancy pair on both anion and cation sites: #:∅ v + v v + v #Schottky defect (charged) – forming an electron–hole pair: #:∅ e + h #Frenkel defect – forming an interstitial and vacancy pair on an anion or cation site: #:∅ v + C v + M (cationic Frenkel defect) #:∅ v + A v + X (anionic Frenkel defect) #Associates – forming an entropically favored site, usually depending on temperature. For the two equations shown below, the right side is usually at high temperature as this allows for more movement of electrons. The left side is usually at low temperature as the electrons lose their mobility due to loss in kinetic energy.
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Deltic acid is considered an acid because it is a particularly acidic enediol, with hydroxyl groups relatively easily losing their protons (pKa1 = 2.57, pKa2 = 6.03), leaving behind the symmetric deltate anion, . The first deltate salts (of lithium and potassium) were described in 1976, also by Eggerding and West. Lithium deltate Li2C3O3 is a water-soluble white solid. Like the other cyclic dianions with formula , the deltate anion has a pronounced aromatic character which contributes to its relative stability.
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Carbides of varying stoichiometries are known for the lanthanides. Non-stoichiometry is common. All of the lanthanides form LnC2 and Ln2C3 which both contain C2 units. The dicarbides with exception of EuC2, are metallic conductors with the calcium carbide structure and can be formulated as Ln3+C22−(e–). The C-C bond length is longer than that in CaC2, which contains the C22− anion, indicating that the antibonding orbitals of the C22− anion are involved in the conduction band.
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Alkali metal alkoxides are often oligomeric or polymeric compounds, especially when the R group is small (Me, Et). The alkoxide anion is a good bridging ligand, thus many alkoxides feature M2O or M3O linkages. In solution, the alkali metal derivatives exhibit strong ion-pairing, as expected for the alkali metal derivative of a strongly basic anion. Structure of the Li4(OBu-t)4(thf)3 cluster, highlighting the tendency of alkoxides to aggregate and bind ether ligands.
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General structural formula of an organotrifluoroborate anion Organotrifluoroborates are organoboron compounds that contain an anion with the general formula [RBF3]−. They can be thought of as protected boronic acids, or as adducts of carbanions and boron trifluoride. Organotrifluoroborates are tolerant of air and moisture and are easy to handle and purify. They are often used in organic synthesis as alternatives to boronic acids (RB(OH)2), boronate esters (RB(OR′)2), and organoboranes (R3B), particularly for Suzuki-Miyaura coupling.
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Solute carrier family 26 member 6 is a protein that in humans is encoded by the SLC26A6 gene. It is an anion-exchanger expressed in the apical membrane of the kidney proximal tubule, the apical membranes of the duct cells in the pancreas, and the villi of the duodenum. This gene belongs to the solute carrier 26 family, whose members encode anion transporter proteins. This particular family member encodes a protein involved in transporting chloride, oxalate, sulfate and bicarbonate.
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Calculating the anion gap is clinically useful because it helps in the differential diagnosis of a number of disease states. The total number of cations (positive ions) should be equal to the total number of anions (negative ions), so that the overall electrical charge is neutral. However, routine tests do not measure all types of ions. The anion gap is representative of how many ions are not accounted for by the lab measurements used in the calculation.
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They used these properties to separate several non-steroidal anti- inflammatory drugs (NSAIDs). The analysis of acidic drugs (salicylic acid: BA; SA; MS; and As) was performed below pH 4.5. MS is hydrophobic only its retention time was affected by an increase in temperature on the column without a terminally modified anion-exchanger (IB column). However, with an anion-exchanger present, dissociated acidic drugs were retained longer at temperatures below LCST, and shorter at temperatures above LCST.
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Potassium ferrooxalate, also known as potassium bisoxalatoferrate(II), is a salt with the formula [], sometimes abbreviated . The ferrooxalate anion (negative ion) is a transition metal complex, consisting of an atom of iron in the +2 oxidation state bound to two bidentate oxalate ions . The anion charge is balanced by two cations (positive ions) of potassium .J. Ladriere (1992): "Mössbauer study on the thermal decomposition of potassium tris (oxalato) ferrate(III) trihydrate and bis (oxalato) ferrate(II) dihydrate".
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Haldane made the point that various common water-related organic compounds have ammonia-related analogs; for instance the ammonia-related amine group (−NH2) is analogous to the water-related hydroxyl group (−OH). Ammonia, like water, can either accept or donate an H+ ion. When ammonia accepts an H+, it forms the ammonium cation (NH4+), analogous to hydronium (H3O+). When it donates an H+ ion, it forms the amide anion (NH2−), analogous to the hydroxide anion (OH−).
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It can be used to synthesise (diphenyl)methyl esters and ethers with carboxylic acids and alcohols respectively. It can also generate the (diphenyl)methyl carbene and nitrogen gas upon illumination by ultraviolet light or heating. It can also be electrolysed to form the Ph2CN anion, which can decompose to form the Ph2C− anion radical. If carried out in dimethylformamide and tetrabutylammonium perchlorate, these can react to form benzophenone azine, which has the formula Ph2C=N-N=CPh2.
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Zeise's salt, potassium trichloro(ethylene)platinate(II), is the chemical compound with the formula K[PtCl3(C2H4)]·H2O. The anion of this air-stable, yellow, coordination complex contains an η2-ethylene ligand. The anion features a platinum atom with a square planar geometry. The salt is of historical importance in the area of organometallic chemistry as one of the first examples of a transition metal alkene complex and is named for its discoverer, William Christopher Zeise.
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The action of GR proceeds through two distinct half reactions, a reductive half mechanism followed by an oxidative half. In the first half, NADPH reduces FAD present in GSR to produce a transient FADH− anion. This anion then quickly breaks a disulfide bond of Cys58 \- Cys63, forming a short lived covalent bond a stable charge-transfer complex between the flavin and Cys63. The now oxidized NADP+ is released and is subsequently replaced by a new molecule of NADPH.
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Raman spectroscopy and single-crystal X-ray diffraction studies reveal that the geometry of the dithionite anion is flexible. The dithionite dianion has C symmetry, with almost eclipsed with a 16° O-S-S-O torsional angle. In the dihydrated form (), the dithionite anion has a shorter S-S bond length and a gauche 56° O-S-S-O torsional angle. A weak S-S bond is indicated by the S-S distance of 239 pm.
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Cyclooctatetraene (C8H8) with eight π electrons has a nonplanar "tub" structure. However the dianion (cyclooctatetraenide anion), with ten π electrons obeys the 4n + 2 rule for n = 2 and is planar, while the 1,4-dimethyl derivative of the dication, with six π electrons, is also believed to be planar and aromatic. Cyclononatetraenide anion () is largest all-cis monocyclic annulene/annulenyl system that is planar and aromatic. These bond angles (140°) differ significantly from the ideal angles of 120°.
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Quan, Z. J. and Wang, X. C. (2014) ‘The 2-phosphaethynolate anion: Convenient synthesis and the reactivity’, Organic Chemistry Frontiers. doi:10.1039/c4qo00189c. Camp, C., Settineri, N., Lefèvre, J., Jupp, A. R., Goicoechea, J. M., Maron, L. and Arnold, J. (2015) ‘Uranium and thorium complexes of the phosphaethynolate ion’, Chemical Science. doi: 10.1039/c5sc02150b. Heift, D., Benko, Z. and Grützmacher, H. (2014) ‘Is the phosphaethynolate anion, (OCP)-, an ambident nucleophile? A spectroscopic and computational study’, Dalton Transactions.
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Hydromelonic acid, is an elusive chemical compound with formula or , whose molecule would of consist of a heptazine molecule with three cyanamido groups or substituted for the hydrogen atoms. The compound had not been properly isolated as of 2010, due to its tendency to polymerize. However, removal of three protons yields the melonate (formerly hydromelonate) anion , whose salts are stable and have been known since the 19th century. Removal of only two protons yields the divalent hydrogenmelonate anion .
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Cristina and Eliud are in love with each other, but Eliud never spoke of his love from loyalty to Elis. At the evening meal, Anion appears, as his father asks that this son be recognised as his heir. He is wearing the gold pin taken from Prestcote's room. Einon accuses him of theft but Anion explains that he thought the pin was Prestcote's and gave it to his father as galanas for the half-brother Prestcote hanged.
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In chemistry, a lyate ion is the anion derived by the deprotonation of a solvent molecule.IUPAC Gold Book - lyate ion For example, a hydroxide ion is formed by the deprotonation of water, and methoxide (CH3O−) is the anion formed by the deprotonation of methanol. Its counterpart is a lyonium ion, the cation formed by the protonation of a solvent molecule. Lyonium and lyate ions, resulting from molecular autoionization, contribute to the molar conductivity of protolytic solvents.
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Sakamoto, Takashi; Ojida, Akio; Hamachi, Itaru"Molecular recognition, fluorescence sensing, and biological assay of phosphate anion derivatives using artificial Zn(II)-Dpa complexes" Chemical Communications 2009, pp.141-152. Huy Tien Ngo, Xuejian Liu, Katrina A. Jolliffe "Anion recognition and sensing with Zn(II)–dipicolylamine complexes" Chem. Soc. Rev., 2012,41, 4928-4965. The compound can be prepared by many methods, alkylation of picolinylamine with picolinyl chloride, deamination of picolinylamine, and reductive amination of picolinyl amine and pyridine-2-carboxaldehyde.
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Hypophosphorus acid contains oxonium ions and is best formulated [H3O+]2 [H2P2O6]2−. The acid is isostructural with the diammonium salt which contains the [HOPO2PO2OH]2− anion with a P−P bond length of 219 pm. The HOPO2PO2OH2− anion in Na2H2P2O6·6H2O has a symmetric,staggered ethane-like structure with a P−P bond of length 219 pm. Each phosphorus atom has two P−O bonds with length 151 pm, and a P−OH bond length of 159 pm.
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Sodium salt are salt composed of sodium cation and the conjugate base anion of some inorganic or organic acid. They can be formed by the neutralization of the acid with sodium hydroxide.
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The very short Re–Re distance was noted. This short distance (and the salt's diamagnetism) indicated Re–Re bonding. These researchers however misformulated the anion as a derivative of Re(II), i.e., .
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As for anhydrite, its solubility in saline solutions and in brines is also strongly dependent on NaCl (common table salt) concentration. Gypsum crystals are found to contain anion water and hydrogen bonding.
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The ferrioxalate anion is sensitive to light and higher-energy electromagnetic radiation, which causes the decomposition of one oxalate to carbon dioxide and reduction of the iron(III) atom to iron(II).
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Cyclopentanepentone can be viewed as the neutral counterpart of the croconate anion . The compound referred to in the literature and trade as "cyclopentanepentone pentahydrate" (C5O5·5H2O) is probably decahydroxycyclopentane (C5(OH)10).
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7 and 2.A.53.2.8) can function as carriers or channels, depending on the transported anion. In these porters, mutating a glutamate, also involved in transport in the CIC family (TC# 2.
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Chromium telluride (Cr2Te3) is an inorganic chemical compound. It is composed of the chromium(III) cation and the telluride anion. It has a shadowy gray color, and has a hexagonal crystal structure.
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The tetrahydrate crystallizes as · and two water molecules. The anion has square planar molecular geometry. The Au–Cl distances are around 2.28 Å. Other d8 complexes adopt similar structures, e.g. [PtCl4]2−.
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Tetranitratoaluminate is an anion of aluminium and nitrate groups with formula [Al(NO3)4]− that can form salts called tetranitratoaluminates. It is unusual in being a nitrate complex of a light element.
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Hanksite The sulfate carbonates are a compound carbonates, or mixed anion compounds that contain sulfate and carbonate ions. Sulfate carbonate minerals are in the 7.DG and 5.BF Nickel-Strunz groupings.
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Thiophosphate chemistry. Anion set X2PS2−, (XPS2)2S2−, and (XPS2)2S22− Roesky, Herbert W.; Tebbe, Fred N.; Muetterties, Earl L. Inorganic Chemistry (1970), 9(4), 831-6. he and Fred established a lifelong friendship.
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The conjugate base of a sulfinic acid is a sulfinate anion. The enzyme cysteine dioxygenase converts cysteine into the corresponding sulfinate. One product of this catabolic reaction is the sulfinic acid derivative hypotaurine.
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Potassium chromate is the inorganic compound with the formula (K2CrO4). This yellow solid is the potassium salt of the chromate anion. It is a common laboratory chemical, whereas sodium chromate is important industrially.
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The anion C60(PhCH2)2Ph functions as an indenyl-like ligand. Fullerenes can also be substituents on otherwise conventional ligands as seen with an isoxazoline fullerene chelating to platinum, rhenium, and iridium compounds.
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For example, an acyl anions are not stable species, but the acyl anion synthon can be used to represent reagents such as lithiated dithianes, which are nucleophilic and often used in umpolung chemistry.
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The twice deprotonated species has a pKa value of 10.81. Due to its rapid decomposition under acidic conditions as described above, however, it is most commonly known as perxenate salts, bearing the anion .
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Caesium dodecaborate is an inorganic compound with the formula Cs2B12H12. It is a salt, with caesium cations and [B12H12]2− anions. This anion has been of great theoretical interest to the chemistry community.
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Best1 primarily functions as an intracellular calcium-activated chloride channel on the cellular membrane that is not voltage-dependent. More recently Best1 has been shown to act as a volume-regulating anion channel.
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A crystallographic study shows that the compound contains the Ce2(SO4)88− anion, where the cerium atoms are 9 coordinated by oxygen atoms belonging to sulfate groups, in a distorted tricapped trigonal prism.
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The potassium and rubidium salts of the monovalent hydrogenperoxocarbonate anion have also been obtained.Mimoza Gjikaj (2001), "Darstellung und strukturelle Charakterisierung neuer Alkali- bzw. Erdalkalimetallperoxide, -hydrogenperoxide, -peroxocarbonate und -peroxohydrate" . Doctoral Thesis, University of Köln.
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At even higher pH, the other carboxylic acid group loses its proton and the acid exists almost entirely as the glutamate anion −OOC-CH()-()2-COO−, with a single negative charge overall. The change in protonation state occurs at pH 4.07. This form with both carboxylates lacking protons is dominant in the physiological pH range (7.35–7.45). At even higher pH, the amino group loses the extra proton and the prevalent species is the doubly-negative anion −OOC-CH()-()2-COO−.
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The electrostatic flux that links the cation core to its bonding electrons now links the cation core to the anion. In this picture, a cation and anion are bonded to each other if they are linked by electrostatic flux, with the flux being equal to the valence of the bond. In a representative set of compounds Preiser et al. have confirmed that the electrostatic flux is the same as the bond valence determined from the bond lengths using Eq. 2.
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The association of the cation bonding electrons with the anion in the ionic model is purely formal. There is no change in physical locations of any electrons, and there is no change in the bond valence. The terms "anion" and "cation" in the bond valence model are defined in terms of the bond topology, not the chemical properties of the atoms. This extends the scope of the ionic model well beyond compounds in which the bonding would normally be considered as "ionic".
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Thr-Arg- Pro-Arg, Thr-Lys-Pro-Lys, Thr-Arg-Pro-Lys are as active as Thr-Lys-Pro-Arg. Thr-Lys-Pro-Pro-Arg is a potent inhibitor. Lys-Pro-Pro-Arg is also an inhibitor of phagocytosis, superoxide anion production and chemotaxis both human and rat PMN leukocytes and monocytes. Tyr-Lys-Pro exert considerable regulatory effect on several macrophage functions including: phagocytosis, cell locomotion, superoxide anion production, IgE-dependent cellular cytotoxicity, β-glycuronidase release, and IL-1 production.
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Initially, pyruvate and thiamine pyrophosphate (TPP or vitamin B1) are bound by pyruvate dehydrogenase subunits. The thiazolium ring of TPP is in a zwitterionic form, and the anionic C2 carbon performs a nucleophilic attack on the C2 (ketone) carbonyl of pyruvate. The resulting hemithioacetal undergoes decarboxylation to produce an acyl anion equivalent (see cyanohydrin or aldehyde-dithiane umpolung chemistry, as well as benzoin condensation). This anion attacks S1 of an oxidized lipoate species that is attached to a lysine residue.
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Different labs use different formulae and procedures to calculate the anion gap, so the reference range (or "normal" range) from one lab isn't directly interchangeable with the range from another. The reference range provided by the particular lab that performed the testing should always be used to interpret the results. Also, some healthy people may have values outside of the "normal" range provided by any lab. Modern analyzers use ion-selective electrodes which give a normal anion gap as <11 mEq/L.
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The calculated value of the anion gap should always be adjusted for variations in the serum albumin concentration. For example, in cases of hypoalbuminemia the calculated value of the anion gap should be increased by 2.3 to 2.5 mEq/L per each 1 g/dL decrease in serum albumin concentration (refer to Sample calculations, below). Common conditions that reduce serum albumin in the clinical setting are hemorrhage, nephrotic syndrome, intestinal obstruction and liver cirrhosis. Hypoalbuminemia is common in critically ill patients.
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The biggest challenge in developing AAEMFCs is the anion exchange membrane (AEM). A typical AEM is composed of a polymer backbone with tethered cationic ion-exchange groups to facilitate the movement of free OH− ions. This is the inverse of Nafion used for PEMFCs, where an anion is covalently attached to the polymer and protons hop from one site to another. The challenge is to fabricate AEM with high OH− ion conductivity and mechanical stability without chemical deterioration at elevated pH and temperatures.
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An ion-exchange membrane is generally made of organic or inorganic polymer with charged (ionic) side groups, such as ion-exchange resins. Anion-exchange membranes contain fixed cationic groups with predominantly mobile anions; because anions are the majority species, most of the conductivity is due to anion transport. The reverse holds for cation-exchange membranes. The so-called heterogeneous ion-exchange membranes have low cost and a thicker composition with higher resistance and a rough surface that can be subject to fouling.
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Many nitrogen oxoacids are known, though most of them are unstable as pure compounds and are known only as aqueous solution or as salts. Hyponitrous acid (H2N2O2) is a weak diprotic acid with the structure HON=NOH (pKa1 6.9, pKa2 11.6). Acidic solutions are quite stable but above pH 4 base-catalysed decomposition occurs via [HONNO]− to nitrous oxide and the hydroxide anion. Hyponitrites (involving the anion) are stable to reducing agents and more commonly act as reducing agents themselves.
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Ascorbic acid is a vinylogous acid and forms the ascorbate anion when deprotonated on one of the hydroxyls. This property is characteristic of reductones: enediols with a carbonyl group adjacent to the enediol group, namely with the group –C(OH)=C(OH)–C(=O)–. The ascorbate anion is stabilized by electron delocalization that results from resonance between two forms: :400px For this reason, ascorbic acid is much more acidic than would be expected if the compound contained only isolated hydroxyl groups.
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The study of rhenium hydrides can be traced to the 1950s and included reports of the "rhenide" anion, supposedly Re−. These reports led to a series of investigations by A. P. Ginsberg and coworkers on the products from the reduction of perrhenate. The rhenide anion, Re−, was based on the product of the reduction of perrhenate salts, such as the reduction of potassium perrhenate () by potassium metal. "Potassium rhenide" was shown to exist as a tetrahydrated complex, with the postulated chemical formula .
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Mesoxalic acid, also called oxomalonic acid or ketomalonic acid, is an organic compound with formula C3H2O5 or HO−(C=O)3−OH. Mesoxalic acid is both a dicarboxylic acid and a ketonic acid. It readily loses two protons to yield the divalent anion , called mesoxalate, oxomalonate, or ketomalonate. These terms are also used for salts containing this anion, such as sodium mesoxalate, Na2C3O5; and for esters containing the −C3O5− or −O−(C=O)3−O− moiety, such as diethyl mesoxalate, (C2H5)2C3O5.
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It has been shown to decrease the probability of intestinal tumors in rats that have been exposed to carcinogens. One of the potential pathways through which juglone achieves its anticancer properties is through the formation of the semiquinone radical; the semiquinone radical causes superoxide anion radicals to form which can lead to apoptosis when present in large concentrations. This conversion from juglone to semiquinone radical that causes the superoxide anion radical to form takes place in the mitochondria as well as the cytosol.
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Silica is the first readily measurable species to be released by a spent anion exchange resin and is therefore used as the trigger for anion resin regeneration. Silica is non-conductive and therefore not detectable by conductivity. Silica is measured on side stream samples with colorimetric analyzers. The measurement adds reagents including a molybdate compound and a reducing agent to produce a blue silico-molybdate complex color which is detected optically and is related to concentration according to the Beer–Lambert law.
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Linus Pauling's second rule of ionic bonding, the Electrostatic Valence Principle states, "An ionic structure will be stable to the extent that the sum of the strengths of the electrostatic bonds that reach an anion equals the charge on that anion." When there is more than one type of bonding in a crystal, strongly anisotropic physical properties can result such as those of graphite. Many other substances have anisotropic physical properties. Such properties are directly related to the atomic structures of the substances.
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This same mechanism can be evoked to explain the formation of mainly formic acid on p-GaP, p-GaAs and p+/p-Si photocathode owing to no adsorption of singly reduced CO2●− radical anion to the surface. In case of p-InP and p-CdTe photocathode, partial adsorption of CO2●− radical anion leads to formation of both carbon monoxide and formic acid. Low catalytic current density for CO2 photoreduction and competitive hydrogen generation are two major drawbacks of this system.
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Because XO is a superoxide-producing enzyme, with general low specificity, it can be combined with other compounds and enzymes and create reactive oxidants, as well as oxidize other substrates. Bovine xanthine oxidase (from milk) was originally thought to have a binding site to reduce cytochrome c with, but it has been found that the mechanism to reduce this protein is through XO's superoxide anion byproduct, with competitive inhibition by carbonic anhydrase. Another reaction catalyzed by xanthine oxidase is the decomposition of S-Nitrosothiols (RSNO), a reactive nitrogen species, to nitric oxide (NO), which reacts with a superoxide anion to form peroxynitrite under aerobic conditions. XO has also been found to produce the strong one-electron oxidant carbonate radical anion from oxidation with acetaldehyde in the presence of catalase and bicarbonate.
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Like other polycyclic aromatic compounds, perylene is reduced by alkali metals to give a deeply colored radical anion and a dianion. The diglyme solvates of these salts have been characterized by X-ray crystallography.
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Magnesium formate is a magnesium salt of formic acid. It is an inorganic compound. It consists of a magnesium cation and formate anion. It can be prepared by reacting magnesium oxide with formic acid.
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The compound features a pyramidal oxonium cation, isoelectronic with triethylamine, and a tetrahedral fluoroborate anion. Reflecting its ionic character, the salt dissolves in polar but inert solvents such as dichloromethane, sulfur dioxide, and nitromethane.
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Each Na+ center is surrounded by three sulfur and three nitrogen ligands provided by the triatomic thiocyanate anion. It is commonly used in the laboratory as a test for the presence of Fe3+ ions.
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Californium oxychloride (CfOCl) is a radioactive salt first discovered in measurable quantities in 1960. It is composed of a single californium cation and one oxychloride anion. It was the first californium compound ever isolated.
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The term "amide" is variously pronounced or or . Different pronunciations may be used for the two main senses, saying for the carbonyl–nitrogen compound and for the anion. Others replace one of these with .
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Benzyl alcohol has moderate solubility in water (4 g/100 mL) and is miscible in alcohols and diethyl ether. The anion produced by deprotonation of the alcohol group is known as benzylate or benzyloxide.
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T. E. (Thomas Edward) Thorpe. A dictionary of applied chemistry (Volume 4) :PBr5 \+ Br2 → PBr7 The structure consists of a PBr4+ cation paired with a tribromide (Br3–) anion, and the tribromide is non- symmetric.
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With alkali metals, 1-methylnaphthalene forms radical anion salts such as sodium 1-methylnaphthalenide. Compared to its structural analog sodium naphthalenide, sodium 1-methylnaphthalenide is more soluble, which is useful for low-temperature reductions.
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Structures of two main types of complexes formed by "methylmercury". X− = anion, L = neutral Lewis base. 3D model of the methylmercury functional group. Methylmercury (sometimes methyl mercury) is an organometallic cation with the formula .
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Sarong torso earns cruel lags it reeled. Engineer: "Erase handbag -- unite ratification!" oaring oaten donkeys unsold, surer rapid saltest tags BUTTERED TIBIA LUGS REWIRING TOILETS anion festers raring edit epilogues. DIRGE ROTOR. linnet oaring.
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Trimethylborane (CH3)3B has a similar-sounding name, and many similar properties, but only has one boron atom. Trimethylhydroborate (CH3)3BH− is an anion with one boron atom. It can form a lithium salt.
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Copper(II) chlorate is a chemical compound of the transition metal copper and the chlorate anion with basic formula Cu(ClO3)2. Copper chlorate is an oxidiser. It commonly crystallizes with four molecules of water.
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Lithium tungstate is the inorganic compound with the formula Li2WO4. It is a white solid that is soluble in water. The compound is one of the several orthotungstates, compounds that feature the tetrahedral WO42− anion.
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Increased levels of pyroglutamic acid in the blood, or 5-oxoprolinuria, can occur following paracetamol overdose, as well as in certain inborn errors of metabolism, causing an acidosis known as high anion gap metabolic acidosis.
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A dehydrating agent, such as concentrated sulfuric acid is typically added: :B(OH)3 \+ 3 ROH → B(OR)3 \+ 3 H2O A variety of salts are also known, involving the planar trigonal BO33– borate anion.
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Claudin-17 is a protein that in humans is encoded by the CLDN17 gene. It belongs to the group of claudins. It forms anion-selective paracellular channels and is localized mainly in kidney proximal tubules.
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Large cation/anion ion exchangers used in demineralization of boiler feedwater. The feedwater must be specially treated to avoid problems in the boiler and downstream systems. Untreated boiler feed water can cause corrosion and fouling.
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Compounds containing the octahedral anion are known, these include Ag6TeO6, Na6TeO6 and Hg3TeO6. There are also hydroxyoxotellurates, containing protonated , such as (NH4)2TeO2(OH)4 (sometimes written as NH4TeO4·2H2O) which contains the octahedral ion.
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The anion [HFe3(CO)11]− is structurally related to Fe3(CO)12, with the hydride replacing one bridging CO ligand. The bonding in the Fe-H-Fe subunit is described using concepts developed for diborane.
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Melonate anion . Alkali melonates are soluble in water without decomposition. Treatment of melonates with alkali gives salts of cyameluric acid. Potassium melonate pentahydrate has planar sheets of melonate anions with potassium cations between the layers.
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Voltage-dependent anion-selective channel protein 3 (VDAC3) is a protein that in humans is encoded by the VDAC3 gene on chromosome 8. The protein encoded by this gene is a voltage-dependent anion channel and shares high structural homology with the other VDAC isoforms. Nonetheless, VDAC3 demonstrates limited pore-forming ability and, instead, interacts with other proteins to perform its biological functions, including sperm flagella assembly and centriole assembly. Mutations in VDAC3 have been linked to male infertility, as well as Parkinson’s disease.
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The mechanism of the Wolff–Kishner reduction has been studied by Szmant and coworkers. According to Szmant's research, the first step in this reaction is the formation of a hydrazone anion 1 by deprotonation of the terminal nitrogen by MOH. If semicarbazones are used as substrates, initial conversion into the corresponding hydrazone is followed by deprotonation. A range of mechanistic data suggests that the rate-determining step involves formation of a new carbon–hydrogen bond at the carbon terminal in the delocalized hydrazone anion.
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Just as aromatic species like the cyclopentadienyl anion and the cyclopropenium cation can coordinate to transition metals, it was recently demonstrated that the B3+ ring can bind to metal centers. Laser ablation of a mixed B/Ir target produces two isomers of IrB3−, a B3+ ring coordinated to a formal Ir2- anion. These are a pseudo- planar η2 adduct and a tetrahedral η3 adduct, the latter of which contains an aromatic triboracyclopropenyl fragment. Both are nearly identical in energy and coexist in the generated cluster beam.
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A calcium silicate feedstock, made from processed steel slag, can also be used to neutralize active acidity in AMD systems by removing free hydrogen ions from the bulk solution, thereby increasing pH. As the silicate anion captures H+ ions (raising the pH), it forms monosilicic acid (H4SiO4), a neutral solute. Monosilicic acid remains in the bulk solution to play many roles in correcting the adverse effects of acidic conditions. In the bulk solution, the silicate anion is very active in neutralizing H+ cations in the soil solution.
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Boron teflate The conjugate base of teflic acid is called the teflate anion, F5TeO− (not to be confused with triflate). Many teflates are known, examples being B(OTeF5)3 and the acid anhydride O(TeF5)2. Pyrolysis of the boron compound gives the dimer (TeF4O)2 :2 B(OTeF5)3 → 2 B(OTeF5)2F + (OTeF4)2 The teflate anion is known to resist oxidation. This property has allowed the preparation several highly unusual species such as the hexateflates M(OTeF5)6− (M = As, Sb, Bi).
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Living polymerization was demonstrated by Michael Szwarc in 1956 in the anionic polymerization of styrene with an alkali metal / naphthalene system in tetrahydrofuran (THF). Szwarc showed that electron transfer occurred from radical anion of naphthalene to styrene. The initial radical anion of styrene converts to a dianion (or equivalently disodio-) species, which rapidly added styrene to form a "two – ended living polymer." An important aspect of his work, Szwarc employed the aprotic solvent tetrahydrofuran, which dissolves but is otherwise unreactive toward the organometallic intermediates.
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The orange to deep- red and highly hygroscopic anhydrous acid can be obtained by low-pressure sublimation of the dihydrate. Like many other enols, rhodizonic acid can lose the hydrogen cations H+ from the hydroxyls (pKa1 = , pKa2 = at 25 °C), yielding the hydrogenrhodizonate anion and the rhodizonate anion . The latter is aromatic and symmetric, as the double bond and the negative charges are delocalized and evenly distributed over the six CO units. Rhodizonates tend to have various shades of red, from yellowish to purplish.
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Dismutation of superoxide anions with a metal-based catalyzer (denoted by M) in a redox cycle. The Mn and Mn-1 show the oxidized and reduced forms of the metallic center, respectively. The metallic center is able to convert a superoxide anion to oxygen in the first half reaction by accepting an electron. In the second half reaction, the reduced metal atom donates the electron to another superoxide anion in order to form hydrogen peroxide, regenerating the metal ion in its original oxidation state.
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In these contexts, it appears that the carbonite ion reacts with excess carbon monoxide to form an anion with the ketene structure, O=C=. Infrared spectroscopy data confirm earlier theoretical studies that the carbonite anion has a bent structure, with the O−C−O angle varying between 120° and 130° depending on the context. The metal atoms interact with both oxygen atoms. However two geometrical arrangements for the lithium and caesium salts were detected, only one of them being symmetrical on the two oxygen atoms.
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FEBS Lett 486:93-98.Hosy E, Vavasseur A, Mouline K, Dreyer I, Gaymard F, Poree F, Boucherez J, Lebaudy A, Bouchez D, Very AA, Simonneau T, Thibaud JB, & Sentenac H (2003) The Arabidopsis outward K+ channel GORK is involved in regulation of stomatal movements and plant transpiration. Proc Natl Acad Sci U S A 100:5549-5554. Anion channels were identified as important controllers of stomatal closing.Keller BU, Hedrich R, & Raschke K (1989) Voltage-dependent anion channels in the plasma membrane of guard cells.
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It is isoelectronic with hydrogen sulfate, . When an organic group is substituted for the anions, organic fluorosulfonates are formed. In solution the fluorosulfate anion is completely ionised. The volume of the ions is 47.8 cm3/mol.
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It is also larger than silylamides. For these reasons, silox anion forms highly unsaturated complexes. Complexes with high coordinative unsaturation display high reactivity so long as they do not undergo intramolecular reactions. Silox offers this possibility.
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Many related salts are known, e.g., RbHPHO3, CsHPHO3, TlHPHO3. These salts are prepared by treating phosphorous acid with the metal carbonate. These compounds contain a layer polymeric anion consisting of HPO3 tetrahedra linked by hydrogen bonds.
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The first X-ray crystal structure that depicted anion–π interactions was reported in 2004. In addition to this being depicted in the solid state, there is also evidence that the interaction is present in solution.
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Tetrahydroxyborate can assimilate a proton into the anion by recombination: Because of this capture of a proton (), tetrahydroxyborate has Arrhenius-basic character. Its protonation product is boric acid. In aqueous solution, most tetrahydroxyborate ions are undissociated.
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Although the structure of the carborane acid differs greatly from conventional acids, both distribute charge and stability in a similar fashion. The carboranate anion distributes its charge by delocalizing the electrons throughout the 12 cage atoms.
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This form of chromatography is widely used in the following applications: water purification, preconcentration of trace components, ligand-exchange chromatography, ion- exchange chromatography of proteins, high-pH anion-exchange chromatography of carbohydrates and oligosaccharides, and others.
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Linden A. , Nugent K.W., Petridis A., James B. D., Inorg. Chim. Acta, 1999, 285, 122. ;Thallium(III) iodide complexes :Salts of are known. The anion is stable even though the triiodide is a thallium(I) compound.
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Therefore, prestin may require an associated cofactor for anion uptake in oocytes; however, this hypothesis is still under question. Experiments have shown that various anions can compete for prestin uptake including malate, chloride, and alkylsulfonic anions.
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The tetrahedral anion BH3(CN)− comprises the salt. The reagent is invariably purchased, although it can be prepared easily. One method involves combining sodium cyanide and borane. Another route entails treating sodium borohydride with mercury(II) cyanide.
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Salicylic acid competitively interferes with anion binding to OHC prestin which thereby reduces motility. This reduction in active displacement is again associated with depression of the cochlear amplifier which decreases the excessive vibrations experienced during noise- exposure.
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Potassium thiocyanate is the chemical compound with the molecular formula KSCN. It is an important salt of the thiocyanate anion, one of the pseudohalides. The compound has a low melting point relative to most other inorganic salts.
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The iodine-starch test was first described by J.-J. Colin and H.-F. Gaultier de Claubry, and F. Stromeyer in 1814. The triiodide anion (I3−) instantly produces an intense blue-black colour upon contact with starch.
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A metal EDTA anion. Pb displaces Ca in to give , which is passed out of the body in urine.Cs uros 1997, p. 124 In humans, heavy metal poisoning is generally treated by the administration of chelating agents.
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In5Br7 is a pale yellow solid. It is formulated InI3(InII2Br6)Br. The InII2Br6 anion has an eclipsed ethane like structure with a metal-metal bond length of 270 pm.M Ruck , H Bärnighausen Z. Anorg. allg. Chem.
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Alkyl tosylates are alkylating agents because tosylate is electron-withdrawing, which makes the tosylate anion a good leaving group. Tosylate is a pseudohalide. Toluenesulfonate esters undergo nucleophilic attack or elimination. Reduction of tosylate esters gives the hydrocarbon.
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This pKa value is close to that of acetic acid. Below a pH of 4.7, the protonated hydroperoxyl radical will dominate in solution while at pH above 4.7 the superoxide radical anion will be the main species.
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Oxalotrophic bacteria are bacteria capable of using oxalate as their sole source of carbon and energy. Oxalate is the anion of a salt of oxalic acid; oxalotrophs often consume calcium oxalate. Oxalotrophic bacteria are often facultative methylotrophs.
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Multidrug resistance-associated protein 2 (MRP2) also called canalicular multispecific organic anion transporter 1 (cMOAT) or ATP-binding cassette sub- family C member 2 (ABCC2) is a protein that in humans is encoded by the ABCC2 gene.
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The lithiated intermediate can be used for various nucleophilic bond-forming reactions, and then the dithioketal hydrolyzed back to its carbonyl form. This overall process, the Corey–Seebach reaction, gives the synthetic equivalent of an acyl anion.
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Trimethylamine is used in the synthesis of choline, tetramethylammonium hydroxide, plant growth regulators, herbicides, strongly basic anion exchange resins, dye leveling agents and a number of basic dyes. Gas sensors to test for fish freshness detect trimethylamine.
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SLCO4C1 belongs to the organic anion transporter (OATP) family. OATPs are involved in the membrane transport of bile acids, conjugated steroids, thyroid hormone, eicosanoids, peptides, and numerous drugs in many tissues (Mikkaichi et al., 2004 [PubMed 14993604]).
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Tetramethylphosphonium bromide is an organophosphorus compound with the formula (CH3)4PBr. It is a white, water-soluble solid, the salt of the cation tetramethylphosphonium and the bromide anion. It is prepared by treating trimethylphosphine with methyl bromide.
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Dicarbonate salts are apparently unstable but may have a fleeting existence in carbonate solutions. The term "dicarbonate" is sometimes used erroneously to refer to bicarbonate, the common name of the hydrogencarbonate anion or organic group the ROCO2H.
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Like most phenols, benzenehexol can lose the six H+ ions from the hydroxyl groups, yielding the hexaanion . The potassium salt of this anion is one of the components of Liebig's so-called "potassium carbonyl", the product of the reaction of carbon monoxide with potassium. The hexaanion is produced by trimerization of the acetylenediolate anion when heating potassium acetylenediolate . The nature of was clarified by R. Nietzki and T. Benckiser in 1885, who found that its hydrolysis yielded benzenehexol. R. Nietzki and T. Benckiser (1885), Berichte Chemie, volume 18, page 1834.
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Structure of the [W12O42]12- framework, emphasizing the coordination polyhedra. In APT, this anion binds two protons and is otherwise associated with ten NH4+ counterions. The anion in (NH4)10(W12O41)·5H2O has been shown to be [H2W12O42]10−, containing two hydrogen atoms, keeping two hydrogen atoms inside the cage. The correct formula notation for ammonium paratungstate is therefore (NH4)10[H2W12O42]·4H2O. The [H2W12O42]10− ion is known as the paratungstate B ion, as opposed to the paratungstate A ion, that has the formula [W7O24]6−, similar to the paramolybdate ion.
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Systematic additive IUPAC name for carbonate anion is trioxidocarbonate(2−). Similarly, cyanide anion CN− is named nitridocarbonate(1−). However, following the same logic for carbonate(4−) (orthocarbonic acid), by similitude to silicate(4−) (orthosilicic acid), in the systematic additive nomenclature makes no sense as this species has never been identified under normal conditions of temperature and pressure. Orthocarbonic acid is energetically much less stable than orthosilicic acid and cannot exist under normal conditions because of energetically unfavorable orbital configuration of a single central carbon atom bound to four oxygen atoms.
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In enzymology, an acetate CoA-transferase () is an enzyme that catalyzes the chemical reaction :acyl-CoA + acetate \rightleftharpoons a fatty acid anion + acetyl-CoA Thus, the two substrates of this enzyme are acyl-CoA and acetate, whereas its two products are fatty acid anion and acetyl-CoA. This enzyme belongs to the family of transferases, specifically the CoA-transferases. The systematic name of this enzyme class is acyl-CoA:acetate CoA-transferase. Other names in common use include acetate coenzyme A-transferase, butyryl CoA:acetate CoA transferase, butyryl coenzyme A transferase, and succinyl- CoA:acetate CoA transferase.
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The effect of adding an ionic sulfide modifier such as a La2S3 molecule to the crystal is to break one of the Ga-S dative bonds and replace it with a S2− anion. This anion links the gallium atom such that its tetrahedral environment is not altered, but what was a tricoordinated S atom now becomes a dicoordinated bridging atom. This process creates a negative void which can then be filled by a La3+ cation. Electrically, the effect of adding La2S3 is to give the glass an essentially ionic character.
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To achieve this chemistry, the [18F]F− is separated from the aqueous solvent by trapping it on an ion-exchange column, and eluted with an acetonitrile solution of 2,2,2-cryptand and potassium carbonate. Evaporation of the eluate gives [(crypt-222)K]+ [18F]F− (2) . The fluoride anion is nucleophilic but its anhydrous conditions are required to avoid competing reactions involving hydroxide, which is also a good nucleophile. The use of the cryptand to sequester the potassium ions avoids ion-pairing between free potassium and fluoride ions, rendering the fluoride anion more reactive.
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The mechanism is shown using the more commonly encountered and commercially available iminium isomer; a similar mechanism, however, is likely to apply to the uronium form. In the first step, the carboxylate anion (formed by deprotonation by an organic base [not shown]) attacks HATU to form the unstable O-acyl(tetramethyl)isouronium salt. The OAt anion rapidly attacks the isouronium salt, affording the OAt-active ester and liberating a stoichiometric quantity of tetramethylurea. Addition of a nucleophile, such as an amine, to the OAt-active ester results in acylation.
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The risk of statin-induced rhabdomyolysis increases with older age, use of interacting medications such as fibrates, and hypothyroidism. Coenzyme Q10 (ubiquinone) levels are decreased in statin use; CoQ10 supplements are sometimes used to treat statin- associated myopathy, though evidence of their efficacy is lacking . The gene SLCO1B1 (Solute carrier organic anion transporter family member 1B1) codes for an organic anion-transporting polypeptide that is involved in the regulation of the absorption of statins. A common variation in this gene was found in 2008 to significantly increase the risk of myopathy.
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An allylic rearrangement mechanism (SN2`) has also been implicated in allyl and propargyl halides. Stereochemical experiments on cyclic phosphites have revealed the presence of both pentavalent phosphoranes and tetravalent phosphonium intermediates in chemical equilibrium being involved in the dealkylation step of the reaction using 31P NMR. The decomposition of these intermediates is driven primarily by the nucleophilicity of the anion. There exists many instances of the intermediate phosphonium salts being sufficiently stable that they can be isolated when the anion is weakly nucleophilic, such as with tetrafluoroborate or triflate anions.
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Voltage-dependent anion channels, or mitochondrial porins, are a class of porin ion channel located on the outer mitochondrial membrane. There is debate as to whether or not this channel is expressed in the cell surface membrane. This major protein of the outer mitochondrial membrane of eukaryotes forms a voltage-dependent anion-selective channel (VDAC) that behaves as a general diffusion pore for small hydrophilic molecules. The channel adopts an open conformation at low or zero membrane potential and a closed conformation at potentials above 30–40 mV.
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The sodium- calcium exchanger exchanges 3 sodium ions for 1 calcium ion and represents a cation antiporter. Cells also contain anion antiporters such as the Band 3 (or AE1) anion transport protein. This cotransporter is an important integral protein in mammalian erythrocytes and moves chloride ion and bicarbonate ion in a one-to-one ratio across the plasma membrane based only on the concentration gradient of the two ions. The AE1 antiporter is essential in the removal of carbon dioxide waste that is converted to bicarbonate inside the erythrocyte.
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The dodecaborate anion was first prepared in modest yield by Pitochelli and Hawthorne from iododecarborane.Anthony R. Pitochelli, Frederick M. Hawthorne "The Isolation of Icosahedral B12H122− Ion" J. Am. Chem. Soc. 1960, volume 82, pp 3228–3229. It is more conventienly prepared in two steps from sodium borohydride. First the borohydride is converted into a triborate anion using the etherate of boron trifluoride: :4 NaBH4 \+ BF3 → NaB3H8 \+ 3 NaF + 4 H2 Pyrolysis of the triborate gives the twelve boron cluster as the sodium salt, which is then treated with caesium hydroxide to precipitate Cs2B12H12.
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When this happens the numerator is large, the denominator is small, and the result is a delta ratio which is high [ > 2 ]. This means a combined high anion gap metabolic acidosis and a pre-existing either respiratory acidosis or metabolic alkalosis (causing the high bicarbonate) – i.e. a mixed acid-base metabolic acidosis. Result 3: if there is a pure HAGMA, the bicarb would be expected to fall at a similar rate as the anion gap rises, since one molecule of acid combines with one molecule of bicarb buffer.
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Xenon does not react with oxygen directly; the trioxide is formed by the hydrolysis of : : + 3 → + 6 HF is weakly acidic, dissolving in alkali to form unstable xenate salts containing the anion. These unstable salts easily disproportionate into xenon gas and perxenate salts, containing the anion. Barium perxenate, when treated with concentrated sulfuric acid, yields gaseous xenon tetroxide: : + 2 → 2 + 2 + To prevent decomposition, the xenon tetroxide thus formed is quickly cooled into a pale-yellow solid. It explodes above −35.9 °C into xenon and oxygen gas, but is otherwise stable.
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This leads to a high overpotential for electrochemical heterogeneous reduction of CO2 to hydrocarbons and alcohols. Even further heterogeneous reduction of singly reduced CO2●− radical anion is difficult because of repulsive interaction between negatively biased electrode and negatively charged anion. Figure 2 shows that in case of a p-type semiconductor/liquid junction photo generated electrons are available at the semiconductor/liquid interface under illumination. The reduction of redox species happens at less negative potential on illuminated p-type semiconductor compared to metal electrode due to the band bending at semiconductor/liquid interface.
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After synthesising the potassium salt of the phosphaethynolate anion in 2013 (see above), Goicoechea et al. began to look into the potential of PCO towards cycloadditions. They found that the anion could react in a [2+2] fashion with a diphenyl ketene to produce the first isolatable example of a four-membered monoanionic phosphorus containing heterocycle. They employed the same method to test other unsaturated substrates such as carbodiimides and found that the likelihood of cyclisation heavily relies on the nature of the substituents on the unsaturated substrate.
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He died in Watford, Hertfordshire, England in September 2001. Space-filling model of [(η2-C2H4)PtCl3]−, the anion of Zeise's salt, based on X-ray crystallographic data Owston's crystallography work included the determination of the structure of Zeise's salt, the anion of which is shown at right. Zeise's salt, was reported in 1831 and was one of the first organometallic compounds ever discovered. However, the nature of the platinum to ethylene bond in the compound was not understood until the development of the Dewar–Chatt–Duncanson model in the 1950s.
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The existence of the dodecaborate(12) anion, [B12H12]2-, was predicted by H. C. Longuet-Higgins and M. de V. Roberts in 1955. Hawthorne and Pitochelli first made it 5 years later, by the reaction of iododecarborane with triethylamine in benzene solution at 80 °C. It is more conveniently prepared in two steps from sodium borohydride. First the borohydride is converted into a triborate anion using the etherate of boron trifluoride: : 5 NaBH4 \+ BF3 → 2 NaB3H8 \+ 3 NaF + 2 H2 Pyrolysis of the triborate gives the twelve boron cluster as the sodium salt.
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Levels of AEC are much lower than for CEC, because of the generally higher rate of positively (versus negatively) charged surfaces on soil colloids, to the exception of variable-charge soils. Phosphates tend to be held at anion exchange sites. Iron and aluminum hydroxide clays are able to exchange their hydroxide anions (OH−) for other anions. The order reflecting the strength of anion adhesion is as follows: :H2PO4− replaces SO42− replaces NO3− replaces Cl− The amount of exchangeable anions is of a magnitude of tenths to a few milliequivalents per 100 g dry soil.
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This gene encodes a member of the tweety family of proteins. Members of this family function as chloride anion channels. The encoded protein functions as a calcium(2+)-activated large conductance chloride(-) channel. [provided by RefSeq, Jul 2008].
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Reprinted in The Development of Chemistry, 1789-1914: Selected essays edited by D. Knight (1998). Online version at books.google.com, accessed on 2010-01-15. The lithium salt of this anion, Li6C6O6 has been considered for electric battery applications.
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These predictions proved quite accurate, although subsequent predictions for XeF8 indicated that it would be not only thermodynamically unstable, but kinetically unstable. As of 2013, XeF8 has not been made, although the octafluoroxenate(VI) anion () has been observed.
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The bromate anion, BrO, is a bromine-based oxoanion. A bromate is a chemical compound that contains this ion. Examples of bromates include sodium bromate, (), and potassium bromate, (). Bromates are formed many different ways in municipal drinking water.
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O. Glemser "Rhenium" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1476-85. This article refers to the oxoanion with the formula although tetrathioperrhenate anion is possible.
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The negative charge in these structures is stored as an alkoxide anion. Such a nucleophilic addition is called a nucleophilic conjugate addition or 1,4-nucleophilic addition. The most important active alkenes are the aforementioned conjugated carbonyls and acrylonitriles.
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Manganese tetrafluoride reacts violently with water and even with sodium-dried petroleum ether. It immediately decomposes on contact with moist air. Reaction with alkali metal fluorides or concentrated hydrofluoric acid gives the yellow hexafluoromanganate(IV) anion [MnF6]2−.
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The anion and cations are strongly hydrogen-bonded.Mootz, D.; Steffen, M. "Crystal structures of acid hydrates and oxonium salts. XX. Oxonium tetrafluoroborates H3OBF4, [H5O2]BF4, and [H(CH3OH)2]BF4", Zeitschrift für Anorganische und Allgemeine Chemie 1981, vol.
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Imidazolate (C3H3N) is the conjugate base of imidazole. It is a nucleophile and a strong base. The free anion has C2v symmetry. Imidazole has a pKa of 14.05, so the deprotonation of imidazole (C3H3N2H) requires a strong base.
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Ball-and-stick model of the hypothetical monothiophosphate trianion. Monothiophosphate is the anion [PO3S]3−, which has C3v symmetry. A common salt is sodium monothiophosphate (Na3PO3S). Monothiophosphate is used in research as an analogue of phosphate in biochemistry.
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Meyer, V.; Locher, J. "Untersuchungen über die Constitution der Nitrolsäuren (Researches on the constitution of the nitrolic acids)" Deut. Chem. Ges. Ber., 1874, volume 7, pp. 670-5. The reaction proceeds via the intermediacy of the nitronate anion.
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Before then it was well known that there were polymolybdates of Mo(VI). Molybdenum(VI)oxide, MoO3, when dissolved in aqueous alkali forms the tetrahedral molybdate anion, . Dissolving molybdate salts in strong acid produces "molybdic acid", MoO3·2H2O.
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ArsA and ArsB form an anion-translocating ATPase. The ArsB protein is distinguished by its overall hydrophobic character, in keeping with its role as a membrane-associated channel. Sequence analysis reveals the presence of 13 putative transmembrane (TM) regions.
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A phosphite anion or phosphite in inorganic chemistry usually refers to [HPO3]2− but includes [H2PO3]− ([HPO2(OH)]−). These anions are the conjugate bases of phosphorous acid (H3PO3). The corresponding salts, e.g. sodium phosphite (Na2HPO3) are reducing in character.
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Thrombin also has two exosites (1 and 2). Thrombin is a little different from other serine proteases as exosite 1 is anion-binding and binds to fibrin and other similar substrates while exosite 2 is a heparin-binding domain.
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The pentazenium cation (also known as pentanitrogen) is a positively charged polynitrogen ion of the chemical formula . Together with dinitrogen, solid nitrogen polymers and the azide anion, it is one of only three polynitrogen species obtained in bulk quantities.
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Thiocyanate (also known as rhodanide) is the anion [SCN]−. It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Organic compounds containing the functional group SCN are also called thiocyanates.
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Potassium nonahydridorhenate(VII) is an inorganic compound having the formula K2ReH9. This colourless salt is soluble in water but only poorly soluble in most alcohols. The anion is a rare example of a coordination complex bearing only hydride ligands.
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In these reactions, anion nucleophiles, such as tetra-n-butylammonium fluoride or methoxytetra-n-butylammonium, can replace the halogen substituents yielding a fluorodiazirine or methoxydiazirine respectively. The diazirine exchange reaction using various anions and the counterion tetra-n-butylammonium.
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A variety of other synthetic methods have been published. Salts of the dodecaborate ion are stable in air and do not react with hot aqueous sodium hydroxide or hydrochloric acid. The anion can be electrochemically oxidised to [B24H23]3−.
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J. Chojnacki: DFT and NBO theoretical study of protonation of tri-tert-butoxysilanethiol and its anion. Polyhedron 27(3) (2008) 969-976. and coordination chemistry with metal ions. It coordinates to metal ions via the sulfur and oxygen donor atoms.
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Gypsum desert rose The sulfate minerals all contain the sulfate anion, [SO4]2−. They tend to be transparent to translucent, soft, and many are fragile., p. 453 Sulfate minerals commonly form as evaporites, where they precipitate out of evaporating saline waters.
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It is the simplest oxocarbon and is isoelectronic with other triply-bonded diatomic species possessing 10 valence electrons, including the cyanide anion, the nitrosonium cation, boron monofluoride and molecular nitrogen. In coordination complexes the carbon monoxide ligand is called carbonyl.
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In the preparation of Ge(II) cationic complexes, triflate is often chosen as a counter anion as it is relatively weakly coordinating. GeCl2•dioxane is often used as a starting material, as it is a convenient source of Ge(II).
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The red tetrathiomolybdate anion results when molybdate solutions are treated with hydrogen sulfide: :[NH4]2[MoO4] + 4 H2S → [NH4]2[MoS4] + 4 H2O Like molybdate itself, undergoes condensation in the presence of acids, but these condensations are accompanied by redox processes.
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A selenite fluoride is a chemical compound or salt that contains fluoride and selenite anions (F− and SeO32−). These are mixed anion compounds. Some have third anions, including nitrate (NO3−), molybdate (MoO42−), oxalate (C2O42−), selenate (SeO42−), silicate (SiO42−) and tellurate (TeO42−).
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Sodium azide is an ionic solid. Two crystalline forms are known, rhombohedral and hexagonal. Both adopt layered structures. The azide anion is very similar in each form, being centrosymmetric with N–N distances of 1.18 Å. The ion has octahedral geometry.
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Initiation can also involve the transfer of an electron from the alkali metal to the monomer to form an anion- radical. Initiation occurs on the surface of the metal, with the reversible transfer of an electron to the adsorbed monomer.
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Potassium hexacyanochromate(III) is an inorganic compound with the formula K3[Cr(CN)6]. It consists of three potassium cations and [Cr(CN)6]3− anion. It is a yellow, air-stable, paramagnetic solid. It is isomorphous with potassium ferricyanide.
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However it has been detected using mass spectrometry. It is the neutral equivalent of the deltate anion C3O32−, known since 1975. An equivalent hydrate hexahydroxycyclopropane or cyclopropane-1,1,2,2,3,3-hexol, (-C(OH)2-)3 also exists. This contains geminal hydroxy groups.
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Lucigenin is an aromatic compound used in areas which include chemiluminescence. Its chemical name is bis-N-methylacridinium nitrate. It exhibits a bluish-green fluorescence. It is used as a probe for superoxide anion in biology, for its chemiluminescent properties.
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Some molecular compounds that adopt square pyramidal geometry are XeOF4, and various halogen pentafluorides (XF5, where X = Cl, Br, I). Complexes of vanadium(IV), such as [VO(acac)2] are square pyramidal (acac = acetylacetonate, the deprotonated anion of acetylacetone (2,4-pentanedione)).
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The structure of a cobalt(IV) coordination complex with the norbornyl anion Reaction of the anhydrous compound with sodium cyclopentadienide gives cobaltocene . This 19-electron species is a good reducing agent, being readily oxidised to the yellow 18-electron cobaltacenium cation .
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Mercury(II) thiocyanate (Hg(SCN)2) is an inorganic chemical compound, the coordination complex of Hg2+ and the thiocyanate anion. It is a white powder. It will produce a large, winding “snake” when ignited, an effect known as the Pharaoh's serpent.
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Lithium cyclopentadienide is an organolithium compound with the formula C5H5Li. The compound is often abbreviated as LiCp, where Cp− is the cyclopentadienide anion. Lithium cyclopentadienide is a colorless solid, although samples often are pink owing to traces of oxidized impurities.
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Displacement of halogen with pyrrolidine affords the alkylation product. The proton on the fused imidazole nitrogen is then removed by reaction with sodium hydride. Treatment of the resulting anion with α,4-dichlorotoluene gives the H1 antihistaminic agent clemizole (5).
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Maricite is a member of the phosphate mineral group. Phosphate minerals have one or more metal cations bonded to the phosphate anion PO4. (Hawthorne, F.C., 1998). In maricite the metals bonded to PO4 are sodium and iron (Sturman, et al.
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Red-shifted CsChrimson or bistable Channelrhodopsin are used for optogenetic activation of neurons (i.e. depolarization), as both allow spectral separation. In order to achieve neuronal silencing (i.e. hyperpolarization), an anion channelrhodopsin discovered in the cryptophyte algae species Guillardia theta (named GtACR1).
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Sodium cobaltinitrite is inorganic compound with the formula Na3Co(NO2)6. The anion of this yellow-coloured salt consists of the coordination complex [Co(NO2)6]3-. It was a reagent for the qualitative test for potassium and ammonium ions.
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The geometry of a molecule of BF3 is trigonal planar. Its D3h symmetry conforms with the prediction of VSEPR theory. The molecule has no dipole moment by virtue of its high symmetry. The molecule is isoelectronic with the carbonate anion, .
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Lithium triflate (lithium triflouromethanesulfonate or LiOTf) is a salt with the chemical formula LiCF3SO3. It is composed of the lithium cation (Li+) and triflate anion (CF3SO3−; TfO−). It is very hygroscopic. The salt is used in lithium-ion battery production.
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Hydronium cerium(III) nitrate hydrate, Ce(NO3)5(H3O)2.H2O It is monoclinic with space group P2/c. The diaquapentanitratocerate(III) anion (Ce(NO3)5(H2O)2)2− occurs in several salts. The salts have extreme non-linear optical properties.
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The cluster anion has the geometry of an incomplete cubane-type cluster with C3v symmetry. The dark colour of the complex is attributed to a number of charge-transfer interactions. Structure of the hydrated ammonium salt of [Fe4S3(NO)7]−.
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Lactobionic acid (4-O-β-galactopyranosyl-D-gluconic acid) is a sugar acid. It is a disaccharide formed from gluconic acid and galactose. It can be formed by oxidation of lactose. The carboxylate anion of lactobionic acid is known as lactobionate.
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Fluoride (). According to this source, is a possible pronunciation in British English. is an inorganic, monatomic anion with the chemical formula (also written ), whose salts are typically white or colorless. Fluoride salts typically have distinctive bitter tastes, and are odorless.
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Hydrazinium azide or hydrazine azide is a chemical compound with formula or . It is a salt of the hydrazinium cation and the azide anion . It can be seen as a derivative of hydrazine and hydrazoic acid . It is an unstable solid.
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In humans, they function as calcium-activated anion channels, each of which has a unique tissue distribution throughout the body. Specifically, the BEST1 gene on chromosome 11q13 encodes the Bestrophin-1 protein in humans whose expression is highest in the retina.
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Conversely, some syntheses entail nucleophilic displacement of phosphide anion equivalents ("R2P−") by aryl- and alkyl halides. Primary (RPH2) and secondary phosphines (RRPH and R2PH) add to alkenes in presence of a strong base (e.g., KOH in DMSO). Markovnikov's rules apply.
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Friedel's salt is an anion exchanger mineral belonging to the family of the layered double hydroxides (LDHs). It has affinity for anions as chloride and iodide and is capable of retaining them to a certain extent in its crystallographical structure.
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Correspondingly, anion exchange resins are typically provided in the form of chloride Cl−, which is a highly mobile couteranion. Counterions are used in phase-transfer catalysis. In a typical application lipophilic countercation such as benzalkonium solubilizes reagents in organic solvents.
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Glycocholic acid, or cholylglycine, is a crystalline bile acid involved in the emulsification of fats. It occurs as a sodium salt in the bile of mammals. It is a conjugate of cholic acid with glycine. Its anion is called glycocholate.
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Extensive studies involving the phosphaethynolate anion have shown that it can react in a variety of ways. It has documented use in cycloadditions, as a phosphorus transfer agent, a synthetic building block and as pseudo halide ligands (as described above).
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Metallabenzene complexes have been classified into three varieties; in such compounds the parent acyclic hydrocarbon ligand is viewed as the anion C5H5−. The 6 π electrons in the metallacycle conform to the Hückel (4n+2) theory. :Three classes of stable metallabenzenes.
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Major contributions of supramolecular chemistry have been devoted to recognition and sensing of anions. Ion pairing is the most important driving force for anion complexation, but selectivity e.g. within the halide series has been achieved, mostly by hydrogen bonds contributions.
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Compounds that contain caesium and another element in addition to the oxalate anion are double salts. The oxalate may form a complex with a transition metal that can make a salt with caesium. Examples include: a caesium neptunium oxalate (CsNpO2C2O4•nH2O).
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Sodium cyclopentadienide is an organosodium compound with the formula C5H5Na. The compound is often abbreviated as NaCp, where Cp− is the cyclopentadienide anion. Sodium cyclopentadienide is a colorless solid, although samples often are pink owing to traces of oxidized impurities.
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400px Electrodialysis (ED) is used to transport salt ions from one solution through ion-exchange membranes to another solution under the influence of an applied electric potential difference. This is done in a configuration called an electrodialysis cell. The cell consists of a feed (dilute) compartment and a concentrate (brine) compartment formed by an anion exchange membrane and a cation exchange membrane placed between two electrodes. In almost all practical electrodialysis processes, multiple electrodialysis cells are arranged into a configuration called an electrodialysis stack, with alternating anion and cation exchange membranes forming the multiple electrodialysis cells.
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Furthermore, this directly alters the energy of emitted light according to the Stokes shift of the material. This quick, post- synthetic anion-tunability is in contrast to other quantum dot systems where emission wavelength is primarily tuned through particle size by altering the degree of quantum confinement. Aside from tuning the absorption edge and emission wavelength by anion substitution, it was also observed that the A-site cation also affects both properties. This occurs as a result of the distortion of the perovskite structure and the tilting of octahedra due to the size of the A-cation.
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Previously, SLC26A6, another member of the same family of anion transporters as DTDST, was thought to provide the mechanism of oxalate- or formate-mediated chloride transport in this nephron segment; however, recent studies in Slc26a6-knockout mice have raised questions regarding its role in this transport process. In contrast, the apical membrane location, and electrochemical properties of SLC26A2 would fit the requirement of an anion exchanger located on the apical membrane of the proximal tubule that would serve as a mechanism of transporting chloride in exchange for oxalate, and/or recycling oxalate in exchange for sulfate.
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The mechanism of the Birch reduction has been the subject of much discussion. The original mechanism of the Birch reduction invoked protonation of a radical anion that was meta to the ring methoxy and alkyl groups. It further proposed that the last step, protonation of a cyclohexadienyl anion, occurred ortho with respect to these substituents. Birch's original mechanism was based on qualitative reasoning, namely that the radical anion's electron density, resulting from the addition of an electron, would be highest meta to an electron donor (such as methoxy or methyl) due to avoiding the usual ortho-para high density in the neutral species.
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Hydrogen atom (center) contains a single proton and a single electron. Removal of the electron gives a cation (left), whereas addition of an electron gives an anion (right). The hydrogen anion, with its loosely held two-electron cloud, has a larger radius than the neutral atom, which in turn is much larger than the bare proton of the cation. Hydrogen forms the only charge-+1 cation that has no electrons, but even cations that (unlike hydrogen) still retain one or more electrons are still smaller than the neutral atoms or molecules from which they are derived.
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Borates are composed of trigonal planar BO3 or tetrahedral BO4 structural units, joined together via shared oxygen atomsWiberg E. and Holleman A.F. (2001) Inorganic Chemistry, Elsevier and may be cyclic or linear in structure. Structure of boric acid, illustrating trigonal planar molecular geometry The simplest borate anion, the orthoborate(3−) ion, [BO3]3−, is known in the solid state, for example, in Ca3(BO3)2, where it adopts a nearly trigonal planar structure. It is a structural analogue of the carbonate anion [CO3]2−, with which it is isoelectronic. Simple bonding theories point to the trigonal planar structure.
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MeAN can undergo electropolymerization, if it is submitted to electroreduction at metallic cathodes in an organic anhydrous medium, for example; acetonitrile. There are two types of polymers that can be obtained at the end of the synthesis; a physisorbed polymer and a grafted polymer. The mechanism accounting for the non-grafted polymer is pretty well understood: it proceeds via the formation of a radical anion (the product of reduction of the vinylic monomer), which dimerizes in solution because of a radical–radical coupling mechanism (RRC) to deliver a di-anion acting as the initiator of a polymerization reaction in solution.
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Structure of sodium nitroprusside in the solid state, obtained by neutron diffraction Space filling model of sodium nitroprusside Nitroprusside is an inorganic compound with the formula Na2[Fe(CN)5NO], usually encountered as the dihydrate, Na2[Fe(CN)5NO]·2H2O. This red-colored sodium salt dissolves in water or ethanol to give solutions containing the free complex dianion [Fe(CN)5NO]2−. Nitroprusside is a complex anion that features an octahedral iron(III) centre surrounded by five tightly bound cyanide ligands and one linear nitric oxide ligand (Fe-N-O angle = 176.2 °). The anion possesses idealized C4vsymmetry.
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Propizepine synthesis: Condensation of 2-chloronicotinic acid (2) with o-phenylenediamine (1) leads directly to the tricyclic lactam (3) Although the reaction involves amide formation and nucleophilic aromatic displacement of chlorine, the order of these steps is not known. Alkylation of the anion obtained by treatment if 3 with the 1-chloro-2-dimethylaminopropane (4) affords the antidepressant compound propizepine (5). The last step in this sequence there is considerable evidence that such alkylations often proceed via the aziridinium ion. Attack of the anion at the secondary or tertiary carbon of the aziridinium ring will lead to different products.
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The trifluoroxenate(II) anion, , has been investigated as a possible first example of an AX3E3 molecule, which might be expected by VSEPR reasoning to have six electron pairs in an octahedral arrangement with both the three lone pairs and the three ligands in a mer or T-shaped orientations. Although this anion has been detected in the gas phase, attempts at synthesis in solution and experimental structure determination were unsuccessful. A computational chemistry study showed a distorted planar Y-shaped geometry with the smallest F–Xe–F bond angle equal to 69°, rather than 90° as in a T-shaped geometry.
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The acidity of LiOH has been measured in the gas phase. The oxidolithium anion, LiO–, was produced by successive decarboxylation and decarbonylation of monolithium oxalate anion, LiO(C=O)(C=O)O–, by collision-induced dissociation and was identified by its exact mass. The gas-phase acidity of LiOH was inferred from the experimentally determined electron affinity of LiO• and previously known heats of formation to give a value of 426 ± 2 kcal/mol. This is considerably higher than the gas-phase acidity of water (390 kcal/mol) and even exceeds that of methane (417 kcal/mol).
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The Enders SAMP/RAMP hydrazone alkylation begins with the synthesis of the hydrazone from a N,N-dialkylhydrazine and a ketone or aldehyde The hydrazone is then deprotonated on the α-carbon position by a strong base, such as lithium diisopropylamide (LDA), leading to the formation of a resonance stabilized anion - an azaenolate. This anion is a very good nucleophile and readily attacks electrophiles, such as alkyl halides, to generate alkylated hydrazones with simultaneous creation of a new chiral center at the α-carbon. Mechanism of hydrazone alkylation The stereochemistry of this reaction is discussed in detail in next section.
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Care must be taken in choosing an electrolyte since an anion from the electrolyte competes with the hydroxide ions to give up an electron. An electrolyte anion with less standard electrode potential than hydroxide will be oxidized instead of the hydroxide, and no oxygen gas will be produced. A cation with a greater standard electrode potential than a hydrogen ion will be reduced instead, and no hydrogen gas will be produced. The following cations have lower electrode potential than H+ and are therefore suitable for use as electrolyte cations: Li+, Rb+, K+, Cs+, Ba2+, Sr2+, Ca2+, Na+, and Mg2+.
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Perxenic acid Perxenic acid is the unstable conjugate acid of the perxenate anion, formed by the solution of xenon tetroxide in water. It has not been isolated as a free acid, because under acidic conditions it rapidly decomposes into xenon trioxide and oxygen gas: : 2 + 6 → 2 + 4 + Its extrapolated formula, H4XeO6, is inferred from the octahedral geometry of the perxenate ion () in its alkali metal salts. The pKa of aqueous perxenic acid has been indirectly calculated to be below 0, making it an extremely strong acid. Its first ionization yields the anion , which has a pKa value of 4.29, still relatively acidic.
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Perxenic acid and the anion are both strong oxidizing agents, capable of oxidising silver(I) to silver(III), copper(II) to copper(III), and manganese(II) to permanganate. The perxenate anion is unstable in acidic solutions, being almost instantaneously reduced to . The sodium, potassium, and barium salts are soluble. Barium perxenate solution is used as the starting material for the synthesis of xenon tetroxide (XeO4) by mixing it with concentrated sulfuric acid: : Ba2XeO6 (s) + 2 H2SO4 (l) → XeO4 (g) + 2 BaSO4 (s) + 2 H2O (l) Most metal perxenates are stable, except silver perxenate, which decomposes violently.
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The human CA1 protein contains an N-terminus active site, zinc binding site, and substrate-binding site. The crystal structure of the human CA1-bicarbonate anion complex reveals the geometry of two H-bonds between the Glu106-Thr199 pair and the Glu117-His119 pair, and one pi H-bond between a water molecule and the phenyl ring of the Tyr114 residue. The product inhibition of CA1 via bicarbonate anions is correlated to the proton localization change on His119. So the Glu117-His119 H-bond is considered to regulate the ionicity of the zinc ion and the binding strength of the bicarbonate anion.
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In HF, SeF4 behaves as a weak base, weaker than sulfur tetrafluoride, SF4 (Kb= 2 X 10−2): :SeF4 \+ HF → SeF3+ \+ HF2−; (Kb = 4 X 10−4) Ionic adducts containing the SeF3+ cation are formed with SbF5, AsF5, NbF5, TaF5, and BF3. With caesium fluoride, CsF, the SeF5− anion is formed, which has a square pyramidal structure similar to the isoelectronic chlorine pentafluoride, ClF5 and bromine pentafluoride, BrF5. With 1,1,3,3,5,5-hexamethylpiperidinium fluoride or 1,2-dimethylpropyltrimethylammonium fluoride, the SeF62− anion is formed. This has a distorted octahedral shape which contrasts to the regular octahedral shape of the analogous SeCl62−.
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The following oxidation–reduction tree for a simple ionic compound, AX, where A is a cation and X is an anion, summarizes the various ways in which intrinsic defects can form. Depending on the cation-to-anion ratio, the species can either be reduced and therefore classified as n-type, or if the converse is true, the ionic species is classified as p-type. Below, the tree is shown for a further explanation of the pathways and results of each breakdown of the substance. Tree diagram representation of the oxidation and reduction states resulting from intrinsic defects in ionic compounds.
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Iminodiacetic acid, HN(CH2CO2H)2, often abbreviated to IDA, is a dicarboxylic acid amine (the nitrogen atom forms a secondary amino group, not an imino group as the name suggests). The iminodiacetate anion can act as a tridentate ligand to form a metal complex with two, fused, five membered chelate rings. The proton on the nitrogen atom can be replaced by a carbon atom of a polymer to create an ion-exchange resin, such as chelex 100. A tridentate metal complex with the iminodiacetate anion IDA forms stronger complexes than the bidentate ligand glycine and weaker complexes than the tetradentate ligand nitrilotriacetic acid.
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These results were initially challenged by some authors, but subsequent experiments involving the detailed analysis of the decomposition products, complemented by computational studies, bore out the initial conclusion. The pentazolide anion is not expected to last longer than a few seconds in aqueous solution without the aid of complexing agents. The discovery of pentazoles spurred attempts to create all-nitrogen salts such as , which should be highly potent propellants for space travel. In 2002 the pentazolate anion was first detected with electrospray ionization mass spectrometry Vij, A., Pavlovich, J. G., Wilson, W. W., Vij, V. and Christe, K. O. (2002), Experimental Detection of the Pentaazacyclopentadienide (Pentazolate) Anion, cyclo-N5−. Angew. Chem. Int. Ed., 41: 3051–3054. In 2016 the ion was also detected in solution.B. Bazanov, U. Geiger, R. Carmieli, D. Grinstein, S. Welner, Y. Haas,Detection of Cyclo-N5− in THF Solution Angew. Chem. Int. Ed. 2016, 55, 13233. In 2017, white cubic crystals of the pentazolate salt, (N5)6(H3O)3(NH4)4Cl were announced.
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Proposed mechanism in mammals and presumably humans: Starting from the completely oxidized form, the reaction begins with the reduction of the selenenylsulfide to the selenolate anion (Se(-1)) with electrons received from NADPH via FAD (Step A). Due to the low pKa value of the selenol the selenolate anion is the predominant form under physiological conditions. A second electron transfer from a second molecule of NADPH reduces the active site tihiol bonds with one Cys residue stabilized by an interaction with FAD (Step B). The selenolate anion then attacks the disulfide bonds of Trx and the resulting enzyme-Trx mixed selenenylsulfide (Step C), which is then subsequently attacked by the neighboring Cys residue to regenerate the selenenylsulfide (Step D). This selenenylsulfide is then reduced by the active-site thiolate from the other subunit (Step E). Adapted from Zhong et al. Consistent with findings that (2,2‘:6‘,2‘‘-terpyridine)platinum(II) complexes inhibit human TrxR.
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Result 4: if the result of the ratio is greater than 2 in a high anion gap metabolic acidosis, it is usually because there was a pre-existing higher than normal bicarbonate level. This is commonly found in people with chronic respiratory acidosis from chronic lung disease such as chronic obstructive pulmonary disease (COPD), who can't breathe off their excess carbon dioxide owing to poor lung function, and retain bicarb in order to counteract the acidosis caused by the retained CO2. Alternatively it could be caused by a concurrent metabolic alkalosis such as vomiting causing acid loss and hence alkalosis, or diuretic use with loss of Cl¯ and a compensatory bicarb retention in order to maintain plasma electrical neutrality.UpToDate.com The Δanion gap/ΔHCO3 ratio in patients with a high anion gap metabolic acidosis Mathematically this is reflected in a high anion gap, but because the bicarbonate was high to start, it will appear to fall only a small amount.
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Fu, Y.K., S. Arkins, G. Fuh, B.C. Cunningham, J.A. Wells, S. Fong, M.J. Cronin, R. Dantzer and K.W. Kelley. 1992. Growth hormone augments superoxide anion secretion of human neutrophils by binding to the prolactin receptor. The Journal of Clinical Investigation 89:451 457.
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Both the free ligand and its tetraanionic chelating agent are abbreviated EDDHA. In contrast to EDDHA, most related aminopolycarboxylic acid chelating agents feature tertiary amines and few have phenolate groups. :Structure of anion [Mn(EDDHA)]−, which is representative of related C2-symmetric complexes.
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It interacts with and accelerates the opening of the mitochondrial voltage-dependent anion channel, which leads to a loss in membrane potential and the release of cytochrome c. This protein also interacts with the tumor suppressor P53 after exposure to cell stress.
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Cyclobutanetetrone can be viewed as the neutral counterpart of the squarate anion , which is stable and has been known at least since 1959. The compound octahydroxycyclobutane or cyclobutaneoctaol (C(OH)2)4 may be referred to in the literature as "hydrated tetraoxocyclobutane".
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In a chemical name, the term tosylate may either refer to the salts containing the anion of p-toluenesulfonic acid, TsO−M+ (M = alkali metal, NR4, PR4, etc), or it may refer to esters of p-toluenesulfonic acid, TsOR (R = organyl group).
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They feature tetrahedral orthotungstate dianions but differ in the packing motif. The WO42− anion adopts a structure like sulfate (SO42−).Carl W. F. T. Pistorius "Phase Diagrams of Sodium Tungstate and Sodium Molybdate to 45 kbar" J. Chem. Phys. 1966, volume 44, 4532.
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In chemical nomenclature when vanadate forms part of the name, it indicates that the compound contains an anion with a central vanadium atom, e.g. ammonium hexafluorovanadate is a common name for the compound (NH4)3VF6 with the IUPAC name of ammonium hexafluoridovanadate(III).
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In2Cl3 is colourless and is formulated InI3 InIIICl6Meyer. G. Z. Anorg. Allgem. Chem. 479 (1981) 7 39 In contrast In2Br3 contains the In2Br6 anion as present in In5Br7, and is formulated InI(InII2Br6) with a structure similar to Ga2Br3.Staffel. T., Meyer.
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Other substituted β-cyclodextrins have since been reported, including thiol-modified cyclodextrins, an anion-selective oligobutylene channel, and various poly- ethyleneoxide linked starburst oligomers. Structure-activity relationships for a large suite of cyclodextrin "half-channels" prepared by "click"-chemistry has been recently reported.
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Ionic liquid is a group of salt modification by anion and cation discret. It has flexibility to exhibit antibiofim activity and has antimicrobial activity, it has many antibiofilm activities and prevents the biofilm formation for many gram-positive and gram- negative bacteria.
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The chlorite ion, or chlorine dioxide anion, is the halite with the chemical formula of . A chlorite (compound) is a compound that contains this group, with chlorine in the oxidation state of +3. Chlorites are also known as salts of chlorous acid.
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The most common biological zwitterionic surfactants have a phosphate anion with an amine or ammonium, such as the phospholipids phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine, and sphingomyelins. Lauryldimethylamine oxide and myristamine oxide are two commonly used zwitterionic surfactants of the tertiary amine oxides structural type.
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The sulfate fluorides are double salts that contain both sulfate and fluoride anions. They are in the class of mixed anion compounds. Some of these minerals are deposited in fumaroles. Fluoride sulfates were first discovered by Jean Charles de Marignac in 1859.
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Bisulfide is an inorganic anion with the chemical formula HS− (also written as SH−). It contributes no color to bisulfide salts, and its salts may have a distinctive putrid smell. It is a strong base. Bisulfide solutions are corrosive and attack the skin.
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Difluorophosphate or difluorodioxophosphate or phosphorodifluoridate is an anion with formula . It has a single negative charge and resembles perchlorate () and monofluorosulfonate (SO3F−) in shape and compounds. These ions are isoelectronic, along with tetrafluoroaluminate, phosphate, orthosilicate, and sulfate. It forms a series of compounds.
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Coenzyme M is a coenzyme required for methyl-transfer reactions in the metabolism of methanogens. The coenzyme is an anion with the formula . It is named 2-mercaptoethanesulfonate and abbreviated HS–CoM. The cation is unimportant, but the sodium salt is most available.
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ArsB proteins are therefore members of a superfamily (called the IT (ion transporter) superfamily). However, ArsB has uniquely gained the ability to function in conjunction with ArsA in order to couple ATP hydrolysis to anion efflux. ArsAB belongs to the ArsA ATPase Superfamily.
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Neridronic acid (INN; the anion is called neridronate) is a bisphosphonate. In Italy it is used to treat Osteogenesis imperfecta and Paget's disease of bone. A 2013 clinical trial suggests CRPS Type I (Complex regional pain syndrome) responds to treatment with intravenous neridronate.
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The negative charge is placed on the oxygen anion and produces a pKa of less than or equal to 12. The basic pKa = -3.4, while the acidic pKa = 9.389. In the gas phase, uracil has 4 sites that are more acidic than water.
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In the solid state, 1,3-indandione occurs as a diketone; in water, it is partially (~2%) enolized. The enolate anion exhibits significant delocalization, and the highest electron density is on the second carbon. This explains many of chemical properties of the compound.
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This transfer of electrons is termed electrovalence in contrast to covalence. In the simplest case, the cation is a metal atom and the anion is a nonmetal atom, but these ions can be of a more complicated nature, e.g. molecular ions like NH4+ or SO42−.
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Rubidium hydroxide is the inorganic compound with the formula RbOH. It consists of rubidium cations and one hydroxide anion. It is a colorless solid that is commercially available as aqueous solutions from a few suppliers. Like other strong bases, rubidium hydroxide is highly corrosive.
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The anion was synthesized and characterized by Alexander Fatiadi in 1978. He obtained the potassium salt by treating dipotassium croconate with malononitrile in water solution at 80–90 °C. Alexander J. Fatiadi (1978), "Synthesis of 1,3-(dicyanomethylene)croconate salts. New bond-delocalized dianion, "Croconate Violet"".
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Cyclopentadiene is an organic compound with the formula C5H6.LeRoy H. Scharpen and Victor W. Laurie (1965): "Structure of cyclopentadiene". The Journal of Chemical Physics, volume 43, issue 8, pages 2765-2766. It is often abbreviated CpH because the cyclopentadienyl anion is abbreviated Cp−.
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Monohydrogen phosphate anion. Monohydrogen phosphate is the inorganic ion with the formula [HPO4]2-. Its formula can also be written as [PO3(OH)]2-, which shows the presence of a O-H bond. Together with dihydrogen phosphate, monohydrogen phosphate occurs widely in natural systems.
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That isomer is next acylated with 4-Chlorobutyryl chloride to give the chloroamide (7). The anion from reaction of the amide with sodium hydride then displaces the chlorine on the end of the chain to form the pyrrolidine ring. There is thus obtained levcromakalim (8).
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The hydride anion is very rarely observed. Almost all of the elements form binary compounds with hydrogen, the exceptions being He,Helium hydride exists as an ion. Ne,Neonium is an ion, and the HNe excimer exists also. Ar,Argonium exists as an ion.
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The structure of the tetrahydroxyborate anion. All borates can be considered derivatives of boric acid, B(OH)3. Boric acid is a weak proton donor (pKa ~ 9) in the sense of Brønsted acid, but is a Lewis acid, i.e., it can accept an electron pair.
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The term perbromate also refers to a compound that contains the anion or the functional group. The perbromate ion is a strong oxidizing agent. The reduction potential for the /Br− couple is +0.68 V at pH 14\. This is comparable to selenite's reduction potential.
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Benzenediazonium cation Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halogen.
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Potassium hypomanganate is the inorganic compound with the formula K3MnO4. Also known as potassium manganate(V), this bright blue solid is a rare example of a salt with the hypomanganate or manganate(V) anion, where the manganese atom is in the +5 oxidation state.
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Barium ferrate is the chemical compound of formula BaFeO4. This is a rare compound containing iron in the +6 oxidation state. The ferrate(VI) ion has two unpaired electrons, making it paramagnetic. It is isostructural with BaSO4, and contains the tetrahedral [FeO4]2− anion.
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Chloride is an anion in the human body needed for metabolism (the process of turning food into energy). It also helps keep the body's acid-base balance. The amount of serum chloride is carefully controlled by the kidneys. Chloride ions have important physiological roles.
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The fluoronium ion is an inorganic cation with the chemical formula . It is one of the cations found in fluoroantimonic acid. The structure of the salt with the anion, has been determined. The fluoronium ion is isoelectronic with the water molecule and the azanide ion.
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K2MnO4 is a salt, consisting of K+ cations and MnO42− anions. X-ray crystallography shows that the anion is tetrahedral, with Mn-O distances of 1.66 Å, ca. 0.03 Å longer than the Mn-O distances in KMnO4. It is isostructural with potassium sulfate.
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Tetrapropylammonium perruthenate (TPAP or TPAPR) is the chemical compound described by the formula N(C3H7)4RuO4. Sometimes known as the Ley–Griffith reagent, this ruthenium compound is used as a reagent in organic synthesis. This salt consists of the tetrapropylammonium cation and the perruthenate anion, .
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Tetrafluoroberyllate or orthofluoroberyllate is an anion containing beryllium and fluorine. The ion has a tetrahedral shape, the same size and outer electron structure as sulfate. Therefore, many compounds that contain sulfate, have equivalents with tetrafluoroberyllate. Examples of these are the Langbeinites, and Tutton's salts.
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CYP2C8 and CYP2C9 form particularly large amounts of superoxide anion (chemical formula ) during their metabolism of polyunsaturated fatty acids; this reactive oxygen species is toxic to cells and may be responsible for some of the activities ascribed to the epoxides made by the two CYPs.
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In erythrocytes, AnkyrinR links the membrane skeleton to the Cl−/HCO3− anion exchanger. Ankyrin 1 links membrane receptor CD44 to the inositol triphosphate receptor and the cytoskeleton. It has been suggested that Ankyrin 1 interacts with KAHRP (shown via selective pull-downs, SPR and ELISA).
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PBr5 is an unstable solid formulated as PBr4+Br−and PI5 is not known. The pentachloride and pentafluoride are Lewis acids. With fluoride, PF5 forms PF6−, an anion that is isoelectronic with SF6. The most important oxyhalide is phosphorus oxychloride, (POCl3), which is approximately tetrahedral.
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Potassium tetraiodomercurate(II) is an inorganic compound consisting of potassium cations and the tetraiodomercurate(II) anion. It is mainly used as Nessler's reagent, a 0.09 mol/L solution of potassium tetraiodomercurate(II) (K2[HgI4]) in 2.5 mol/L potassium hydroxide, used to detect ammonia.
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Nevertheless, the nitro anion- free radical formed during nitro reduction could still be associated with hepatotoxicity in humans, especially when using relatively high dosage employed for androgen blockage. Nilutamide causes side-effects which limit its usage, such as pneumonitis and delayed adaption to darkness.
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Meyer G., Blachnik R.Z. Anorg. Allg. Chem. 1983, 503, 126 The reason for this abundance of compounds is that indium forms 4 and 6 coordinate anions containing indium(III) e.g. In, In as well as the anion In2 that surprisingly contains an indium-indium bond.
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Molecular orbitals of an enolate, showing the occupancy corresponding to the anion. Enolate anions are electronically related to allyl anions. The anionic charge is delocalized over the oxygen and the two carbon sites. Thus they have the character of both an alkoxide and a carbanion.
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Potassium heptafluorotantalate is an inorganic compound with the formula K2[TaF7]. It is the potassium salt of the heptafluorotantalate anion [TaF7]2−. This white, water-soluble solid is an intermediate in the purification of tantalum from its ores and is the precursor to the metal.
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Osmium tetraoxide adds to C60 to give, in the presence of pyridine (py), the diolate C60O2OsO2(py)2. The pentaphenyl anion C60Ph5− behaves as a cyclopentadienyl ligand. Ferrocene-like complex of C60Ph5−. In this example, the binding of the ligand is similar to ferrocene.
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Another difference is that the iron cation is not diamagnetic low spin Fe(II) as in pyrite. In the crystal structure, each metal ion is tetrahedrally coordinated to 4 sulfur anions. Each sulfur anion is bonded to two copper atoms and two iron atoms.
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In some cases, methylene blue may be used as a prophylaxis before further doses of ifosfamide are administered. Other treatments include albumin and thiamine, and dialysis as a rescue modality. Ifosfamide may also cause a normal anion gap acidosis, specifically renal tubular acidosis type 2.
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Cadmium oxide is an inorganic compound with the formula CdO. It is one of the main precursors to other cadmium compounds. It crystallizes in a cubic rocksalt lattice like sodium chloride, with octahedral cation and anion centers.Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. .
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So for example, sodium methoxide can produce the 6,6-dimethoxy-1,3-dinitro-1,3-cyclohexadiene anion. When heated under pressure with water and ammonia DNAN is converted to 2,4-dinitroaniline. With iron and acetic acid DNAN nitro groups can be reduced to amines forming 2,4-diaminoanisole.
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The lightest heteronuclear ion is the helium hydride ion (HeH+). This is in contrast to a homonuclear ion, which contains all the same kind of atom, such as the dihydrogen cation, or atomic ions that only contain one atom such as the hydrogen anion (H−).
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Typical substrate constants are 0.66 for ethyl tosylate, 0.77 for β-propiolactone, 1.00 for 2,3-epoxypropanol, 0.87 for benzyl chloride, and 1.43 for benzoyl chloride. The equation predicts that, in a nucleophilic displacement on benzyl chloride, the azide anion reacts 3000 times faster than water.
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Hydrogen cyanide is a linear molecule, with a triple bond between carbon and nitrogen. A minor tautomer of HCN is HNC, hydrogen isocyanide. Hydrogen cyanide is weakly acidic with a pKa of 9.2. It partially ionizes in water solution to give the cyanide anion, CN−.
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Sulfide 3 is first silylated by reaction with tert- butyllithium and then trimethylsilyl chloride 4 and then the second acyl proton is removed and reacted with optically active (−)-epichlorohydrin 6 replacing chlorine. This compound serves as the substrate for reaction with the other dithiane 9 to the oxirane ring opening product 10. Under influence of the polar base HMPA, 10 rearranges in a 1,4-Brook rearrangement to the silyl ether 11 reactivating the formaldehyde dithiane group as an anion (hence the anion relay concept). This dithiane group reacts with oxirane 12 to the alcohol 13 and in the final step the sulfide groups are removed with (bis(trifluoroacetoxy)iodo)benzene.
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The two-coordinate hydridocadmium group (-CdH) in hydridocadmiums such as dihydridocadmium can accept an electron-pair donating ligand into the molecule by adduction: :] + L → Because of this acceptance of the electron-pair donating ligand (L), dihydridocadmium has Lewis-acidic character. Dihydridocadmium can accept two electron-pairs from ligands, as in the case of the tetrahydridocadmate(2−) anion (). The compound, Cs3CdH5, prepared by the reaction of caesium hydride, CsH, and cadmium metal powder at high temperature contains the ion, along with caesium cations, Cs+, and hydride anions, H−. The tetrahedral anion is an example of an ionic complex of CdH2. The average Cd-H bond length in is 182pm.
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Then in 1990 and 1993 a method was finally devised to experimentally assess whether the anisole and toluene radical anion protonated ortho or meta. The esoteric method began with the premise that the isotope selectivity in protonation in a protium–deuterium medium would be greater for the radical anion, of the first protonation step, than for the carbanion of the penultimate step. The reasoning was that carbanions are much more basic than the corresponding radical anions and thus will react more exothermically and less selectively in protonation. Experimentally it was determined that less deuterium at the ortho site than meta resulted (1:7) for a variety of methoxylated aromatics.
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The hydrogen is used to reduce two molecules of NAD+, a hydrogen carrier, to give NADH + H+ for each triose. Hydrogen atom balance and charge balance are both maintained because the phosphate (Pi) group actually exists in the form of a hydrogen phosphate anion (HPO42−), which dissociates to contribute the extra H+ ion and gives a net charge of -3 on both sides. Here, arsenate (AsO43−), an anion akin to inorganic phosphate may replace phosphate as a substrate to form 1-arseno-3-phosphoglycerate. This, however, is unstable and readily hydrolyzes to form 3-phosphoglycerate, the intermediate in the next step of the pathway.
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Asymmetric counteranion directed catalysis (ACDC) or chiral anion catalysis in enantioselective synthesis is the "induction of enantioselectivity in a reaction proceeding through a cationic intermediate by means of ion pairing with a chiral, enantiomerically pure anion provided by the catalyst". Although chiral Brønsted acid catalyzed reactions may well fall into this category of catalysis under the definition given here (e.g., protonation of an imine by a chiral phosphoric acid), the extent of proton transfer and the demarcation between hydrogen bonding and full proton transfer is often ambiguous. Hence, some authors may exclude ion pair formation by proton transfer as a type of chiral counteranion catalysis.
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Ethynylene-linked bistellurophene anion receptor In 2016, Taylor et al. developed a bidentate and electron-deficient bistellurophene receptor in which the tellurophenes were linked through an ethynylene bridge. As the tellurophene was thought to function as a Lewis acid in its interaction with the anion (Lewis base), 2,5-diaryltellurophenes with electron-deficient arene substitutents were synthesized. Through monitoring the change in the optical absorption spectrum upon addition of Bu4N+Cl− in tetrahydrofuran (THF), it was found that 2,5-bis[(perfluoro)aryl]tellurophene was able to bind Cl− with an association constant (Ka) of 310 ± 20 L mol−1, and would also bind Br− and BzO−.
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OAT1 functions as organic anion exchanger. When the uptake of one molecule of an organic anion is transported into a cell by an OAT1 exchanger, one molecule of an endogenous dicarboxylic acid (such as glutarate, ketoglutarate, etc.) is simultaneously transported out of the cell. As a result of the constant removal of endogenous dicarboxylic acid, OAT1-positive cells are at risk of depleting their supply of dicarboxylates. Once the supply of dicarboxylates is depleted, the OAT1 transporter can no longer function. To prevent the loss of endogenous dicarboxylates, OAT1-positive cells also express a sodium-dicarboxylate cotransporter called NaDC3 that transports dicarboxylates back into the OAT1-positive cell.
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The phosphotungstate anion, an example of a polyoxometalate In chemistry, a polyoxometalate (abbreviated POM) is a polyatomic ion, usually an anion, that consists of three or more transition metal oxyanions linked together by shared oxygen atoms to form closed 3-dimensional frameworks. The metal atoms are usually group 6 (Mo, W) or less commonly group 5 (V, Nb, Ta) transition metals in their high oxidation states. They are usually colorless or orange, diamagnetic anions. Two broad families are recognized, isopolymetalates, composed of only one kind of metal and oxide, and heteropolymetalates, composed of one metal, oxide, and a main group oxyanion (phosphate, silicate, etc.).
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Ghosh is reported to have done extensive researches on Anion recognition, molecular capsules, chemical sensing of Ions, inorganic salt extraction, supramolecular aggregations and interlocking molecules. He has developed several ligands with varying anion recognition elements as well as methodologies for selective sensing of phosphates, separation of hydrated metal sulphates/potassium bromide and bromide removal using halogen bonding. The development of Gypsum chalk replacing the calcium carbonate-made chalk which was in use traditionally was one of his notable contributions. His researches have been documented by way of a number of peer-reviewed articles; ResearchGate, an online article repository of scientific articles, has listed 112 of them respectively.
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The cagelike structure formed by the 11 boron atoms and 1 carbon atom allows the electrons to be highly delocalized through the 3D cage (the special stabilization of the carborane system has been termed "σ-aromaticity"), and the high energy required to disrupt the boron cluster portion of the molecule is what gives the anion its remarkable stability. Because the anion is extremely stable, it will not behave as a nucleophile toward the protonated substrate, while the acid itself is completely non-oxidizing, unlike the Lewis acidic components of many superacids like antimony pentafluoride. Hence, sensitive molecules like C60 can be protonated without decomposition.Kean, Sam.
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In addition to the weakly coordinating nature of the anion, salts are often more soluble in organic solvents (lipophilic) than the related nitrate or halide salts. Related to are hexafluorophosphate, , and hexafluoroantimonate, , both of which are even more stable toward hydrolysis and other chemical reactions and whose salts tend to be more lipophilic. Illustrative of a fluoroborate salt is [Ni(CH3CH2OH)6](BF4)2, a kinetically labile octahedral complex, which is used as a source of Ni2+. Extremely reactive cations such as those derived from Ti, Zr, Hf, and Si do in fact abstract fluoride from , so in such cases is not an "innocent" anion and less coordinating anions (e.g.
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Apart from formic acid, other products observed for CO2 photoreduction are formaldehyde, methanol and carbon monoxide. On p-GaP, p-GaAs and p+/p-Si photocathode, the main product is formic acid with small amount of formaldehyde and methanol. However, for p-InP and p-CdTe photocathode, both carbon monoxide and formic acid are observed in similar quantities. Mechanism proposed by Hori based on CO2 reduction on metal electrodes predicts formation of both formic acid (in case of no adsorption of singly reduced CO2●− radical anion to the surface) and carbon monoxide (in case of adsorption of singly reduced CO2●− radical anion to the surface) in aqueous media.
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Inorganic as well as organic ions display at moderate ionic strength I similar salt bridge association ΔG values around 5 to 6 kJ/mol for a 1:1 combination of anion and cation, almost independent of the nature (size, polarizability etc) of the ions. The ΔG values are additive and approximately a linear function of the charges, the interaction of e.g. a doubly charged phosphate anion with a single charged ammonium cation accounts for about 2x5 = 10 kJ/mol. The ΔG values depend on the ionic strength I of the solution, as described by the Debye-Hückel equation, at zero ionic strength one observes ΔG = 8 kJ/mol.
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12-Phosphotungstic acid, the compound J.F. Keggin used to determine the structure, can be purchased commercially. Other compounds that contain the α-Keggin anion such as silicotungstic acid and phosphomolybdic acid are also commercially available at Aldrich Chemicals, Fisher Chemicals, Alfa Aesar, VWR Chemical, American Elements, etc.
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Ferrocenium hexafluorophosphate is an organometallic compound with the formula [Fe(C5H5)2]PF6. This salt is composed of the cation [Fe(C5H5)2]+ and the hexafluorophosphate anion (). The related tetrafluoroborate is also a popular reagent with similar properties. The cation is often abbreviated Fc+ or Cp2Fe+.
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The sulfate chlorides are double salts containing both sulfate (SO42–) and chloride (Cl–) anions. They are distinct from the chlorosulfates, which have a chlorine atom attached to the sulfur as the ClSO3− anion. Many minerals in this family exist. Many are found associated with volcanoes and fumaroles.
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This is a consequence of the greater selectivity of the radical anion protonation. Computations (e.g. ROHF/6-31g) of the electron densities concurred with the experimental observations. Also, it was ascertained that frontier orbital densities did not, and these had been used in some previous reports.
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657–60 In hydroxides, the dominant anion is the hydroxyl ion, OH−. Bauxites are the chief aluminium ore, and are a heterogeneous mixture of the hydroxide minerals diaspore, gibbsite, and bohmite; they form in areas with a very high rate of chemical weathering (mainly tropical conditions)., pp.
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Moreover, BAK1 is believed to induce the opening of the mitochondrial voltage-dependent anion channel, leading to release of cytochrome c from the mitochondria. Alternatively, BAK1 itself forms an oligomeric pore, MAC, in the MOM, through which pro-apoptotic factors leak in a process called MOM permeabilization.
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Skeletal formula of the nonaflate anion Nonaflate, , is the common name given to nonafluorobutanesulfonates, the salts or esters of perfluorobutanesulfonic acid. Its uses are similar to those of triflate. It is a good leaving group. It is a substitute for more toxic long-chain PFAS chemicals.
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Higher selectivity: for example, positive, negative and neutral substances could be separated by a reversed phase (RP)/anion-cation exchange (ACE) column in a single run. X.D. Liu, C.A. Pohl, J. Sep. Sci. 33 (2010) 779. Higher loading capacity, N.H. Davies, M.R. Euerby, D.V. McCalley, J. Chromatogr.
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LDA dimer with THF coordinated to Li centers. LDA is commonly formed by treating a cooled (0 to −78 °C) tetrahydrofuran (THF) solution of diisopropylamine with n-butyllithium. When dissociated, the diisopropylamide anion can become protonated to form diisopropylamine. Diisopropylamine has a pKa value of 36.
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Sodium silox is the name for an organosilicon compound that serves as a source of the siloxide anion [(CH3)3C]3SiO−. Complexes of this bulky anionic ligand often adopt with low coordination numbers. Examples include Ti(silox)3, Nb(silox)3(PMe3), and [Cr(silox)3]−.
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Ferrocenium tetrafluoroborate is an organometallic compound with the formula [Fe(C5H5)2]BF4. This salt is composed of the cation [Fe(C5H5)2]+ and the tetrafluoroborate anion (). The related hexafluorophosphate is also a popular reagent with similar properties. The cation is often abbreviated Fc+ or Cp2Fe+.
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The protein encoded by this gene is a urate transporter and urate-anion exchanger which regulates the level of urate in the blood. This protein is an integral membrane protein primarily found in kidney. Two transcript variants encoding different isoforms have been found for this gene.
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This reagent is useful for introducing the trichloromethyl group into other molecules. Decarboxylation produces the trichloromethyl anion, which is a sufficiently strong nucleophile to attack various carbonyl functional groups, such as aldehydes, carboxylic acid anhydrides, ketones (making a precursor for the Jocic–Reeve reaction), and acyl halides.
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Phosphoenolpyruvate (2-phosphoenolpyruvate, PEP) is the ester derived from the enol of pyruvate and phosphate. It exists as an anion. PEP is an important intermediate in biochemistry. It has the highest-energy phosphate bond found (−61.9 kJ/mol) in organisms, and is involved in glycolysis and gluconeogenesis.
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The increased binding arises from the formation of a 2:1 complex, with two cyanostars sandwiching the anion on each side. An extended version of this structural pattern is a 4:3 alternating stack of cyanostar molecules complexing a hydrogen-bonded chain of dihydrogen phosphate units.
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Ternary metal hydrides have the formula AxMHn, where A+ is an alkali or alkaline earth metal cation, e.g. K+ and Mg2+. A celebrated example is K2ReH9, a salt containing two K+ ions and the ReH92− anion. Other homoleptic metal hydrides include the anions in Mg2FeH6 and Mg2NiH4.
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1986, 108:11, pp. 3075-3077\. . This anion, which appears as a blue solution, is an eight- coordinate vanadium complex. A Ca2+ cation is often used to crystallize amavadin to obtain a good quality X-ray diffraction. Oxidized amavadin can be isolated as its PPh4+ salt.
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Calcium cyanamide is the inorganic compound with the formula CaCN2. It is the calcium salt of the cyanamide () anion. This chemical is used as fertilizer and is commercially known as nitrolime. It was first synthesized in 1898 by Adolph Frank and Nikodem Caro (Frank-Caro process).
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Sodium phenoxide (sodium phenolate) is an organic compound with the formula NaOC6H5. It is a white crystalline solid. Its anion, phenoxide, also known as phenolate, is the conjugate base of phenol. It is used as a precursor to many other organic compounds, such as aryl ethers.
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The complex anion is octahedral. Like related d2 dioxo complexes, the oxo ligands are trans.R. K. Murmann, C. L. Barnes "Redetermination of the crystal structure of potassium trans-(dioxo)-tetra(hydroxo)osmate(VI), K2[Os(OH)4(O)2]" Z. Kristallogr. NCS 217, 2002, pp. 303–304.
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Calcium carbide. Several carbides are assumed to be salts of the acetylide anion C22– (also called percarbide), which has a triple bond between the two carbon atoms. Alkali metals, alkaline earth metals, and lanthanoid metals form acetylides, e.g., sodium carbide Na2C2, calcium carbide CaC2, and LaC2.
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Like tetracyanoethylene (TCNE), TCNQ is easily reduced to give a blue-coloured radical anion. The reduction potential is about −0.3 V relative to the ferrocene/ferrocenium couple. This property is exploited in the development of charge transfer salts. TCNQ also forms complexes with electron-rich metal complexes.
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Asymmetric Strecker reactions are well developed. By replacing ammonia with (S)-alpha-phenylethylamine as chiral auxiliary the ultimate reaction product was chiral alanine. Catalytic asymmetric Strecker reaction can be effected using thiourea-derived catalysts. In 2012, a BINOL-derived catalyst was employed to generate chiral cyanide anion.
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The telluride iodides are chemical compounds that contain both telluride ions (Te2−) and iodide ions (I−). They are in the class of mixed anion compounds or chalcogenide halides. Tellurium does not normally bond with iodine, but can form many different units with bonds to other tellurium atoms.
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Nitronium tetrafluoroborate is an inorganic compound with formula NO2BF4. It is a salt of nitronium cation and tetrafluoroborate anion. It is a colorless crystalline solid, which reacts with water to form the corrosive acids HF and HNO3. As such, it must be handled under water-free conditions.
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Sodium decavanadate describes any member of the family of inorganic compounds with the formula Na6[V10O28](H2O)n. These are sodium salts of the orange- colored decavanadate anion [V10O28]6−. Numerous other decavanadate salts have been isolated and studied since 1956 when it was first characterized.
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The Si-F bond is likewise polarized with only 10% of the charge on silicon. When the silylenoid is irradiated or heated a disilene forms probably via a silylene intermediate. With electrophiles it reacts as an anion and with organolithium compounds it reacts as a silylene.
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These halves come together to form the anion pore. The pore has a filter through which chloride and other anions can pass, but lets little else through. These water-filled pores filter anions via three binding sites—Sint, Scen, and Sext—which bind chloride and other anions.
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In reductive hydrodefluorination the fluorocarbon is reduced in a series of single electron transfer steps through the radical anion, the radical and the anion with ultimate loss of a fluorine anion. An example is the conversion of pentafluorobenzoic acid to 3,4,5-tetrafluorobenzoic acid in a reaction of zinc dust in aqueous ammonia. Specific systems that have been reported for fluoroalkyl group HDF are triethylsilane / carborane acid,Meier, G. and Braun, T. (2009), Catalytic C[BOND]F Activation and Hydrodefluorination of Fluoroalkyl Groups. Angew. Chem. Int. Ed., 48: 1546–1548. Hydrodefluorination and Other Hydrodehalogenation of Aliphatic Carbon−Halogen Bonds Using Silylium Catalysis Christos Douvris, C. M. Nagaraja, Chun-Hsing Chen, Bruce M. Foxman, and Oleg V. Ozerov Journal of the American Chemical Society 2010 132 (13), 4946-4953 and NiCl2(PCy3)2 / (LiAl(O-t-Bu)3H) Juan Xiao, Jingjing Wu, Wenwen Zhao, Song Cao and NiCl2(PCy3)2-catalyzed hydrodefluorination of fluoroarenes with LiAl(O-t-Bu)3H, Journal of Fluorine Chemistry, Volume 146, February 2013, Pages 76-79, ISSN 0022-1139, .
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In organic chemistry, brosyl (or para-bromophenylsulfonyl) is a functional group with the chemical formula BrC6H4SO2. This group is usually introduced using the compound brosyl chloride, BrC6H4SO2Cl, which forms sulfonyl esters and amides of p-bromophenylsulfonic acid. The term brosylate refers to the anion of p-bromophenylsulfonic acid (BrC6H4SO3−).
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An actinide cyaphide complex can be prepared by C−O bond cleavage of the phosphaethynolate anion, the phosphorus analogue of cyanate. Reaction of the uranium complex [] with [ in the presence of 2.2.2-cryptand results in the formation of a dinuclear, oxo-bridged uranium complex featuring a C≡P ligand.
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Hydrogenation gives the more saturated compound acenaphthene. Chemical reduction affords the radical anion sodium or potassium acenaphthalenide, which is used as a strong reductant (E = -2.26 V vs FC). N. G. Connelly and W. E. Geiger, "Chemical Redox Agents for Organometallic Chemistry", Chem. Rev. 1996, 96, 877-910.
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The RFC members appear to transport reduced folate by an energy-dependent, pH-dependent, Na+-independent mechanism. Folate:H+ symport, folate:OH−antiport and folate:anion antiport mechanisms have been proposed. Intracellular anions are able to promote folate derivative uptake. A bidirectional anion antiport mechanism for RFC family members is favored.
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It is important historically as a model weakly coordinating anion. But in the twenty-first century fluorosulfate was superseded in this use, in particular by BARF. Many pseudobinary fluorosulfate salts are known. They are called pseudobinary, because although there is one other element, there are four kinds of atoms.
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Phillips, W. D.; Rowell, J. C. Electron spin paramagnetic resonance (EPR) studies of the tetracyanoethylene anion radical. Journal of Chemical Physics (1960), 33 626-7.Goll, R. J.; Phillips, W. D.. Pressure dependence of the methyltriphenylphosphonium (TCNQ)2 phase change. Journal of Chemical Physics (1965), 43(3), 1076.
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In order to attract a negative charge, the charge distribution of the π system has to be reversed. This is achieved by placing several strong electron withdrawing substituents along the π system (e. g. hexafluorobenzene). The anion–π effect is advantageously exploited in chemical sensors for specific anions.
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Potassium hydrosulfide is the inorganic compound with the formula KHS. This colourless salt consists of the cation K+ and the bisulfide anion [SH]−. It is the product of the half-neutralization of hydrogen sulfide with potassium hydroxide. The compound is used in the synthesis of some organosulfur compounds.
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Isocitric acid is a structural isomer of citric acid. Salts and esters of isocitric acid are known as isocitrates. The isocitrate anion is a substrate of the citric acid cycle. Isocitrate is formed from citrate with the help of the enzyme aconitase, and is acted upon by isocitrate dehydrogenase.
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A space-filling model of the sulfite anion. Sulfites or sulphites are compounds that contain the sulfite ion (or the sulfate(IV) ion, from its correct systematic name), . The sulfite ion is the conjugate base of bisulfite. Although its acid (sulfurous acid) is elusive, its salts are widely used.
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Cell membranes are generally impermeable to charged ions (i.e. H+, HCO3− ) but RBCs are able to exchange bicarbonate for chloride using the anion exchanger protein Band 3. Thus, the rise in intracellular bicarbonate leads to bicarbonate export and chloride intake. The term "chloride shift" refers to this exchange.
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In supramolecular chemistry, cyclodextrins are precursors to mechanically interlocked molecular architectures, such as rotaxanes and catenanes. Illustrative, α-cyclodextrin form second-sphere coordination complex with tetrabromoaurate anion ([AuBr4]-). Beta-cyclodextrin complexes with certain carotenoid food colorants have been shown to intensify color, increase water solubility and improve light stability.
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Upon deprotonation, thiophene converts to the thienyl group, C4H3S−. Although the anion per se does not exist, the organolithium derivatives do. Thus reaction of thiophene with butyl lithium gives 2-lithiothiophene, also called 2-thienyllithium. This reagent reacts with electrophiles to give thienyl derivatives, such as the thiol.
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This salt has been used in the manufacture of dense aqueous solutions. Sodium metatungstate exists as white solid. The anion is the polyoxotungstate [H2W12O40]6-, which features six- coordinated tungsten(VI) centers interconnected with doubly- and triply bridging oxo ligands. Due to its very high solubility in water (max.
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To illustrate the mechanism, the Japp-Klingemann ester variation will be considered. The first step is the deprotonation of the β-keto-ester. The nucleophilic addition of the enolate anion 2 to the diazonium salt produces the azo compound 3. Intermediate 3 has been isolated in rare cases.
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Hexafluorophosphoric acid is the inorganic compound with the chemical formula (also written ). This strong Brønsted acid features a non-coordinating anion, hexafluorophosphate (). It is formed from the reaction of hydrogen fluoride with phosphorus pentafluoride. Like many strong acids, hexafluorophosphoric acid is not isolable but is handled only in solution.
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The sulfate or sulphate (see spelling differences) ion is a polyatomic anion with the empirical formula . Sulfate is the spelling recommended by IUPAC, but sulphate is used in British English. Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life.
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Nitrosonium tetrafluoroborate, also called nitrosyl tetrafluoroborate, is a chemical compound with the chemical formula NOBF4. This colourless solid is used in organic synthesis as a nitrosating agent. NOBF4 is the nitrosonium salt of fluoroboric acid, and is composed of a nitrosonium cation, [NO]+, and a tetrafluoroborate anion, [BF4]−.
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It is not effective against Mycobacterium tuberculosis and bacterial spores. Longer expositions may inactivate some viruses. Benzododecinium bromide is an active ingredient in the trademarked antiseptic product Ajatin produced in the Czech Republic. In place of bromide, the benzododecinium cation may be used with chloride or another anion.
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These proteins may include sodium-potassium-2 chloride co-transporter, chloride anion exchangers, and chloride channels. As a result of the reduce activity in these transporters, another suggested mechanism is a depletion in concentration gradient which would allow for the passive diffusion of chloride in and out the tubule.
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When a solution containing this anion is dehydrated, the precipitate contains mixed oxides. Many antimony ores are sulfides, including stibnite (), pyrargyrite (), zinkenite, jamesonite, and boulangerite. Antimony pentasulfide is non-stoichiometric and features antimony in the +3 oxidation state and S–S bonds. Several thioantimonides are known, such as and .
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Chloroauric acid refers to inorganic compounds with the chemical formula .(H2O)x. Both the trihydrate and tetrahydrate are known. Both are orange- yellow solids consisting of the planar [AuCl4]− anion. Often chloroauric acid is handled as a solution, such as those obtained by dissolution of gold in aqua regia.
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Tetrasodium pyrophosphate, also called sodium pyrophosphate, tetrasodium phosphate or TSPP, is an inorganic compound with the formula Na4P2O7. As a salt, it is a white, water-soluble solid. It is composed of pyrophosphate anion and sodium ions. Toxicity is approximately twice that of table salt when ingested orally.
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Tetrahydroxyborate (systematically named tetrahydroxyboranuide and tetrahydroxidoborate(1−)) is an inorganic anion with the chemical formula (also written as or ). It contributes no colour to tetrahydroxyborate salts. It is found in the mineral hexahydroborite, Ca(B(OH)4)2 (originally formulated CaB2O4).Glossary of Geology,5th edition, 2005, ed.
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Due to the unknown structure and mechanism of MAO, alternatives have been found in tetrakisperfluoroarylborate salts such as tetrakis[3,5-bis(trifluoromethyl)phenyl]borate anion (BArF4−). Such well- defined activators may be used stoichiometrically, whereas MAO is typically present in a reaction mixture in approximately hundredfold to thousandfold excess.
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A second SN2 substitution by the benzoate anion gives the desired diester (6). The mechanism of the Prévost reaction In the final step hydrolysis of the ester groups gives the anti-diol. This outcome is the opposite of that of the related Woodward cis-hydroxylation which gives syn addition.
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The fluoride phosphates or phosphate fluorides are inorganic double salts that contain both fluoride and phosphate anions. In mineralogy, Hey's Chemical Index of Minerals groups these as 22.1. The Nickel-Strunz grouping is 8.BN. Related mixed anion compounds are the chloride phosphates, the fluoride arsenates and fluoride vanadates.
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They are part of the family of halocarbonates. In turn these halocarbonates are a part of mixed anion materials. The carbonate chlorides do not have a bond from chlorine to carbon, however "chlorocarbonate" has also been used to refer to the chloroformates which contain the group ClC(O)O-.
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Drago, R. S. Physical Methods for Chemists 2nd ed.; Surfside Scientific Publishers: Gainesville, FL 1992. The metatellurate anion has a chemical shift around 610 ppm when analyzed using 125Te NMR at 25 °C at a frequency of 94.735 MHz and referenced externally against aqueous 1.0 M telluric acid.
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The bisulfide anion can accept a proton: Because of its affinity to accept a proton (H+), bisulfide has a basic character. In aqueous solution, it has a corresponding pKa value of 6.9. Its conjugate acid is hydrogen sulfide (). However, bisulfide's basicity stems from its behavior as an Arrhenius base.
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His experiments led him to the two laws of electrochemistry. Together with Whewell, Faraday introduced the basic vocabulary for the subject, the words electrode, anode, cathode, electrolysis, electrolyte, ion, anion, and cation. They remain in standard usage. But Faraday's work was of value to more then just chemists.
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The product is paramagnetic, as expected for a salt of the anion. It hydrolyses readily to give a mixture of sodium hydroxide, oxygen and hydrogen peroxide.Sasol Encyclopaedia of Science and Technology , G.C. Gerrans, P. Hartmann-Petersen , p.243 "sodium oxides" , google books link It crystallizes in the NaCl motif.
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Nitroxylic acid or hydronitrous acid is an unstable reduced oxonitrogen acid. It has formula H4N2O4 containing nitrogen in the +2 oxidation state. The corresponding anion called nitroxylate is or . The first clue that nitroxylic acid exists was when Edward Bedford Maxted electrolysed sodium nitrite dissolved in liquid ammonia.
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Other conditions that may present similarly include other causes of high anion gap metabolic acidosis including diabetic ketoacidosis. Treatment is generally with intravenous normal saline and intravenous sugar solution. Thiamine and measures to prevent alcohol withdrawal are also recommended. Treatment of low blood potassium may also be required.
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Fluorocitric acid is a fluorinated carboxylic acid derived from citric acid by substitution of one hydrogen by a fluorine atom. The appropriate anion is called fluorocitrate. Fluorocitrate is formed in two steps from fluoroacetate. Fluoroacetate is first converted to fluoroacetyl-CoA by acetyl-CoA synthetase in the mitochondria.
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Unlike sodium percarbonate and sodium perphosphate, the compound is not simply an adduct with hydrogen peroxide. Rather, it contains a perborate anion consisting of a cyclic –B–O–O–B–O–O– core with two hydroxy groups attached to each boron atom. The ring adopts a chair conformation.
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In chemistry, a trimer ( tri-, "three" + -mer, "parts") is a molecule or an anion formed by combination or association of three molecules or ions of the same substance. In technical jargon, a trimer is a kind of oligomer derived from three identical precursors often in competition with polymerization.
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Nitromethane is a relatively acidic carbon acid. It has a pKa of 17.2 in DMSO solution. This value indicates an aqueous pKa of about 11. The reason of that being so acidic is due to the resonance structure below: The anion is resonance stabilized It is slow to deprotonate.
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The CLC family of chloride channels contains 10 or 12 transmembrane helices. Each protein forms a single pore. It has been shown that some members of this family form homodimers. In terms of primary structure, they are unrelated to known cation channels or other types of anion channels.
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Schottky defects consist of unoccupied anion and cation sites in a stoichiometric ratio. For a simple ionic crystal of type A−B+, a Schottky defect consists of a single anion vacancy (A) and a single cation vacancy (B), or v + v following Kröger–Vink notation. For a more general crystal with formula AxBy, a Schottky cluster is formed of x vacancies of A and y vacancies of B, thus the overall stoichiometry and charge neutrality are conserved. Conceptually, a Schottky defect is generated if the crystal is expanded by one unit cell, whose a priori empty sites are filled by atoms that diffused out of the interior, thus creating vacancies in the crystal.
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Charge-transfer insulators are a class of materials predicted to be conductors following conventional band theory, but which are in fact insulators due to a charge-transfer process. Unlike Mott insulators, where the insulating properties arise from electrons hopping between unit cells, the electrons in charge-transfer insulators move between atoms within the unit cell. In the Mott–Hubbard case, it's easier for electrons to transfer between two adjacent metal sites (on-site Coulomb interaction U); in the charge-transfer case, it's easier from the anion to the metal (charge-transfer energy Δ). U is determined by repulsive/exchange effects between the cation valence electrons. Δ is tuned by the chemistry between the cation and anion.
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An isodesmic reaction is a chemical reaction in which the type of chemical bonds broken in the reactant are the same as the type of bonds formed in the reaction product. This type of reaction is often used as a hypothetical reaction in thermochemistry. An example of an isodesmic reaction is :CH3− \+ CH3X -> CH4 \+ CH2X− (1) :X = F, Cl, Br, I Equation 1 describes the deprotonation of a methyl halide by a methyl anion. The energy change associated with this exothermic reaction which can be calculated in silico increases going from fluorine to chlorine to bromine and iodine making the CH2I− anion the most stable and least basic of all the halides.
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Crystal formation can be divided into two types, where the first type of crystals are composed of a cation and anion, also known as a salt, such as sodium acetate. The second type of crystals are composed of uncharged species, for example menthol. Crystal formation can be achieved by various methods, such as: cooling, evaporation, addition of a second solvent to reduce the solubility of the solute (technique known as antisolvent or drown-out), solvent layering, sublimation, changing the cation or anion, as well as other methods. The formation of a supersaturated solution does not guarantee crystal formation, and often a seed crystal or scratching the glass is required to form nucleation sites.
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Many S-N compounds are prepared from S4N4. Reaction with piperidine generates [S4N5]−: :3 S4N4 \+ 4 C5H10NH → (C5H10NH2)+[S4N5]− \+ (C5H10N)2S + ⅜ S8 \+ N2 A related cation is also known, i.e. [S4N5]+. Treatment with tetramethylammonium azide produces the heterocycle [S3N3]−: :S4N4 \+ NMe4N3 → NMe4[S3N3] + ⅛ S8 \+ 2 N2 Cyclo-[S3N3]− has 10 pi-electrons: 2e−/S plus 1e−/N plus 1e− for the negative charge. In an apparently related reaction, the use of PPN+N3 gives a salt containing the blue [NS4]− anion: :2 S4N4 \+ PPN(N3) → PPN[NS4] + ½ S8 \+ 5 N2 The anion NS4− has a chain structure described using the resonance [S=S=N–S–S]− ↔ [S–S–N=S=S]−. S4N4 reacts with electron-poor alkynes.
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Retrieved 15 April 2018.H-J Meyer: Festkörperchemie in: H-J Meyer (ed.), Riedel Moderne Anorganische Chemie, Walter de Gruyter, 2012, . Retrieved 15 April 2018. Although the charges of A and B in the prototypical spinel structure are +2 and +3, respectively (), other combinations incorporating divalent, trivalent, or tetravalent cations, including magnesium, zinc, iron, manganese, aluminium, chromium, titanium, and silicon, are also possible. The anion is normally oxygen; when other chalcogenides constitute the anion sublattice the structure is referred to as a thiospinel. A and B can also be the same metal with different valences, as is the case with magnetite, Fe3O4 (as ), which is the most abundant member of the spinel group.
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The coordination number of each atom in this structure is 6: each cation is coordinated to 6 anions at the vertices of an octahedron, and similarly, each anion is coordinated to 6 cations at the vertices of an octahedron. The interatomic distance (distance between cation and anion, or half the unit cell length a) in some rock-salt- structure crystals are: 2.3 Å (2.3 × 10−10 m) for NaF, 2.8 Å for NaCl, and 3.2 Å for SnTe. Other compounds showing rock salt like structure are LiF,J. Aigueperse, P. Mollard, D. Devilliers, M. Chemla, R. Faron, R. Romano, J. P. Cuer, "Fluorine Compounds, Inorganic" (section 4) in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. .
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Finally, being highly reactive, iodomethane is more dangerous for laboratory workers than related chlorides and bromides. For example, it can be used for the methylation of carboxylic acids or phenols: :Methylation of a carboxylic acid or phenol with MeI In these examples, the base (K2CO3 or Li2CO3) removes the acidic proton to form the carboxylate or phenoxide anion, which serves as the nucleophile in the SN2 substitution. Iodide is a "soft" anion which means that methylation with MeI tends to occur at the "softer" end of an ambidentate nucleophile. For example, reaction with thiocyanate ion favours attack at rather than "hard" , leading mainly to methyl thiocyanate (CH3SCN) rather than methyl isothiocyanate CH3NCS.
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Glyoxalase I was originally believed to operate by the transfer of a hydride, which is a proton surrounded by two electrons (H-). In this, it was thought to resemble the classic Cannizzaro reaction mechanism, in which the attack of a hydroxylate on an aldehyde renders it into a tetravalent alcohol anion; this anion donates its hydrogens to a second aldehyde, forming a carboxylic acid and an alcohol. (In effect, two identical aldehydes reduce and oxidize each other, leaving the net oxidation state the same.) In glyoxalase I, such a hydride-transfer mechanism would work as follows. The attack of the glutathione would leave a charged O- and the aldehyde hydrogen bound to C1.
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Although the tetrahedron is the common coordination geometry for silicon compounds, silicon may also occur with higher coordination numbers. For example, in the anion hexafluorosilicate , the silicon atom is surrounded by six fluorine atoms in an octahedral arrangement. This structure is also seen in the hexahydroxysilicate anion that occurs in thaumasite, a mineral found rarely in nature but sometimes observed among other calcium silicate hydrates artificially formed in cement and concrete submitted to a severe sulfate attack. At very high pressure, even SiO2 adopts the six-coordinated octahedral geometry in the mineral stishovite, a dense polymorph of silica found in the lower mantle of the Earth and also formed by shock during meteorite impacts.
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In the anhydrous solid, the metasilicate anion is actually polymeric, consisting of corner-shared {SiO4} tetrahedra, and not a discrete SiO32− ion. In addition to the anhydrous form, there are hydrates with the formula Na2SiO3·nH2O (where n = 5, 6, 8, 9), which contain the discrete, approximately tetrahedral anion SiO2(OH)22− with water of hydration. For example, the commercially available sodium silicate pentahydrate Na2SiO3·5H2O is formulated as Na2SiO2(OH)2·4H2O, and the nonahydrate Na2SiO3·9H2O is formulated as Na2SiO2(OH)2·8H2O.Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications The pentahydrate and nonahydrate forms have their own CAS Numbers, 10213-79-3 and 13517-24-3 respectively.
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In some cases, this leads to alternative formulae that differ in bond orders (the full set of which is called the resonance formulas). Consider the sulfate anion ( with 32 valence electrons; 24 from oxygens, 6 from sulfur, 2 of the anion charge obtained from the implied cation). The bond orders to the terminal oxygens have no effect on the oxidation state so long as the oxygens have octets. Already the skeletal structure, top left, yields the correct oxidation states, as does the Lewis structure, top right (one of the resonance formulas): :450px The bond-order formula at bottom is closest to the reality of four equivalent oxygens each having a total bond order of 2.
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However, deionization does not significantly remove uncharged organic molecules, viruses or bacteria, except by incidental trapping in the resin. Specially made strong base anion resins can remove Gram-negative bacteria. Deionization can be done continuously and inexpensively using electrodeionization. Three types of deionization exist: co-current, counter-current, and mixed bed.
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Zinc chromate, Zn Cr O4, is a chemical compound containing the chromate anion, appearing as odorless yellow powder or yellow-green crystals, but, when used for coatings, pigments are often added. It is used industrially in chromate conversion coatings, having been developed by the Ford Motor Company in the 1920s.
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Such behavior, called Faraday transition, is observed in the cation conductors Na2S and Li4SiO4 and anion conductors PbF2, CaF2, SrF2, SrCl2 and LaF3. Later in 1891, Johann Wilhelm Hittorf reported on the ion transport numbers in electrochemical cells, and in the early 20th century those numbers were determined for solid electrolytes.
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The chloride ion . is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride salts such as sodium chloride are often very soluble in water.
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Structure of allylpalladium chloride dimer Transition-metal allyl complexes are coordination complexes with allyl and its derivatives as ligands. Allyl is the radical with the connectivity CH2CHCH2, although as a ligand it is usually viewed as an allyl anion CH2=CH−CH2−, which is usually described as two equivalent resonance structures.
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Triphenylmethyl hexafluorophosphate is an organic salt with the formula or , consisting of the triphenylmethyl cation and the hexafluorophosphate anion] . The cation is also called triphenylcarbenium, trityl cation, or tritylium.U. S. National Institutes of Health (2019) "PubChem ID 2723954 - Triphenylcarbenium hexafluorophosphate". Entry in NCBI's PubChem database, accessed on 2019-07-25.
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Theoretically, CFTR channel blockers may also be useful as male contraceptives. CFTR channels mediate bicarbonate anion entry which is essential for sperm capacitation. Various types of substances have been known to block CFTR chloride ion channels. Some of the best-known and studied substances include sulfonylureas, arylaminobenzenoates, and disulfonic stilbenes.
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Carbon monophosphide is a diatomic chemical with formula CP. It is cousin of CS and the cyanide radical (CN). CP and CN are both open-shell species with doublet Π ground electronic states while the ground states of CS and CO are closed-shell. The related anion, CP−, is called cyaphide.
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Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, a ligand, a nucleophile, and a catalyst.
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However, it was discovered afterwards that secondary interactions can be applied for improving separation power. In 1986, Regnier’s group synthesized a stationary phase that had characteristics of anion exchange chromatography (AEX) and hydrophobic interaction chromatography (HIC) on protein separation. L.A. Kennedy, W. Kopaciewicz, F.E. Regnier, J. Chromatogr. 359 (1986) 73.
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The cations and anions are shown by separate ternary plots. The apexes of the cation plot are calcium, magnesium and sodium plus potassium cations. The apexes of the anion plot are sulf ate , chloride and carbonate plus hydrogen carbonate anions. The two ternary plots are then projected onto a diamond.
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The chloride anion is an essential nutrient for metabolism. Chlorine is needed for the production of hydrochloric acid in the stomach and in cellular pump functions. The main dietary source is table salt, or sodium chloride. Overly low or high concentrations of chloride in the blood are examples of electrolyte disturbances.
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At this point, there are two proposed mechanisms to achieve halogenation. In the first, flavin hydroperoxide attacks the C6-C7 double bond of tryptophan, generating an epoxide. This epoxide is then opened by regioselective nucleophilic attack of halide anion at C7. The resultant halohydrin is dehydrated to form 7-chlorotryptophan.
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Several members should be stabilized taking into account a dipolar mesomeric form with for instance sesquifulvalene 4, which can be thought of as a tropylium cation joined to a cyclopentadienyl anion (both stable and aromatic). In this compound the dipolar structure is calculated to contribute 23% to the total structure.
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The telluride ion is the anion Te2− and its derivatives. It is analogous to the other chalcogenide anions, the lighter O2−, S2−, and Se2−, and the heavier Po2−. In principle, Te2− is formed by the two-e− reduction of tellurium. The redox potential is −1.14 V."Standard Reduction Potentials" , Indiana University.
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The anion exchanger family (TC# 2.A.31, also named bicarbonate transporter family) is a member of the large APC superfamily of secondary carriers. Members of the AE family are generally responsible for the transport of anions across cellular barriers, although their functions may vary. All of them exchange bicarbonate.
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Boysen H., Kaiser-Bischoff I. and Lerch M. (2007) Anion Diffusion Processes in O- and N-Mayenite Investigated by Neutron Powder Diffraction. Bunsen Colloquium: Diffusion and Reactions in Advanced Materials (September 27th–28th, Clausthal-Zellerfeld, Germany) / The Open-Access Journal for the Basic Principles of Diffusion Theory, Experiment and Application.
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KOtBu, are also effective. The mechanism begins by generation of Si(CH3)3X and a highly reactive [CF3]− (trifluoromethide) intermediate. The [CF3]− attacks the carbonyl to generate an alkoxide anion. The alkoxide is silylated by the reagent to give the overall addition product, plus [CF3]−, thus propagating an anionic chain reaction.
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Nitronium perchlorate, NO2ClO4, also known as nitryl perchlorate and nitroxyl perchlorate, is an inorganic chemical, the salt of the perchlorate anion and the nitronium cation. It forms colorless monoclinic crystals. It is hygroscopic, and is a strong oxidizing and nitrating agent. It may become hypergolic in contact with organic materials.
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Trinitromethane as a neutral molecule is colorless. It is highly acidic, easily forming an intensely yellow anion, (NO2)3C−. The pKa of trinitromethane has been measured at 0.17 ± 0.02 at 20 °C, which is remarkably acidic for a methane derivative. Trinitromethane easily dissolves in water to form an acidic yellow solution.
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In the anion, cobalt is bound by six nitrito ligands, the overall complex having octahedral molecular geometry. The oxidation state of cobalt is 3+. Its low-spin d6 configuration confers kinetic stability and diamagnetism. The compound is prepared by combining cobalt(II) and nitrite salts in the presence of oxygen.
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It is a readily available source of the nitrate anion (NO3−), which is useful in several reactions carried out on industrial scales for the production of fertilizers, pyrotechnics and smoke bombs, glass and pottery enamels, food preservatives (esp. meats), and solid rocket propellant. It has been mined extensively for these purposes.
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Tetrabutylammonium tribromide, abbreviated to TBATB, is a pale orange solid with the formula [N(C4H9)4]Br3. It is a salt of the lipophilic tetrabutylammonium cation and the linear tribromide anion. The salt is sometimes used as a reagent used in organic synthesis as a conveniently weighable, solid source of bromine.
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In water the H+ "cation" exists as an H13O6+ ion, with a delocalised proton in a central OHO group.Stoyanov et al. Nitrogen forms an N5+ pentazenium cation; bulk quantities of the salt N5+SbF6− can be prepared. Coincidentally, the NH4+ ammonium cation behaves in many respects as an alkali metal anion.
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Magnesium stearate is the chemical compound with the formula . It is a soap, consisting of salt containing two equivalents of stearate (the anion of stearic acid) and one magnesium cation (Mg2+). Magnesium stearate is a white, water-insoluble powder. Its applications exploit its softness, insolubility in many solvents, and low toxicity.
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Each ion is 4-coordinate and has local tetrahedral geometry. Zinc blende is its own antitype—you can switch the anion and cation positions in the cell and it doesn't matter (as in NaCl). In fact, replacement of both the zinc and sulfur with carbon gives the diamond structure.Toreki, Rob.
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An organic cation transport protein mediates the transport of organic cations across the cell membrane. These proteins are members of the solute carrier family, subfamily 22. This family of proteins can also transport zwitterions and anions, though it is a different subfamily of solute carrier proteins than the organic anion transporters.
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An oxyacid, oxoacid, or ternary acid is an acid that contains oxygen. Specifically, it is a compound that contains hydrogen, oxygen, and at least one other element, with at least one hydrogen atom bond to oxygen that can dissociate to produce the H+ cation and the anion of the acid.
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Nifurtimox forms a nitro- anion radical metabolite that reacts with nucleic acids of the parasite causing significant breakdown of DNA. Its mechanism is similar to that proposed for the antibacterial action of metronidazole. Nifurtimox undergoes reduction and creates oxygen radicals such as superoxide. These radicals are toxic to T. cruzi.
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The nitrite ion, which has the chemical formula . Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. Nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name nitrite can also refer to organic compounds with the -ONO group, which are esters of nitrous acid.
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The Shikimate Dehydrogenase Reaction Shikimate Dehydrogenase catalyzes the reversible NADPH-dependent reaction of 3-dehydroshikimate to shikimate. The enzyme reduces the carbon-oxygen double bond of a carbonyl functional group to a hydroxyl (OH) group, producing the shikimate anion. The reaction is NADPH dependent with NADPH being oxidised to NADP+.
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The similar Schiemann reaction uses the tetrafluoroborate anion as the fluoride donor. Gatterman reaction can also be used to convert diazonium salt to chlorobenzene or bromobenzene by using copper powder instead of copper chloride or copper bromide. But this must be done in the presence of HCl and HBr respectively.
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Alternatively, it dissolves in alkaline solutions to form xenates. The anion is the predominant species in xenate solutions. These are not stable and begin to disproportionate into perxenates (+8 oxidation state) and xenon and oxygen gas. Solid perxenates containing have been isolated by reacting with an aqueous solution of hydroxides.
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It contains tetrahedral borate anion instead of planar BO3 group, which is more common among minerals. Schiavinatoite is one of the most simple niobium minerals. It forms a solid solution with its tantalum-analogue, béhierite. Both minerals possess zircon-type structure (tetragonal, space group I41/amd) and occur in pegmatites.
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Upon treatment with a standard base, it converts to a metal tetrahydroxygallanuide (the anion Ga(OH)4−) and hydrogen gas. With strong bases, it can be deprotonated to give . Reduction of gallane gives gallium metal. Upon treatment with a standard acid, it converts to a gallium(3+) salt and hydrogen gas.
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The polyborate anion is polarisable and flexible. The 5f, 6d, 7s, and 7p orbitals of californium are all involved on the bonding. Most valence electrons are in the 5f orbital, and a significant fraction () in the 6d orbital, and smaller fractions of one electron are in the 7s and 7p orbitals.
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It was biochemically characterized as a 140 kDa complex. The bovine EClC protein has 903 amino acids and four putative transmembrane segments. The purified complex, when reconstituted in a planar lipid bilayer, behaved as an anion- selective channel. It was regulated by Ca2+ via a calmodulin kinase II- dependent mechanism.
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The C-terminal domain makes numerous electrostatic interactions with an anion-binding exosite of thrombin, while the last five residues are in a helical loop that forms many hydrophobic contacts. Natural hirudin contains a mixture of various isoforms of the protein. However, recombinant techniques can be used to produce homogeneous preparations of hirudin.
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Apart from acting as the synthetic equivalent of an ethyl anion synthon for nucleophilic addition, ethylmagnesium bromide may be used as a strong base to deprotonate various substrates such as alkynes: :RC≡CH + EtMgBr → RC≡CMgBr + EtH In this application, ethylmagnesium bromide has been supplanted by the wide availability of organolithium reagents.
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Chambers & Holliday 1975, p. 144Bashilova & Khomutova 1984, p. 1546Ropp 2012, p. 484 It forms anionic thallates such as Tl3TlO3, Na3Tl(OH)6, NaTlO2, and KTlO2, and is present as the Tl− thallide anion in the compound CsTl.King & Schleyer 2004, p. 19 Thallium forms Zintl phases, such as Na2Tl, Na2K21Tl19, CsTl and Sr5Tl3H.
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The anion was synthesized and characterized by A. Fatiadi in 1978, together with croconate violet. He obtained the corresponding acid, croconate acid blue by treating croconic acid with malononitrile in water solution at 80–90 °C. Alexander J. Fatiadi (1978), "Synthesis of 1,3-(dicyanomethylene)croconate salts. New bond-delocalized dianion, Croconate Violet".
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The structural motif adopted by fluorite is so common that the motif is called the fluorite structure. Element substitution for the calcium cation often includes certain rare earth elements (REE), such as yttrium and cerium. Iron, sodium, and barium are also common impurities. Some fluoride anions may be replaced by the chloride anion.
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Denatonium is a quaternary ammonium cation. It is a compound of a salt with an inert anion like benzoate or saccharide. The structure of denatonium is related to the local anesthetic lidocaine, differing only by the addition of a benzyl group to the amino nitrogen. Other similar compounds are procaine and benzocaine.
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Silver nitrate is a traditional and less expensive halide abstraction reagent, as indicated by its widespread use in qualitative tests for halides. Relative to AgPF6, however, silver nitrate is poorly soluble in weakly basic solvents: the nitrate anion is Lewis basic and presents an interfering ligand that precludes its use in stringent applications.
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Right: Five subunits symmetrically arranged about the central chloride anion conduction pore. The extracellular loops are not depicted for the sake of clarity. The GABAA receptor (GABAAR) is an ionotropic receptor and ligand-gated ion channel. Its endogenous ligand is γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system.
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Most DVD-R/+R and some CD-R discs use blue azo dye as the recording layer. phenolic diazo dyes participate in tautomeric equilibria shown here in simplified form (Ar = aryl). Azo dyes are solids. Most are salts, the colored component being the anion usually, although some cationic azo dyes are known.
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Although less common, transition metal complexes can act as cationic photoinitiators as well. In general, the mechanism is more simplistic than the onium ions previously described. Most photoinitiators of this class consist of a metal salt with a non-nucleophilic counter anion. For example, ferrocinium salts have received much attention for commercial applications.
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Octachlorodirhenate(III) is a precursor to other complexes with multiply-bonded rhenium centers as the quadruple bond is quite stable and is often maintained in ligand substitution reactions. For example, upon treatment with concentrated HBr, the complex forms the analogous anion [Re2Br8]2−, which can easily be converted into other dirhenium species.
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It is also a substrate of the hepatic uptake transporter organic anion-transporting polypeptides (OATPs) OATP1B1, OATP1B3, and OATP2B1. Elimination of bosentan is mostly hepatic, with minimal contribution from renal and fecal excretion. Use of bosentan with cyclosporine is contraindicated because cyclosporine A has been shown to markedly increase serum concentration of bosentan.
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Many drugs are supplied as salts, with a cation and an anion. The way the INN system handles these is explained by the WHO at its "Guidance on INN" webpage. For example, amfetamine and oxacillin are INNs, whereas various salts of these compounds – e.g., amfetamine sulfate and oxacillin sodium – are modified INNs (INNM).
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Fluoroform is weakly acidic with a pKa = 25–28 and quite inert. Attempted deprotonation results in defluorination to generate F− and difluorocarbene (CF2). Some organocopper and organocadmium compounds have been developed as trifluoromethylation reagents. Fluoroform is a precursor of Ruppert's reagent CF3Si(CH3)3, which is a source of the nucleophilic CF3− anion.
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The 1,2-rearrangement belongs to a broad class of chemical reactions called rearrangement reactions. A rearrangement involving a hydrogen atom is called a 1,2-hydride shift. If the substituent being rearranged is an alkyl group, it is named according to the alkyl group's anion: i.e. 1,2-methanide shift, 1,2-ethanide shift, etc.
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Potassium superoxide is the inorganic compound with the formula KO2. It is a yellow paramagnetic solid that decomposes in moist air. It is a rare example of a stable salt of the superoxide anion. Potassium superoxide is used as a scrubber, dehumidifier and generator in rebreathers, spacecraft, submarines and spacesuit life support systems.
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The mechanism of the Boekelheide reaction begins by an acyl transfer from the trifluoroacetic anhydride to the N-oxide oxygen. The α-methyl carbon is then deprotonated by the trifluoroacetate anion. This sets the molecule up for a [3.3]-sigmatropic rearrangement which furnishes the trifluoroacetylated methylpyridine. Hydrolysis of the trifluoroacetate releases the hydroxymethylpyridine.
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In the laboratory, cobalt(II) chloride serves as a common precursor to other cobalt compounds. Generally, aqueous solutions of the salt behave like other cobalt(II) salts since these solutions consist of the ion regardless of the anion. For example, such solutions give a precipitate of cobalt sulfide upon treatment with hydrogen sulfide .
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The anion is tetrahedral with B-C bond lengths of approximately 1.65 Angstroms. The salt has only been obtained as the etherate, and the crystallography confirms that four ether (OEt2) molecules are bound to the lithium cation, with Li-O bond lengths of approximately 1.95 Å. The [Li(OEt2)4]+ complex is tetrahedral.
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With alkali metals, naphthalene forms the dark blue-green radical anion salts such as sodium naphthalenide, Na+C10H. The naphthalenide salts are strong reducing agents. Naphthalene can be hydrogenated under high pressure in the presence of metal catalysts to give 1,2,3,4-tetrahydronaphthalene(), also known as tetralin. Further hydrogenation yields decahydronaphthalene or decalin ().
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The dihydrogen phosphate anion consists of a central phosphorus atom surrounded by 2 equivalent oxygen atoms and 2 hydroxy groups in a tetrahedral arrangement. The phosphorus atom is in the 5+ oxidation state. The dihydrogen phosphate ion carries an overall charge of −1 and it is the conjugate base of phosphoric acid.
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Pentanitratoaluminate is an anion of aluminium and nitrate groups with formula [Al(NO3)5]2− that can form salts called pentanitratoaluminates. It is unusual being a complex with five nitrate groups, and being a nitrate complex of a light element with nitrate. Such a complex with five nitrate groups is called a pentanitratometallate.
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1-Propanol is thought to be similar to ethanol in its effects on the human body, but 2–4 times more potent. Oral LD50 in rats is 1870 mg/kg (compared to 7060 mg/kg for ethanol). It is metabolized into propionic acid. Effects include alcoholic intoxication and high anion gap metabolic acidosis.
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Disodium hydrogen phosphite is the name for inorganic compounds with the formula Na2HPO3.(H2O)x. The commonly encountered salt is the pentahydrate. A derivative of phosphorous acid (HP(O)(OH)2), it contains the anion HPO32−. Its common name suggests that it contains an acidic hydrogen atom, as in sodium hydrogen carbonate.
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Apatite Phosphate minerals contain the tetrahedrally coordinated phosphate (PO43−) anion along sometimes with arsenate (AsO43−) and vanadate (VO43−) substitutions. Chlorine (Cl−), fluorine (F−), and hydroxide (OH−) anions that also fit into the crystal structure. The phosphate class of minerals is a large and diverse group, however, only a few species are relatively common.
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Homoisocitric acid is an isomer of homocitric acid in which the hydroxyl is on the 2 position. It is an intermediate in the α-aminoadipate pathway of lysine biosynthesis where it is produced by homocitrate synthase and is a substrate for homoaconitase. Homoisocitrate is an anion, salt, or ester of homoisocitric acid.
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Potassium chlorochromate was originally prepared by treating potassium dichromate with hydrochloric acid. An improved route involves the reaction of chromyl chloride and potassium chromate: :K2CrO4 \+ CrO2Cl2 → 2KCrO3Cl The salt consists of the tetrahedral chlorochromate anion. The average Cr=O bond length is 159 pm, and the Cr-Cl distance is 219 pm.
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Chemistry of the Elements (2nd Edn.), Oxford: Butterworth-Heinemann. . Analogous selenates also occur. The possible combinations of univalent cation, trivalent cation, and anion depends on the sizes of the ions. A Tutton salt is a double sulfate of the typical formula , where A is a univalent cation, and B a divalent metal ion.
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Nitroxyl (common name) or azanone (IUPAC name) is the chemical compound HNO. It is well known in the gas phase. Nitroxyl can be formed as a short-lived intermediate in the solution phase. The conjugate base, NO−, nitroxide anion, is the reduced form of nitric oxide (NO) and is isoelectronic with dioxygen.
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Murl involves a two-step process to catalyze the glutamate enantiomers to D-glutamate. The first step is a deprotonation of the substrate to form an anion. Subsequently, the substrate gets reprotonated. Once the glutamate is in the active site of the enzyme it undergoes a very large conformational change of its domains.
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Tantalum halides span the oxidation states of +5, +4, and +3. Tantalum pentafluoride (TaF5) is a white solid with a melting point of 97.0 °C. The anion [TaF7]2- is used for its separation from niobium. The chloride , which exists as a dimer, is the main reagent in synthesis of new Ta compounds.
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Another recent development is the solid-state alkaline fuel cell, utilizing a solid anion exchange membrane instead of a liquid electrolyte. This resolves the problem of poisoning and allows the development of alkaline fuel cells capable of running on safer hydrogen-rich carriers such as liquid urea solutions or metal amine complexes.
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Anion exchange protein 2 (AE2) is a membrane transport protein that in humans is encoded by the SLC4A2 gene. AE2 is functionally similar to the Band 3 Cl−/HCO3− exchange protein. Mice have been used to explore the function of AE2. AE2 contributes to basolateral membrane HCO3− transport in the gastrointestinal tract.
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The dealkalization of water refers to the removal of alkalinity ions from water. Chloride cycle anion ion exchange dealkalizers remove alkalinity from water. Chloride cycle dealkalizers operate similar to sodium cycle cation water softeners. Like water softeners, dealkalizers contain ion exchange resins that are regenerated with a concentrated salt (brine) solution - NaCl.
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The stable tetrahydrate was originally reported to be rhombohedral but is now believed to be monoclinic. Additionally there is an unstable monoclinic form. The dihydrate is triclinic, with hydrogen bonding between the two water molecules and hydrogen bonds to the O atoms on the anion. An hexagonal dihydrate has also been reported.
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Metal acetylacetonates are coordination complexes derived from the acetylacetonate anion () and metal ions, usually transition metals. The bidentate ligand acetylacetonate is often abbreviated acac. Typically both oxygen atoms bind to the metal to form a six-membered chelate ring. The simplest complexes have the formula M(acac)3 and M(acac)2.
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The Nest is a type of protein structural motif. It is a small recurring anion- binding feature of both proteins and peptides. Each consists of the main chain atoms of three consecutive amino acid residues. The main chain NH groups bind the anions while the side chain atoms are often not involved.
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The sizes are arbitrary and not necessarily similar as illustrated. The cation is coloured red and the anion is coloured blue. The green area represents solvent molecules in a primary solvation shell; secondary solvation is ignored. When both ions have a complete primary solvation sphere, the ion pair may be termed fully solvated.
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Leucine-rich repeat-containing protein 8E is a protein that in humans is encoded by the LRRC8E gene. Researchers have found out that this protein, along with the other LRRC8 proteins LRRC8A, LRRC8B, LRRC8C, and LRRC8D, is sometimes a subunit of the heteromer protein volume-regulated anion channel. Volume-Regulated Anion Channels (VRACs) are crucial to the regulation of cell size by transporting chloride ions and various organic osmolytes, such as taurine or glutamate, across the plasma membrane, and that is not the only function these channels have been linked to. While LRRC8E is one of many proteins that can be part of VRAC, research has found that it is not as crucial to the activity of the channel in comparison to LRRC8A and LRRC8D.
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Leucine-rich repeat-containing protein 8D is a protein that in humans is encoded by the LRRC8D gene. Researchers have found out that this protein, along with the other LRRC8 proteins LRRC8A, LRRC8B, LRRC8C, and LRRC8E, is a subunit of the heteromer protein Volume-Regulated Anion Channel. Volume- Regulated Anion Channels (VRACs) are crucial to the regulation of cell size by transporting chloride ions and various organic osmolytes, such as taurine or glutamate, across the plasma membrane, and that is not the only function these channels have been linked to. While LRRC8D is one of many proteins that can be part of VRAC, it is in fact one of the most important subunits for the channel’s ability to function; the other protein of importance is LRRC8A.
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The product of transamination reactions depend on the availability of α-keto acids. The products usually are either alanine, aspartate or glutamate, since their corresponding alpha-keto acids are produced through metabolism of fuels. Being a major degradative aminoacid pathway, lysine, proline and threonine are the only three amino acids that do not always undergo transamination and rather use respective dehydrogenase. :Alternative Mechanism :A second type of transamination reaction can be described as a nucleophilic substitution of one amine or amide anion on an amine or ammonium salt. For example, the attack of a primary amine by a primary amide anion can be used to prepare secondary amines: :RNH2 \+ R'NH− → RR'NH + NH2− :Symmetric secondary amines can be prepared using Raney nickel (2RNH2 → R2NH + NH3).
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The CO ligand is often susceptible to attack by nucleophiles. For example, trimethylamine oxide and bis(trimethylsilyl)amide convert CO ligands to CO2 and CN−, respectively. In the "Hieber base reaction", hydroxide ion attacks the CO ligand to give a metallacarboxylic acid, followed by the release of carbon dioxide and the formation of metal hydrides or carbonylmetalates. A well-known example of this nucleophilic addition reaction is the conversion of iron pentacarbonyl to hydridoiron tetracarbonyl anion: :Fe(CO)5 \+ NaOH → Na[Fe(CO)4CO2H] :Na[Fe(CO)4COOH] + NaOH → Na[HFe(CO)4] + NaHCO3 Protonation of the hydrido anion gives the neutral iron tetracarbonyl hydride: :Na[HFe(CO)4] + H+ → H2Fe(CO)4 \+ Na+ Organolithium reagents add with metal carbonyls to acylmetal carbonyl anions.
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The use of photoredox catalysis to generate reactive heteroatom-centered radicals was first explored in the 1990s. [Ru(bipy)3]2+ was found to catalyze the fragmentation of tosylphenylselenide to phenylselenolate anion and tosyl radical and that a radical chain propagation mechanism allowed the addition of tosyl radical and phenylseleno- radical across the double bond of electron rich alkyl vinyl ethers. Since phenylselenolate anion is readily oxidized to diphenyldiselenide, the low quantities of diphenyldiselenide observed was taken as an indication that photoredox-catalyzed fragmentation of tosylphenylselenide was only important as an initiation step, and that most of the reactivity was due to a radical chain process. Addition of Tosylphenylselenide across an olefin Heteroaromatic additions to olefins include multicomponent oxy- and aminotrifluoromethylation reactions.
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In the presence of a very high concentration of base, the aldehyde first forms a doubly charged anion from which a hydride ion is transferred to the second molecule of aldehyde to form carboxylate and alkoxide ions. Subsequently, the alkoxide ion acquires a proton from the solvent. Animation of the mechanism of the cannizzaro reaction center Overall, the reaction follows third-order kinetics. It is second order in aldehyde and first order in base: ::: rate = k[RCHO]2[OH−] At very high base a second path (k') becomes important that is second order in base: ::: rate = k[RCHO]2[OH−] + k'[RCHO]2[OH−]2 The k' pathway implicates a reaction between the doubly charged anion (RCHO22−) and the aldehyde.
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Salts of the octafluoroxenate(VI) anion (XeF) are very stable, decomposing only above 400 °C. This anion has been shown to have square antiprismatic geometry, based on single-crystal X-ray counter analysis of its nitrosonium salt, . The sodium and potassium salts are formed directly from sodium fluoride and potassium fluoride: :2 NaF + → :2 KF + → These are thermally less stable than the caesium and rubidium salts, which are synthesized by first forming the heptafluoroxenate salts: :CsF + → :RbF + → which are then pyrolysed at 50 °C and 20 °C, respectively, to form the yellow octafluoroxenate salts: :2 → + :2 → + These salts are hydrolysed by water, yielding various products containing xenon and oxygen. The two other binary fluorides of xenon do not form such stable adducts with fluoride.
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The mechanism of thiol–disulfide exchange between oxidoreductases is understood to begin with the nucleophilic attack on the sulfur atoms of a disulfide bond in the oxidised partner, by a thiolate anion derived from a reactive cysteine in a reduced partner. This generates mixed disulfide intermediates, and is followed by a second, this time intramolecular, nucleophilic attack by the remaining thiolate anion in the formerly reduced partner, to liberate both oxidoreductases. The balance of evidence discussed thus far supports a model in which oxidising equivalents are sequentially transferred from Ero1 via a thiol–disulfide exchange reaction to PDI, with PDI then undergoing a thiol–disulfide exchange with the nascent polypeptide, thereby enabling the formation of disulfide bonds within the nascent polypeptide.
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NO exerts antiproliferative effects by cGMP-dependent inhibiting Ca2+ influx or by directly inhibiting the activity of arginase and ornithine decarboxylase, decreasing the generation of polyamides required for DNA synthesis. NO also has antithrombotic effects that result of its diffusion across platelet membrane and sGC activation, resulting in inhibition of platelet aggregation. Moreover, NO affects leukocyte adhesion to the vascular endothelium by inhibiting the nuclear factor kappa B (NF-κB), which induces vascular endothelial expression of chemokines and adhesion molecules. In addition to these functions, NO produced by eNOS has antioxidant properties as it reduces superoxide anion formation as a result of NO-induced increases in the expression of superoxide dismutase, an antioxidant enzyme that catalyzes the conversion of superoxide anion to hydrogen peroxide.
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Leucine-rich repeat-containing protein 8C is a protein that in humans is encoded by the LRRC8C gene. Researchers have found out that this protein, along with the other LRRC8 proteins LRRC8A, LRRC8B, LRRC8D, and LRRC8E, is sometimes a subunit of the heteromer protein Volume-Regulated Anion Channel. Volume-Regulated Anion Channels (VRACs) are crucial to the regulation of cell size by transporting chloride ions and various organic osmolytes, such as taurine or glutamate, across the plasma membrane, and that is not the only function these channels have been linked to. While LRRC8C is one of many proteins that can be part of VRAC, research has found that it is not as crucial to the activity of the channel in comparison to LRRC8A and LRRC8D.
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Vinyl tributyltin is an organotin compound with the formula Bu3SnCH=CH2 (Bu = butyl). It is a white, air-stable solid. It is used as a source of vinyl anion equivalent in Stille coupling reactions. As a source of vinyltin reagents, early work used vinyl trimethyltin, but trimethyltin compounds are avoided nowadays owing to their toxicity.
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PTU inhibits the enzyme thyroperoxidase, which normally acts in thyroid hormone synthesis by oxidizing the anion iodide (I−) to iodine (I0), facilitating iodine's addition to tyrosine residues on the hormone precursor thyroglobulin. This is one of the essential steps in the formation of thyroxine (T4).Boron, WF & Boulpaep, EL. 2005. Medical Physiology, Updated Edition.
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The initial steps are straightforward. The phenyl sulfone anion (2) reacts with an aldehyde to form the alkoxide (3). The alkoxide is functionalized with R3-X to give the stable intermediate (4). The exact mechanism of the sodium amalgam reduction is unknown but has been shown to proceed through a vinylic radical species (5).
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Commercially available, this compound may be prepared by oxidizing ferrocene with ferric salts followed by addition of hexafluorophosphoric acid. The compound has been characterized by X-ray crystallography. The cation and anion are well separated. The average Fc-C bond lengths is 2.047 Å, which is virtually indistinguishable from the Fe-C distance in ferrocene.
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Earl Muetterties joined DuPont Central Research Department and was promoted to research supervisor in 1955. His early contributions were on the inorganic fluorine compounds, especially of sulfur and phosphorus.Roesky, Herbert W.; Tebbe, Fred N.; Muetterties, Earl L.. Thiophosphate chemistry. Anion set X2PS2-, (XPS2)2S2-, and (XPS2)2S22-. Inorganic Chemistry (1970), 9(4), 831-6.
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Monofluorophosphate is an anion with the formula PO3F2−, which is a phosphate group with one oxygen atom substituted with a fluoride atom. The charge of the ion is −2. The ion resembles sulfate in size, shape and charge, and can thus form compounds with the same structure as sulfates. These include Tutton's salts and langbeinites.
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In 2006 the negatively charged hexatriyne anion of this molecule, C6H−, was the first negatively charged ion to be discovered to exist in the interstellar medium, using the Green Bank Telescope. Negative ions were thought to be unstable in this environment due to the prevalence of ultraviolet light, which dislodges extra electrons such as this.
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The principal method for synthesizing the starting amino alcohols is through the addition of cyanide anion to a cyclic ketone. The resulting hydroxynitrile is then reduced, forming the desired amino alcohol. This method forms diastereomers, possibly affecting the regioselectivity of the reaction. For nearly all asymmetric precursors, one product isomer is formed preferentially to another.
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Ferrate(VI) is an inorganic anion of chemical formula [FeO4]2−. It is photosensitive and contributes a pale violet colour to its compounds and solutions. It is one of the strongest water-stable oxidising species known. Although it is classified as a weak base, concentrated solutions of ferrate(VI) are only stable at high pH.
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It involve hydrophobic gating and resembles conduction by Cys-loop ligand-gated anion channels. Possibly, the tendency of hydrophobic or amphipathic transmembrane helices to self-organize into oligomers creates novel ionic pathways through membranes: hydrophobic nanopores, pathways of low selectivity governed by the chaotropic behavior of individual ionic species under the influence of membrane voltage.
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An organic anion transporter is required for this transportation process. Recent studies show that the mitochondria respiratory system is another target of citrinin. Citrinin can interfere with the electron transport system, Ca2+ fluxes and membrane permeability. Also several experiments have been conducted in livestocks, such as pigs and chickens, to see the effect of citrinin.
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The complementary base is the sulfoxylate anion which is much more stable. In between these states is the ion, also somewhat stable. Sulfoxylate ions can be made by decomposing thiourea dioxide in an alkaline solution. To do this, thiourea dioxide first forms a tautomer, aminoiminomethanesulfinic acid (H2NC(=NH)SO2H, abbreviated AIMS) which breaks apart.
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Aryl halides lacking electron-withdrawing groups react through an elimination-addition mechanism involving benzyne intermediates.Hoffmann, H. Dehydrobenzene and Cycloarynes, Academic Press, New York, 1967. Aryl phosphates and ammoniums react through the SRN1 pathway, which involves the generation of an aryl radical anion, fragmentation, and bond formation with a nucleophile.Bunnett, J.; Gloor, B. J. Org. Chem.
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Typical ligands used in the isolobal analogy are two- electron donors such as phosphines, halogens or carbonyls. However, other types of ligands can be employed. If ligands donate multiple pairs of electrons, they will occupy multiple coordination sites. For example, the cyclopentadienyl anion is a six-electron donor, so it occupies three coordination sites.
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246x246px Ferrocyanide is the name of the anion [Fe(CN)6]4−. Salts of this coordination complex give yellow solutions. It is usually available as the salt potassium ferrocyanide, which has the formula K4Fe(CN)6. [Fe(CN)6]4− is a diamagnetic species, featuring low-spin iron(II) center in an octahedral ligand environment.
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Because the dimethylamide anion is a poor leaving group, the intermediate does not collapse and another nucleophilic addition does not occur. Upon acidic workup, the alkoxide is protonated to give 4, then the amine is protonated to give 5. Elimination of a neutral molecule of dimethylamine and loss of a proton give benzaldehyde, 6.
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Action potentials can also involve calcium (Ca2+),Bullock, Orkand, and Grinnell, pp. 153–54. which is a divalent cation that carries a double positive charge. The chloride anion (Cl−) plays a major role in the action potentials of some algae, but plays a negligible role in the action potentials of most animals.Schmidt-Nielsen, p. 483.
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Generally, the E-alkene will favor the formation of anti product, while Z-alkene will favor formation of syn product. center Diastereoselectivity can be high for Z-alkene with alkynyl, alkenyl, or aryl anion-stabilizing group. Diastereoselectivity is usually lower with E-alkenes. Hydrocarbon groups will prefer exo orientation in the envelope-like transition state.
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Dilute solutions dissociate according to the following equilibrium: :PCl5 \+ Cl− At higher concentrations, a second equilibrium becomes more prevalent: :2 PCl5 \+ The cation and the anion are tetrahedral and octahedral, respectively. At one time, PCl5 in solution was thought to form a dimeric structure, P2Cl10, but this suggestion is not supported by Raman spectroscopic measurements.
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Tetranitratoborate is an anion composed of boron with four nitrate groups. It has formula [B(NO3)4]−. It can form salts with large cations such as tetramethylammonium nitratoborate, or tetraethylammonium tetranitratoborate. The ion was first discovered by C. R. Guibert, M. D. Marshall in 1966 after failed attempts to make neutral (non-ionic) boron nitrate.
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Sodium pyruvate is a salt of the conjugate anion form of pyruvic acid, known as pyruvate. It is commonly added to cell culture media as an additional source of energy, but may also have protective effects against hydrogen peroxide. This was reported by Giandomenico et al. and has been confirmed by several independent groups.
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There are formally five double bonds in acepentalene, so that the molecule formally contains four double bonds on the exterior, and one double bond from the central carbon to the exterior of the ring system. The acepentalene dianion, which can be stabilized by two lithium atoms, is more stable. The radical anion is also known.
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In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogen carbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula . Bicarbonate serves a crucial biochemical role in the physiological pH buffering system. The term "bicarbonate" was coined in 1814 by the English chemist William Hyde Wollaston.
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Normal lead styphnate exists as α and β polymorphs, both being monoclinic crystals. The lead centres are seven-coordinate and are bridged via oxygen bridges. The water molecule is coordinated to the metal and is also hydrogen- bonded to the anion. Many of the Pb-O distances are short, indicating some degree of covalency.
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Roussin's black salt is a chemical compound with the formula KFe4S3(NO)7. It consists of the potassium salt of the [Fe4S3(NO)7]− anion, metal nitrosyl compound. First described by Zacharie Roussin in 1858, it is one of the first synthetic iron-sulfur clusters along with the red salt also bearing his name.
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This protein functions as a multispecific organic anion transporter, with oxidized glutathione, cysteinyl leukotrienes, and activated aflatoxin B1 as substrates. This protein also transports glucuronides and sulfate conjugates of steroid hormones and bile salts. Alternative splicing by exon deletion results in several splice variants but maintains the original open reading frame in all forms.
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Its chemistry is largely covalent in nature, noting it can form salt-like phosphides with highly electropositive metals. Compared to nitrogen, electrons have more space on phosphorus, which lowers their mutual repulsion and results in anion formation requiring less energy. The common oxide of phosphorus (P2O5) is a medium-strength acidic oxide. Wiberg 2001, p.
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Structures of two main types of complexes derived from "ethylmercury". X− = anion, L = neutral Lewis base. Ethylmercury (C2H5Hg+) is a substituent of compounds: it occurs as a component of compounds of the formula C2H5HgX where X = chloride, thiolate, or another organic group. Most famously X = the mercaptide group of thiosalicylic acid as in thiomersal.
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Ion chromatogram displaying anion separation Ion-exchange chromatography separates molecules based on their respective charged groups. Ion-exchange chromatography retains analyte molecules on the column based on coulombic (ionic) interactions. The ion exchange chromatography matrix consists of positively and negatively charged ions. Essentially, molecules undergo electrostatic interactions with opposite charges on the stationary phase matrix.
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The telluride oxides or oxytellurides are double salts that contain both telluride and oxide anions (Te2− and O2−). They are in the class of mixed anion compounds. Compounds that can be mistakenly called "telluride oxides" are tellurium dioxide and tellurite. Some of these are under investigation as photovoltaic materials, eg oxygen doped zinc telluride.
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Ammonium triiodide (NH4I3) is the salt of the ammonium cation with the triiodide anion. It is a very unstable compound and very easily ignited just by touch. Sometimes the name ammonium triiodide is mistakenly used to refer to a different compound, nitrogen triiodide (NI3), or more precisely, the slightly more stable ammine, NI3 · NH3.
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A persulfate (sometimes known as peroxysulfate or peroxodisulfate) is a compound containing the anions or . The anion contains one peroxide group per sulfur center, whereas in , the peroxide group bridges the sulfur atoms. In both cases, sulfur adopts the normal tetrahedral geometry typical for the S(VI) oxidation state. These salts are strong oxidizers.
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In the context of acid-base reactions, the abbreviation HAc is sometimes used, where Ac in this case is a symbol for acetate (rather than acetyl). Acetate is the ion resulting from loss of from acetic acid. The name acetate can also refer to a salt containing this anion, or an ester of acetic acid.
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Solute carrier organic anion transporter family member 1B1 is a protein that in humans is encoded by the SLCO1B1 gene. Pharmacogenomic research indicates that genetic variations in this gene are associated with response to simvastatin. Clinical guidelines exist that can guide dosing of simvastatin based on SLCO1B1 gene variant using genotyping or whole exome sequencing.
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2]nonatrienyl cation was predicted to be destabilised and the corresponding anion predicted to be stabilised by bicycloaromaticity. Bicycloaromaticity has been studied by others in relation to the bicyclo[3.2.2]nonatrienyl cation and in relation to specific carbanions. In 2017 experimental evidence was reported for bicycloaromaticity (dual aromaticity) to exist in a bicyclic porphyrinoid.
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McConnell equation describes the proportional dependence of the hyperfine splitting constant a on the spin density \rho (the probability of an unpaired electron being on a particular atom) in aromatic radical compounds such as benzene radical anion C_6H_6^-. a=Q \rho Q is an empirical constant that can range from 2.0 to 2.5 mT.
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Caesium fluoride or cesium fluoride is an inorganic compound with the formula CsF and it is a hygroscopic white solid. Caesium fluoride can be used in organic synthesis as a source of the fluoride anion. Caesium also has the highest electropositivity of all non-radioactive elements and fluorine has the highest electronegativity of all elements.
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Cycloaddition reactions involving the phosphaethynolate anion have also been shown by Grutzmacher and co-workers to be a viable synthetic route to other heterocycles. One simple example is the reaction between the NaPCO and an α-pyrone. This reaction yields the sodium phosphinin-2-olate salt which is stable to both air and moisture.
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Whereas SO2 tends to be molecular and SeO2 is a one-dimensional chain, TeO2 is a cross- linked polymer. SeO2 is considered an acidic oxide: it dissolves in water to form selenous acid. Often the terms selenous acid and selenium dioxide are used interchangeably. It reacts with base to form selenite salts containing the anion.
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Tetrabutylammonium hexafluorophosphate is a salt with the formula NBu4PF6. It is a white powder that is used as an electrolyte in nonaqueous electrochemistry. It is highly soluble in polar organic solvents such as acetone and acetonitrile. The salt consists of a positively charged tetrabutylammonium, a quaternary ammonia cation and a weakly basic hexafluorophosphate anion.
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Large cation/anion ion exchangers used in demineralization of boiler feedwater. Feed water for boilers needs to be as pure as possible with a minimum of suspended solids and dissolved impurities which cause corrosion, foaming and water carryover. The most common options for demineralization of boiler feedwater are reverse osmosis (RO) and ion exchange (IX).
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In 1929, Pauling published five rules which help to predict and explain crystal structures of ionic compounds. These rules concern (1) the ratio of cation radius to anion radius, (2) the electrostatic bond strength, (3) the sharing of polyhedron corners, edges and faces, (4) crystals containing different cations, and (5) the rule of parsimony.
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The Ritchie equation, derived in 1972, is another free-energy relationship:Gold Book definition (Ritchie) LinkNucleophilic reactivities toward cations Calvin D. Ritchie Acc. Chem. Res.; 1972; 5(10); 348-354. AbstractCation–anion combination reactions. XIII. Correlation of the reactions of nucleophiles with esters Calvin D. Ritchie J. Am. Chem. Soc.; 1975; 97(5); 1170–1179.
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Nevertheless, will be referred to as the "hydron", for the sake of consistency with the article title. Unlike most other ions, the hydron consists only of a bare atomic nucleus. The negatively charged counterpart of the hydron is the hydride anion, . In contrast to , "hydride", not "protide", is the commonly used name for this species.
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PBR forms a multimeric complex with the voltage- dependent anion channel (VDAC) and adenine nucleotide carrier. Molecular modeling of PBR suggested that it might function as a channel for cholesterol. Indeed, cholesterol uptake and transport by bacterial cells was induced upon PBR expression. Mutagenesis studies identified a cholesterol recognition/interaction motif (CRAC) in the cytoplasmic C terminus of PBR.
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The outer mitochondrial membrane, which encloses the entire organelle, is 60 to 75 angstroms (Å) thick. It has a protein-to-phospholipid ratio similar to that of the cell membrane (about 1:1 by weight). It contains large numbers of integral membrane proteins called porins. A major trafficking protein is the pore-forming voltage-dependent anion channel (VDAC).
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More recently Wright has discovered its extensive coordination chemistry. By virtue of a combination of mesomeric and aromatic stabilization of its anion, pentacyanocyclopentadiene is a superacid, with an estimated aqueous pKa of −11. The free acid was prepared by Reed in 2004 and was assigned a polymeric structure with protons that bridge planar C5(CN)5 units.
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Electro-chemical reaction Diagram of PEM MEA A membrane electrode assembly (MEA) is an assembled stack of proton exchange membranes (PEM) or alkali anion exchange membrane (AAEM), catalyst and flat plate electrode used in fuel cells and electrolyzers.Bentham, Daniel WIPO patent WO/2008/007108 Current distribution system for electrochemical cells. Freepatentsonline.com (2008-01-17). Retrieved on 2013-04-19.
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A sulfite sulfate is a chemical compound that contains both sulfite and sulfate anions [SO3]2− [SO4]2−. These compounds were discovered in the 1980s as calcium and rare earth element salts. Minerals in this class were later discovered. Minerals may have sulfite as an essential component, or have it substituted for another anion as in alloriite.
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Many characteristic reactions of metal cyanides arise from ambidentate nature of cyanide, i.e. both the nitrogen and the carbon termini of the anion are basic. Thus cyanometalates can be alkylated to give isocyanide complexes.Fehlhammer, W. P. Fritz, M., "Emergence of a CNH and Cyano Complex Based Organometallic Chemistry", Chemical Reviews, 1993, volume 93, pp. 1243-80.
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Potassium regulates the opening and closing of the stomata by a potassium ion pump. Since stomata are important in water regulation, potassium regulates water loss from the leaves and increases drought tolerance. Potassium deficiency may cause necrosis or interveinal chlorosis. The potassium ion (K+) is highly mobile and can aid in balancing the anion (negative) charges within the plant.
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Sodium hexachloroplatinate, the sodium salt of chloroplatinic acid, is an inorganic compound with the formula Na2[PtCl6], consisting of the sodium cation and the hexachloroplatinate anion. As explained by Cox and Peters, anhydrous sodium hexachloroplatinate, which is yellow, tends to form the orange hexahydrate upon storage in humid air. The latter can be dehydrated upon heating at 110 ºC.
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A slurry of resin, such as DEAE- Sephadex is poured into the column. The matrix that is used is insoluble with charged groups that are covalently attached. These charged groups are referred to as exchangers like cation and anion exchangers. After it settles, the column is pre-equilibrated in buffer before the protein mixture is applied.
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The more rigid and the higher its denticity, the more inert will be the macrocyclic complex. Heme is a good example: the iron atom is at the centre of a porphyrin macrocycle, being bound to four nitrogen atoms of the tetrapyrrole macrocycle. The very stable dimethylglyoximate complex of nickel is a synthetic macrocycle derived from the anion of dimethylglyoxime.
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14 The significance of this structural property will be explained further by coordination polyhedra. The second substitution occurs between Na+ and Ca2+; however, the difference in charge has to accounted for by making a second substitution of Si4+ by Al3+., p. 585 Coordination polyhedra are geometric representations of how a cation is surrounded by an anion.
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This gene is one member of a family of sulfate/anion transporter genes. Family members are well conserved in their genomic (number and size of exons) and protein (aa length among species) structures yet have markedly different tissue expression patterns. This gene is expressed primarily in spermatocytes. Two transcript variants encoding different isoforms have been found.
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Cystic fibrosis is a progressive, genetic disease that is linked to CF transmembrane regulator (CFTR) dysfunction. Blockage of this channel by certain cytoplasmic, negatively-charged substances results in reduced chloride ion and bicarbonate anion transport, as well as reduced fluid and salt secretion. This results in a buildup of thick mucus, which is characteristic of cystic fibrosis.
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When stressed under elevated levels of the superoxide radical anion O2−, bacteria respond by invoking the superoxide stimulon. Superoxide-generating compounds activate SoxR regulator by the one-electron oxidation of the 2Fe-2S clusters. Oxidized SoxR then induces the expression of SoxS protein, which in turn activates the transcription of structural genes of the SoxRS regulon.
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The auride anion here behaves as a pseudohalogen. The compound reacts violently with water, yielding caesium hydroxide, metallic gold, and hydrogen gas; in liquid ammonia it can be reacted with a caesium-specific ion exchange resin to produce tetramethylammonium auride. The analogous platinum compound, red caesium platinide (Cs2Pt), contains the platinide ion that behaves as a pseudochalcogen.
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A cyanide is a chemical compound that contains the group C≡N. This group, known as the cyano group, consists of a carbon atom triple-bonded to a nitrogen atom.IUPAC Gold Book cyanides In inorganic cyanides, the cyanide group is present as the anion CN−. Salts such as sodium cyanide and potassium cyanide are highly toxic.
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Solute carrier organic anion transporter family member 1A2 is a protein that in humans is encoded by the SLCO1A2 gene. This gene encodes a sodium- independent transporter which mediates cellular uptake of organic ions in the liver. Its substrates include bile acids, bromosulphophthalein, and some steroidal compounds. The protein is a member of the SLC21A family of solute carriers.
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Structure of the methoxide anion. Although alkali metal alkoxides are not salts and adopt complex structures, they behave chemically as sources of RO−. An alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as RO−, where R is the organic substituent.
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1,1,1,3,3,3-Hexafluoroisopropylbis(pentafluorophenyl)borinate can greatly increase solubility of LiF by complexing the F− anion. This has potential to improve lithium batteries. Borinic esters are being researched as bacterial growth inhibitors due to their ability to disable some bacterial enzymes such as menaquinone methyltransferase and CcrM. This may result in development of treatments for topical application on skin.
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Although no true manganese(III) acetate is known, salts of basic manganese(III) acetate are well characterized. Basic manganese acetate adopts the structure reminiscent of those of basic chromium acetate and basic iron acetate. The formula is [Mn3O(O2CCH3)6Ln]X where L is a ligand and X is an anion. The coordination polymer [Mn3O(O2CCH3)6]O2CCH3.
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Nickel(II) bis(acetylacetonate) is a coordination complex with the formula [Ni(acac)2]3, where acac is the anion C5H7O2− derived from deprotonation of acetylacetone. It is a dark green paramagnetic solid that is soluble in organic solvents such as toluene. It reacts with water to give the blue-green diaquo complex Ni(acac)2(H2O)2.
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Corderoite has crankshaft chains that are crosswise linked by additional Hg²+. The bond distance between the cation Hg and anion S is 2.422 Angstroms. It has two angles, Hg-S-HG= 94.1º and S-Hg-S= 165.1º. Various sulfide halides of Hg share the feature of being face-sharing [HgS2X4] −6 polyhedral, as corderoite's polyhedra X=Cl.
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Stable salts of xenon containing very high proportions of fluorine by weight (such as tetrafluoroammonium heptafluoroxenate, NF4XeF7, and the related tetrafluoroammonium octafluoroxenate (NF4)2XeF8), have been developed as highly energetic oxidisers for use as propellants in rocketry. Karl O. Christe, William W. Wilson. Perfluoroammonium salt of heptafluoroxenon anion. , June 24, 1982 Xenon fluorides are good fluorinating agents.
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The Encyclopedia of Gemstones and Minerals (1991). Martin Holden. Publisher: Facts on File Major dissolved components are chlorine, sodium, calcium, magnesium and potassium, and other important components include iron, manganese, copper, zinc, lead, sulfur (as SO42− or S2− or both) carbon (as HCO3− and CO2) and nitrogen (as NH4). Most ore fluids contain chloride as the dominant anion.
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Sodium ferrioxalate is a chemical compound with the formula . It is also called sodium oxalatoferrate or sodium trisoxalatoferrate. The compound is a salt consisting of ferrioxalate anions, , and sodium cations . The anion is a transition metal complex consisting of an iron atom in the +3 oxidation state and three bidentate oxalate ions anions acting as ligands.
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There is a total of 95 grams of chlorine in a typical 70-kilogram human. Some bromine in the form of the bromide anion is present in all organisms. A biological role for bromine in humans has not been proven, but some organisms contain organobromine compounds. Humans typically consume 1 to 20 milligrams of bromine per day.
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Sulfoxylic acid disproportionates into sulfur and hydrogensulfite . Some of this in turn reacts to form thiosulfate . Sulfoxylates are sensitive to air, and will be oxidised by the oxygen in it. Sulfoxylate is oxidised to sulfur dioxide radical anion and then to sulfur dioxide. : + O2 → + : + O2 → SO2 \+ :2 (dithionite) The known sulfoxylate salts include cobalt sulfoxylate CoSO2·3H2O.
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This interrupts the citric acid cycle and also causes citrate to accumulate in the tissues and eventually in the plasma. MFA is mainly biotransformed by glutathione transferase enzyme in a phase 2 biotransformation process. The GSH-dependent enzyme couples glutathione to MFA and thereby defluorinating MFA. As a result, a fluoride anion and S-carboxymethyl glutathione are produced.
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Generally pyridinium photoinitiators are N-substituted pyridine derivatives, with a positive charge placed on the nitrogen. The counter ion is in most cases a non-nucleophilic anion. Upon radiation, homolytic bond cleavage takes place generating a pyridinium cationic radical and a neutral free radical. In most cases, a hydrogen atom is abstracted from the oligomer by the pyridinium radical.
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Arsenic pentasulfide hydrolyzes in boiling water, giving arsenous acid and sulfur: : As2S5 \+ 6 H2O → 2 H3AsO3 \+ 2 S + 3 H2S It oxidizes in air at elevated temperatures producing arsenic oxides, the products and yields of which are variable. In alkali metal sulfide solutions arsenic pentasulfide forms a thioarsenate anion, [AsS4]3−, which contain As(V) centres.
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Bropirimine synthesis: other syntheses: For the first step, the dianion from malonic acid half-ester is formed by treatment with butyllithium. Acylation of the anion with benzoyl chloride proceeds at the carbanion, which is more nucleophilic (because of the higher charge density). This tricarbonyl compound decarboxylates on acidification to the β-ketoester. Condensation with guanidine leads to the pyrimidone.
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Conjugate addition is the vinylogous counterpart of direct nucleophilic addition. A nucleophile reacts with a α,β-unsaturated carbonyl compound in the β position. The negative charge carried by the nucleophile is now delocalized in the alkoxide anion and the α carbon carbanion by resonance. Protonation leads through keto-enol tautomerism to the saturated carbonyl compound.
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When trialkylaluminums are combined with hydrogen cyanide prior to the introduction of the carbonyl compound, a cyanoaluminate anion forms and acts as the active cyanating agent (after activation of the carbonyl compound by a proton). Formation of the dicyano compound is rapid under these conditions, but conversion back to the keto form occurs under basic workup.Bonitz, E. Chem. Ber.
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The chemical garden relies on most transition metal silicates being insoluble in water and colored. When a metal salt, such as cobalt chloride, is added to a sodium silicate solution, it will start to dissolve. It will then form insoluble cobalt silicate by a double displacement reaction (anion metathesis). This cobalt silicate is a semipermeable membrane.
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Fullerenes react as electrophiles with a host of nucleophiles in nucleophilic additions. The intermediary formed carbanion is captured by another electrophile. Examples of nucleophiles are Grignard reagents and organolithium reagents. For example, the reaction of C60 with methylmagnesium chloride stops quantitatively at the penta-adduct with the methyl groups centered around a cyclopentadienyl anion which is subsequently protonated.
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A selenide is a chemical compound containing a selenium anion with oxidation number of −2 (Se2−), much as sulfur does in a sulfide. The chemistry of the selenides and sulfides is similar. Similar to sulfide, in aqueous solution, the selenide ion, Se2−, is prevalent only in very basic conditions. In neutral conditions, hydrogen selenide ion, HSe−, is most common.
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Isocyanic acid is a chemical compound with the formula HNCO or H–N=C=O. It is a colourless substance, volatile and poisonous, with a boiling point of 23.5 °C. It is the predominant tautomer of cyanic acid H–O–C≡N. The derived anion is the same as that of cyanic acid, and is called cyanate.
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Positive charges of soil minerals can retain anions by the same principle as cation exchange. The surfaces of kaolinite, allophane and iron and aluminium oxides often carry positive charges. In most soils the cation-exchange capacity is much greater than the anion-exchange capacity, but the opposite can occur in highly weathered soils, such as ferralsols (oxisols).
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If farms are unable to provide separate diets for far-off and close-up cows, producers may chose to manage their diets with a shorter dry period and a negative DCAD (dietary cation-anion difference) ration diet. These diets are acidic and help calcium be reabsorbed within the cows body and reduce the risk of milk fever.
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In theory, the two-coordinate hydridoberyllium group (-BeH) in hydridoberylliums such as dihydridoberyllium can accept an electron-pair donating ligand into the molecule by adduction: : + L → Because of this acceptance of the electron-pair donating ligand (L), dihydridoberyllium has Lewis-acidic character. Dihydridoberyllium can accept two electron pairs from ligands, as in the case of the tetrahydridoberyllate(2-) anion ().
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Like oxide, fluoride is a highly basic anion and is known to stabilize metal ions in high oxidation states. Both copper(III) and even copper(IV) fluorides are known, K3CuF6 and Cs2CuF6, respectively. Some copper proteins form oxo complexes, which also feature copper(III). With tetrapeptides, purple-colored copper(III) complexes are stabilized by the deprotonated amide ligands.
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Along with these fluorocarbonates form the larger family of halocarbonates. In turn halocarbonates are a part of mixed anion materials. Compounds where fluorine connects to carbon making acids are unstable, fluoroformic acid decomposes to carbon dioxide and hydrogen fluoride, and trifluoromethyl alcohol also breaks up at room temperature. Trifluoromethoxide compounds exist but react with water to yield carbonyl fluoride.
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Attempted isolation of the common salts of bisulfite results in dehydration of the anion with formation of metabisulfite (), also known as disulfite: :2 HSO3− ⇌ S2O52− \+ H2O Because of this equilibrium, anhydrous sodium and potassium salts of bisulfite cannot be obtained. However, there are some reports of anhydrous bisulfites with large counter ions. Structure of disulfite ion.
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Silver acetylide is an inorganic chemical compound with the formula Ag2C2, a metal acetylide. The compound can be regarded as a salt of the weak acid, acetylene. The salt's anion consists of two carbon atoms linked by a triple bond. The alternate name "silver carbide" is rarely used, although the analogous calcium compound CaC2 is called calcium carbide.
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The pure (β) form of cobalt(II) hydroxide has the brucite crystal structure. As such, the anion and cation packing are like those in cadmium iodide, in which the cobalt(II) cations have octahedral molecular geometry. The beta form can be obtained as platelets with partial hexagonal geometry, 100-300 nm wide and 5-10 nm thick.
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In organosulfur chemistry, 1,3-dithioles are a class of heterocycles based on the parent compound 1,3-dithiacyclopentene (also known as 1,3-dithiole). The ligand dmit2- is a 1,3-dithiole. Heating solutions of Na2dmit gives the isomeric disulfide, a 1,2-dithiole. Structure of the anion [Zn(dmit)2]2-, featuring two 1,3-dithiole-4,5-dithiolate ligands complexed to zinc.
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It is odorless and soluble in water (200 g/100 ml). It is not especially toxic, but is a mild acidic irritant. The compound is known by a variety of different names and acronyms (see 'other names' section of infobox). In these names the "12" or "dodeca" reflects the fact that the anion contains 12 tungsten atoms.
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Similar to silver nitrate, silver perchlorate is an effective reagent for replacing halides ligands with perchlorate, which is a weakly or non-coordinating anion. The use of silver perchlorate in chemical synthesis has declined due to concerns about explosiveness of perchlorate salts. Other silver reagents are silver tetrafluoroborate, and the related silver trifluoromethanesulfonate and silver hexafluorophosphate.
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Mercury doublets form part of an infinite chain: SO4 \- Hg - Hg - SO4 \- Hg - Hg - … The Hg - Hg - O bond angle is 165°±1°. The chain crosses the unit cell diagonally. The mercury sulfate structure is held together by weak Hg-O interactions. The SO4 does not act as a single anion, but rather is coordinated to the mercury metal.
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In June 2010 he along with American and Japanese colleagues had studied acid soils and discovered that certain species of crop plants are resistant to soluble aluminum. The way how they do, he explained, is that the genes of ALMT and MATE families encode membrane proteins which produce anion efflux called TaALMT1 across the cell membrane.
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Mevalonic acid (MVA) is a key organic compound in biochemistry; the name is a contraction of dihydroxymethylvalerolactone. The carboxylate anion of mevalonic acid, which is the predominant form in biological environments, is known as mevalonate and is of major pharmaceutical importance. Drugs like statins (which lower levels of cholesterol) stop the production of mevalonate by inhibiting HMG-CoA reductase.
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Carbons 4 and 5 also have a double bond, represented by 'Δ4,5'. The reaction involves a stereospecific and permanent break of the Δ4,5 with the help of NADPH as a cofactor. A hydride anion (H−) is also placed on the α face at the fifth carbon, and a proton on the β face at carbon 4.
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Perchloratoborate is an anion of the form [B(ClO4)4]−. It can form partly stable solid salts with heavy alkali metals. They are more stable than nitratoborate salts. K[B(ClO4)4] decomposes at 35 °C, Rb[B(ClO4)4] is stable to 50 °C, and Cs[B(ClO4)4] can exist up to 80 °C.
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Vanadium hexacarbonyl is thermally unstable. Its primary reaction is reduction to the monoanion , salts of which are well studied. It is also susceptible to substitution by tertiary phosphine ligands, often leading to disproportionation. V(CO)6 reacts with sources of the cyclopentadienyl anion to give the orange four-legged piano stool complex (C5H5)V(CO)4 (m.p.
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Unlike oxides of phosphorus and arsenic, these oxides are amphoteric, do not form well-defined oxoacids, and react with acids to form antimony salts. Antimonous acid is unknown, but the conjugate base sodium antimonite () forms upon fusing sodium oxide and . Transition metal antimonites are also known. Antimonic acid exists only as the hydrate , forming salts as the antimonate anion .
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This protein is reported to interact with, and increase the opening of, the mitochondrial voltage-dependent anion channel (VDAC), which leads to the loss in membrane potential and the release of cytochrome c. The expression of this gene is regulated by the tumor suppressor P53 and has been shown to be involved in P53-mediated apoptosis.
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Cadmium telluride is the only thin film material so far to rival crystalline silicon in cost/watt. However cadmium is highly toxic and tellurium (anion: "telluride") supplies are limited. The cadmium present in the cells would be toxic if released. However, release is impossible during normal operation of the cells and is unlikely during fires in residential roofs.
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In non-phagocytic cells, oxidative burst products are used in intracellular signalling pathways. The generated ROS achieve this via shifting the cell redox state. This may be monitored by the ratio of the antioxidant enzyme glutathione to its oxidised product, glutathione disulphide (GSH:GSSG). Antioxidant enzymes counterbalance redox signalling by eliminating the involved molecules, importantly superoxide anion and nitric oxide.
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Respiratory burst (or oxidative burst) is the rapid release of the reactive oxygen species (ROS), superoxide anion () and hydrogen peroxide (), from different cell types. This is usually utilised for mammalian immunological defence, but also plays a role in cell signalling. Respiratory burst is also implicated in the ovum of animals following fertilization. It may also occur in plant cells.
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Structure of a boranophosphate analogue of ATP, the borane substituent is highlighted in red. Boranophosphates are salts with an anion consisting of borane (BH3) and phosphite groups. One of the simplest examples is [(CH3O)2OPBH3]-, prepared by base hydrolysis of the adduct of borane and trimethylphosphite. Boranophosphates have gained attention as structural surrogates of phosphate group in living systems.
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Technetium (99mTc) sestamibi (INN) (commonly sestamibi; USP: technetium Tc 99m sestamibi; trade name Cardiolite) is a pharmaceutical agent used in nuclear medicine imaging. The drug is a coordination complex consisting of the radioisotope technetium-99m bound to six (sesta=6) methoxyisobutylisonitrile (MIBI) ligands. The anion is not defined. The generic drug became available late September 2008.
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For imides derived from ammonia, the N–H center is weakly acidic. Thus, alkali metal salts of imides can be prepared by conventional bases such as potassium hydroxide. The conjugate base of phthalimide is potassium phthalimide. These anion can be alkylated to give N-alkylimides, which in turn can be degraded to release the primary amine.
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Chemical structure of carbamates A carbamate is a category of organic compounds that is formally derived from carbamic acid (NH2COOH). The term includes organic compounds (e.g., the ester ethyl carbamate), formally obtained by replacing one or more of the hydrogen atoms by other organic functional groups; as well as salts with the carbamate anion (e.g. ammonium carbamate).
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The selenide iodides are chemical compounds that contain both selenide ions (Se2−) and iodide ions (I−) and one or metal atoms. They are in the class of mixed anion compounds or chalcogenide halides. Some related compounds do not actually contain a selenide ion, instead containing an iodoselenium cation. These cations include SeI3+, Se2I42+, Se6I22+, and polymeric Se6I+.
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An example is gold cyanidation, where pulverized ores are extracted with a solution of sodium cyanide, which, in the presence of air, dissolves the gold, leaving behind the nonprecious residue. :Ball-and-stick model of the aurocyanide or dicyanoaurate(I) complex anion, [Au(CN)2]−.Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth- Heinemann. .
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The telluride bromides are chemical compounds that contain both telluride ions (Te2−) and bromide ions (Br−). They are in the class of mixed anion compounds or chalcogenide halides. In many tellurium bromide compounds, tellurium atoms link up in a helix, similar to pure tellurium structure. In Rhenium compounds tellurium atoms form a cluster with rhenium atoms.
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It can also act as an extremely weak acid, losing a proton to produce the amide anion, . It thus undergoes self- dissociation, similar to water, to produce ammonium and amide. Ammonia burns in air or oxygen, though not readily, to produce nitrogen gas; it burns in fluorine with a greenish-yellow flame to give nitrogen trifluoride.
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Potassium atoms are 9-coordinated and may be viewed as distorted monocapped square prisms. At temperatures above 230 °C this converts to β-K2[TaF7], which is orthorhombic (space group: Pnma). This structure also consists of potassium ions and the complex anion [TaF7]2−. The structure of the 7-coordinate [TaF7]2− units is essentially unchanged.
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A key candidate transporter is INDY (I'm not dead yet), a sodium-independent anion exchanger, which moves both dicarboxylate and citrate into the bloodstream. Amino acid sequence of GPR91. Succinate binds to GPR91, a 7-transmembrane G-protein coupled receptor, located on a variety of cell types. Red amino acids represent those involved in binding succinate.
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This compound exhibits strongly reducing properties, and slowly yields hydrogen gas when dissolved in water. The lithium and thallous salts were also reported. Later research, however, indicates that the "rhenide" ion is actually a hydridorhenate complex. "Potassium rhenide" was shown to be in fact the nonahydridorhenate, , containing the anion in which the oxidation state of rhenium is actually +7.
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Nickel can be part of a negatively charged ion (anion) making what is called a nickellate. Numerous quaternary compounds (with four elements) of nickel have been studied for superconductivity properties, as nickel is adjacent to copper and iron in the periodic table can can form compounds with the same structure as the high-temperature superconductors that are known.
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The dimeric made up of two edge sharing {TeO6} octahedra is found in the compound, Li4TeO5. A similar hydroxy-oxy anion, Te2O6(OH)4 is found in sodium potassium ditellurate(VI) hexahydrate,Na0.5K3.5Te2O6(OH)4·6H2O which contains pairs of edge sharing octahedra. Polymeric chain anions consisting of corner-shared {TeO6} octahedra (TeO5) are found, for example in Li4TeO5.
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Idealized structure of a Tp ligand bound to a metal center MLn. In inorganic chemistry, the trispyrazolylborate ligand, abbreviated Tp−, is an anionic tridentate and tripodal ligand. Trispyrazolylborate refers specifically to the anion [HB(C3N2H3)3]−, but the term trispyrazolylborate refers to derivatives substituted at on the pyrazolyl rings. This family of compounds are sometimes called scorpionate ligands.
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"Oxide" itself is the dianion of oxygen, an O2– (molecular) ion. Metal oxides thus typically contain an anion of oxygen in the oxidation state of −2. Most of the Earth's crust consists of solid oxides, the result of elements being oxidized by the oxygen in air or in water. Even materials considered pure elements often develop an oxide coating.
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Sodium bifluoride is the inorganic compound with the formula NaHF2. It is a salt of sodium cation (Na+) and bifluoride anion (HF2−). It is a white, water- soluble solid that decomposes upon heating .Perry, Dale L.; Handbook of Inorganic Compounds; CRC Press (2011); page 381; Sodium bifluoride is non- flammable, hygroscopic, and has a pungent smell.
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The sulfide anion is not formed in aqueous solution. Hydrogen sulfide reacts with metal ions to form metal sulfides, which are insoluble, often dark colored solids. Lead(II) acetate paper is used to detect hydrogen sulfide because it readily converts to lead(II) sulfide, which is black. Treating metal sulfides with strong acid often liberates hydrogen sulfide.
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Hydrogen sulfide is commonly found in raw natural gas and biogas. It is typically removed by amine gas treating technologies. In such processes, the hydrogen sulfide is first converted to an ammonium salt, whereas the natural gas is unaffected. :RNH2 \+ H2S RNH + SH− The bisulfide anion is subsequently regenerated by heating of the amine sulfide solution.
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Many sulfate esters are used in detergents, and some are useful reagents. Alkyl sulfates consist of a hydrophobic hydrocarbon chain, a polar sulfate group (containing an anion) and either a cation or amine to neutralize the sulfate group. Examples include: sodium lauryl sulfate (also known as sulfuric acid mono dodecyl ester sodium salt) and related potassium and ammonium salts.
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Superoxides are also used in firefighters' oxygen tanks to provide a readily available source of oxygen. In this process, acts as a Brønsted base, initially forming the hydroperoxyl radical (HO2). The superoxide anion, , and its protonated form, hydroperoxyl, are in equilibrium in an aqueous solution:Reactivity of HO2/O2− Radicals in Aqueous Solution. J Phys Chem Ref Data, 1985.
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Sodium ferrocyanide is the sodium salt of the coordination compound of formula [Fe(CN)6]4−. In its hydrous form, Na4Fe(CN)6 (sodium ferrocyanide decahydrate), it is sometimes known as yellow prussiate of soda. It is a yellow crystalline solid that is soluble in water and insoluble in alcohol. The yellow color is the color of ferrocyanide anion.
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Zinc chloride Zinc compounds, like those of main group elements, are mostly colourless. Exceptions occur when the compound contains a coloured anion or ligand. However, zinc selenide and zinc telluride are both coloured due to charge- transfer processes. Zinc oxide turns yellow when heated due to the loss of some oxygen atoms and formation of a defect structure.
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By condensing propadienedithione SCCCS or thioxopropadienone OCCCS in solid argon and irradiating with ultraviolet radiation, CCS is formed. Another way is via a glow discharge in a mixture of carbon disulfide and helium. Yet another way is through electron irradiation of sulfur containing heterocycles. CCS and the anion CCS− can be formed in solid neon matrices also.
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These include the bifluoride anion (), tetrafluorobromate (), metal pentafluorides ( where M is Ge, Sn, or Ti), hexafluorides ( where M is P, As, Sb, Bi, or Pt), heptafluorides ( where M is W, U, or Xe), octafluorides (), various oxyfluorides ( where M is W or U; , ), and perchlorate (). Attempts to make the nitrate salt, , were unsuccessful because of quick fluorination: + → + .
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The mixed sulfite-sulfate represents an intermediate in the oxidation of the sulfite to the sulfate, as is practiced in the production of gypsum. This solid solution consists of [Ca3(SO3)2(H2O)12]2+ cations and either sulfite or sulfate as the anion. Structure of the [Ca3(SO3)2(H2O)12]2+ in calcium sulfite tetrahydrate.
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Anion exchange protein 3 is a membrane transport protein that in humans is encoded by the SLC4A3 gene. AE3 is functionally similar to the Band 3 Cl−/HCO3− exchange protein but it is expressed primarily in brain neurons and in the heart. Like AE2 its activity is sensitive to pH. AE3 mutations have been linked to seizures.
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Acute hypoxemia was due to bronchoconstriction and pulmonary edema. Hypoxemia was associated with metabolic acidosis and the increase in the anion gap may have been due to increased blood lactates induced by hypoxia. There was also a measured decrease in PCO₂, which may be explained by decreased cardiac output. decreasing carbon dioxide transport to the lung.
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In basic solutions (pH > 10), rhodizonic acid quickly converts to the THBQ anion in the absence of oxygen, and to croconic acid in its presence. At pH 8.3 and exposure to light, solutions are stable for days in the absence of oxygen, and decompose to croconic acid and other products (possibly including cyclohexanehexone or dodecahydroxycyclohexane) in its presence.
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The popularization of has led to decreased use of in the laboratory as a weakly coordinating anion. With organic compounds, especially amine derivatives, forms potentially explosive derivatives. Disadvantages to include its slight sensitivity to hydrolysis and decomposition via loss of a fluoride ligand, whereas does not suffer from these problems. Safety considerations, however, overshadow this inconvenience.
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Diagnosis is generally based on symptoms. An elevated anion gap metabolic acidosis and ketosis is the classic present. However, a mixed acid-base disorder may be present especially if vomiting is contributing to a hypochloremic alkalosis. The ketone which is present is mostly beta-hydroxybutryate rather than acetoacetate resulting in only a weakly positive nitroprusside test.
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Viral protein 5 is an inducer of apoptosis for DF-1 cells. It relies on inhibiting the voltage- dependent anion channel 2 (VDCA2) located on the mitochondria. The inhibition will be aided by VP2, which will close the channel allowing for proliferation of the virus in host cells. Also, VDCA2 will bind to RACK1 that will allow replication.
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In organic chemistry, quaternary ammonium salts are employed as phase transfer catalysts (PTCs). Such catalysts accelerate reactions between reagents dissolved in immiscible solvents. The highly reactive reagent dichlorocarbene is generated via PTC by reaction of chloroform and aqueous sodium hydroxide. Anion exchange resins, in the form of beads, contain quaternary ammonium ions bound to a polymer.
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A number of biological effects of paeonol in vitro or in animal models have been observed. Paeonol increases levels of cortical cytochrome oxidase and vascular actin and improves behavior in a rat model of Alzheimer's disease. Paeonol also reduced cerebral infarction involving the superoxide anion and microglia activation in ischemia-reperfusion injured rats. Paeonol shows antimutagenic activities.
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In the naming of inorganic compounds zincate is a suffix that indicates that a polyatomic anion contains a central zinc atom. Examples include tetrachlorozincate, ZnCl42−, the tetrahydroxozincate, Zn(OH)42− and tetranitratozincate, Zn(NO3)42−. More recent recommendations (2005), that are not widely used, would call the first two ions tetrachloridozincate(2−) and tetrahydroxidozincate(2−) respectively.
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There is one particular reaction studied by Grutzmacher et al. that exhibits the rearrangement of coordination character of PCO. Initially when reacting the anion with triorganyl silicon compounds, it binds via the oxygen forming the kinetic oxyphosphaalkyne product. The thermodynamic silyl phosphaketene product is generated when the kinetic product rearranges to allow PCO to coordinate through phosphorus.
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"Methylmercury" is a shorthand for the hypothetical "methylmercury cation", sometimes written "methylmercury(1+) cation" or "methylmercury(II) cation". This functional group is composed of a methyl group bonded to a mercury. Its chemical formula is + (sometimes written as MeHg+). Methylmercury exists as a substituent in many complexes of the type [MeHgL]+ (L = Lewis base) and MeHgX (X = anion).
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Hypothiocyanite is the anion [OSCN]− and the conjugate base of hypothiocyanous acid (HOSCN). It is an organic compound part of the thiocyanates as it contains the functional group SCN. It is formed when an oxygen is singly bonded to the thiocyanate group. Hypothiocyanous acid is a fairly weak acid; its acid dissociation constant (pKa) is 5.3.
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2D diagram of mellitate , one of the oxocarbon anions. Black circles are carbon atoms, red circles are oxygen atoms. Each blue halo represents one half of a negative charge. In chemistry, an oxocarbon anion is a negative ion consisting solely of carbon and oxygen atoms, and therefore having the general formula for some integers x, y, and n.
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The structural formula of the docusate anion is , where R is the 2-ethylhexyl group . The conjugate acid can be described as the twofold carboxylate ester of sulfosuccinic acid with 2-ethylhexanol. The compound is a white, wax-like, plastic solid, with an odor suggestive of octyl alcohol. It starts to decompose at about 220 °C.
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Sulfide inclusion as manganese sulfide (MnS) can also be the cause of severe pitting corrosion problems in low-grade stainless steel such as AISI 304 steel. Under oxidizing conditions and in the presence of moisture, when sulfide oxidizes it produces thiosulfate anions as intermediate species and because thiosulfate anion has a higher equivalent electromobility than chloride anion due to its double negative electrical charge, it promotes the pit growth. Indeed, the positive electrical charges born by Fe2+ cations released in solution by Fe oxidation on the anodic zone inside the pit must be quickly compensated / neutralised by negative charges brought by the electrokinetic migration of anions in the capillary pit. Some of the electrochemical processes occurring in a capillary pit are the same than these encountered in capillary electrophoresis.
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The acidity of carbon 5 (between the two carbonyl groups) allows simple alkylation and acylation of Meldrum's acid at this position. For example, deprotonation and reaction with a simple alkyl halide () attaches the alkyl group () at that position: alt=Alkylation of Meldrum's anion at carbon 5 alkyl halide The analogous reaction with an acyl chloride () attaches the acyl () instead: alt=Acylation of Meldrum's anion at carbon 5 acyl chloride These two reactions allow Meldrum's acid to serve as a starting scaffold for the synthesis of many different structures with various functional groups. The alkylated products can be further manipulated to produce various amide and ester compounds. Heating the acyl product in the presence of an alcohol leads to ester exchange and decarboxylation in a process similar to the malonic ester synthesis.
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Cyclohexanehexone can be viewed as the neutral counterpart of the rhodizonate anion . The singly charged anion has been detected in mass spectrometry experiments, formed by oligomerization of carbon monoxide through the formation of molybdenum carbonyls. According to X-ray diffraction analysis, the reagent traded under the name "cyclohexanehexone octahydrate" or equivalent names is actually dodecahydroxycyclohexane dihydrate—the geminal diol derivative of the six ketone groups with an additional two molecules of water—a solid that decomposes at 95 °C. In 1966, Howard E. Worne of Natick Chemical Industries patented compounds with formulas C10O8 and C14O10, which can be described as the fusion of two or three molecules of C6O6, claimed to be produced by the action of ultraviolet radiation on a hot water solution of the parent compound.
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Potassium octachlorodimolybdate (systematically named potassium bis(tetrachloridomolybdate)(Mo–Mo)(4−)) is an inorganic compound with the chemical formula (also written as ). It is known as a red-coloured, microcrystalline solid. The anion is of historic interest as one of the earliest illustrations of a quadruple bonding. The salt is usually obtained as the pink-coloured dihydrate. The octachlorodimolybdate(II) anion, [Mo2Cl8]4−, which features a quadruple Mo-Mo bond The compound is prepared in two steps from molybdenum hexacarbonyl: :2 Mo(CO)6 \+ 4 HO2CCH3 → Mo2(O2CCH3)4 \+ 2 H2 \+ 12 CO :Mo2(O2CCH3)4 \+ 4 HCl + 4 KCl → K4Mo2Cl8 \+ 4 HO2CCH3 The reaction of the acetate with HCl was first described as providing trimolybdenum compounds, but subsequent crystallographic analysis confirmed that the product contains the ion with D4h symmetry.
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The simplest possible thallium compound, thallane (TlH3), is too unstable to exist in bulk, both due to the instability of the +3 oxidation state as well as poor overlap of the valence 6s and 6p orbitals of thallium with the 1s orbital of hydrogen. The trihalides are more stable, although they are chemically distinct from those of the lighter group 13 elements and are still the least stable in the whole group. For instance, thallium(III) fluoride, TlF3, has the β-BiF3 structure rather than that of the lighter group 13 trifluorides, and does not form the complex anion in aqueous solution. The trichloride and tribromide disproportionate just above room temperature to give the monohalides, and thallium triiodide contains the linear triiodide anion () and is actually a thallium(I) compound.
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Lemieux studied biochemistry at Dalhousie University. During her undergraduate studies she worked alongside Catherine Mezei, studying membrane proteins within the myelinating peripheral nerve. She remained there for her master's studies, where she continued studying the myelinating peripheral nerve, but instead specialised on lipoproteins. After graduating with her master's degree, Lemieux moved to New York University, where she researched the human erythrocyte anion exchanger.
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Calcium iodates are inorganic compound composed of calcium and iodate anion. Two forms are known, anhydrous Ca(IO3)2 and the hexahydrate Ca(IO3)2(H2O). Both are colourless salts that occur naturally as the minerals called lautarite and bruggenite, respectively. A third mineral form of calcium iodate is dietzeite, a salt containing chromate with the formula Ca2(IO3)2CrO4.
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2-Iodobenzoic acid can be synthesized via a Sandmeyer reaction consisting of the diazotization of anthranilic acid followed by a diazo replacement. First anthranilic acid is treated with nitrous acid in order to convert the amino group into the diazo group. The diazo group is ejected, yielding a carbocation which is then attacked by highly nucleophilic I− anion. Diazo replacement of anthranilic acid.
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Molten anhydrous ZnCl2 at 500–700 °C dissolves zinc metal, and, on rapid cooling of the melt, a yellow diamagnetic glass is formed, which Raman studies indicate contains the ion. A number of salts containing the tetrachlorozincate anion, Zn, are known. "Caulton's reagent", V2Cl3(thf)6Zn2Cl6 is an example of a salt containing Zn2. The compound Cs3ZnCl5 contains tetrahedral Zn and Cl− anions.
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This mechanism also proceeds with inversion at the carbon center. This reaction is known to be reversible. Depending on the relative stabilities of the carbanion and oxy-anion formed, a silyl ether is perfectly capable of rearranging to a species with the silicon bonded to the carbon atom, and the free alcohol being present. This would be termed a Retro-Brook rearrangement.
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An anion exchanger will then be used to secrete DIC at the site of calcification. This DIC pool is also utilized by algal symbionts (dinoflagellates) that live in the coral tissue. These algae photosynthesize and produce nutrients, some of which are passed to the coral. The coral in turn will emit ammonium waste products which the algae uptake as nutrients.
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Acetonitrile, often abbreviated MeCN (methyl cyanide), is the chemical compound with the formula . This colourless liquid is the simplest organic nitrile (hydrogen cyanide is a simpler nitrile, but the cyanide anion is not classed as organic). It is produced mainly as a byproduct of acrylonitrile manufacture. It is used as a polar aprotic solvent in organic synthesis and in the purification of butadiene.
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The aryl selenium anion displaces tributylphosphine oxide forming the alkyl aryl selenide species. The selenide is then treated with excess hydrogen peroxide leading to the selenoxide which eliminates the β-hydrogen through a 5-member cyclic transition state, yielding an alkene. frameless The electron-withdrawing nitro group was found to increase both the rate of elimination and the final yield of the olefin.
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The alkali metal naphthalenides are prepared by stirring the metal with naphthalene in an ethereal solvent, usually as tetrahydrofuran or dimethoxyethane. The resulting salt is dark green. The anion is a radical, giving a strong EPR signal near g = 2.0, with a reduction potential near -2.5 V vs NHE. Its deep green color arises from absorptions centered at 463, 735 nm.
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Since tyrosine kinase inhibitors (TKIs) are metabolized in the liver, interaction of TKIs with OATP1B1 and OATP1B3 can be considered as important molecular targets for transporter mediated drug-drug interactions. Along with the organic anion transporters, organic cation transporters and the ATP-binding cassette transporters, the OATPs play an important role in the absorption, distribution, metabolism and exretion (ADME) of many drugs.
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A number of minerals contain arsenite anions: reinerite, Zn3(AsO3)2; finnemanite, Pb5Cl(AsO3)3; paulmooreite, Pb2As2O5; stenhuggarite, CaFeSbAs2O7 (contains a complex polymeric anion); schneiderhöhnite, FeFe(As2O5)2AsO3;Hawthorne, Frank C. "Schneiderhoehnite, , a densely packed arsenite structure." The Canadian Mineralogist 23.4 (1985): 675–679. magnussonite, Mn5(OH)(AsO3)3; trippkeite, CuAs2O4; trigonite, Pb3Mn(AsO3)2(HAsO3); tooeleite, Fe6(AsO3)4SO4(OH)4·4H2O.
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Different phenomena are studies, from pitting corrosion of steel, to crystal dissolution. Highly oriented pyrolytic graphite (HOPG) is widely employed as an electrode for EC-AFM. In fact, various surface phenomena are studied, from the application to lithium batteries to anion intercalation leading to blister formation on the electrode surface. A rather interesting application is the EC-AFM Dip pen nanolithography.
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The orthosilicate ion or group has tetrahedral shape, with one silicon atom surrounded by four oxygen atoms. In the anion, each oxygen carries a unit negative charge. The Si–O bond is 162 pm long. In organic compounds like tetramethyl orthosilicate, each oxygen is formally neutral and is connected to the rest of the molecule by a single covalent bond.
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In August 2020 researchers reported the creation of the brightest fluorescent solid optical materials so far by enabling the transfer of properties of highly fluorescent dyes via spatial and electronic isolation of the dyes by mixing cationic dyes with anion-binding cyanostar macrocycles. According to a co-author these materials may have applications in areas such as solar energy harvesting, bioimaging, and lasers.
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The acid can lose one proton from its second carboxyl group to form the conjugate base, the singly-negative anion glutamate −OOC- CH()-()2-COO−. This form of the compound is prevalent in neutral solutions. The glutamate neurotransmitter plays the principal role in neural activation.Robert Sapolsky (2005), Biology and Human Behavior: The Neurological Origins of Individuality (2nd edition); The Teaching Company. pp.
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The sensation of umami is due to the detection of the carboxylate anion of glutamate in specialized receptor cells present on the human and other animal tongues. Some 52 peptides may be responsible for detecting umami taste. Its effect is to balance taste and round out the overall flavor of a dish. Umami enhances the palatability of a wide variety of foods.
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Illustrative chromium dye derived from azo coupling to an azo-ligand. Two such ligands are attached to the Cr(III) center, giving an overall anion. Metal- complex dyes are a family of dyes that contain metals coordinated to the organic portion. Many azo dyes, especially those derived form naphthols, form metal complexes by complexation of one of the azo nitrogen centers.
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Hyperpolarization is a change in a cell's membrane potential that makes it more negative. It is the opposite of a depolarization. It inhibits action potentials by increasing the stimulus required to move the membrane potential to the action potential threshold. Hyperpolarization is often caused by efflux of K+ (a cation) through K+ channels, or influx of Cl- (an anion) through Cl- channels.
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Ammonium tetrathiomolybdate is the chemical compound with the formula (NH4)2MoS4. This bright red ammonium salt is an important reagent in the chemistry of molybdenum and has been used as a building block in bioinorganic chemistry. The thiometallate anion has the distinctive property of undergoing oxidation at the sulfur centers concomitant with reduction of the metal from Mo(VI) to Mo(IV).
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Cystic Fibrosis transmembrane regulators (CFTRs) function in chloride ion, bicarbonate anion, and fluid transport. They are expressed primarily in apical membranes of epithelial cells in respiratory, pancreatic, gastrointestinal, and reproductive tissues. Abnormally-elevated CFTR function results in excessive fluid secretion. High-affinity CFTR inhibitors, such as CFTRinh-172 and GlyH-101, have been shown to be efficient in treatment of secretory diarrheas.
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Structure of a carboxylic acid Carboxylate Anion 3D structure of a carboxylic acid A carboxylic acid is an organic compound that contains a carboxyl group (C(=O)OH) attached to an R-group. The general formula of a carboxylic acid is R–COOH, with R referring to the alkyl group. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids.
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Free hydride anions exist only under extreme conditions and are not invoked for homogeneous solution. Instead, many compounds have hydrogen centres with hydridic character. Aside from electride, the hydride ion is the simplest possible anion, consisting of two electrons and a proton. Hydrogen has a relatively low electron affinity, 72.77 kJ/mol and reacts exothermically with protons as a powerful Lewis base.
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The decarboxylation of indole-3-acetate is chemically difficult since it leaves an unstable carbanion because of the direct elimination of CO2. This chemical reaction is promoted by 1-electron oxidation of indole-3-acetate through a proton-coupled electron transfer (PCET), which requires the transfer of the indolic-NH proton to a suitably positioned base, producing an indoleacetate anion radical intermediate.
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The crystal structure of magnesiopascoite consists of the decavanadate anion (V10O28)6− and interstitial {Ca2Mg(H2O)16}6+ consisting of Mg(H2O)6 octahedra and seven- fold coordinated CaO2(H2O)5. The structure differs from that of pascoite primarily in cation coordination in the interstitial complex. In addition to calcium and magnesium, magnesiopascoite contains minute quantities of zinc and cobalt.
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Chloroplatinic acid (also known as hexachloroplatinic acid) is an inorganic compound with the formula [H3O]2[PtCl6](H2O)x (0 ≤ x ≤ 6). A red solid, it is an important commercial source of platinum, usually as an aqueous solution. Although often written in shorthand as H2PtCl6, it is the hydronium (H3O+) salt of the hexachloroplatinate anion (). Hexachloroplatinic acid is highly hygroscopic.
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Treatment of chlorobis(dppe)iron hydride with sodium tetrafluorborate under an atmosphere of hydrogen is one example: :HFeCl(dppe)2 \+ NaBF4 \+ H2 → [HFe(H2)(dppe)2]BF4 \+ NaCl Many metal hydrides can be protonated to give dihydrogen complexes: :H2Fe(dppe)2 \+ H+ → [HFe(H2)(dppe)2]+ In such cases the acid usually is derived from a weakly coordinating anion, e.g., Brookhart's acid.
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Zhou and Mopper showed that nitrate enhanced the photodegradation of PABA by a factor of 2. However, in the presence of free radical scavengers such as carbonate forms and natural organic matter (NOM), the photodegradation of PABA decreased. It was proposed that the indirect photolysis of PABA was mainly due to the NO3 photolysis product •OH. The Bicarbonate anion is abundant in water.
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The reaction mechanism of the Perkow reaction consists of a nucleophilic addition of the phosphite at the carbonyl carbon forming a zwitterionic intermediate. The zwitterionic intermediate rearranges to a cationic species while eliminating the halide. The cationic species then dealkylates through a second nucleophilic displacement in which the halide anion attacks one of the phosphite alkoxide substituents forming an enol phosphate.Organophosphorus chemistry. XVII.
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He then returned to his home state of Missouri as head of the International Institute of Nano and Molecular Medicine at University of Missouri. Hawthorne was long associated with the journal Inorganic Chemistry, being the longest serving editor-in-chief. :The dodecaborate anion ([B12H12]2−) was discovered by Pitochelli and Hawthorne. Hawthorne's contributions focused on the chemistry of boron hydride clusters.
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Basic lead phosphite is an inorganic compound with the proposed composition Pb3O(OH)2(HPO3). The compound contains the phosphite anion, which provides the reducing properties associated with the application of this material. It is widely used as a stabilizer for chlorine-containing polymers, especially polyvinylchloride.. Other lead phosphites are known, including normal lead phosphite, PbHPO3, although the basic salt is especially effective.
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Scandium nitride (ScN) is a binary III-V indirect bandgap semiconductor. It is composed of the scandium cation and the nitride anion. It forms crystals that can be grown on tungsten foil through sublimation and recondensation. It has a rock-salt crystal structure with lattice constant of 0.451 nanometer, a indirect bandgap of 0.9 eV and direct bandgap of 2 to 2.4 eV.
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Park et al. created an orthogonal receptor-ligand interface between PYR1 and mandipropamid. PYR1 normally binds to abscisic acid which together then bind and inactivate to PP2C as a drought stress response, which stops PP2C from deactivating SnRK2. This causes a cascade that leads to the activation of the slow anion channel 1 and closing of the leaf guard cells and stomata.
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This mechanism is dubious due to the long channel separating the flavin cofactor from the tryptophan substrate. Tryptophan 7-halogenase mechanism, depicting the halogenating chloramine intermediate. angstrom. Note the long (>10Å) channel between the chloride ion and tryptophan as well as the intervening Lys79. () Another proposed mechanism involves the interception of flavin hydroperoxide by a halide anion, generating an equivalent of hypohalous acid.
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