What made you want to get your own reagent kit?
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"What changed was they just said, don't use that reagent."
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He said he's still getting kits with the faulty reagent included.
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"I don't know where the glitch came from with that reagent," he added.
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To conduct the test, blood is drawn and added to a reagent solution.
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Thanks to Guy Jones from Reagent Tests UK for the science advice and the concern.
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Unlike liquid reagent tests, they can look for more than one substance at a time.
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Microchannels maximize the amount of reagent exposed to light and accelerate the reaction, he said.
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The Washington State Public Health Lab was among those who received shipments containing the defective reagent.
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On February 12, the CDC announced that the problem was the result of a faulty reagent.
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The CDC manufactured new test kits through the International Reagent Resource, a branch of the CDC.
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However, Hayashi says he's now working on some sort of artificial reagent to replace the fetal cells.
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But some of those kits were flawed, thanks to a contaminated reagent, leaving labs with inconclusive results.
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These are updated test kits following the first release which contained a reagent that gave inconclusive results.
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One of the many different kinds of reagent kits used to test for illegal drugs in the field.
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Like a chemical reagent applied to crime scene fingerprints, the pink paint renders visible the traces of misconduct.
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If the past reaction included hives, a rash, swelling or shortness of breath, patients should have penicillin skin testing, which involves a skin prick test using a small amount of penicillin reagent, followed by a second test that places the reagent under the skin if the first test is negative.
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Reagent kits are not sophisticated enough to detect the synthetic opioid, known to show up in drugs like MDMA.
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A sensor is inserted into the small LeadCare unit and the blood-reagent mix is added to the sensor.
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The procedure starts with a nasal or throat swab, which gets placed in one reagent to store and stabilize it.
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Image: AmazonHere's a filter reagent, the main ingredient of which can be combined with glycerine to make a lot of flames.
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"We need to bring down the cost because reagent tests have their limitations, they can only do so much," he said.
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Its dry reagent technology allows materials to be stored at room temperature, removing the need for cold chain or refrigerated storage.
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Some state labs, like those in Washington and Wisconsin, received additional CDC tests without the third reagent from February 26 onward.
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Forecast other revenue assumes the receipt of milestone payments contingent upon achievement of regulatory approval for certain conventional reagent products under development.
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The device picks up sweat secretions from a person's skin and channels the fluid into a chemical reagent mixed with food dye.
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"One pill will have such a miniscule amount, it's very unlikely you're going to detect that with a reagent kit," said Crawford.
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The method not only does away with solvents, but also uses bismuth oxide, a safe reagent, in lieu of toxic bismuth salts.
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Initial tests in the U.S. were hampered by the distribution of test kits which contained a faulty reagent — rendering the kits useless.
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The DIY version didn't use the herpes virus to enter the body's cells, as the mouse work did, but instead a transfection reagent.
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The previous Crackdown game came out in 2010, and the new title is being made by British developers Reagent Games and Sumo Digital.
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Finally, on February 26, the CDC and FDA gave all 50 state labs permission to use the original tests without the third reagent.
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Whether it's tallying the number of galaxies in the universe or probing reagent reactions that last mere femtoseconds, nothing quantitative seems beyond our reckoning.
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But liquid reagent tests don't test for all drugs, and they can't tell you the amount of each substance your drugs contain, Palamar warns.
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Guy Jones, a chemist at Reagent-Tests U.K., said this is a consequence of drug laws forcing manufacturers to work cheaply and in secret.
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"Right now, I have reagents to run the testing vials that I need to, hopefully the reagent suppliers, chemical suppliers, will keep up," he said.
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Shi called hospitals all over Wuhan, trying in vain to find one with the confirmation test -- a reagent test which chemically tests for the virus.
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Ultimately, the same rules apply abroad as at home: If in doubt, leave it out; reagent test where you can; and be aware of potential dangers.
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But instead, the FDA eventually gave all 50 state labs permission to use the original tests without one reagent that was to blame for the inconclusive results.
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If you want to test your drugs yourself, your best bet is a liquid reagent test, Palamar says, which you can order online for between $20 and $50.
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But those officials say long waits for kits and issues with the reagent used in diagnosis mean they are able to test only the most high-risk patients.
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Some states notified the CDC that they were unable to validate the test, and the agency is remanufacturing a reagent used in the test that's not performing consistently.
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In most cases this is carried out by a handful of harm reduction non-profit organizations, using cheap reagent kits that can test for 15 or so different substances.
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To make the vaccine, the plasmid coding for the modified virus got mixed with a transfection reagent, something called Lipofectamine intended to allow the plasmid to enter the body's cells.
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"Testing remains important for those with a trusted supply and much experience," says Guy Jones, Technical Lead at Reagent Tests UK, that sells an "MDMA and Psychedelics multipack" testing kit.
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She said the CDC had already shipped the test to the International Reagent Resource, the central distributor for diagnostic tests, so it would be available as soon as approval came through.
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I actually work very closely with The Loop and, in a way, that's a terrible decision, because the more widespread their service becomes the less people have a need for reagent tests.
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Like some binary poisonous reagent, these dynamics combined to foster an environment ripe for political abuse and leakage — a fairly transparent attempt, from the point of view of any discerning intelligence officer.
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Alexei Kiselyov, an official at Greenpeace Russia, said iron salts are a mildly toxic reagent and it was impossible to say if there was damage to local fauna without investigating the site.
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Starting on February 5, the CDC finally began sending out 163 of those kits to the 115 domestic public health labs qualified to run the test through its distribution arm, the International Reagent Resource.
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To work out whether they are in fact helpful or not, I spoke to Guy Jones, the founder of Reagent Tests UK, and Harry Sumnall, a professor in Substance Use for the Public Health Institute.
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"There were several laboratories that did successfully verify, but because of the problems with the other laboratories, chose not to pursue testing until the CDC reagent is fixed," said Kelly Wroblewski, APHL director of infectious diseases.
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More blood was found by using a "chemical reagent" that reacts to the presence of blood that may not be visible to the eye, such as when a person has attempted to clean it up, the documents state.
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Unit cash costs jumped 9 percent to $631 per ounce of gold produced, in keeping with its tone in February when it warned of higher costs due to increasing input costs and rising fuel, reagent and consumable prices.
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Cyrus and Hemsworth have known each other for well over a decade now — if any brainwashing was going on, they both had plenty of time to consult fairy godmothers and/or produce a reagent that would counteract the brainwashing.
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Elsewhere, Takara Bio Inc jumped 11.1% following a Nikkei report that the company is set to produce 50 times more of a coronavirus testing reagent at its plant in Dalian in response to an urgent request from the Chinese city.
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Investigators discovered evidence of more blood by using a "chemical reagent" that reacts to the presence of blood that may not be visible to the eye, such as when a person has attempted to clean it up, the documents state.
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And, as Guy Jones, technical lead at drug testing kit supplier Reagent Tests UK and senior scientist at drugs harm reduction NGO The Loop explains, drugs such as methamphetamine, crack cocaine, and heroin are traditionally vaped anyway, albeit not through an electronic device.
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Inside the device (which, honestly looked like an old school PC tower, ironic given Holmes' obsession with making it look like an Apple product) a robotic arm was supposed to mimic what a chemist did in an IRL lab: take samples, dilute them, add antibodies and a reagent, and reveal a result.
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The Xbox One exclusive Crackdown 3 is largely selling itself on the promise of spectacular environmental destruction—like Just Cause 3, then, but without sticking explosives exclusively to objects marked with red paint, as Reagent Games' revival of a series on the furthest-back burner since 2010 is promising that anything in the game can be blown to smithereens.
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LSD can be detected using an Ehrlich's reagent and a Hofmann's reagent.
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DPT changes Ehrlich's reagent violet and causes the marquis reagent to turn yellow.
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The slow step in most instances is generation of carbene. A well-known reagent employed for alkene-to-cyclopropane reactions is Simmons-Smith reagent. This reagent is a system of copper, zinc, and iodine, where the active reagent is believed to be iodomethylzinc iodide. Reagent is complexed by hydroxy groups such that addition commonly happens syn to such group.
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The Tebbe reagent and the Petasis reagent share a similar reaction mechanism. The active olefinating reagent, Cp2TiCH2, is generated in situ upon heating. With the organic carbonyl, this titanium carbene forms a four membered oxatitanacyclobutane that releases the terminal alkene. :Formation of the active olefinating reagent :Reaction of the active olefinating reagent with a carbonyl compound In contrast to the Tebbe reagent, homologs of the Petasis reagent are relatively easy to prepare by using the corresponding alkyllithium instead of methyllithium, allowing the conversion of carbonyl groups to alkylidenes.
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Reaction between alkaloid extract from Capparis spinosa L and Dragendorff’s reagent Dragendorff's reagent is a color reagent to detect alkaloids in a test sample. Alkaloids, if present in the solution of sample, will react with Dragendorff's reagent and produce an orange or orange-red precipitate. This reagent was invented by the German pharmacologist, Johann Georg Dragendorff (1836-1898) at the University of Dorpat.
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Different stoichiometric ratios of reagents can result in different ratios of products formed. On the industrial scale, adding a large amount of reagent A to reagent B may take time. During this, the reagent A that is added is exposed to a much higher stoichiometric amount of reagent B until it is all added, and this imbalance can lead to reagent A prematurely reacting, and subsequent products to also react with the huge excess of reagent B.
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Some common reagent gases include: methane, ammonia, and isobutane. Inside the ion source, the reagent gas is present in large excess compared to the analyte. Electrons entering the source will preferentially ionize the reagent gas. The resultant collisions with other reagent gas molecules will create an ionization plasma.
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The reagent was generated in situ by conversion of different halogenides of molybdenum or tungsten with methyllithium at low temperatures (−78 °C). 600px During the warm-up process the formation of the active reagent occurs. NMR- experiments have shown that the active reagent is not a Schrock carbene (e.g. Tebbe-reagent).
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The chemistry of Lawesson's reagent and related substances has been reviewed by several groups. The main use of Lawesson's reagent is the thionation of carbonyl compounds. For instance, Lawesson's reagent will convert a carbonyl into a thiocarbonyl. Additionally, Lawesson's reagent has been used to thionate enones, esters, lactones, amides, lactams, and quinones.
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The main use of Woollins' reagent is the selenation of carbonyl compounds. For instance, Woollins' reagent will convert a carbonyl into a selenocarbonyl. Additionally, Woollins' reagent has been used to selenonate carboxylic acids, alkenes, alkynes, and nitriles.
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A "tooth" of the hydnoid fungus Auriscalpium vulgare, stained with Melzer's reagent Melzer's reagent (also known as Melzer's solution or informally as Melzer's) is a chemical reagent used by mycologists to assist with the identification of fungi.
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The main area of application is the synthesis of synthetically challenging organic structures such as macrocycles and heterometallacycles. Rosenthal's reagent allows the selective preparation of these compounds with high yields. Currently, Rosenthal's reagent is often used instead of Negishi's reagent (1-butene)zirconocene to generate zirconocene fragments as it offers a number of compelling advantages. Unlike Negishi's reagent, Rosenthal's reagent is stable at room temperature and can be stored indefinitely under an inert atmosphere.
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Mephedrone does not react with most reagent testing kits. The exception is the Liebermann reagent, which gives a bright yellow reaction.
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Woollins' reagent is an organic compound containing phosphorus and selenium. Analogous to Lawesson's reagent, it is used mainly as a selenation reagent. It is named after Professor John Derek Woollins, who is currently the Provost of Khalifa University, Abu Dhabi.
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This reagent is part of the Lowry protein assay, and will also react with some nitrogen-containing compounds such as hydroxylamine and guanidine. The reagent has also been shown to be reactive towards thiols, many vitamins, the nucleotide base guanine, the trioses glyceraldehyde and dihydroxyacetone, and some inorganic ions. Copper complexation increases the reactivity of phenols towards this reagent. This reagent is distinct from Folin's reagent, which is used to detect amines and sulfur-containing compounds.
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The reagent is prepared from trimethylsilyl chloride and bromotrifluoromethane in the presence of a phosphorus(III) reagent that serves as a halogen acceptor.
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The reagent is soluble in common organic solvents and alcohol dehydration takes place with syn elimination through an intramolecular elimination reaction. The Burgess reagent is a carbamate and an inner salt. A general mechanism is shown below. :General Mechanism for the Burgess reagent.
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Yousif has published many new reactions of Lawesson's reagent. Prof T. B. Rauchfuss, who is in the United States did some very important work on Lawesson's reagent. He did the 31P NMR experiment which proved that Lawesson's reagent could form the dithiophosphine ylides in solution.
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An acidic solution of mercury sulfate is known as Denigés' reagent. It was commonly used throughout the 20th century as a qualitative analysis reagent. If Denigés' reagent is added to a solution containing compounds that have tertiary alcohols, a yellow or red precipitate will form.
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Many derivatives of early metal metallocenes are active catalysts for olefin polymerization. Unlike traditional and still dominant heterogeneous Ziegler–Natta catalysts, metallocene catalysts are homogeneous. Early metal metallocene derivatives, e.g. Tebbe's reagent, Petasis reagent, and Schwartz's reagent are useful in specialized organic synthetic operations.
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Thiones are usually prepared from ketones using reagents that exchange S and O atoms. A common reagent is phosphorus pentasulfide and the related reagent Lawesson's reagent. Other methods uses a mixture of hydrogen chloride combined with hydrogen sulfide. Bis(trimethylsilyl)sulfide has also been employed.
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Electrons entering the source with energy around 200-500 eV will preferentially ionize the reagent gas. Then, the ion/molecule reactions produces more stable reagent ions and the resultant collisions with other reagent gas molecules will create an ionization plasma. Positive and negative ions of the analyte are formed by reactions with this plasma. The following reactions are possible with methane as the reagent gas.
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The inability of Fétizon's reagent to oxidize tertiary alcohols makes it extremely useful in the monooxidation of a [1,2] diol in which one of the alcohols is tertiary while avoiding cleavage of the carbon-carbon bond. Fetizon's reagent oxidizes secondary alcohols selectively in the presence of tertiary alcohols The mildness and structural sensitivity of the reagent also makes this reagent ideal for the monooxidation of a symmetric diol. Fetizon's reagent is capable of monooxidizing a symmetric diol Lactols are extremely sensitive to Fétizon's reagent, being oxidized very quickly to a lactone functionality. This allows for the selective oxidation of lactols in the presence of other alcohols.
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The high reagent specificity can be a problem, however, as it often requires that a wide range of biocatalysts be screened before an effective reagent is found.
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Although syntheses using the isolated Tebbe reagent give a cleaner product, successful procedures using the reagent "in situ" have been reported. Instead of isolating the Tebbe reagent, the solution is merely cooled in an ice bath or dry ice bath before adding the starting material. An alternative but less convenient synthesis entails the use of dimethyltitanocene (Petasis reagent): ::Cp2Ti(CH3)2 \+ Al(CH3)2Cl -> Cp2TiCH2AlCl(CH3)2 \+ CH4 One drawback to this method, aside from requiring Cp2Ti(CH3)2, is the difficulty of separating product from unreacted starting reagent.
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A dialkyltitanium species is implicated for Ti-promoted cyclopropanations starting from a Grignard reagent and an ester. This reaction is the basis of the Kulinkovich reaction: Kulinkovich reaction "Lombardo's reagent" is used for methylenation.. It is functionally related to the Dibromomethane-Zinc-Titanium(IV) Chloride reagent. This chemistry addresses a shortcoming of the Wittig reagent by methylenating enolisable carbonyl groups without loss of stereochemical integrity (Lombardo Methylenation). It can for example also be applied in a conversion of a ketene into an allene: :Reaction of the Lombardo reagent.
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The Tebbe reagent converts esters and lactones to enol ethers and amides to enamines. In compounds containing both ketone and ester groups, the ketone selectively reacts in the presence of one equivalent of the Tebbe reagent. :500px The Tebbe reagent methylenates carbonyls without racemizing a chiral α carbon. For this reason, the Tebbe reagent has found applications in reactions of sugars where maintenance of stereochemistry can be critical.
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Since bent metallocenes typically have other ligands, often halides, these additional sites are centers of reactivity. For example, reduction of zirconacene dichloride gives the corresponding hydrido chloride called Schwartz's reagent: :(C5H5)2ZrCl2 \+ 1/4 LiAlH4 → (C5H5)2ZrHCl + 1/4 "LiAlCl4" This hydride reagent is useful for organic synthesis. Related titanium-based complexes Petasis reagent and Tebbe's reagent also feature bent metallocenes. Titanocene pentasulfide is used in research on polysulfur rings.
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Sodium trifluoromethanesulfinate (CF3SO2Na) is the sodium salt of trifluoromethanesulfinic acid. Together with t-butyl hydroperoxide, an oxidant, this compound was found to be a suitable reagent for introducing trifluoromethyl groups onto electron-rich aromatic compounds by Langlois; this reagent is also known as the Langlois reagent. This reaction operates via a free radical mechanism. This reagent is also able to trifluoromethylate electron-deficient aromatic compounds under biphasic conditions.
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Schwartz's reagent will selectively reduce the amide over any readily reducible esters that may be present in the reaction mixture. Vinylation of ketones in high yields is a possible use of Schwartz's reagent. Schwartz's reagent is used in the synthesis of some macrolide antibiotics, (−)-motuporin, and antitumor agents.
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The Comins' reagent is a triflyl-donating reagent that is used to synthesize vinyl triflates from the corresponding ketone enolates or dienolates. Sample Reaction With Comin's Reagent It was first reported in 1992 by Daniel Comins. The vinyl triflates prepared are useful as substrates in the Suzuki reaction.
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Stryker's reagent ([(PPh3)CuH]6), also known as the Osborn complex, is a hexameric copper hydride ligated with triphenylphosphine. It is a brick red, air-sensitive solid. Stryker's reagent is a mildly hydridic reagent, used in homogeneous catalysis of conjugate reduction reactions of enones, enoates, and related substrates.
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Lawesson's reagent, or LR, is a chemical compound used in organic synthesis as a thiation agent. Lawesson's reagent was first made popular by Sven-Olov Lawesson, who did not, however, invent it. Lawesson's reagent was first made in 1956 during a systematic study of the reactions of arenes with P4S10.
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Berthelot's reagent is an alkaline solution of phenol and hypochlorite, used in analytical chemistry. It is named after its inventor, Marcellin Berthelot. Ammonia reacts with Berthelot's reagent to form a blue product which is used in a colorimetric method for determining ammonia. The reagent can also be used for determining urea.
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In thin layer chromatography (TLC) color reactions are frequently used to detect compound spots by dipping the plate into the reagent or by spraying the reagent onto the plates.
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The reagent is sold by Sigma-Aldrich by the name TRI Reagent; by Invitrogen under the name TRIzol; by Bioline as Trisure; and by Tel-Test as STAT-60.
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"Nysted Reagent." Comprehensive Organic Name Reactions and Reagents. 2010; John Wiley and Sons, Inc. In the Nysted olefination, the Nysted reagent reacts with TiCl4 to methylenate a carbonyl group.
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Ishikawa's reagent is a mixture of N,N-diethyl-(1,1,2,3,3,3-hexafluoropropyl)amine (left) and N,N-diethyl-(E)-pentafluoropropenylamine (right) Ishikawa's reagent is a fluorinating reagent used in organic chemistry. It is used to convert alcohols into alkyl fluorides and carboxylic acids into acyl fluorides. Aldehydes and ketones do not react with it. The reagent consists of a mixture of N,N-diethyl-(1,1,2,3,3,3-hexafluoropropyl)amine and N,N-diethyl-(E)-pentafluoropropenylamine in varying proportions.
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The Folin–Ciocâlteu reagent (FCR) or Folin's phenol reagent or Folin–Denis reagent, also called the gallic acid equivalence method (GAE), is a mixture of phosphomolybdate and phosphotungstate used for the colorimetric in vitro assay of phenolic and polyphenolic antioxidants. It is named after Otto Folin, Vintilă Ciocâlteu, and Willey Glover Denis. Absorbance of different concentrations of tyrosine reacted with Folin-Ciocalteu's reagent are detected at 660 nm The reagent does not measure only phenols, but will react with any reducing substance. It therefore measures the total reducing capacity of a sample, not just phenolic compounds.
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Mayer's reagent is an alkaloidal precipitating reagent used for the detection of alkaloids in natural products. Mayer’s reagent is freshly prepared by dissolving a mixture of mercuric chloride (1.36 g) and of potassium iodide (5.00 g) in water (100.0 ml). Most alkaloids are precipitated from neutral or slightly acidic solution by Mayer’s reagent (potassiomercuric iodide solution) to give a cream coloured precipitate. This test was invented by the German Chemist, Julius Robert Von Mayer (1814-1878).
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Methoxymethylenetriphenylphosphine is a Wittig reagent used as a reagent in the homologization of aldehydes and ketones to extended aldehydes, an organic reaction first reported in 1958 . This reagent is quite unstable to even mild temperatures and water. As such it must be made in situ, taking on a blood red color, indicative of destabilized ylides.
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This reagent is useful for the conversion of esters into vinyl ethers. The Tebbe reagent Cp2TiCl(CH2)Al(CH3)2, arises by the action of 2 equivalents Al(CH3)3 on Cp2TiCl2.
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Tris(pentafluorophenyl)borane is prepared using a Grignard reagent derived from bromopentafluorobenzene: :3 C6F5MgBr + BCl3 → (C6F5)3B + 3MgBrCl Originally the synthesis employed C6F5Li, but this reagent can detonate with elimination of LiF.
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Tris(2,2,2-trifluoroethyl) borate, also commonly referred to as the Sheppard amidation reagent, is a chemical compound with the formula B(OCH2CF3)3. This borate ester reagent is used in organic synthesis.
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2005, 2, 231–250. (Review) This conversion can also be effected using the Wittig reaction, although the Tebbe reagent is more efficient especially for sterically encumbered carbonyls. Furthermore, the Tebbe reagent is less basic than the Wittig reagent and does not give the β-elimination products. Methylenation reactions also occur for aldehydes as well as esters, lactones and amides.
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The Burgess reagent (methyl N-(triethylammoniumsulfonyl)carbamate) is a mild and selective dehydrating reagent often used in organic chemistry. It was developed in the laboratory of Edward M. Burgess at Georgia Tech. The Burgess reagent is used to convert secondary and tertiary alcohols with an adjacent proton into alkenes. Dehydration of primary alcohols does not work well.
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Schweizer's reagent was once used in production of cellulose products such as rayon and cellophane. Cellulose, which is quite insoluble in water (hence its utility as clothing), dissolves in the presence of Schweizer's reagent. Using the reagent, cellulose can be extracted from wood pulp, cotton fiber, and other natural cellulose sources. Cellulose precipitates when the solution is acidified.
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Trifluoromethyltrimethylsilane (known as Ruppert-Prakash reagent, TMSCF3) is an organosilicon compound with the formula CF3Si(CH3)3. It is a colorless liquid. The compound is a reagent used in organic chemistry for the introduction of the trifluoromethyl group. The compound was first prepared in 1984 by Ingo Ruppert and further developed as a reagent by G. K. Surya Prakash.
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Oxidation of an alcohol to aldehyde with the Collins reagent. As a base, pyridine can be used as the Karl Fischer reagent, but it is usually replaced by alternatives with a more pleasant odor, such as imidazole. Pyridinium chlorochromate, pyridinium dichromate, and the Collins reagent (the complex of chromium(VI) oxide are used for the oxidation of alcohols.
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2-Iminothiolane is a cyclic thioimidate compound also known as Traut's reagent. It is a thiolating reagent that reacts with primary amine groups, such as those of amino acids, to form sulfhydryl groups.
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It reacts with magnesium to give the corresponding Grignard reagent.
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While tertiary alcohols are typically not affected by Fétizon's reagent, tertiary propargylic alcohols have been shown to oxidize under these conditions and results in the fragmentation of the alcohol with an alkyne leaving group. A tertiary propargylic alcohol is fragmented upon treatment with Fetizon's reagent Halohydrins that possess a trans stereochemistry have been demonstrated to form epoxides and transposed products in the presence of Fétizon's reagent. Halohydrins possessing a cis- stereochemistry seem to perform a typical Fétizon's oxidation to a ketone. Trans-halohydrins can transpose or form epoxides upon treatment with Fetizon's reagent [1,3] diols have a tendency to eliminate water following the monooxidation by Fétizon's reagent to form an enone.
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The limiting reagent (or limiting reactant or limiting agent) in a chemical reaction is a reactant that is totally consumed when the chemical reaction is completed. The amount of product formed is limited by this reagent, since the reaction cannot continue without it. If one or more other reagents are present in excess of the quantities required to react with the limiting reagent, they are described as excess reagents or excess reactants (xs). The limiting reagent must be identified in order to calculate the percentage yield of a reaction since the theoretical yield is defined as the amount of product obtained when the limiting reagent reacts completely.
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This is also similar to CI and the difference lies in the production of a radical cation with an odd number of electrons. The reagent gas molecules are bombarded with high energy electrons and the product reagent gas ions abstract electrons from the analyte to form radical cations. The common reagent gases used for this technique are toluene, benzene, NO, Xe, Ar and He. Careful control over the selection of reagent gases and the consideration toward the difference between the resonance energy of the reagent gas radical cation and the ionization energy of the analyte can be used to control fragmentation. The reactions for charge-exchange chemical ionization are as follows.
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Compared with the Wittig reagent, it has more functional group tolerance.
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This reagent has recently been improved considerably by inclusion of acetone.
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N,N′-Dimethyl-1,3-propanediamine (DMPA) is a chemical crosslinking reagent.
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Ehrlich's reagent is also used as a stain in thin layer chromatography and as a reagent to detect urobilinogen in fresh, cool urine. If a urine sample is left to oxidize in air to form urobilin the reagent will not detect the urobilinogen. By adding few drops of reagent to 3 mL of urine in a test tube one can see a change of color, to dark pink or red. The degree of color change is proportional to the amount of urobilinogen in the urine sample.
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If we have high levels of bilirubin in the blood, the Van den Bergh chemical reaction is used to determine if the bilirubin is conjugated or unconjugated. Azobilirubin can also be used to determine how much conjugated bilirubin is the blood compared to that of unconjugated bilirubin. This process is done by using both forms of bilirubin alongside a diazo reagent and a caffeine-benzoate reagent. Conjugated bilirubin with the azo reagent will react, whilst the unconjugated bilirubin will not react with the azo reagent.
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The original Collins oxidation calls for the Sarett reagent to be removed from the excess pyridine and dissolved in the less basic methylene chloride. While the new solvent improves the overall yield of the reaction, it also requires the dangerous transfer of the pyrophoric reagent. The 1970 Ratcliffe variation reduced the risk of explosion by calling for the Sarett reagent to be made in situ. This was achieved by creating the Sarett reagent according to the original protocol using a stirred mixture of pyridine and methylene chloride.
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The Petasis reagent is prepared by the salt metathesis reaction of methylmagnesium chloride or methyllithium with titanocene dichloride: : Cp2TiCl2 \+ 2 CH3MgCl -> Cp2Ti(CH3)2 \+ 2 MgCl2 This compound is used for the transformation of carbonyl groups to terminal alkenes. It exhibits similar reactivity to the Tebbe reagent and Wittig reaction. Unlike the Wittig reaction, the Petasis reagent can react with a wide range of aldehydes, ketones and esters. The Petasis reagent is also very air stable, and is commonly used in solution with toluene or THF.
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Dimethyl (diazomethyl)phosphonate can be generated in situ from dimethyl-1-diazo-2-oxopropylphosphonate (also called the Ohira-Bestmann reagent) by reaction with methanol and potassium carbonate. Reaction of Bestmann's reagent with aldehydes gives terminal alkynes often in very high yield. Bestmann's reagent The use of the milder potassium carbonate makes this procedure much more compatible with a wide variety of functional groups.
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Millon's reagent is an analytical reagent used to detect the presence of soluble proteins. A few drops of the reagent are added to the test solution, which is then heated gently. A reddish-brown coloration or precipitate indicates the presence of tyrosine residue which occur in nearly all proteins. The test was developed by the French chemist Auguste Nicolas Eugene Millon (1812-1867).
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Synthesizing Rosenthal's reagent of a titanocene source yields golden-yellow crystals of the titanocene bis(trimethylsilyl)acetylene complex with a melting point of 81–82 °C. This reagent enables the generation of the themselves unstable titanocene and zirconocene under mild conditions. The reagent is named after the German chemist (born 1950) and was first synthesized by him and his co-workers in 1995.
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Vilsmeier reagent is the active intermediate in the formylation reactions, the Vilsmeier reaction or Vilsmeier-Haack reaction that use mixtures of dimethylformamide and phosphorus oxychloride to generate the Vilsmeier reagent, which in turn attacks a nucleophilic substrate and eventually hydrolyzes to give formyl. It is a source of "O=CH+". Pathway for formation of Vilsmeier reagent and its mode of action.
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Although the Sarett reagent gives good yields of ketones, its conversion of primary alcohols is less efficient. Furthermore, the isolation of products from the reaction solution can be difficult. These limitations were partially addressed with the introduction of the Collins oxidation. The active ingredient in both the Sarett reagent is identical to that in the so-called "Collins reagent", i.e.
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A CI experiment involves the use of gas phase acid-base reactions in the chamber. Ions are produced through the collision of the analyte with ions of a reagent gas that are present in the ion source. Some common reagent gases include: methane, ammonia, water and isobutane. Inside the ion source, the reagent gas is present in large excess compared to the analyte.
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PyBOP (benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate) is a peptide coupling reagent used in solid phase peptide synthesis. It is used as a substitute for the BOP reagent - avoiding the formation of the carcinogenic waste product HMPA.
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Diethylaluminum cyanide ("Nagata's reagent") is the organoaluminum compound with formula ((C2H5)2AlCN)n. This colorless compound is usually handled as a solution in toluene. It is a reagent for the hydrocyanation of α,β-unsaturated ketones.
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Tollens' test for aldehyde: left side positive (silver mirror), right side negative Ball-and-stick model of the diamminesilver(I) complex Tollens' reagent is a chemical reagent used to determine the presence of aldehyde and aromatic aldehyde functional groups along with some alpha-hydroxy ketone which can tautomerize into aldehyde. The reagent consists of a solution of silver nitrate, ammonia and some sodium hydroxide (to maintain a basic pH of the reagent solution). It was named after its discoverer, the German chemist Bernhard Tollens. A positive test with Tollens' reagent is indicated by the precipitation of elemental silver, often producing a characteristic "silver mirror" on the inner surface of the reaction vessel.
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An oxygen-sensitive colourless solid, it is a reagent in organometallic and organic chemical research. The dioxane solvated sodium salt is known as Collman's reagent, in recognition of James P. Collman an early popularizer of its use.
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Para-methoxybenzyl (PMB) is a commonly used protecting group for alcohols against Fétizon's reagent. As Fétizon's oxidation is a neutral reaction, acid and base sensitive protecting groups are also compatible with the reagent and by products generated.
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Either geometric isomer of this compound may be prepared by preparing by brominating 5-octene-1-ol, then preparing the appropriate Grignard reagent. Triethyl orthoformate is treated with this Grignard reagent, then hydrolyzed to give 6-nonenal.
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Barfoed's reagent consists of a 0.33 molar solution of copper (II) acetate in 1% acetic acid solution. The reagent does not keep well and it is therefore advisable to make it up when it is actually required.
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Ehrlich's reagent is similar but uses ethyl alcohol or 1-propyl alcohol.
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Carpronium chloride (INN) is a hair growth reagent with a vasodilatory action.
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The Stanbio Single Reagent Glucose Method is based upon the Trinder technique.
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Subseqent to the conversion to the Sarett reagent, it is immediately used.
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It is also a reagent in the synthesis of various pharmaceutical intermediates.
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On the other hand, in the presence of TiCl4, TiCl3 or TiCl2 and BF3•OEt2, the reagent can methylenate ketones. Most commonly, it is used to methylenate ketones because of their general difficulty to methylenate due to crowding around the carbonyl group. The Nysted reagent is able to overcome the additional steric hindrance found in ketones, and more easily methylenate the carbonyl group. There is little research on Nysted reagent because of the hazards and high reactivity and the difficulty of keeping the reagent stable while it is in use.
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The reagent competes with the carbonyl for the reactive intermediate, rapidly sequestering [CF3]− in a reversibly-generated -ate complex [(CF3)2Si(CH3)3]−. This -ate complex is unable to react directly with the carbonyl, resulting in powerful inhibition of the chain reaction by the reagent. This inhibitory process is common to all anion-initiated reactions of the reagent, with the identity of the counter- cation (M+) playing a major role in controlling the overall rate. The reagent has largely supplanted trifluoromethyllithium, which is not isolable and rapidly decomposes to yield lithium fluoride and difluorocarbene.
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In kinetic nephelometry, the rate of scatter is measured right after the reagent is added. As long as the reagent is constant the rate of change can be seen as directly related to the amount of antigen present.
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Bis(pyridine)iodonium(I) tetrafluoroborate or Barluenga's reagent, named after José Barluenga, is a mild iodinating reagent. Commercially available, it may be prepared by reacting iodine with pyridine in the presence of silver tetrafluoroborate supported on silica gel.
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Tetramethylazodicarboxamide (also known as TMAD and diamide) is a reagent used in biochemistry for oxidation of thiols in proteins to disulfides. It has also been used as a reagent in the Mitsunobu reaction in place of diethyl azodicarboxylate.
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This means that for a kit with 100 columns, you end up with enough reagent for another 10 to 15 preps after you run out of columns. Normally, this excess reagent is tossed out. UPrep columns allow you to use this extra reagent for additional preps. Genesee Scientific has also been responsible for developing Blue Devil autoradiography filmDell, Emily A., Bowman, Daniel, Rufty, Thomas, Shi, Wei.
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Upon oxidation with Fetizon's reagent, a 1,3 diol may eliminate water to produce an enone Under differing structural conditions, [1,2] diols can form diketones in the presence of Fétizon's reagent. However, oxidative carbon-carbon bond cleavage may also occur.
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In Ellman's original paper, he prepared this reagent by oxidizing 2-nitro-5-chlorobenzaldehyde to the carboxylic acid, introducing the thiol via sodium sulfide, and coupling the monomer by oxidization with iodine. Today, this reagent is readily available commercially.
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Selectfluor reagent also serves as a strong oxidant, a property that is useful in other reactions in organic chemistry. Oxidation of alcohols and phenols. As applied to electrophilic iodination, Selectfluor reagent activates the I–I bond in I2 molecule.
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In these reactions Thorium (IV) Chloride is the initial reagent but it is first changed into ThCl4(DME)2. ThCl4(DME)2 is a versatile reagent that can be converted into ThCl4(TMEDA)2, ThBr4(DME)2.and others.
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For example, it is an effective reagent for the desulfurization of organic disulfides.
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Alternative methods are based on ortho- Phthalaldehyde (OPA), Ellman's reagent (DTNB) and epicocconone.
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Tetrahydroxydiboron is a chemical reagent which can be used to prepare boronic acids.
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Mukulesh Mondal "Sodium methylsulfinylmethylide: A versatile reagent" Synlett 2005, vol. 17, 2697-2698.
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Indigo dye is a product of the reaction of indoxyl by a mild oxidizing agent such as atmospheric oxygen. Indoxyl can be found in urine and is titrated with Obermayer's reagent. Obermayer's reagent is a dilute solution FeCl3 in hydrochloric acid.
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While several different routes to the 1,3,2,4-dithiadiphosphetane 2,4-disulfides exist the most commonly used is the electrophilic aromatic substitution reaction of an arene with PS. An alternative reaction is the reaction of a thiol with PS to form a substance like the Davy reagent. The Davy reagent is identical to Lawesson's reagent except in place of the para-methoxyphenyl groups it has aryl sulfide groups. While the Davy reagent is more soluble than the Lawesson's reagent it is likely that the very vile nature of the thiol starting material is likely to make the synthesis of this compound not worth the trouble. In both the patent and academic chemical literature are examples of 1,3,2,4-dithiadiphosphetane 2,4-disulfides with higher solubilities.
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The disadvantage of the accelerators is that they may simultaneously promote several oxidation routes thereby reducing the selectivity of the reaction. In its chemical structure and functions, the Cornforth reagent is closely related to other pyridinium salts of hexavalent chromium oxide, such as pyridinium chlorochromate [PyH][CrO3Cl] and to pyridine complexes such as the Collins reagent, CrO3·2Py in dichloromethane and the Sarret reagent, CrO3·2Py in pyridine.
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There are five primary color-tests reagents used for general screening purposes. The Marquis reagent turns into a variety of colors when in the presence of different substances. Dille-Koppanyi reagent uses two chemical solutions which turns a violet-blue color in the presence of barbiturates. Duquenois-Levine reagent is a series of chemical solutions that turn to the color of purple when the vegetation of marijuana is added.
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Sodium trifluoroacetate is a useful reagent for trifluoromethylation. :The trifluoromethylation process with sodium trifluoroacetate.
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It can be prepared by carboxylation of the Grignard reagent generated from 1-Bromonaphthalene.
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In the heyns oxidation the oxidizing reagent is a combination of oxygen and platinum.
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This also allows for a classic use of Fétizon's reagent to form lactones from a primary diol. By oxidizing one of the alcohols to an aldehyde, the second alcohol equilibrates with the aldehyde to form a lactol which is reacted quickly with more Fétizon's reagent to trap the cyclic intermediate as a lactone. This method allows for the synthesis of seven-member lactones which are traditionally more challenging to synthesize. Fetizon's reagent oxidize lactols into lactones Treatment of a terminal diol with Fetizon's reagent can result in lactone formation Phenol functional groups can be oxidized to their respective quinone forms.
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Caps range in size from narrow mouthed to wide mouthed and often a glass or plastic funnel is needed to properly fill a reagent bottle from a larger or equal sized container's mouth. Reagent bottle caps are commonly said to be "autoclavable". Antique or vintage reagent bottles tend to resemble the classic apothecary bottle and have a glass stopper, very often not of standard size, so that very old bottles and samples should be stored with care, as replacing a missing glass stopper would require dedicated glassworking. Reagent bottles are subject to OSHA regulations, and global scientific standards.
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The active species is the hexafluoropropylamine; any enamine is converted into this by the hydrogen fluoride byproduct as the reaction proceeds. Ishikawa's reagent is a popular alternative to the DAST reagent, since it is shelf-stable and easily prepared from inexpensive and innocuous reagents. It is an improvement on Yarovenko's reagent, the adduct of chlorotrifluoroethylene and diethylamine, which must be prepared in a sealed vessel and once prepared keeps only for a few days, even in the refrigerator. The reagent is mostly used to convert primary alcohols to alkyl fluorides under mild conditions with high yield.
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More specifically, it can form explosive peroxides when exposed to air and is extremely flammable. Also, it reacts violently with water. These make this reagent very dangerous to work with.Nysted Reagent. MSDS No.381985; Sigma-Aldrich; St. Louis, MO, April 3, 2009.
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In peptide coupling the BOP reagent works well because it forms reactive intermediates which allow for the amines to bond together with little energy loss. In the reduction of carboxylic acids using the BOP reagent with NaBH4 resulted in high percent yields.
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Selenium monochloride is mainly used as a reagent for the synthesis of Se-containing compounds.
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This reagent is used in the confirmation of E. coli and many other pathogenic microorganisms.
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Silver iodide is used as a reagent. The base is at Maribor Edvard Rusjan Airport.
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The spores are large, thick-walled, and display a variable dextrinoid reaction to Melzer's reagent.
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Trimethylsilyl azide ((CH3)3SiN3) is a chemical compound used as a reagent in organic chemistry.
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Isopropyl alcohol is esterified to give isopropyl acetate, another solvent. It reacts with carbon disulfide and sodium hydroxide to give sodium isopropylxanthate, a herbicide and an ore flotation reagent. Isopropyl alcohol reacts with titanium tetrachloride and aluminium metal to give titanium and aluminium isopropoxides, respectively, the former a catalyst, and the latter a chemical reagent. This compound may serve as a chemical reagent in itself, by acting as a dihydrogen donor in transfer hydrogenation.
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Dithiothreitol (DTT) is the common name for a small-molecule redox reagent also known as Cleland's reagent. DTT's formula is C4H10O2S2 and the chemical structure of one of its enantiomers in its reduced form is shown on the right; its oxidized form is a disulfide bonded 6-membered ring (shown below). The reagent is commonly used in its racemic form, as both enantiomers are reactive. Its name derives from the four-carbon sugar, threose.
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Lawesson's reagent has a four membered ring of alternating sulfur and phosphorus atoms. With heating, the central phosphorus/sulfur four-membered ring can open to form two reactive dithiophosphine ylides (R-PS2). Much of the chemistry of Lawessons's reagent is in fact the chemistry of these reactive intermediates. :300px In general, the more electron rich a carbonyl is, the faster the carbonyl group will be converted into the corresponding thiocarbonyl by Lawesson's reagent.
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These tests are widely available and affordable. The use of several reagents is generally necessary to positively identify a substance with Marquis, Mandelin, and Mecke reagents being used to detect MDMA and Ehrlich's reagent common for detecting LSD. However, reagent testing only indicates the presence of a substance, not the absence of contaminants or other substances. This can provide a false sense of security when illicit drugs are deliberately adulterated to fool reagent tests.
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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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An example hydroxylation reaction involves the oxidation of barbituric acid to alloxane. Another application of the reagent in organic synthesis is in coupling reactions of alkanes. As an example tert-butanol is dimerized with Fenton's reagent and sulfuric acid to 2,5-dimethyl-2,5-hexanediol.
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Gunzberg's test is a chemical test used for detecting the presence of hydrochloric acid. Gunzberg's reagent is made by dissolving two grams of phloroglucinol and one gram of vanillin in 100 millilitres of 95% ethanol. Hydrochloric acid catalyses Gunzberg's reagent to form a red complex.
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The cis isomer is used primarily as a reagent for the synthesis of other platinum compounds.
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In immunology, an MHC pentamer is a reagent used to detect antigen-specific CD8+ T cells.
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Sulfur chloride pentafluoride is the only commercially available reagent for adding the group to organic compounds.
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Nitrous acid is the main chemphore in the Liebermann reagent, used to spot-test for alkaloids.
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Treatment of this tertiary alcohol with the Burgess reagent (32) gave exocyclic alkene 33. Scheme 3.
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Pimeloyl chloride is a di-acyl chloride. It is used as a reagent in organic synthesis.
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Trifluoromethanesulfonyl azide or triflyl azide is an organic azide used as a reagent in organic synthesis.
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Reagent Chemicals is a publication of the American Chemical Society (ACS) Committee on Analytical Reagents, detailing standards of purity for over four hundred of the most widely used chemicals in laboratory analyses and chemical research. Chemicals that meet this standard may be sold as “ACS Reagent Grade” materials. These standards relieve working chemists of concerns about how pure their chemicals are: if they order “ACS Reagent Grade,” they are assured of consistent purity, no matter which supplier they order from. ACS Reagent Grade chemicals can also be used for procedures that require stringent quality specifications and a purity of equal to or greater than 95% .
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Denigés' reagent is used to detect isolefin or tertiary alcohols which can be easily dehydrated to form isoolefin in the presence of acid. Treatment of solutions containing either isolefin or tertiary alcohols with this reagent will result in the formation of a solid yellow or red precipitate.
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Phenyl isothiocyanate (PITC) is a reagent used in reversed phase HPLC. PITC is less sensitive than o-phthaldehyde (OPA) and cannot be fully automated. PITC can be used for analysing secondary amines, unlike OPA. It is also known as Edman's reagent and is used in Edman degradation.
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Propyne is a convenient three-carbon building block for organic synthesis. Deprotonation with n-butyllithium gives propynyllithium. This nucleophilic reagent adds to carbonyl groups, producing alcohols and esters. Whereas purified propyne is expensive, MAPP gas could be used to cheaply generate large amounts of the reagent.
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Owing to the important role of titanium compounds as polymerization catalyst, compounds with Ti-C bonds have been intensively studied. The most common organotitanium complex is titanocene dichloride ((C5H5)2TiCl2). Related compounds include Tebbe's reagent and Petasis reagent. Titanium forms carbonyl complexes, e.g. (C5H5)2Ti(CO)2.
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Fehling's solution is a chemical reagent used to differentiate between water- soluble carbohydrate and ketone functional groups, and as a test for reducing sugars and non-reducing sugars, supplementary to the Tollens' reagent test. The test was developed by German chemist Hermann von Fehling in 1849.
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Henry John Horstman Fenton (18 February 1854 – 13 January 1929) was a British chemist who, in the 1890s invented Fenton's reagent,Fenton's Reagent Definition Page at toxics.usgs.gov a solution of hydrogen peroxide and an iron catalyst that is used to oxidize contaminants or waste waters. Fenton's reagent can be used to destroy organic compounds such as trichloroethylene (TCE) and tetrachloroethylene (PCE). Born in London, Henry Fenton was educated at Magdalen College School, King's College London and Christ's College, Cambridge.
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In case of the above mentioned Turbo-Hauser bases where the alkyl group of a Grignard is replaced by an amido group (R = R'2N−) this hypothesis could not be confirmed because no SSIP [Li(THF)4]+ was detectable. LiCl has been shown to increase solubility of RZnX reagent as well. Without LiCl, organozinc reagent remains on surface of zinc particle. With LiCl organozinc reagent forms a RZnX-LiCl complex, which is more soluble in THF.
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For instance the reaction of para-nitrophenolate would form a compound similar to parathion. Lawesson's reagent has been used as a starting material for a herbicide by reaction with a 1-alkoxy-2,3-dihydroxy propane. This formed a compound which could be used to kill plants. This reaction of a 1,2-diol with lawesson's reagent results in a symmetric breaking of the PS ring, both halves of the lawesson's reagent end up being converted to the same product.
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Microscopically, the fungus is characterized by the almost negative reaction of the skeletal hyphae to Melzer's reagent.
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Guanidine can be selectively detected using sodium 1,2-naphthoquinone-4-sulfonic acid (Folin's reagent) and acidified urea.
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They have thin walls, do not react with Melzer's reagent and measure 7–9 × 3–4 µm.
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Use of diazomethane has been significantly reduced by the introduction of the safer and equivalent reagent trimethylsilyldiazomethane.
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The Nysted reagent is a reagent used in organic synthesis for the methenylation of a carbonyl group. It was discovered in 1975 by Leonard N. Nysted in Chicago, Illinois. It was originally prepared by reacting dibromomethane and activated zinc in THF.Nysted, L.N. US Patent, 1975, 3 865 848.
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Bromobenzene is prepared by the action of bromine on benzene in the presence of Lewis acid catalysts such as ferric bromide. Bromobenzene is used to introduce a phenyl group into other compounds. One method involves its conversion to the Grignard reagent, phenylmagnesium bromide. This reagent can be used, e.g.
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Trimethylsilyldiazomethane is the organosilicon compound with the formula (CH3)3SiCHN2. It is classified as a diazo compound. Trimethylsilyldiazomethane is a commercially available reagent used in organic chemistry as a methylating agent and as a source of CH2 group. Its behavior is akin to the less convenient reagent diazomethane.
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Traditional Fenton's reagent applications can be very exothermic when significant iron, manganese or contaminant (i.e. NAPL concentrations) are present in an injection zone. Over the course of the reaction, the groundwater heats up and, in some cases, reagent and vapors can surface out of the soil. Stabilizing the peroxide can significantly increase the residence time and distribution of the reagent while reducing the potential for excessive temperatures by effectively isolating the peroxide from naturally occurring divalent transition metals in the treatment zone.
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In contrast to titanocene itself, titanocene dichloride and to some extent titanocene monochloride have rich and well defined chemistries. Tebbe's reagent, prepared from titanocene dichloride and trimethylaluminium, is used as a methylenation agent (conversion of R2C=O to R2C=CH2). center Tebbe's reagent adds simple alkenes to give titanocyclobutanes, which can be regarded as stable olefin metathesis intermediates. These compounds are reagents in itself such as 1,1-bis(cyclopentadienyl)-3,3-dimethyltitanocyclobutane, the adduct of Tebbe's reagent with isobutene catalysed with 4-dimethylaminopyridine.
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Schwartz's reagent can be used for a number of reactions. It has been shown that it can be used to reduce amides to aldehydes. Reducing tertiary amides with Schwartz's reagent can reach efficient yields, but primary and secondary amides will show decreased yields. The use of Schwartz's reagent in this manner will not require any added heat and can be done quickly, and reduction of the alcohol form is not a problematic side reaction as it can be with other reducing agents.
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Formaldehyde and an 18 M (concentrated) sulfuric acid makes Marquis reagent—which can identify alkaloids and other compounds.
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Because it is non- hygroscopic, potassium dichromate is a common reagent in classical "wet tests" in analytical chemistry.
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Aged reagent can be destroyed with dilute acid to prevent the formation of the highly explosive silver nitride.
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Alternatively, if the analyte itself is an antibody, its target antigen can be used as the binding reagent.
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Cyanogen chloride is a precursor to the sulfonyl cyanides and chlorosulfonyl isocyanate, a useful reagent in organic synthesis.
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Important enol ethers include the reagent 3,4-dihydropyran and the monomers methyl vinyl ether and ethyl vinyl ether.
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Alkenes undergo hydrozirconation in the presence of this reagent, affording functionalized products after quenching with an electrophile.Hart, W.; Schwartz, J. J. Am. Chem. Soc. 1974, 96, 8115. Functional groups containing heteroatoms other than oxygen may also be reduced to the corresponding hydrocarbons in the presence of an alkoxyaluminium hydride reagent.
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For example, sec-BuLi react with carbonyl compounds and esters to form alcohols. With copper(I) iodide sec-BuLi forms lithium di-sec-butylcuprates. The first two reactions can also be accomplished by using sec-butylmagnesium bromide, a Grignard reagent; in fact, the latter is the typical reagent for this purpose.
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Halonium ylides can be prepared from allyl halides and metal carbenoids. After a [2,3]-rearrangement a homoallylhalide is obtained. The active form of Tebbe's reagent is often considered a titanium ylide. Like the Wittig reagent, it is able to replace the oxygen atom on carbonyl groups with a methylene group.
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Dan retrieves the satchel containing West's reagent and notes. As Dan and Megan flee the morgue, one of the reanimated corpses attacks and strangles Megan. Dan takes her to the hospital emergency room and tries to revive her, but she is dead. In despair, he injects her with West's reagent.
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Chlorosulfonyl isocyanate is the chemical compound ClSO2NCO, known as CSI. This compound is a versatile reagent in organic synthesis.
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Bromopyrogallol red is frequently used in analytical chemistry as a reagent for spectrophometric analysis and as an complexometric indicator.
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In nitrile reduction a nitrile is reduced to either an amine or an aldehyde with a suitable chemical reagent.
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This reaction is under review for use as a catalyst for chemical dehalogenation, organic reagent and photosensitized catalyst systems.
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There were also reagent shortages in the United States. Some hospitals manufactured their own reagents from publicly-available recipes.
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Tertiary alcohols lacking an alpha hydrogen are selected against and generally do not oxidize in the presence of Fétizon's reagent. The oxidation of an alcohol with an alpha hydrogen sterically hindered by axial hydrogens proceeds slower with Fetizon's reagent Increasing the amount of celite used in the reagent accelerates the rate of the reaction by increasing the surface area available to react. However, increasing the amount of celite past 900 grams per mole of silver(I) carbonate begins to slow the reaction due to dilution effects.
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These quinones can further couple within solution producing numerous dimerizations depending upon their substituents. Fetizon's reagent oxidizes phenols to quinones which can oxidatively couple to one another Amines have been shown to oxidize in the presence of Fétizon's reagent to enamines and iminium cations that have been trapped, but can also be selected against in a compound with more easily oxidized alcohol functionalities. Fétizon's reagent can also being used to facilitate cycloaddition of a 4-hydroxy-2-furoquinilone and an olefin to form dihydrofuroquinolinones.
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Disulfide reshuffling is generally much faster than oxidation/reduction reactions, which change the number of disulfide bonds within a protein. The oxidation and reduction of protein disulfide bonds in vitro also generally occurs via thiol–disulfide exchange reactions. Typically, the thiolate of a redox reagent such as glutathione or dithiothreitol attacks the disulfide bond on a protein forming a mixed disulfide bond between the protein and the reagent. This mixed disulfide bond when attacked by another thiolate from the reagent, leaves the cysteine oxidized.
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Tebbe's reagent itself does not react with carbonyl compounds, but must first be treated with a mild Lewis base, such as pyridine, which generates the active Schrock carbene. :Tebbe reagent equilib Also analogous to the Wittig reagent, the reactivity appears to be driven by the high oxophilicity of Ti(IV). The Schrock carbene (1) reacts with carbonyl compounds (2) to give a postulated oxatitanacyclobutane intermediate (3). This cyclic intermediate has never been directly isolated, presumably because it breaks down immediately to the produce the desired alkene (5).
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Steven M. Weinreb (born May 10, 1941) is an American chemist and is a professor of chemistry at Pennsylvania State University in United States. Together with Steven Nahm, he developed the Weinreb ketone synthesis, which allows for mono-addition of an organometallic reagent such as a Grignard reagent or organolithium reagent to an amide. Weinreb received his PhD for work with Marshall Gates at the University of Rochester in 1967. After post- docs with Gilbert Stork and George H. Buchi, he worked at Fordham University.
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Zinc–copper couple is an alloy of zinc and copper that is employed as a reagent in organic synthesis. The “couple” was popularized after the report by Simmons and Smith in 1959 of its application as an activated source of zinc required for formation of an organozinc reagent in the Simmons–Smith cyclopropanation of alkenes. The couple has been widely applied as a reagent in other reactions requiring activated zinc metal. Zinc–copper couple does not refer to a rigorously defined chemical structure or alloy composition.
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The first reported syntheses of ferrocene were nearly simultaneous. Pauson and Kealy synthesised ferrocene using iron(III) chloride and a Grignard reagent, cyclopentadienyl magnesium bromide. Iron(III) chloride is suspended in anhydrous diethyl ether and added to the Grignard reagent. A redox reaction occurs, forming the cyclopentadienyl radical and iron(II) ions.
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Kovac's reagent consist of amyl alcohol and para-dimethylaminobenzaldehyde and concentrated hydrochloric acid. Kovac's reagent is actually used to determine ability of an organism to separate indole from amino acid tryptophan and it is added after incubation. A positive result is indicated by a pink/red layer forming on top of the liquid.
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The reagent is used for synthetic reactions wherein medium- and large-sized lactones are formed from hydroxycarboxylic acids via intramolecular ring closure (Shiina macrolactonization). The reaction proceeds at room temperature under basic or neutral conditions. This reagent can be used not only for macrolactonization but also for esterification, amidation, and peptide coupling.
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"California Mastitis Test" , Milking Management, retrieved 2008-11-18 A special reagent for the test is marketed under the name 'CMT-Test', but domestic detergents are frequently used instead, being cheaper and more readily available. Fairy Liquid is as suitable as a reagent for the CMT, although many cheaper detergents are not.
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Effectene Reagent spontaneously forms micelle structures exhibiting no size or batch variation (as may be found with pre-formulated liposome reagents). This feature ensures reproducibility of transfection-complex formation. The process of highly condensing DNA molecules and then coating them with Effectene Reagent is an effective way to transfer DNA into eukaryotic cells.
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Zirconocene dichloride reacts with lithium aluminium hydride to give Cp2ZrHCl Schwartz's reagent: :(C5H5)2ZrCl2 \+ 1/4 LiAlH4 -> (C5H5)2ZrHCl + 1/4 LiAlCl4 Since lithium aluminium hydride is a strong reductant, some over-reduction occurs to give the dihydrido complex, Cp2ZrH2; treatment of the product mixture with methylene chloride converts it to Schwartz's reagent.
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Ethylmagnesium bromide is a Grignard reagent with formula C2H5MgBr. It is widely used in the laboratory synthesis of organic compounds.
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It is used as a reagent in sulfonation and sulfomethylation agent. It is used in the production of sodium thiosulfate.
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Hypofluorous acid in acetonitrile (generated in situ by passing gaseous fluorine through "wet" acetonitrile) is commonly known as Rozen's reagent.
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They do not react with Melzer's reagent, and acyanophilous (having cell walls that do not readily absorb cotton blue stain).
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The developed plate was dried using hot air to evaporate solvents from the plate and sprayed with stannic chloride reagent.
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The biggest problem with these reagents are that the reactivity has not been well documented. It is believed that the TiCl4 acts as a mediator in the reaction. Nysted reagent can methylenate different carbonyl groups in the presence of different mediators. For example, in the presence of BF3•OEt2, the reagent will methylenate aldehydes.
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Urobilinogen content is determined by a reaction with Ehrlich's reagent, which contains para-Dimethylaminobenzaldehyde and may be measured in Ehrlich units. Ehrlich's reagent reacts with urobilinogen to give a pink-red color. One Ehrlich unit is equal to one milligram of urobilinogen per deciliter of sample (1 mg/dL).Urobilinogenfrom Information and Courses MediaLab, Inc.
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Lowry assay is similar to biuret assays, but it uses Folin reagent which is more accurate for quantification. Folin reagent is stable at only acidic conditions and the method is susceptible to skewing results depending on how much tryptophan and tyrosine is present in the examined protein. The Folin reagent binds to tryptophan and tyrosine which means the concentration of the two amino acids affects the sensitivity of the method. The method is sensitive at concentration ranges similar to the Bradford method, but requires a minuscule amount more of protein.
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Vegetable peroxidase and bacterial enzymes, including an Escherichia coli peroxidase, may also cause false-positive reactions. Therefore, sediments containing bacteria should be checked closely for the presence of red blood cells. Traditionally, ascorbic acid (vitamin C) has been associated with false-negative reagent strip reactions for blood. Both Multistix and Chemstrip have modified their reagent strips to reduce this interference to very high levels of ascorbic acid, and Chemstrip overlays the reagent pad with an iodate-impregnated mesh that oxidizes the ascorbic acid prior to its reaching the reaction pad.
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Methyl cyanoformate is the organic compound with the formula CH3OC(O)CN. It is used as a reagent in organic synthesis as a source of the methoxycarbonyl group,Simon R. Crabtree, W. L. Alex Chu, Lewis N. Mander "C-Acylation of Enolates by Methyl Cyanoformate: An Examination of Site- and Stereoselectivity"Synlett 1990; 1990: 169–170. in which context it is also known as Mander's reagent. When a lithium enolate is generated in diethyl ether or methyl t-butyl ether (but not THF), treatment with Mander's reagent will selectively afford the C-acylation product.
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The method combines the reactions of copper ions with the peptide bonds under alkaline conditions (the Biuret test) with the oxidation of aromatic protein residues. The Lowry method is based on the reaction of Cu+, produced by the oxidation of peptide bonds, with Folin–Ciocalteu reagent (a mixture of phosphotungstic acid and phosphomolybdic acid in the Folin–Ciocalteu reaction). The reaction mechanism is not well understood, but involves reduction of the Folin–Ciocalteu reagent and oxidation of aromatic residues (mainly tryptophan, also tyrosine). Experiments have shown that cysteine is also reactive to the reagent.
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These hyphae stain red when mounted in Melzer's reagent and yellow in potassium hydroxide. Clamp connections are absent from the hyphae.
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The compound is used infrequently as an oxidizing reagent in organic synthesis. It also serves as a ligand in coordination chemistry.
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Comprehensive Inorganic Chemistry II (2013), 3, 323-342. Ammonium metavanadate is used to prepare Mandelin reagent, a qualitative test for alkaloids.
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Diphenylphosphoryl azide (DPPA) is an organic compound. It is widely used as a reagent in the synthesis of other organic compounds.
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Some ketones, esters, and imides are converted to the corresponding thiocarbonyls. Amides give thioamide. With 1,4-diketones the reagent forms thiophenes.
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Other N-methylated nucleosides in tRNA are not demethylated by this reagent. :Lithium 2-methylpropane-2-thiolate reaction with 7-methylguanosine.
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2,4-Dinitrophenylhydrazine (DNPH, Brady's reagent, Borche's reagent) is the chemical compound C6H3(NO2)2NHNH2. Dinitrophenylhydrazine is a red to orange solid. It is a substituted hydrazine, and is often used to qualitatively test for carbonyl groups associated with aldehydes and ketones. The hydrazone derivatives can also be used as evidence toward the identity of the original compound.
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Adding ASA (acetylsalicylic acid) reagent to a blood sample reduces the aggregation responses in ASPItest and COLtest. ASA irreversibly inhibits COX1 in platelets, thereby inhibiting the production of TXA2. The ASA Reagent is used as a quality control in the platelet function testing with Multiplate, allowing the assessment of abnormal platelet responses in ASPItest and COLtest.
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Cp2TiCl2 is a generally useful reagent that effectively behaves as a source of Cp2Ti2+. A large range of nucleophiles will displace chloride. With NaSH and with polysulfide salts, one obtains the sulfido derivatives Cp2Ti(SH)2 and Cp2TiS5. The Petasis reagent, Cp2Ti(CH3)2, is prepared from the action of methylmagnesium chloride or methyllithium on Cp2TiCl2.
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The biuret test is a chemical test for proteins and polypeptides. It is based on the biuret reagent, a blue solution that turns violet upon contact with proteins, or any substance with peptide bonds. The test and reagent do not actually contain biuret; they are so named because both biuret and proteins have the same response to the test.
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Organometallic compounds of the higher alkali metals are even more reactive than organosodium compounds and of limited utility. A notable reagent is Schlosser's base, a mixture of n-butyllithium and potassium tert-butoxide. This reagent reacts with propene to form the compound allylpotassium (KCH2CHCH2). cis-2-Butene and trans-2-butene equilibrate when in contact with alkali metals.
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In academic research, trichloroacetonitrile is used as a reagent in the Overman rearrangement, converting allylic alcohols into allylic amines. The reaction is based on a [3,3]-sigmatropic and diastereoselective rearrangement. Benzyl trichloroacetimidate is easily accessible from benzyl alcohol and trichloroacetonitrile. Benzyl trichloroacetimidate is useful as a benzylating reagent for sensitive alcohols under mild conditions and to preserve chirality.
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Perilla ketone was synthesized in 1957 by Matsuura from 3-furoyl chloride and an organocadmium compound similar to the Gilman reagent made from an isoamyl Grignard reagent and cadmium chloride. Perilla ketone (3-Furyl isoamyl ketone) has been prepared in 74% yield via the Stille reaction from a 3-furyl-organotin compound and isocaproyl chloride in tetrahydrofuran solvent.
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Collins reagent, the complex CrO3(pyridine)2, is a reagent in organic chemistry. Four-coordinate complexes include tetrahedral and square planar derivatives. Examples of homoleptic tetrahedral complexes include [M(py)4]n+ for Mn+ = Cu+, M = Ni2+, Ag+, and Ag2+. Examples of homoleptic square planar complexes include the d8 cations [M(py)4]n+ for Mn+ = Pd2+, Pt2+, Au3+.
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94 The Cornforth reagent is a strong oxidizing agent which can convert primary and secondary alcohols to aldehydes and ketones respectively. In its chemical structure and functions it is closely related to other compounds made from hexavalent chromium oxide, such as pyridinium chlorochromate and Collins reagent. Because of their toxicity, these reagents are rarely used nowadays.
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This is dissimilar to other common acidic oxidation reactions such as the Baeyer-Villiger oxidation, which would remove or alter such groups. Additionally, the Sarett reagent is relatively inert towards double bonds and thioether groups. These groups cannot effectively interact with the chromium of the Sarett reagent, as compared to the chromium in oxidizing complexes used prior to 1953.
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The Olah reagent is a nucleophilic fluorinating agent. It consists of a mixture of 70% hydrogen fluoride and 30% pyridine; alcohols react with this reagent to give alkyl fluorides: 300px It acts as a stabilized, less volatile form of hydrogen fluoride. It is used in the fluorination of steroids and in deprotection of peptides.C. G. Bergstrom et al.
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Terthiophene is prepared by the nickel- or palladium- catalysed coupling reaction of 2,5-dibromothiophene with the Grignard reagent derived from 2-bromothiophene.
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Triphenylmethyl hexafluorophosphate is a brown powder that hydrolyzes readily to triphenylmethanol. It is used as a catalyst and reagent in organic syntheses.
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Hexanoyl chloride is a six-carbon acyl chloride with a straight-chain structure that is used as a reagent in organic synthesis.
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Octanoyl chloride is an eight-carbon acyl chloride with a straight-chain structure that is used as a reagent in organic synthesis.
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Heptanoyl chloride is a seven-carbon acyl chloride with a straight-chain structure that is used as a reagent in organic synthesis.
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1,1'-Thiocarbonyldiimidazole (TCDI) is a thiourea containing two imidazole rings. It is the sulfur analog of the peptide coupling reagent carbonyldiimidazole (CDI).
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It functions by binding to vicinal diols. Presently, the reagent is used in the analysis of the molecular weight of cellulose samples.
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Diazodiphenylmethane is an organic reagent with the chemical formula C13H10N2. It exists as red-black crystals that melts just above room temperature.
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1975, volume B31, p. 2510-2512. . The informal name is derived from its method of preparation which includes phenol as a reagent.
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4-Methoxybenzylthiol is an organosulfur compound with the formula CH3OC6H4CH2SH. A colorless, odiferous oil, it is a reagent used as a protected thiol.
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DEPBT (3-(diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one) is a peptide coupling reagent used in peptide synthesis. It shows remarkable resistance to racemization.
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It is the precursor to hydrated iron(III) oxides that are magnetic pigments. FeCl2 finds some use as a reagent in organic synthesis.
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1-Trifluoromethyl-1,2-benziodoxol-3(1H)-one or Togni Reagent II is a chemical compound used in organic synthesis for direct electrophilic trifluoromethylation.
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The reagent is ideal for reductive aminations ("Borch Reaction"). In conjunction with tosylhydrazine, sodium cyanoborohydride is used in the reductive deoxygenation of ketones.
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Sodium nitroprusside is also used as an analytical reagent under the name sodium nitroferricyanide for the detection of methyl ketones, amines, and thiols.
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Dragendroff's reagent is a solution of potassium bismuth iodide prepared from basic bismuth nitrate (Bi(NO3)3), tartaric acid, and potassium iodide (KI).
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BCl3 is used as a reagent in the synthesis of organic compounds. Like the corresponding bromide, it cleaves C-O bonds in ethers.
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On 30 July 2013 Science Exchange launched a program with reagent supplier antibodies-online.com, based in Aachen, Germany, to independently validate research antibodies.
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The oval spores are 6–7.5 µm long by 3.5–5 µm wide, and are dextrinoid – they turn red-brown in Melzer's reagent.
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The reagent appears as a clear, yellow liquid without odour. It is harmful if inhaled, a recognised carcinogen and can cause eye burns.
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Solvent effects and the epimerization of a chiral Grignard reagent. The cis form of the reagent is stabilized, and so more strongly favored, in the reaction solvent THF, over diethyl ether; a larger equilibrium constant is observed in THF. A modern example of the study of solvent effects on chemical equilibrium can be seen in a study of the epimerization of chiral cyclopropylnitrile Grignard reagents. This study reports that the equilibrium constant for the cis to trans isomerization of the Grignard reagent is much greater—the preference for the cis form is enhanced—in THF as a reaction solvent, over diethyl ether.
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BOP (benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate) reagent is a reagent commonly used in the synthesis of peptides. Its use is discouraged because coupling using BOP liberates HMPA which is carcinogenic, although for small scale use in an organic laboratory this is not a great disadvantage as it is in large scale industrial usage. BOP has been used for peptide coupling, synthesis of esters, esterification of carboxylic acids, or as a catalyst. This reagent is advantageous in peptide coupling to other derived reagents because there are no side reactions from the dehydration of asparagine or glutamine.
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Several relatively simple chemical tests — commercially available as reagent testing kits — can be used to assess the presence of psilocybin in extracts prepared from mushrooms. The drug reacts in the Marquis test to produce a yellow color, and a green color in the Mandelin test. Neither of these tests, however, is specific for psilocybin; for example, the Marquis test will react with many classes of controlled drugs, such as those containing primary amino groups and unsubstituted benzene rings, including amphetamine and methamphetamine. Ehrlich's reagent and DMACA reagent are used as chemical sprays to detect the drug after thin layer chromatography.
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In terms of mechanism, the reaction proceeds through single electron transfer:Garst, J. F.; Ungvary, F. "Mechanism of Grignard reagent formation". In Grignard Reagents; Richey, R. S., Ed.; John Wiley & Sons: New York, 2000; pp 185–275. .Advanced Organic chemistry Part B: Reactions and Synthesis F.A. Carey, R.J. Sundberg 2nd Ed. 1983. Page 435Garst, J.F.; Soriaga, M.P. "Grignard reagent Formation", Coord. Chem. Rev.
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This reagent is used as a quality control in Multiplate platelet function testing. The GPIIb/IIIa antagonist blocks the binding of fibrinogen to the GPIIb/IIIa receptors, preventing the formation of platelet-fibrinogen bonds and resulting in significantly reduced platelet aggregation in response to all agonists. The antagonist reagent is used together with TRAP-test, and allows assessment of a positive control.
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1993, 115, 1593. The reaction used a terminal alkyne (A) as the substrate which generated alkenylborate reagent (B) through monohydroboration reaction. After transmetalation with diethylzinc, the generated alkenylzinc reagent (C) further reacted with the aldehyde (D) through exclusive addition to the π-face under the control of (-)-3-exo-(dimethylamino)isoborneol (DAIB) as a ligand (Figure "(b) Detailed steps for the reaction").
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Therefore, the absolute concentration of trace constituents [R] can be easily calculated without the need of calibration or gas standards. Furthermore, it gets obvious that the overall sensitivity of a PTR-MS instrument is dependent on the reagent ion yield. Fig. 1 gives an overview of several published (in peer-reviewed journals) reagent ion yields during the last decades and the corresponding sensitivities.
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In 2012 he co-founded Cloudgine, a games development company focusing on cloud computing. In the same year Jones founded Reagent Games, serving as Creative Director, to lead the development of Microsoft Xbox One title Crackdown 3. In December 2017, Cloudgine was acquired by Epic Games; with this, Jones became Director, Cloud Strategy for Epic Games, and resigned from Reagent Games.
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Coombs reagent (also known as Coombs antiglobulin or antihuman globulin) is used in both the direct Coombs test and the indirect Coombs test. Coombs reagent is antihuman globulin. It is made by injecting human globulin into animals, which produce polyclonal antibodies specific for human immunoglobulins and human complement system factors. More specific Coombs reagents or monoclonal antibodies can be used.
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Modern fluorination methods have rendered sulfur trifluoride essentially obsolete. Use of the more easily handled reagent DAST (diethylaminosulfur trifluoride) is now preferred to SF4 for nucleophilic fluorination reactions. DAST is more selective in fluorinations of alcohols and promotes fewer rearrangements and eliminations in acid-sensitive substrates. The inconvenience of handling gaseous SF4 is a disadvantage of fluorinations employing this reagent.
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Electropositive metals such as sodium, potassium, magnesium, zinc, etc. can insert into alkyl halides, breaking the carbon-halide bond ( halide could be chlorine, bromine, iodine ) and forming a carbon-metal bond. This reaction happens via a SET mechanism ( single-electron-transfer mechanism ). If magnesium reacts with an alkyl halide, it forms a Grignard reagent, or if lithium reacts, an organolithium reagent is formed.
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The Hinsberg reaction is a test for the detection of primary, secondary and tertiary amines. In this test, the amine is shaken well with Hinsberg reagent in the presence of aqueous alkali (either KOH or NaOH). A reagent containing an aqueous sodium hydroxide solution and benzenesulfonyl chloride is added to a substrate. A primary amine will form a soluble sulfonamide salt.
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A range of analysis techniques are in use by drug checking services. The most common are reagent testing, fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, raman spectroscopy, and gas chromatography mass spectroscopy. Developing technologies include nuclear magnetic resonance spectroscopy and ion-trap mass spectroscopy. Reagent testing uses chemical indicators that show a colour change in the presence of particular drugs.
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The Trinder spot test is a diagnostic test used in medicine to determine exposure to salicylates, particularly to salicylic acid. The test employs the Trinder reagent (a.k.a. Trinder solution) which is mixed with a patient's urine. The colour change, resulting from the Trinder reaction, is immediate, enabling rapid bedside assessment. The Trinder solution/reagent is a pre-mixed solution of 10% ferric chloride.
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In the presence of an anionic initiator (M+ X−), the reagent reacts with aldehydes and ketones to give a trimethylsilyl ether, the net product of insertion of the carbonyl into the Si-CF3 bond. Hydrolysis gives trifluoromethyl methanols. The reagent also converts esters to trifluoromethyl ketones. A typical initiator is a soluble fluoride-containing species such as tetrabutylammonium fluoride, however simple alkoxides, e.g.
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Despite its highly pyrophoric nature, diethylzinc is an important chemical reagent. It is used in organic synthesis as a source of the ethyl carbanion in addition reactions to carbonyl groups. For example, the asymmetric addition of an ethyl group to benzaldehyde and imines. Additionally, it is commonly used in combination with diiodomethane as a Simmons-Smith reagent to convert alkenes into cyclopropyl groups.
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Intermediate-strength hydrochloric acid solutions are quite stable upon storage, maintaining their concentrations over time. These attributes, plus the fact that it is available as a pure reagent, make hydrochloric acid an excellent acidifying reagent. Hydrochloric acid is the preferred acid in titration for determining the amount of bases. Strong acid titrants give more precise results due to a more distinct endpoint.
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2, 519 (1992), . as a transesterification reagent (but showing less reactivity than trimethoxymethane) and as a reagent for the synthesis of 2-aminobenzoxazoles, which are used as molecular building blocks in pharmaceutical active ingredients used in neuroleptics, sedatives, antiemetics, muscle relaxants, fungicides and others.C. L. Cioffi et al., Synthesis of 2-Aminobenzoxazoles Using Tetramethyl Orthocarbonate or 1,1-Dichloro-diphenoxymethane, J. Org. Chem.
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Successive catalytic reduction and saponification affords aminoalcohol 4. Oxidation of the sulfide to the sulfoxide with a reagent such as metaperiodate gives sulfinalol (5).
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Many technologies exist for the treatment of AMD from traditional high cost water treatment plants to simple in situ water treatment reagent dosing methods.
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The cap flesh is dextrinoid, meaning it will turn reddish-brown in Melzer's reagent. Clamp connections are present in the hyphae of M. overholtsii.
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"Glyoxal Bisulfite", Organic Syntheses, Collected Volume 3, p.438 (1955). Selenious acid is a key component of the Mecke reagent used for drug checking.
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The Appel reaction is also useful for preparing alkyl halides. The reagent is tetrahalomethane and triphenylphosphine; the co-products are haloform and triphenylphosphine oxide.
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Bromobenzene is an aryl halide, C6H5Br. It is a colourless liquid although older samples can appear yellow. It is a reagent in organic synthesis.
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The spores are ellipsoid, thin-walled, smooth, hyaline (translucent), and do not react with Melzer's reagent. They measure 3–3.5 by 1.2–1.4 µm.
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The Petasis reagent, named after Nicos A. Petasis, is an organotitanium compound with the formula Cp2Ti(CH3)2. It is an orange-colored solid.
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In a complementary reaction, Collman's reagent can be used to convert acyl chlorides to aldehydes. Similar reactions can be achieved with [HFe(CO)4]− salts.
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Iodobenzene dichloride (PhICl2) is a complex of iodobenzene with chlorine. As a reagent for organic chemistry, it is used as an oxidant and chlorinating agent.
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It is a reagent in organic synthesis for the conversion of aryl diazonium salts to aryl aldehydes. It is generated by combining hydroxylamine and formaldehyde.
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Reagent testing kits are available online and also sold at some head shops. These kits claim to be able to identify common adulterants in ecstasy.
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Diisopropylzinc is an organozinc compound with the chemical formula ZnC6H14. It is the key reagent in the Soai reaction, which is both autocatalytic and enantiospecific.
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Eaton's reagent (7.7 wt% phosphorus pentoxide solution in methanesulfonic acid) is used as an alternative to polyphosphoric acid in chemical synthesis to promote acylation reactions.
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Within industry ammonium sulfamate is used as a flame retardant, a plasticiser and in electro-plating. Within the laboratory it is used as a reagent.
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Boron trichloride is the inorganic compound with the formula BCl3. This colorless gas is a reagent in organic synthesis. It is highly reactive toward water.
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1]nonane (9-BBN) as the hydroborating reagent provides a solution to this problem.Jacob, III, P.; Brown, H. C. J. Org. Chem. 1977, 42, 579.
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The first tellurol to be synthesized, ethanetellurol, was prepared in 1926 via the Grignard reagent. The most frequently used method involves reduction of the ditellurides ().
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Hexamethylphosphoramide, often abbreviated HMPA, is a phosphoramide (an amide of phosphoric acid) with the formula This colorless liquid is a useful reagent in organic synthesis.
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Stanley Rossiter Benedict (17 March 1884 – 21 December 1936) was an American chemist best known for discovering Benedict's reagent, a solution that detects certain sugars.
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Zinc uranyl acetate is sometimes called "sodium reagent" since pale yellow NaZn(UO2)3(C2H3O2)9 is one of the very few insoluble sodium compounds.
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However, NAPL contaminant concentrations can still result in rapid oxidation reactions with an associated temperature increase and more potential for surfacing even with reagent stabilization. The hydroxyl radicals can be scavenged by carbonate, bicarbonate, and naturally occurring organic matter in addition to the targeted contaminant, so it important to evaluate a site's soil matrix and apply additional reagent when these soil components are present in significant abundance.
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The diketopiperazine obtains from glycylserine is a reagent for the preparation of C-alkylated derivatives of glycine. This approach is useful for the production of unnatural amino acids with stereochemical control. The diketopiperazine skeleton protects both the N and O termini of the glycine. For this application, the diketopiperazine is O-alkylated with concomitant N-deprotonation to give what is called the Schöllkopf reagent.
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Methyllithium is the simplest organolithium reagent with the empirical formula CH3Li. This s-block organometallic compound adopts an oligomeric structure both in solution and in the solid state. This highly reactive compound, invariably used as a solution in ethers, is a reagent in organic synthesis as well as organometallic chemistry. Operations involving methyllithium require anhydrous conditions, because the compound is highly reactive toward water.
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5-MeO-MiPT is in a class of compounds commonly known as tryptamines, and is the N-methyl-N-isopropyl homologue of the psychedelic, 5-MeO-DMT. The full name of the chemical is 5-methoxy-N-methyl-N- isopropyltryptamine. 5-MeO-MiPT causes the ehrlich reagent to turn purple then fade to faint blue. It causes the marquis reagent to go yellow through to black.
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Mechanism of oxidation of primary alcohols to carboxylic acids via aldehydes and aldehyde hydrates Reagents useful for the transformation of primary alcohols to aldehydes are normally also suitable for the oxidation of secondary alcohols to ketones. These include Collins reagent and Dess-Martin periodinane. The direct oxidation of primary alcohols to carboxylic acids can be carried out using potassium permanganate or the Jones reagent.
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Schweizer's reagent is the metal ammine complex with the formula [Cu(NH3)4(H2O)2](OH)2. This deep-blue compound is used in purifying cellulose. It is prepared by precipitating copper(II) hydroxide from an aqueous solution of copper sulfate using sodium hydroxide or ammonia, then dissolving the precipitate in a solution of ammonia. Aqueous solution of Schweizer's reagent It forms an azure solution.
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Titration is called volumetric analysis since it relies on volume measurements to determine the quantity of a chemical. A reagent with a known volume and concentration is added to a solution with an unknown substance and concentration. The amount of reagent required for a change to occur is proportional to the amount of the unknown substances. This reveals the amount of the unknown substance present.
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It is recommended that the reagent be used within three hours of reconstitution. The sensitivity of the reagent may become altered after the recommended time period. _Microtox Osmotic Adjustment Solution (MOAS)_ is a nontoxic solution that is made up of 22% Sodium Chloride (NaCl) and Ultra Pure Water. This solution is added to a sample to adjust the osmotic pressure to approximately 2% NaCl.
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In the Lowry protein assay Cu+ is oxidized back to Cu2+ by MoVI in the Folin–Ciocalteu reagent, which forms molybdenum blue (MoIV). Tyrosine residues in the protein also form molybdenum blue under these circumstances. In this way, proteins can be detected in concentrations between 0.005 and 2 mg/mL.O.H. Lowry, N.J. Rosebrough, A.L. Farr, R.J. Randall: Protein Measurement With the Folin Phenol Reagent, J. Biol. Chem.
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Diazonium reagent and SWNT reaction has a two step mechanism. First, the diazonium reagent adsorbs noncovalently to an empty site on the nanotube surface, forming a charge-transfer complex. This is a fast, selective noncovalent adsorption and diazonium group in this complex partially dopes the nanotube, diminishing the tangential mode in the Raman spectrum. Desorption of A from nanotube is negligible (k−1 ~ 0).
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Sodium hydrosulfide is the chemical compound with the formula NaHS. This compound is the product of the half-neutralization of hydrogen sulfide (H2S) with sodium hydroxide. NaHS is a useful reagent for the synthesis of organic and inorganic sulfur compounds, sometimes as a solid reagent, more often as an aqueous solution. Solid NaHS is colorless, and typically smells like H2S owing to hydrolysis by atmospheric moisture.
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General form of ylide reagent used Many types of ylides can be prepared with various functional groups both on the anionic carbon center and on the sulfur. The substitution pattern can influence the ease of preparation for the reagents (typically from the sulfonium halide, e.g. trimethylsulfonium iodide) and overall reaction rate in various ways. The general format for the reagent is shown on the right.
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400px The Sakaguchi test is a chemical test used for detecting the presence of arginine in proteins. It is named after the Japanese Food Scientist and Organic Chemist, Shoyo Sakaguchi (1900-1995) who described the test in 1925. Sakaguchi reagent consists of 1-Naphthol and a drop of sodium hypobromite. The guanidine group in arginine reacts with Sakaguchi reagent to form a red- coloured complex.
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There are a number of technologies available for the in situ water treatment. Reagent can be mixed into a slurry in a vertical mixing tank, or similar, and dosed directly into the water body (e.g. a tailings storage facility (TSF) or pond) via a pipeline. Some systems mix the reagent in a tank and spray it into the water body using a spray cannon.
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US: Springer. pp. 281–288. Silver carbonate on celite oxidizes alcohols through single electron oxidation by the silver cations Even weakly associating functionalities such as olefins can interfere with the association of the reactant alcohol with Fetizon's reagent The rate limiting step of this reaction is proposed to be the initial association of the alcohol to the silver ions. As a result, the presence of even weakly associating ligands to the silver can inhibit the reaction greatly. As a result, even slightly polar solvents of any variety, such as ethyl acetate or methyl ethyl ketone, are avoided when using this reagent as they competitively associate with the reagent.
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In chemical ionization (CI) a reagent gas, typically methane or ammonia is introduced into the mass spectrometer. Depending on the technique (positive CI or negative CI) chosen, this reagent gas will interact with the electrons and analyte and cause a 'soft' ionization of the molecule of interest. A softer ionization fragments the molecule to a lower degree than the hard ionization of EI. One of the main benefits of using chemical ionization is that a mass fragment closely corresponding to the molecular weight of the analyte of interest is produced. In positive chemical ionization (PCI) the reagent gas interacts with the target molecule, most often with a proton exchange.
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A specialized use of manganese dioxide is as oxidant in organic synthesis.. The effectiveness of the reagent depends on the method of preparation, a problem that is typical for other heterogeneous reagents where surface area, among other variables, is a significant factor.. The mineral pyrolusite makes a poor reagent. Usually, however, the reagent is generated in situ by treatment of an aqueous solution with a Mn(II) salt, typically the sulfate. oxidizes allylic alcohols to the corresponding aldehydes or ketones: (this procedure illustrates the use of MnO2 for the oxidation of an allylic alcohol. ::cis-RCH= + → cis-RCH=CHCHO + MnO + The configuration of the double bond is conserved in the reaction.
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Chemical tests in mushroom identification are methods that aid in determining the variety of some fungi. The most useful tests are Melzer's reagent and potassium hydroxide.
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Other common ylides include sulfonium ylides and sulfoxonium ylides, for instance the Corey-Chaykovsky reagent used in the preparation of epoxides or in the Stevens rearrangement.
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Methylenecyclopropane is an organic compound with the formula (CH2)2CCH2. It is a colourless easily condensed gas that is used as a reagent in organic synthesis.
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This reagent was first utilized by Edwin Vedejs as an efficient alpha-hydroxylating agent in 1974 and an effective preparative procedure was later published in 1978.
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A 1951 paper entitled "Protein measurement with the Folin phenol reagent" was the most cited paper in the 1945–1988 Science Citation Index, with 187,652 citations.
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By changing the reagent in the second step of the reaction, the Kowalski ester homologation can also be used for the preparation of silyl ynol ethers.
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The reagent is commonly used in the biuret protein assay, a colorimetric test used to determine protein concentration by UV/VIS spectroscopy at wavelength 540 nm.
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Benzophenone imine is available via the addition of MeOH to the complex of a nitrile and a Grignard reagent or the reaction between benzophenone and ammonia.
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Vanadium tetrachloride is the inorganic compound with the formula VCl4. This bright red liquid serves as a useful reagent for the preparation of other vanadium compounds.
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It is an important chemical reagent and an industrial chemical, mainly used in paper pulp industry (Kraft process), textiles, synthetic flavors, coloring brasses, and iron control.
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Ammonium oxalate is used as an analytical reagent and general reducing agent. It and other oxalates are used as anticoagulants, to preserve blood outside the body.
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The Tebbe reagent is used in organic synthesis for carbonyl methylenation. Pine, S. H. Org. React. 1993, 43, 1. (Review)Beadham, I.; Micklefield, J. Curr. Org. Synth.
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Cadmium acetate is used for glazing ceramics and pottery; in electroplating baths, in dyeing and printing textiles; and as an analytic reagent for sulfur, selenium and tellurium.
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Dihydromorphine is widely used in Japan. The dihydromorphine can be quantitatively converted to hydromorphone using potassium tert butoxide. Dihydrocodeine can be presumptively detected by the Froehde reagent.
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In this case the enzyme urease is used to catalyze the hydrolysis of urea into carbon dioxide and ammonia. The ammonia is then determined with Berthelot's reagent.
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In a more recent synthesis by M. Basato et al., silver acetate was reacted with platinum(II) chloride. Silver(I) is used as a halide-abstraction reagent.
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Julius Neßler (June 6, 1827 - March 19, 1905) was a German chemist. He devised the chemical solution Nessler's reagent which provides a colorimetric measure of ammonia concentration.
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Tetrakis(trimethylsilyloxy)silane (TTMS) is an organosilicon compound with the formula Si[OSi(CH3)3]4. This colourless liquid is used as a reagent in organic synthesis.
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Given the balanced chemical equation, which describes the reaction, there are several equivalent ways to identify the limiting reagent and evaluate the excess quantities of other reagents.
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The same results were observed where in AGPs appear to need at least 5–7 β-1,3-linked Gal units to make aggregates with the Yariv reagent.
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Besides its use in the synthesis of banana oil, isoamyl alcohol is also an ingredient of Kovac's reagent, used for the bacterial diagnostic indole test. It is also used as an antifoaming agent in the chloroform isoamyl alcohol reagent. Isoamyl alcohol is used in a phenol–chloroform extraction mixed with the chloroform to further inhibit RNase activity and prevent solubility of RNAs with long tracts of poly-adenine.
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Cyclization and tautomerization give intermediate 10, which will react with a third equivalent of the Grignard reagent (2) to give a dimagnesium indole salt (12). Reaction workup eliminates water and gives the final desired indole (13). Therefore, three equivalents of the Grignard reagent are necessary, as one equivalent becomes carbonyl compound 6, one equivalent deprotonates 10 forming an alkene (11), and one equivalent gets incorporated into the indole ring.
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As a reagent, chloroform serves as a source of the dichlorocarbene :CCl2 group. It reacts with aqueous sodium hydroxide usually in the presence of a phase transfer catalyst to produce dichlorocarbene, :CCl2. This reagent effects ortho-formylation of activated aromatic rings such as phenols, producing aryl aldehydes in a reaction known as the Reimer–Tiemann reaction. Alternatively, the carbene can be trapped by an alkene to form a cyclopropane derivative.
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The transition state for axial attack (IV) suffers from steric strain between any axial substituents and the incoming hydride reagent. The transition state for equatorial attack (V) suffers from torsional strain between the incoming hydride reagent and adjacent equatorial hydrogens. The difference between these two strain energies determines which direction of attack is favored, and when R is small, torsional strain in V dominates and the equatorial alcohol product is favored.
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Using this protected alkyne, as opposed to acetylene itself, prevents further coupling reactions and also has the benefit of being a liquid. A less expensive alternative reagent is 2-methylbut-3-yn-2-ol, which after alkynylation is deprotected with base. Trimethylsilylacetylene is commercially available. It may also be prepared in a manner similar to other silyl compounds: deprotonation of acetylene with a Grignard reagent, followed by reaction with trimethylsilyl chloride.
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Rosenthal's reagent, Cp2TiMe3(η2-SiC≡CSiMe3), can be prepared by this method. Two structures are shown, A and B, which are both resonance contributors to the actual structure of Rosenthal's reagent. 686x686px Titanocene equivalents react with alkenyl alkynes followed by carbonylation and hydrolysis to form bicyclic cyclopentadienones, related to the Pauson–Khand reaction). A similar reaction is the reductive cyclization of enones to form the corresponding alcohol in a stereoselective manner.
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Kovacs reagent is a biochemical reagent consisting of isoamyl alcohol, para- dimethylaminobenzaldehyde (DMAB), and concentrated hydrochloric acid. It is used for the diagnostical indole test, to determine the ability of the organism to split indole from the amino acid tryptophan. The indole produced yields a red complex with para-dimethylaminobenzaldehyde under the given conditions. This was invented by the Hungarian-Swiss Chemist, Ervin Kovats (Erwin Kovacs) (1927-2010).
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In Molisch's test, 1-naphthol dissolved in ethanol, known as Molisch's reagent, is used as reagent for detecting the presence of carbohydrates. The test known as Molisch's test would give a red- or purple-colored compound to indicate the presence of carbohydrate. The rapid furfural test, similar to Molisch's test, also uses 1-naphthol. The Sakaguchi test uses 1-naphthol with sodium hypobromite to detect the presence of arginine in proteins.
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These cells have irregular projections that can range in size from 1.5–18.8 by 1.5–6.5 μm and are variously shaped, from knob-like to cylindrical. The cells contain brownish contents that will stain darkly with Melzer's reagent, a common chemical reagent used in mushroom identification. With the exception of the medullary hyphae of the stem (longitudinally- arranged hyphae making up the stem surface), all hyphae contain clamp connections.
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Detailed procedures for the cobalt thiocyanate test are available. The reagent consists of 2% cobalt thiocyanate dissolved in dilute acid. Glycerol is often added to stabilise the cobalt complex, ensuring it only goes blue when in contact with an analyte and not due to drying. Addition of the cobalt thiocyanate reagent to cocaine hydrochloride results in the surface of the particles turning a bright blue (faint blue for cocaine base).
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In carbohydrate chemistry carbohydrate acetalisation is an organic reaction and a very effective means of providing a protecting group. The example below depicts the acetalisation reaction of D-ribose 1. With acetone or 2,2-dimethoxypropane as the acetalisation reagent the reaction is under thermodynamic reaction control and results in the pentose 2. The latter reagent in itself is an acetal and therefore the reaction is actually a cross- acetalisation.
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It is these forms that are responsible for much of the chemical properties of this reagent, which is also the reason that the substance is sometimes written as [(C5H5)2TiCl] or [Cp2TiCl], where Cp− represents the cyclopentadienyl anion. An example of an application of this reagent is in the preparation of vinorelbine, a chemotherapeutic agent which can be prepared in three steps from the naturally-occurring alkaloid leurosine.
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The DMACA reagent is an histological dye specific to polyphenols used in microscopy analyses. The autofluorescence of polyphenols can also be used, especially for localisation of lignin and suberin. Where fluorescence of the molecules themselves is insufficient for visualization by light microscopy, DPBA (diphenylboric acid 2-aminoethyl ester, also referred to as Naturstoff reagent A) has traditionally been used, at least in plant science, to enhance the fluorescence signal.
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The highly oxophilic reagent Si2Cl6 stereospecifically deoxygenates phosphine oxides.David P. Sebesta "Hexachlorodisilane" in Encyclopedia of Reagents for Organic Synthesis John Wiley, London, 2001. Article Online Posting Date: April 15, 2001. Phosphorus pentasulfide and the related Lawesson's reagent convert certain organic carbonyls to the corresponding sulfur derivatives: :P4S10 \+ n R2C=O → P4S10−nOn \+ n R2C=S Owing to the high stability of carbon dioxide, many carbon compounds such as phosgene are oxophilic.
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Molecular structure of the Sarett/Collins reagent The reaction is named after the American chemist Lewis Hastings Sarett (1917–1999). The first description of its use appears in a 1953 article co-authored by Sarett that relates to the synthesis of adrenal steroids. The paper proposes the use of the pyridine chromium complex CrO3-2C5H5N to oxidize primary and secondary alcohols. The complex would later become known as the "Sarett Reagent".
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The molybdovanadate reagent is a solution containing both the molybdate and vanadate ions. It is commonly used in the determination of phosphate ion content. The reagent used is ammonium molybdovanadate with the addition of 70% perchloric acid (sulfuric acid is also known to be used). It is used for purposes such as the analysis of wine, canned fruits and other fruit-based products such as jams and syrups.
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Other uses for RFNA include fertilizers, dye intermediates, explosives, and pharmaceutic aid as acidifier. It can also be used as a laboratory reagent in photoengraving and metal etching.
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However, since the dimethylglyoxime ligands contains two acidic H atoms in the oxime group, the Grignard reagent must be used in three-fold excess to compensate the loss.
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Acetic anhydride is a versatile reagent for acetylations, the introduction of acetyl groups to organic substrates.. In these conversions, acetic anhydride is viewed as a source of CH3CO+.
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Alternative in vitro measurements of antioxidant content in foods - also based on the presence of polyphenols - include the Folin-Ciocalteu reagent, and the Trolox equivalent antioxidant capacity assay.
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2,4-Dimethoxybenzaldehyde (DMBA) is a reagent used to specifically quantify phlorotannins. This product reacts specifically with 1,3-and 1,3,5-substituted phenols (e.g., phlorotannins) to form a colored product.
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The manufacture and degradation of o-dianisidine, like other benzidene derivatives, has attracted regulatory attention. It is also used as a reagent in biochemistry in testing for peroxides.
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2,4-Dinitroaniline is a chemical compound with a formula of C6H5N3O4. It is used as an explosive and as a reagent to detect and characterize aldehydes and ketones.
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In chemistry, a reoxidant is a reagent that regenerates a catalyst by oxidation. In some cases they are used stoichiometrically, in other cases only small amounts are required.
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Bindone is an aromatic triketone. Bindone is used as a colour test when detecting primary amines. It turns violet in their presence. Aromatic amines turn this reagent blue.
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Isopropylmagnesium chloride is an organometallic compound with the general formula (CH3)2HCMgCl. This highly flammable, colorless, and moisture sensitive material is the Grignard reagent derived from isopropyl chloride. It is commercially available, usually as a solution in tetrahydrofuran. This reagent is used to prepare Grignard reagents by transmetalation reactions as well as installing isopropyl groups. An illustrative generic reaction involves the generation of the Grignard reagent derived from bromo-3,5-bis(trifluoromethyl)benzene: :(CH3)2HCMgCl + (CF3)2C6H3Br → (CH3)2HCCl + (CF3)2C6H3MgBr Isopropylmagnesium chloride is also used to prepare other isopropyl compounds, such as chlorodiisopropylphosphine: :PCl3 \+ 2 (CH3)2CHMgCl → [(CH3)2CH]2PCl + 2 MgCl2 This reaction exploits the bulky nature of the isopropyl substituent.
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Sulfur tetrachloride is an inorganic compound with chemical formula SCl4. It has only been obtained as an unstable pale yellow solid. The corresponding SF4 is a stable, useful reagent.
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Alkynes react similarly, forming the tetrahalo compounds. This is sometimes known as "decolorizing" the halogen, since the reagent X2 is colored and the product is usually colorless and odorless.
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Chloro(triphenylphosphine)gold(I) or triphenylphosphinegold(I) chloride is a coordination complex with the formula (Ph3P)AuCl. This colorless solid is a common reagent for research on gold compounds.
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Ecarin is an enzyme that is derived from the venom of the Indian saw-scaled viper, Echis carinatus, It is the primary reagent in the Ecarin clotting time test.
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It is also used to deoxygenate sulfoxides. The use of P4S10 has been displaced by Lawesson's reagent P4S10s. P2S5 reacts with pyridine to form the complex P2S5(pyridine)2.
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Many molybdenum oxides are used as heterogeneous catalysts, e.g. for oxidations. Molybdic acid and its salts are used to make the Froehde reagent for the presumptive identification of alkaloids.
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Oxalyl chloride is a chemical compound with the formula (COCl)2. This colourless, sharp-smelling liquid, the diacyl chloride of oxalic acid, is a useful reagent in organic synthesis.
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Unfortunately, the contaminated groundwater that needs to be treated has a pH level that is at or near neutral. Due to this, there are controversies on whether ISCO using Fenton's reagent is really a Fenton reaction. Instead, scientists call these reactions Fenton-like. However, some ISCO vendors successfully apply pH neutral Fenton's reagent by chelating the iron which keeps the iron in solution and mitigates the need for acidifying the treatment zone.
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Schuetze reagent, also written as Schütze reagent, is made up of iodine pentoxide, I2O5, and sulfuric acid on granular silica gel. It is used to convert carbon monoxide, CO, into carbon dioxide, CO2, at room temperature.The Gravimetric Determination of Carbon in Uranium-Plutonium Carbide Materials, Los Alamos Publication LA-7981 This can be used as a method for assaying carbon content in quality control of the production of uranium carbide fuel for nuclear reactors.
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With H3O+ as the reagent ion the proton transfer process is (with being the trace component) Fig. 1: Evolution of reagent ion yields and sensitivities of PTR-MS instruments taken from peer reviewed journal articles Reaction () is only possible if energetically allowed, i.e. if the proton affinity of is higher than the proton affinity of H2O (691 kJ/molR.S. Blake, P.S. Monks, A.M. Ellis, Proton-Transfer Reaction Mass Spectrometry, Chem. Rev., 109, 861-896 (2009)).
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YbCl3 is an NMR shift reagent that produces different resonances with nuclei in contact with the YbCl3 versus those nuclei not in contact with the shift reagent. Generally paramagnetic species, such as a (lanthanide)+3 ion, are desirable shift reagents. Membrane biology has been greatly influenced by YbCl3, where39K+ and23Na+ ion movement is critical in establishing electrochemical gradients. Nerve signaling is a fundamental aspect of life that may be probed with YbCl3 using NMR techniques.
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A solution of KMnO4 in water, in a volumetric flask A major application of KMnO4 is as a reagent for the synthesis of organic compounds. Significant amounts are required for the synthesis of ascorbic acid, chloramphenicol, saccharin, isonicotinic acid, and pyrazinoic acid. KMnO4 is used in qualitative organic analysis to test for the presence of unsaturation. It is sometimes referred to as Baeyer's reagent after the German organic chemist Adolf von Baeyer .
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The limiting reagent determines the theoretical yield—the relative quantity of moles of reactants and the product formed in a chemical reaction. Other reactants are said to be present in excess. The actual yield—the quantity physically obtained from a chemical reaction conducted in a laboratory—is often less than the theoretical yield. The theoretical yield is what would be obtained if all of the limiting reagent reacted to give the product in question.
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By using the Bradford protein assay, one can avoid all of these complications by simply mixing the protein samples with the Coomassie Brilliant Blue G-250 dye (Bradford reagent) and measuring their absorbances at 595 nm, which is in the visible range. The procedure for Bradford protein assay is very easy and simple to follow. It is done in one step where the Bradford reagent is added to a test tube along with the sample.
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Humans have long performed at exponential levels, and in widely varying contexts and domains. As with other phenomena, when we notice similar results when applying a reagent or catalyst across many contexts and domains, we associate the power to produce or induce those results with the reagent, here the human animal. Stephen Jay Kline presented an interesting visualization of this exponential phenomenon in his 1995 book. See page 173, figure 14-1.
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In stoichiometry of a chemical reaction to produce a chemical product, it may be observed or predicted that with amounts supplied in specified proportions, one of the reactants will be consumed by the reaction before the others. The amount of product is thus limited by the supply of this reagent. This limiting reagent determines the theoretical yield of the reaction. The other reactants are said to be non-limiting or in excess.
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It has been investigated for use as an oxidizer in bipropellant rockets; however, its high melting point makes it unsuitable. Highly purified tetranitromethane cannot be made to explode, but its sensitivity is increased dramatically by oxidizable contaminants, such as anti-freezing additives. This makes it effectively unusable as a propellant. In the laboratory it is used as a reagent for the detection of double bonds in organic compounds and as a nitrating reagent.
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Berthelot's reagent has been used in a range of situations. It is often used in colorimetric methods, through an AutoAnalyzer, spectrophotometer, or multiwell plate spectrophotometer. The reagent lacks sensitivity in situations where there may be amines as well as ammonia, however this can be overcome in part by the use of 2-phenylphenol to replace phenol. An ion selective electrode, or distillation/titration method can often be used in cases where Berthelot chemistry is ineffective.
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Fenton's reagent is a solution of hydrogen peroxide (H2O2) with ferrous iron (typically iron(II) sulfate, FeSO4) as a catalyst that is used to oxidize contaminants or waste waters. Fenton's reagent can be used to destroy organic compounds such as trichloroethylene (TCE) and tetrachloroethylene (perchloroethylene, PCE). It was developed in the 1890s by Henry John Horstman Fenton as an analytical reagent.Hayyan M., Hashim M.A., AlNashef I.M., Superoxide ion: Generation and chemical implications. Chem. Rev.
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Schlosser's base (or Lochmann-Schlosser base) describes various superbasic mixtures of an alkyllithium compound and a potassium alkoxide. The reagent is named after Manfred Schlosser, although he uses the term LICKOR superbase (LIC denoting the alkyllithium, and KOR denoting the potassium alkoxide). The superbasic nature of the reagent is a consequence of the in situ formation of the corresponding organopotassium compound, as well as changes to the aggregation state of the alkyllithium species.
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This method is most useful when there are only two reactants. One reactant (A) is chosen, and the balanced chemical equation is used to determine the amount of the other reactant (B) necessary to react with A. If the amount of B actually present exceeds the amount required, then B is in excess and A is the limiting reagent. If the amount of B present is less than required, then B is the limiting reagent.
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Chromotropic acid is a chemical compound with the formula (HO)2C10H4(SO3H)2. It can be used for as a reagent in the quantitative determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Chromotropic acid is also used for testing for the presence of formaldehyde. The usefulness of this reagent in quantitative determination is the formation of a red coloration (peaking at 580 nm wavelength) when chromotropic acid in 50% sulfuric acid reacts with formaldehyde.
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It is used as a traditional method of treating wood panelling on houses, either alone, dissolved in water, or as a component of water-based paint. Green vitriol is also a useful reagent in the identification of mushrooms. It is used as the iron catalyst component of Fenton's reagent. In the early 19th century, chemist Friedrich Accum discovered that in England the dark beer porter often contained Iron(II) sulfate as a frothing agent.
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The flesh in the cap is made up of irregularly arranged cylindrical hyphae from 5 to 15 μm wide. They stain a dark reddish-brown in Melzer's reagent or Lugol's solution. The flesh in the stem is made up of hyphae which run down the stem and measure 4 to 11 μm in thickness. The smooth cell walls are colorless, but again stain a dark reddish-brown in Melzer's reagent or Lugol's solution.
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Effectene Reagent is used in conjunction with the enhancer and the DNA condensation buffer (Buffer EC) to achieve high transfection efficiency. In the first step of Effectene–DNA complex formation, the DNA is condensed by interaction with the enhancer in a defined-buffer system. Effectene Reagent is then added to the condensed DNA to produce condensed Effectene–DNA complexes. The Effectene–DNA complexes are mixed with the medium and directly added to the cells.
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Therefore, cysteine residues in protein probably also contribute to the absorbance seen in the Lowry assay. The result of this reaction is an intense blue molecule known as heteropolymolybdenum Blue. The concentration of the reduced Folin reagent (heteropolymolybdenum Blue) is measured by absorbance at 660 nm. As a result, the total concentration of protein in the sample can be deduced from the concentration of tryptophan and tyrosine residues that reduce the Folin–Ciocalteu reagent.
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Reagent Chemicals is primarily of interest to manufacturers and suppliers of chemicals to laboratories worldwide. Most chemists simply specify “ACS Reagent Grade,” knowing that these chemicals will be sufficiently pure for their needs, without knowing the details. Many standards organizations and federal agencies that set guidelines require the use of ACS-grade regent chemicals for many test procedures. This includes the United States Pharmacopeia (USP) and the U.S. Environmental Protection Agency (EPA).
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An exception would be those working on trace analyses (measuring contaminants in the environment, for example), where small impurities in reagents would be significant. Reagent Chemicals Online After eleven paper editions over 68 years, Reagent Chemicals became an electronic resource in 2017. This allows content to be updated as standards change and new reagents are added. The publication is updated several times a year with new reagents and new methods of analysis.
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Sodium trifluoroacetate as a reagent for trifluoromethylations was introduced by Matsui in 1981. In the original scope the substrate was an aromatic halide and the metal salt copper(I)iodide.
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Many different color reagents have been developed for determining the concentrations of different substances. For example, Nessler's reagent can be used to determine the concentration of a solution of ammonia.
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Eric K. Eisenhart, Bernard Bessieres "Vinyllithium" e-EROS Encyclopedia of Reagents for Organic Synthesis, 2001. . The low temperatures suppress the reaction of the strongly basic organolithium reagent with the THF.
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Methyl triflate, for example, is a strong methylating reagent. Sulfonates are commonly used to confer water solubility to protein crosslinkers such as N-hydroxysulfosuccinimide (Sulfo-NHS), BS3, Sulfo-SMCC, etc.
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1,3-Propanedithiol is the chemical compound with the formula HSCH2CH2CH2SH. This dithiol is a useful reagent in organic synthesis. This liquid, which is readily available commercially, has an intense stench.
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Transmetalation involves the exchange of two metals between organic molecules by a redox exchange mechanism. For example, transmetalations often form a reaction between an organolithium reagent and a metal salt.
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Tomatine has been used as a reagent in analytical chemistry for precipitating cholesterol from solution. Also, tomatine is known to be an immune adjuvant in connection with certain protein antigens.
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Usually, both occur without preference. The result is racemization. The SN2 mechanism has just one step. The attack of the reagent and the expulsion of the leaving group happen simultaneously.
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At one time CarbolabsREACTION OF SULFOXIDES WITH DIETHYLAMINOSULFUR TRIFLUORIDE: FLUOROMETHYL PHENYL SULFONE, A REAGENT FOR THE SYNTHESIS OF FLUOROALKENES, Organic Syntheses, Coll. Vol. 9, p.446 (1998); Vol. 72, p.
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A variation on this test using Ehrlich's reagent (using ethyl alcohol in place of isoamyl alcohol, developed by Paul Ehrlich) is used when performing the test on nonfermenters and anaerobes.
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Instant positive film (which produced a print) uses diffusion transfer to move the dyes from the negative to the positive via a reagent. The process varies according to the film type.
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Numerous partially fluorinated alcohols are known. Trifluoroethanol is a popular solvent. Fluorotelomer alcohols are precursors to perfluorocarboxylic acids. Pirkle's alcohol is used a chiral shift reagent in nuclear magnetic resonance spectroscopy.
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In particular, he has developed a silicon/pseudoephedrine allylation reagent for the highly enantioselective allylation of aldehydes and aldehyde/ketone derived hydrazones to give chiral alcohols and secondary/tertiary carbinamines, respectively.
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Wittig reagents are found to react as nucleophiles in SN2' substitution: :Wittig reagent in allylic rearrangement. 8% ene product not depicted The initial addition reaction is followed by an elimination reaction.
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Several species have a distinct, often rubbery, smell. The spore print is white to cream. The spores are usually (but not always) dextrinoid (turning red-brown in an iodine-based reagent).
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4-Bromofluorobenzene forms a Grignard reagent used in the synthesis of 4-fluorophenyl containing compounds,Patent US4605655 - Neuroleptic agents; no movement disorder side effects - Google Patents such as the pesticides Flusilazole.
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The basidia (spore-bearing cells) are club-shaped with a basal clamp, and have four sterigmata. The spores are cylindric, large, hyaline and smooth, and are non-reactive to Melzer's reagent.
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As such, its major application is for cellulose acetate, a synthetic textile also used for photographic film. Acetic anhydride is also a reagent for the production of heroin and other compounds.
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Two drops of gastric juice are mixed with two drops of Gunzberg's reagent in an evaporating dish. The mixture is evaporated and if red is seen, free hydrochloric acid is present.
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Dimanganese decacarbonyl is the chemical compound with the formula Mn2(CO)10. This metal carbonyl is an important reagent in the organometallic chemistry of manganese.Elschenbroich, C. "Organometallics" (2006) Wiley-VCH: Weinheim.
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The compound is bifunctional, containing reactive trichlorsilyl and allyl groups. The SiCl3 group undergoes the usual alcoholysis to give the trialkxoyallylsilane. In the presence of Lewis bases, the reagent allylates aldehydes.
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Flow- through tests typically come in the form of cassettes divided into four parts: an upper casing, a reactive membrane panel, an absorbent panel, and a lower casing. To perform a test, a diluted sample is applied to the reactive membrane panel and flows through to the absorbent pad, with the target analyte being captured in the membrane. The membrane is then washed to remove unbound, non-target molecules, washed again with a solution containing a signal reagent, and washed again to remove unbound signal reagent. If the analyte was present in the original sample, then by the end of this process it should be bound to the membrane, with the signal reagent bound to it, revealing (usually visually) the presence of the analyte on the membrane.
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A chiral shift reagent is a reagent used in analytical chemistry for determining the optical purity of a sample. Some analytical techniques such as HPLC and NMR, in their most commons forms, cannot distinguish enantiomers within a sample, but can distinguish diastereomers. Therefore, converting a mixture of enantiomers to a corresponding mixture of diastereomers can allow analysis. One method involves the reaction of a chiral derivatizing agent (CDA) with a mixture of enantiomers to produce diastereomers via covalent attachment.
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Since its discovery as a useful method of oxidation, Fétizon's reagent has been used in the total synthesis of numerous molecules such as (±)-bukittinggine. Fétizon's reagent has also been employed extensively in the study of various sugar chemistry, to achieve selective oxidation of tri and tetra methylated aldoses to aldolactones, oxidation of D-xylose and L-arabinose to D-threose and L-erythrose respectively, and oxidation of L-sorbose to afford L-threose among many others.
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The time delay can be varied up to the maximum corresponding to the flow time over that known distance. By studying how quickly the reagent species disappears in the presence of differing concentrations of a (usually stable) co-reagent species the reaction rate constant at the low temperature of the CRESU flow can be determined. Reactions studied by the CRESU technique typically have no significant activation energy barrier. In the case of neutral-neutral reactions (i.e.
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Tebbe's reagent contains two tetrahedral metal centers linked by a pair of bridging ligands. The titanium has two cyclopentadienyl (, or Cp) rings and aluminium has two methyl groups. The titanium and aluminium atoms are linked together by both a methylene bridge (-CH2-) and a chloride atom in a nearly square-planar (Ti–CH2–Al–Cl) geometry. The Tebbe reagent was the first reported compound where a methylene bridge connects a transition metal (Ti) and a main group metal (Al).
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Owing to the presence of the electron-withdrawing cyanide substituent, [B(CN)H3]− is less reducing than is [BH4]−. As a mild reducing agent, it is used to convert imines to amines. It is especially favored for reductive aminations, wherein aldehydes or ketones are treated with an amine in the presence of this reagent: : R2CO + R'NH2 \+ NaBH3CN + CH3OH → R2CH-NHR' + "NaCH3OBH2CN" The reagent is typically used in excess. Selectivity is achieved at mildly basic solutions (pH 7-10).
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The Dess–Martin oxidation is an organic reaction for the oxidation of primary alcohols to aldehydes and secondary alcohols to ketones using Dess-Martin periodinane. It is named after the American chemists Daniel Benjamin Dess and James Cullen Martin who developed the periodinane reagent in 1983. The reaction uses a hypervalent iodine reagent similar to IBX to selectively and mildly oxidize alcohols to aldehydes or ketones. The reaction is commonly conducted in chlorinated solvents such as dichloromethane or chloroform.
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Structure of Rosenthal's reagent with titanium and zirconium. Molecular structure of Titanocene-bis(trimethylsilyl)acetylene Rosenthal's reagent is a metallocene bis(trimethylsilyl)acetylene complex with zirconium (Cp2Zr) or titanium (Cp2Ti) used as central atom of the metallocene fragment Cp2M. Additional ligands such as pyridine or THF are commonly used as well. With zirconium as central atom and pyridine as ligand, a dark purple to black solid with a melting point of 125–126 °C is obtained.
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The Takayama reagent is added to a slide with a presumptive blood sample. The slide is dried at 115 degrees Celsius following the addition of the Takayama reagent. Then it is placed under a microscope and a positive result is the visualization of dark red, feathery crystals. For the immunochromatographic test, it functions similar to a pregnancy test where antigens present in blood are detected and a positive result is a band at the test site and control site.
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Lithium tetrakis(pentafluorophenyl)borate is primarily used to prepare cationic transition metal complexes: :LiB(C6F5)4) + MLnCl → LiCl + [MLn]B(C6F5)4 LiB(C6F5)4 is converted to the trityl reagent [Ph3C][B(C6F5)4], which is useful activator of Lewis-acid catalysts.Cordoneanu, Adina, Drewitt, Mark, Bavarian, Neda, Baird, Michael. "Synthesis and Characterization of Weakly Coordinating Anion Salts of a New, Stable Carbocationic Reagent, the Dibenzosuberenyl (Dibenzotropylium) Ion." New Journal of Chemistry, 2008, 32, 1890-1898.
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Space-filling model of dimethylcadmium The first organocadmium compounds, dimethylcadmium, CH3-Cd-CH3, and diethylcadmium, CH3CH2-Cd-CH2CH3, were prepared in 1917 by Erich Krause. In general, they are prepared by transmetalation or by an exchange reaction between an organometallic reagent and a cadmium salt. One procedure for the synthesis of diethylcadmium is by the reaction of cadmium bromide with two equivalents of the Grignard reagent ethylmagnesium bromide in diethyl ether. A byproduct is magnesium bromide.
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Many modifications have been reported that influence the reactivity of this reagent. The compound adopts a complex cluster structure (the adjacent picture is a simplified cartoon), and additives that modify the cluster affect the reactivity of the reagent. For example, DMF, DMSO, hexamethylphosphoramide (HMPA), and 18-crown-6 interact with the potassium center, enhancing the basicity of the butoxide. Schlosser's base, a mixture of the alkoxide and an alkyl lithium compound, is a related but stronger base.
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Copper nitrate, in combination with acetic anhydride, is an effective reagent for nitration of aromatic compounds, known as the Menke nitration in honor of the Dutch chemist who discovered that metal nitrates are effective reagents for nitration. Hydrated copper nitrate adsorbed onto clay affords a reagent called "Claycop". The resulting blue- colored clay is used as a slurry, for example for the oxidation of thiols to disulfides. Claycop is also used to convert dithioacetals to carbonyls.
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These reagents were discovered by Henry Gilman and coworkers. Lithium dimethylcopper (CH3)2CuLi can be prepared by adding copper(I) iodide to methyllithium in tetrahydrofuran at −78 °C. In the reaction depicted below,Modern Organocopper Chemistry, N. Krause Ed. Wiley-VCH, 2002. the Gilman reagent is a methylating reagent reacting with an alkyne in a conjugate addition, and the negative charge is trapped in a nucleophilic acyl substitution with the ester group forming a cyclic enone.
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Microfluidic devices can be manufactured using variations of wax printing, inkjet printing, photolithography, flexographic printing, plasma treatment, laser treatment, etching (microfabrication), screen printing, Digital light processing (DLP) 3-D printer, and wax screening. Each technique aims to create hydrophobic physical barriers on hydrophilic paper that passively transport aqueous solutions. Biological and chemical reagents must then be deposited selectively along the device by either dipping the substrate into a reagent solution or locally spotting a reagent onto the substrate.
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The precipitation method is the one used for the determination of the amount of calcium in water. Using this method, an excess of oxalic acid, H2C2O4, is added to a measured, known volume of water. By adding a reagent, here ammonium oxalate, the calcium will precipitate as calcium oxalate. The proper reagent, when added to aqueous solution, will produce highly insoluble precipitates from the positive and negative ions that would otherwise be soluble with their counterparts (equation 1).
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A selenium version of this ring type has been made, one notable example has been named Woollins' reagent and is PhPSe, this is made by the reaction of (PhP) with selenium metal. The solubility of this compound is very low but the group of Prof John Derek Woollins have published some reactions of this compound. For instance the reaction of Woollins' reagent (WR) with a dialkyl cyanamide has been found to form a bicyclic PCNSe system.
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Indole test positive: appearance of pink layer at top (e.g. Escherichia coli) Like many biochemical tests on bacteria, results of an indole test are indicated by a change in color following a reaction with an added reagent. Pure bacterial culture must be grown in sterile tryptophan or peptone broth for 24–48 hours before performing the test. Following incubation, five drops of Kovac's reagent (isoamyl alcohol, para- Dimethylaminobenzaldehyde, concentrated hydrochloric acid) are added to the culture broth.
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Copper peroxide is prepared by the reaction of cold solutions of hydrogen peroxide and Schweizer's reagent, the latter prepared from copper hydroxide and dilute ammonia solution. The Schweizer's reagent used must not contain excess ammonia. Copper peroxide may also be produced by the reaction of an ice-cold solution of hydrogen peroxide with a suspension of copper hydroxide. It may also form from the very slow reaction of finely divided cupric oxide with cold hydrogen peroxide.
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Jones reagent interacts with secondary alcohols resulting in oxidation to ketones.See Oxidation of Alcohols to Aldehydes and Ketones. Treatment of compounds, containing both primary and secondary alcohols, with Jones reagent leads to formation of ketoacids. Problems encountered with the use of large quantities of chromium trioxide, which is toxic and dangerous for the environment, prompted the development by Zhao of a catalytic procedure, involving treatment with excess of periodic acid (H5IO6) in presence of about 1.2 mol% of CrO3.
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Oxalyl chloride is mainly used together with a N,N-dimethylformamide catalyst in organic synthesis for the preparation of acyl chlorides from the corresponding carboxylic acids. Like thionyl chloride, the reagent degrades into volatile side products in this application, which simplifies workup. One of the minor byproducts from the N,N-dimethylformamide catalyzed reaction is a potent carcinogen, stemming from the N,N-dimethylformamide decomposition. Relative to thionyl chloride, oxalyl chloride tends to be a milder, more selective reagent.
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When Tollen's reagent is added to an aldehyde, it precipitates silver metal, often forming a silver mirror on clean glassware. 3,5-dinitrosalicylic acid is another test reagent, one that allows quantitative detection. It reacts with a reducing sugar to form 3-amino-5-nitrosalicylic acid, which can be measured by spectrophotometry to determine the amount of reducing sugar that was present. Sugars having acetal or ketal linkages are not reducing sugars, as they do not have free aldehyde chains.
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Lithium hypochlorite is the colorless, crystalline lithium salt of hypochlorous acid with the chemical formula of LiClO. It is used as a disinfectant for pools and a reagent for some chemical reactions.
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Common oxidants used in this process are permanganate (both sodium permanganate and potassium permanganate), Fenton's Reagent, persulfate, and ozone. Other oxidants can be used, but these four are the most commonly used.
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Vanadium oxytrichloride is the inorganic compound with the formula VOCl3. This yellow distillable liquid hydrolyzes readily in air. It is an oxidizing agent. It is used as a reagent in organic synthesis.
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1-Fluoro-2,4-dinitrobenzene (commonly called Sanger's reagent, dinitrofluorobenzene, DNFB or FDNB) is a chemical that reacts with the N-terminal amino acid of polypeptides. This can be helpful for sequencing proteins.
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Ellman's reagent (5,5'-dithiobis-(2-nitrobenzoic acid) or DTNB) is a chemical used to quantify the number or concentration of thiol groups in a sample. It was developed by George L. Ellman.
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N-Bromosuccinimide or NBS is a chemical reagent used in radical substitution, electrophilic addition, and electrophilic substitution reactions in organic chemistry. NBS can be a convenient source of Br•, the bromine radical.
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Cross-metathesis is synthetically equivalent to (and has replaced) a procedure of ozonolysis of an alkene to two ketone fragments followed by the reaction of one of them with a Wittig reagent.
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SBT can be produced from 3-(2-aminoethanethio)-4-methylhex-2-enenitrile; however, it is also possible to synthesize SBT from ethanolamine and 2-methylbutanoic acid, using Lawesson's reagent and microwave irradiation.
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The trans isomer is isolated and reacts with the cadmium methyl Grignard reagent to 1-acetyl-2-isobutyryl-1-methylcyclopropane. This undergoes an aldol cyclization on treatment with dilute base to umbellulone.
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Bartlett and Beaudry discovered that IBX is a valuable reagent for the transformation of β-hydroxyketones to β-diketones. IBX provides yields superior to both the Swern and Dess–Martin oxidation protocols.
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The application of this reagent to oxidations was discovered by G. I. Poos, G. E. Arth, R. E. Beyler and L.H. Sarett in 1953. It was popularized by Collins several years later.
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His name is associated with Dragendorff's reagent, which is a solution of potassium bismuth iodide used to ascertain the presence of alkaloids. Dragendorff's test is a qualitative test formerly used for bile.
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On the other hand, Grubbs did not rule out the possibility of a tetramethylene intermediate. The first practical metathesis system was introduced in 1978 by Tebbe based on the (what later became known as the) Tebbe reagent. In a model reaction isotopically labeled carbon atoms in isobutene and methylenecyclohexane switched places: :Metathesis Tebbe reagent The Grubbs group then isolated the proposed metallacyclobutane intermediate in 1980 also with this reagent together with 3-methyl-1-butene: :Metathesis Grubbs 1980 They isolated a similar compound in the total synthesis of capnellene in 1986: :Metathesis Grubbs 1986 In that same year the Grubbs group proved that metathesis polymerization of norbornene by Tebbe's reagent is a living polymerization system and a year later Grubbs and Schrock co-published an article describing living polymerization with a tungsten carbene complex While Schrock focussed his research on tungsten and molybdenum catalysts for olefin metathesis, Grubbs started the development of catalysts based on ruthenium, which proved to be less sensitive to oxygen and water and therefore more functional group tolerant.
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The aldehydes will react further with (KMnO4), being oxidized to become carboxylic acids. Controlling the temperature and concentration of the reagent can keep the reaction from continuing past the formation of the glycol.
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Fétizon's reagent is typically prepared by adding silver nitrate to an aqueous solution of a carbonate, such as sodium carbonate or potassium bicarbonate, while being vigorously stirred in the presence of purified celite.
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Chloramine-T is the organic compound with the formula CH3C6H4SO2NClNa. Both the anhydrous salt and its trihydrate are known. Both are white powders. Chloramine-T is used as a reagent in organic synthesis.
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2-Acetylfuran was prepared by Ashina in 1914 via the reaction of the methyl Grignard reagent on 2-furonitrile. Modern industrial synthesis generally involves the Friedel–Crafts acylation of furan with acetic anhydride.
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Cyclopropylacetylene is used as reagent in organic reactions. It is, for example, a building block of the antiretroviral and psychotropic drug efavirenz. It can also be used in the azide-alkyne Huisgen cycloaddition.
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Mercury(II) acetate is the chemical compound with the formula Hg(O2CCH3)2. Commonly abbreviated Hg(OAc)2, this compound is employed as a reagent to generate organomercury compounds from unsaturated organic precursors.
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In 2014 this number had increased to 55%, in 2015, based on 2,445 respondents, to 66%. Popular ClojureScript projects include implementations of the React library such as Reagent, re-frame, Rum, and Om.
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Basidiospores are spherical to broadly ellipsoid, thin- to thick-walled, smooth, hyaline, and have a negative reaction to Melzer's reagent. Species of Oxyporus grow on both conifers and hardwoods, causing a white rot.
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Dimedone, 5,5-dimethyl-1,3-cyclohexanedione is a well established reagent. Several herbicides are formal derivatives of 1,3-cyclohexanedione. Examples of commercial products include cycloxydim, clethodim, tralkoxydim, butroxydim, profoxydim, mesotrione and quizalofop-P-ethyl.
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Vinyllithium is an organolithium compound with the formula LiC2H3. A colorless or white solid, it is encountered mainly as a solution in tetrahydrofuran (THF). It is a reagent in synthesis of organic compounds..
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The halogen group is an effective leaving group, leading to its use in both elimination and substitution reactions. In addition, the compound is also a candidate for coupling reactions via a Grignard reagent.
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As an alkyl halide, 2-chlorobutane can be used to prepare a Grignard reagent for use in forming a carbon-carbon bond.Bauld, N. (n.d.). Formation of Grignard Reagents from Organic Halides. In utexas.edu.
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Addition of Kovac's reagent to the SIM tube following growth typically indicates no indole formation (serotypes 2, 7, and 8 produce indole). Mannitol tests yields negative results. Ornithine Decarboxylase tests yield negative results.
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It is a potentially explosive material and is not commercially available, but it can be quickly prepared as needed. Its use as a laboratory reagent was pioneered and developed by William D. Emmons.
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Trioctylphosphine is an organophosphorus compound with the formula P(C8H17)3 sometimes abbreviated TOP. It is a common reagent in the chemical synthesis of nanoparticles. Trioctylphosphine reacts with oxygen to form trioctylphosphine oxide.
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Chicago: Society of American Archivists, 1984. The first instant films produced sepia tone photos. A negative sheet is exposed inside the camera, then lined up with a positive sheet and squeezed through a set of rollers which spread a reagent between the two layers, creating a developing film "sandwich". The negative develops quickly, after which some of the unexposed silver halide grains (and the latent image it contains) are solubilized by the reagent and transferred by diffusion from the negative to the positive.
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When the quaternary reagent, or substrate, is applied, the enzymatic end of the tertiary reagent converts the substrate into a pigment reaction product, which produces a color (many colors are possible; brown, black, red, etc.,) in the same location that the original primary antibody recognized that antigen of interest. Some examples of substrates used (also known as chromogens) are AEC (3-Amino-9-EthylCarbazole), or DAB (3,3'-Diaminobenzidine). Use of one of these reagents after exposure to the necessary enzyme (e.g.
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DMPD TMPD The oxidase test is a test used in microbiology to determine if a bacterium produces certain cytochrome c oxidases. It uses disks impregnated with a reagent such as N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD) or N,N-dimethyl-p-phenylenediamine (DMPD), which is also a redox indicator. The reagent is a dark-blue to maroon color when oxidized, and colorless when reduced. Oxidase-positive bacteria possess cytochrome oxidase or indophenol oxidase (an iron-containing hemoprotein).. Isenberg HD, editor.
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Pirkle's alcohol is an off-white, crystalline solid that is stable at room temperature when protected from light and oxygen. This chiral molecule is typically used, in nonracemic form, as a chiral shift reagent in nuclear magnetic resonance spectroscopy, in order to simultaneously determine absolute configuration and enantiomeric purity of other chiral molecules. The molecule is named after William H. Pirkle, Professor of Chemistry at the University of Illinois whose group reported its synthesis and its application as a chiral shift reagent.
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Several groups have also invoked Ni(I) as the active nickel catalyst. In these instances, it is possible that an initial transmetalation results in a LnNiIIXR intermediate, which can undergo disproportionation to LNiX2 and LNiR2. Subsequent reductive elimination from LNiR2 results in a Ni(0) intermediate which can disproportionate into LnNiIX. If the coupling reagent is not an organometallic, a sacrificial organometallic reagent such as AlMe3, Et2Zn, or MeMgBr can be added to the reaction to reduce the Ni(II) to Ni(0).
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The general form of the trivalent phosphorus reagent can be considered as follows: ABP-OR with A and B generally being alkyl, alkoxy or aryloxy groups. Electron-withdrawing groups are known to slow down the rate of the reaction, with electron donating groups increasing the rate of the reaction. This is consistent with initial attack of the phosphorus reagent on the alkyl halide as the rate-determining step of the reaction. The reaction proceeds smoothly when the R group is aliphatic.
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639 G 1.1.1 ;GaI :GaI is produced as a reactive green powder, which has been hailed as a "versatile reagent for the synthetic chemist".Baker R.J., Jones C. Dalton Trans. 2005 Apr 21;(8):1341-8 The chemical structure of the reagent termed ‘GaI’ produced from reacting gallium metal with iodine in toluene using ultrasound has only recently been investigated using 69/71Ga solid-state NMR and a tentative structure assigned which includes gallium metal atoms, [Ga0]2[Ga]+[GaI4]−.
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Although hemiamyloidity is a very valuable taxonomic marker that permits differentiation between species or genera, this type of reaction, in particular the red reaction in IKI, is often overlooked. This neglect occurred since mycologists switched to Melzer's reagent, which was introduced in 1924 and almost completely displaced the previously used Lugol's solution. Hemiamyloidity was first reported by applying Melzer's reagent which gave a negative result without KOH, but a blue reaction when treated with KOH beforehand. Kohn, L.M., and R.P. Korf. 1975.
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Cyanogen bromide is a common reagent in organic synthesis. As stated earlier, the reagent is prone to attack by nucleophiles such as amines and alcohols because of the electrophilic carbon. In the synthesis of cyanamides and dicyanamides, primary and secondary amines react with BrCN to yield mono- and dialkylcyanamides, which can further react with amines and hydroxylamine to yield guanidines and hydroxyguanidines. In the von Braun reaction, tertiary amines react with BrCN to yield disubstituted cyanamides and an alkyl bromide.
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Scandium trifluoromethanesulfonate, commonly called scandium triflate, is a chemical compound with formula Sc(SO3CF3)3, a salt consisting of scandium cations Sc3+ and triflate SO3CF3− anions. Scandium triflate is used as a reagent in organic chemistry as a Lewis acid. Compared to other Lewis acids, this reagent is stable towards water and can often be used in organic reactions as a true catalyst rather than one used in stoichiometric amounts. The compound is prepared by reaction of scandium oxide with trifluoromethanesulfonic acid.
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Borane dimethylsulfide is one of the most common bulk reducing agents used in the Corey–Itsuno reduction. The dimethylsulfide ligand attenuates the reactivity of the borane. Activation by the nitrogen of the chiral oxazoborolidine catalyst of the stoichiometric reducing agent allows for asymmetric control of the reagent. In general BMS does not lead to significantly greater enantiomeric selectivities than borane-THF, however its increased stability in the presence of moisture and oxygen makes it the reagent of choice for the reduction.
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Several qualitative tests are used to detect the presence of reducing sugars. Two of them use solutions of copper(II) ions: Benedict's reagent (Cu2+ in aqueous sodium citrate) and Fehling's solution (Cu2+ in aqueous sodium tartrate). The reducing sugar reduces the copper(II) ions in these test solutions to copper(I), which then forms a brick red copper(I) oxide precipitate. Reducing sugars can also be detected with the addition of Tollen's reagent, which consist of silver ions (Ag+) in aqueous ammonia.
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Jelly, R.; Lewis, S. W.;Lennard, C.; Lim, K. F.; Almog, J. Lawsone: a novel reagent for the detection of latent fingermarks on paper surfaces. Chem.Commun. 2008, 3513-3515 Recent research has been conducted on lawsone's potential applications in the forensic science field. Since lawsone shows many similarities with ninhydrin, the current reagent for latent fingerprint development, studies have been conducted to see if lawsone can be used in this field. As of now the research is inconclusive, but optimistic.
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The bottles are called "graduated" when they have marks on the sides indicating the approximate (often with a 10% error) amount of liquid at a given level within the container. A reagent bottle is a type of laboratory glassware. The term "reagent" refers to a substance that is part of a chemical reaction (or an ingredient of which), and "media" is the plural form of "medium" which refers to the liquid or gas which a reaction happens within, or is a processing chemical tool such as (for example) a flux. Several companies produce reagent bottles, including Wheaton, Kimble, Corning, Schott AG and trademark glass names include Pyrex, Kimax, Duran, Boro and Bomex. Common bottle sizes include 100 ml, 250 ml, 500 ml, 1000 ml (1 liter) and 2000 ml (2 liter).
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382x382px In the synthesis of the Negishi reagent, treatment of zirconocenedichloride in tetrahydrofuran with two equivalents of n-butyllithium at −78 °C gives (1-butene)zirconocene, which is represented by the resonance structures A and B. 632x632pxIf bis(trimethylsilyl)acetylene is used instead of n-butyllithium, a higher yield is can be obtained. In this case, zirconocene complexes are synthesized to Rosenthal's reagent, represented by the resonance structures A and B. This reagent is stable at room temperature, can be stored under an inert atmosphere and allows a more precise control over the stoichiometry of reactions as it can be formed quantitatively. A fine tune of the general reaction shown below is feasible by using different substituted cyclopentadienyl ligands as well as additional ligands (e. g. THF, pyridine).
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NHCs and boranes form stable NHC borane adducts. Triethylborane adducts can be synthesised directly from the imidazolium salt and lithium triethylborohydride. Members of this compound class are investigated for use as reagent or catalyst.
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Sartorius Stedium has developed several reagents for the Virus Counter since acquiring it in 2016. These reagents include Combodye, a duel stained reagent for enveloped viruses and Virotag, specific fluorescently labeled, high-affinity reagents.
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The assay is separated into three main parts: preparation of the Diluted Albumin (BSA) Standards, preparation of the bicinchoninic acid (BCA) working reagent, and quantification of proteins (using either test tube or microplate procedure).
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Tributyltin azide is an organotin compound with the formula (C4H9)3SnN3. It is a colorless solid although older samples can appear as yellow oils. The compound is used as a reagent in organic synthesis.
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This production method, whilst cleaner and resulting in a much more pure product than ECF, is not known to have been widely used except for the production of reagent grade PFOS and analytical standards.
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Sulfur trioxide is an essential reagent in sulfonation reactions. These processes afford detergents, dyes, and pharmaceuticals. Sulfur trioxide is generated in situ from sulfuric acid or is used as a solution in the acid.
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Benzophenone imine is an organic compound with the formula of (C6H5)2C=NH. Benzophenone imine is widely used as a reagent for the protection of primary amines, and the starting materials to synthesize aniline.
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Diethylaminosulfur trifluoride (DAST) is the organosulfur compound with the formula Et2NSF3. This liquid is a fluorinating reagent used for the synthesis of organofluorine compounds. The compound is colourless; older samples assume an orange colour.
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Applications include olefin metathesis and hydrogenation. The metal oxides require some activating reagent, usually a reducing agent, to enter the catalytic cycle. Often catalytic cycles show the conversion of a precatalyst to the catalyst.
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Methylmagnesium chloride is an organometallic compound with the general formula CH3MgCl. This highly flammable, colorless, and moisture sensitive material is the simplest Grignard reagent and is commercially available, usually as a solution in tetrahydrofuran.
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Mercury(II) bromide or mercuric bromide is the chemical compound composed of mercury and bromine with the formula HgBr2. This white crystalline solid is a laboratory reagent. Like mercury(II) chloride, it is extremely toxic.
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The salt was first prepared by the group of Albert Eschenmoser after whom the reagent is named. Analogous salts, dimethyl(methylidene)ammonium chloride (Böhme's salt, after Horst Böhme) and trifluoroacetate, have similar properties and applications.
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Benzeneselenol, also known as selenophenol, is the organoselenium compound with the formula C6H5SeH, often abbreviated PhSeH. It is the selenium analog of phenol. This colourless, intensely malodorous compound is a useful reagent in organic synthesis.
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J. Am. Chem. Soc. 1981, 103, 4985. Upon exposure to aldehydes and ketones, alkenylalanes form secondary or tertiary allylic alcohols. Formaldehyde is a useful reagent in this context for the introduction of a hydroxymethyl unit.
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Similarly Hg(OAc)2 is a standard reagent to convert thiocarbonate esters into dithiocarbonates: :(RS)2C=S + H2O + Hg(OAc)2 → (RS)2C=O + HgS + 2 HOAc Mercury(II) acetate is used for oxymercuration reactions.
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Solubility of organic materials and gases increases by several orders of magnitude and the water itself can act as a solvent, reagent, and catalyst in industrial and analytical applications, including extraction, chemical reactions and cleaning.
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AL-LAD does not cause a color change with the Marquis, Mecke or Mandelin reagents, but does cause the Ehrlich's reagent to turn purple because of the presence of the indole moiety in its structure.
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Niobium oxychloride is the inorganic compound with the formula NbOCl3. It is a white, crystalline, diamagnetic solid. It is often found as an impurity in samples of niobium pentachloride, a common reagent in niobium chemistry.
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Since styrene oxide has a chiral center at the benzylic carbon atom, there are (R)-styrene oxide and (S)-styrene oxide. If optically pure reagent is used, only one optically pure compound will be obtained.
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550x550px Carbolithiation is the addition of an organolithium reagent across a carbon-carbon pi-bond. The organolithium reagents used in this transformation can be commercial (such as n-butyllithium) or can be generated through deprotonation or lithium halogen exchange. Both inter- and intramolecular examples of carbolithiation exist and can be used in synthesis to generate complexity. Organolithiums are highly reactive chemicals and often the resulting organolithium reagent generated from the carbolithiation can continue to react with electrophiles or remaining starting material (resulting in polymerization).
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A proposed mechanism for the oxidation of an alcohol by Fétizon's reagent involves single electron oxidation of both the alcoholic oxygen and the hydrogen alpha to the alcohol by two atoms of silver(I) within the celite surface. The carbonate ion then proceeds to deprotonate the resulting carbonyl generating bicarbonate which is further protonated by the additionally generated hydrogen cation to cause elimination of water and generation of carbon dioxide.Tojo, Gabriel (2006) "Fétizon's reagent: Silver Carbonate on Celite." Oxidation of Alcohols to Aldehydes and Ketones.
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Fétizon's reagent is used primarily in the oxidation of primary or secondary alcohols to aldehydes or ketones with a slight selectivity toward secondary alcohols and unsaturated alcohols. The reaction is typically done in a refluxing dry non-polar organic solvent with copious stirring. The reaction time varies with the structure of the alcohol and is typically completed within three hours. A very attractive property of Fétizon's reagent is its ability to be separated from the reaction product by physically filtering it out and washing with benzene.
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The final step involves reacting this product with BH3 in THF, then reacting the product with piperazine in MeOH at reflux. 6-chloro-2-fluoro-3-pyridineacetamide is used as an intermediate in most syntheses, which is then reacted through these three general steps to produce phantasmidine. The structure of this intermediate is shown as the starting reagent in the general reaction mechanism above. Modern synthetic procedures, however, generally begin with 2-chloro-6-fluoropyridine as the starting reagent, due to its commercial availability.
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By reacting the bromopyrogallol red with niobium(V) in a tartrate medium at pH 6.0, an intense blue coloured 3:1 reagent was formed. The sensitivity and conditional selectivity of bromopyrogallol red was also studied and results show that trace amounts of silver can be detected from the formation of a ternary complex between 1,10-phenanthroline, bromopyrogallol red and silver ion. This is because of the two adjacent phenol groups in the structure of bromopyrogallol red. Bromopyrogallol red is used as indicating reagent for rare-earth elements.
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This salt is used as a flotation agent in molybdenite mineral concentration from ores, where it is usually known as "Nokes reagent." The salt is generated by the reaction of phosphorus pentasulfide with sodium hydroxide, often using impure reagents to obtain a mixture of the desired salt and related thiophosphates and oxidized species. Molybdenite particles, which are normally hydrophobic, become hydrophilic in the presence of this salt. In this context, the Nokes reagent is called a "depressant," since it suppresses the flotation tendency of the solids.
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In organic synthesis, reagent control is an approach to selectively forming one stereoisomer out of many, the stereoselectivity is determined by the structure and chirality of the reagent used. When chiral allylmetals are used for nucleophilic addition reaction to achiral aldehydes, the chirality of the newly generated alcohol carbon is determined by the chirality of the allymetal reagents (Figure 1). The chirality of the allymetals usually comes from the asymmetric ligands used. The metals in the allylmetal reagents include boron, tin, titanium, silicon, etc. Fig.
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Fuchsin solutions appear colored due to the visible wavelength absorbance of its central quinoid structure—see also for example viologen —but are "decolorized" upon sulfonation of the dye at its central carbon atom by sulfurous acid or its conjugate base, bisulfite. This reaction disrupts the otherwise favored delocalized extended pi-electron system and resonance in the parent molecule. The structure of the "decolorized" Schiff reagent. The further reaction of the Schiff reagent with aldehydes is complex with several research groups reporting multiple reaction products with model compounds.
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In synthesis, metallated reagents are typically involved in nucleophilic substitution, single-electron-transfer (SET), and redox chemistry with functional groups on other molecules (including but not limited to ketones, aldehydes, and alkyl halides). Metallated molecules may also participate in acid-base chemistry, with one organometallic reagent deprotonating an organic molecule to create a new organometallic reagent. The most common classes of metallated compounds are organolithium reagents and Grignard reagents. However, other organometallic compounds — such as organozinc compounds — also experience common use in both laboratory and industrial applications.
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When Dan insists, the dean implies that Dan and West have gone mad. Barred from the school, West and Dan sneak into the morgue to test the reagent on a human subject in an attempt to prove that the reagent works, and thereby salvage their medical careers. The corpse they inject comes back to life, but in a frenetic and violent zombie-like state. Dr. Halsey stumbles upon the scene and is killed by the reanimated corpse, which West then kills with a bone-saw.
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Cellulose dissolution in tetraaminecopper(II) hydroxide Schweizer's reagent is an alkaline solution of copper sulfate in ammonia, [Cu(NH3)4] (OH)2–3H2O, or CuH14N4O2. Schweizer's reagent may be prepared by covering technical grade, stabilized Copper(II) hydroxide with ammonium hydroxide. It was the basis for the process patented in 1890 by the French chemist Louis-Henri Despeissis for making fibers from cuprammonium rayon. He extruded the cuprammonium solution of cellulose into water, then used dilute sulfuric acid to neutralize the ammonia and precipitate the cellulose fibers.
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Pre-column derivatization may use the Edman reagent to produce a derivative that is detected by UV light. Greater sensitivity is achieved using a reagent that generates a fluorescent derivative. The derivatized amino acids are subjected to reversed phase chromatography, typically using a C8 or C18 silica column and an optimised elution gradient. The eluting amino acids are detected using a UV or fluorescence detector and the peak areas compared with those for derivatised standards in order to quantify each amino acid in the sample.
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Two examples of the Wittig reaction using methylenetriphenylphosphorane Because of its reliability and wide applicability, the Wittig reaction has become a standard tool for synthetic organic chemists. The most popular use of the Wittig reaction is for the introduction of a methylene group using methylenetriphenylphosphorane (Ph3P=CH2). Using this reagent, even a sterically hindered ketone such as camphor can be converted to its methylene derivative. In this case, the Wittig reagent is prepared in situ by deprotonation of methyltriphenylphosphonium bromide with potassium tert- butoxide.
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It has been demonstrated by Cummins and coworkers that thermolysis of compounds of the general form C14H10PC(=PPh3)R leads to the extrusion of C14H10 (anthracene), triphenylphosphine, and the corresponding substituted phosphaacetylene: R-C≡P. Unlike the previous method, which derives the phosphaalkyne substituent from an acyl chloride, this method derives the substituent from a Wittig reagent. Synthesis of phosphaalkynes from an anthracene based phosphine chloride and a Wittig reagent, as demonstrated by Cummins and coworkers. Here, R=H, Me, Et, iPr, or sBu.
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Seahorse Bioscience sells instruments and consumables. The XF Extracellular Flux Analyzer is the best-selling instrument. Consumables include Flux Paks, Microplates, and Stress Kits. The XF Palmitate-BSA FAO Reagent is a solution absorbed by cells.
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The National Science Foundation (NSF) funded Wiki project Open Wetware (OWW) provides a resource for reagent, project and laboratory notebook sharing. A somewhat related NSF consortium Synthetic Biology Engineering Research Center (SynBERC) constructs and distributes wetware.
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Mycoleptodonoides species have fruitbodies with caps with "teeth" on the underside. It has a monomitic hyphal system with generative hyphae containing clamp connections. Spores are small and smooth, and non-reactive with Melzer's reagent (non-amyloid).
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Aluminium isopropoxide is the chemical compound usually described with the formula Al(O-i-Pr)3, where i-Pr is the isopropyl group (-CH(CH3)2). This colourless solid is a useful reagent in organic synthesis.
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It can be also made by passing acetylene through solutions of hypochlorous acid. As a laboratory reagent, both DCA and TCA are used as precipitants to prompt macromolecules such as proteins to precipitate out of solution.
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Digestion with trypsin is very dependent on temperature. Higher temperatures digest the matrix faster but create more damage. Collagenase is less temperature dependent, and damages fewer cells, but takes longer and is a more expensive reagent.
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Collins reagent is the complex of chromium(VI) oxide with pyridine in dichloromethane. This metal-pyridine complex, a red solid, is used to oxidize primary alcohols to the aldehyde. This complex is a hygroscopic orange solid.
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Rhenium(IV) oxide or rhenium dioxide is the inorganic compound with the formula ReO2. This gray to black crystalline solid is a laboratory reagent that can be used as a catalyst. It adopts the rutile structure.
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It is often used as a sensitive spot test for ammonia. Similarly, Cu2HgI4 is used as a precipitating reagent to test for alkaloids. Aqueous alkaline iodine solution is used in the iodoform test for methyl ketones.
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The so-called Jones reagent is prepared by dissolving chromium trioxide (CrO3) in aqueous sulfuric acid, which results in formation of a reddish solution containing chromic acid (H2CrO4) and oligomers thereof. Addition of Jones reagent to a solution of a primary alcohol in acetone (as first described by Jones ) results in oxidation of the alcohol to a carboxylic acid. This classical protocol, involving a direct addition, is used very often regardless of the fact that it frequently leads to the formation of substantial amounts of esters (possessing the structure R-CO-O- CH2-R) derived from oxidative dimerization of primary alcohols. Holland and Gilman proved that this side reaction can be greatly suppressed by following the inverse addition protocol whereby a solution of the primary alcohol in acetone is slowly added to Jones reagent under conditions as dilute as practical.
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Prolinol is used in broad variety of chemical reactions as chiral ligand, chiral catalyst or chiral auxiliary reagent in the Hajos–Parrish–Eder–Sauer–Wiechert reaction, the Baylis–Hillman reaction, Noyori type reactions and the Michael reaction.
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Some synthetic processes can even generate phantasmidine from using epibatidine as a starting reagent. Epibatidine and epibatidine-related compounds have an LD50 of around 4 µg in mice; however, the exact LD50 of phantasmidine is not known.
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Propanoic anhydride is an organic compound with the formula (CH3CH2CO)2O. This simple acid anhydride is a colourless liquid. It is a widely used reagent in organic synthesis as well as for producing specialty derivatives of cellulose.
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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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Allylmagnesium bromide is a Grignard reagent used for introducing the allyl group. It is commonly available as a solution in diethyl ether. If desired, it may be synthesized in the normal method from magnesium and allyl bromide.
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This produces the species in relatively high amounts. In negative chemical ionization (NCI) the reagent gas decreases the impact of the free electrons on the target analyte. This decreased energy typically leaves the fragment in great supply.
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Fruit bodies of Xenasmataceae fungi are usually crust-like, with a waxy or gelatinous texture. The fungi have a monomitic hyphal system, and the hyphae are frequently gelatinous. Spores are translucent, and often stain with Melzer's reagent.
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Industrial applications include wood preservation, manufacturing other zinc salts, polymers, manufacture of ethyl acetate, as a dye mordant, and analytical reagent. It is used in commercial nuclear power plants as a plating inhibitor on primary water piping.
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2-3 drops of Barfoed's reagent is added to 1 mL of given sample in a test tube and boiled for 30 seconds and then allowed to cool. If a red precipitate occurs, a monosaccharide is present.
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Hexamethylenetetramine is a versatile reagent in organic synthesis. It is used in the Duff reaction (formylation of arenes), the Sommelet reaction (converting benzyl halides to aldehydes), and in the Delepine reaction (synthesis of amines from alkyl halides).
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Potassium azide is the inorganic compound having the formula . It is a white, water-soluble salt. It is used as a reagent in the laboratory. It has been found to act as a nitrification inhibitor in soil.
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If SLOS goes undetected until after birth, diagnosis may be based on the characteristic physical features as well as finding increased plasma levels of 7DHC. There are many different ways of detecting 7DHC levels in blood plasma, one way is using the Liebermann–Burchard (LB) reagent. This is a simple colorimetric assay developed with the intention of use for large scale screening. When treated with the LB reagent, SLOS samples turn pink immediately and gradually become blue; normal blood samples are initially colorless and develop a faint blue color.
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Fétizon oxidation is the oxidation of primary and secondary alcohols utilizing the compound silver(I) carbonate absorbed onto the surface of celite also known as Fétizon's reagent first employed by Marcel Fétizon in 1968. It is a mild reagent, suitable for both acid and base sensitive compounds. Its great reactivity with lactols makes the Fétizon oxidation a useful method to obtain lactones from a diol. The reaction is inhibited significantly by polar groups within the reaction system as well as steric hindrance of the α-hydrogen of the alcohol.
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In one of its main uses in organic synthesis, DMF was a reagent in the Vilsmeier–Haack reaction, which is used to formylate aromatic compounds. The process involves initial conversion of DMF to a chloroiminium ion, [(CH3)2N=CH(Cl)]+, known as a Vilsmeier reagent, which attacks arenes. Organolithium compounds and Grignard reagents react with DMF to give aldehydes after hydrolysis in a reaction named after Bouveault. Dimethylformamide forms 1:1 adducts with a variety of Lewis acids such as the soft acid I2, and the hard acid phenol.
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Since late 2000s, propanephosphonic acid anhydride, sold commercially under various names such as "T3P", has become a useful reagent for amide bond formation in commercial applications. It converts the oxygen of the carboxylic acid into a leaving group, whose peptide-coupling byproducts are water soluble and can be easily washed away. In a performance comparison between propanephosphonic acid anhydride and other peptide coupling reagents for the preparation of a nonapeptide drug, it was found that this reagent was superior to other reagents with regards to yield and low epimerization.J. Hiebl et al, J. Pept. Res.
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Grignard is most noted for devising a new method for generating carbon-carbon bonds using magnesium to couple ketones and alkyl halides. This reaction is valuable in organic synthesis. It occurs in two steps: #Formation of the "Grignard reagent", which is an organomagnesium compound made by the reaction an organohalide, R-X (R = alkyl or aryl; and X is a halide, usually bromide or iodide) with magnesium metal. The Grignard reagent is usually described with the general chemical formula R-Mg-X, although its structure is more complex.
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L-selectride is an organoborane. It is used in organic chemistry as a reducing agent, for example in the reduction of a ketone, as part of Overman's synthesis of strychnine. 470px Under certain conditions, L-selectride can selectively reduce enones by conjugate addition of hydride, owing to the greater steric hindrance the bulky hydride reagent experiences at the carbonyl carbon relative to the (also-electrophilic) β-position. L-Selectride can also stereoselectively reduce carbonyl groups in a 1,2-fashion, again due to the steric nature of the hydride reagent.
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There are many different reagents which can be used to label terminal amino acids. They all react with amine groups and will therefore also bind to amine groups in the side chains of amino acids such as lysine - for this reason it is necessary to be careful in interpreting chromatograms to ensure that the right spot is chosen. Two of the more common reagents are Sanger's reagent (1-fluoro-2,4-dinitrobenzene) and dansyl derivatives such as dansyl chloride. Phenylisothiocyanate, the reagent for the Edman degradation, can also be used.
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Due to hydrolysis by atmospheric moisture, P4S10 evolves H2S, thus P4S10 is associated with a rotten egg odour. Aside from H2S, hydrolysis of P4S10 eventually gives phosphoric acid: :P4S10 \+ 16 H2O → 4 H3PO4 \+ 10 H2S Other mild nucleophiles react with P4S10, including alcohols and amines. Aromatic compounds such as anisole, ferrocene and 1-methoxynaphthalene react to form 1,3,2,4-dithiadiphosphetane 2,4-disulfides such as Lawesson's reagent. P4S10 is used as a thionation reagent. Reactions of this type require refluxing solvents such as benzene, dioxane, or acetonitrile with P4S10 dissociating into P2S5.
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Collins reagent is especially useful for oxidations of acid sensitive compounds. Primary and secondary alcohols are oxidized respectively to aldehydes and ketones in yields of 87-98%. Like other oxidations by Cr(VI), the stoichiometry of the oxidations is complex because the metal undergoes 3e reduction and the substrate is oxidized by 2 electrons: :3 RCH2OH + 2 CrO3(pyridine)2 → 3 RCHO + 3 H2O + Cr2O3 \+ 4 pyridine The reagent is typically used in a sixfold excess. Methylene chloride is the typical solvent, with the solubility of 12.5 g/100 mL.
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This reagent is a good formylating agent and can regenerate the unsubstituted imidazole (with formation of carbon monoxide) upon heating. Yet another reaction involves the acylation of triphenylalkelynephosphoranes. ::(C6H5)3P=CHR + R'-CO-Im → (C6H5)3P+-CHR-COR' + Im− (C6H5)3P+-CHR-COR' + (C6H5)3P=CHR → (C6H5)3P=CR-COR' + (C6H5)3P+-CH2R These can undergo the Wittig reaction to form α,β unsaturated ketones or aldehydes. The reagent can even undergo reaction with peroxide to form the peroxycarboxylic acid, which can react further to form diacyl peroxides.
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Metal-catalyzed C-H Borylation reactions are transition metal catalyzed organic reactions that produce an organoboron compound through functionalization of aliphatic and aromatic C-H bonds. A common reagent in this type of reaction is bis(pinacolato)diboron.
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Aliquat 336 (Starks' catalyst) is a quaternary ammonium salt used as a phase transfer catalyst and metal extraction reagent. It contains a mixture of C8 (octyl) and C10 (decyl) chains with C8 predominating. It is an ionic liquid.
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Synthesis, properties, and reactivity of the compound were first described in 2006 by Antonio Togni and his coworkers at ETH Zurich. The article also contains information on 1,3-Dihydro-3,3-dimethyl-1-(trifluoromethyl)-1,2-benziodoxole (Togni Reagent I).
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Due to the application of microfluidics, neither initial biotin nor reagent treatment is necessary prior to primer extension. Rather the unlabelled, hybridized microRNA behaves as the primer for enzymatic elongation, a process in which biotinylated nucleotides are assembled.
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In the cluster [Co6H(CO)15]−, the hydride is "interstitial", occupying a position at the center of the Co6 octahedron. The assignment for cluster hydrides can be challenging as illustrated by studies on Stryker's reagent [Cu6(PPh3)6H6].
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Mosher worked on many other natural products including both plant pigments and toxic substances. Mosher also invented the "Mosher reagent" or Mosher's acid, which is used to measure the degree of left- or right-handedness in organic molecules.
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It is a white solid that rapidly degrades upon exposure to atmospheric moisture, although it is robust enough to be weighed and dispensed quickly without the benefit of inert atmosphere protection. Triethyloxonium tetrafluoroborate is a closely related reagent.
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Known as Nessler's reagent, potassium tetraiodomercurate(II) () is still occasionally used to test for ammonia owing to its tendency to form the deeply colored iodide salt of Millon's base. Mercury fulminate is a detonator widely used in explosives.
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Herman Eisen. During this time, Alain de Weck made initial contributions to what later became one of his signature research areas: penicillin allergy. In particular he developed penicilloyl-polylysine (PPL) as a test reagent for detecting penicillin allergy.
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This is a S-adenosylmethionine (SAM) precursor. SAM is a common reagent in biological methylation reactions. For example, it methylates guanidines of DNA and certain lysines of histones. Thus it is part of gene expression and epigenetic regulation.
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Sodium methoxide is a chemical compound with the formula CH3ONa. This white solid, which is formed by the deprotonation of methanol, is a widely used reagent in industry and the laboratory. It is also a dangerously caustic base.
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Ligand- modified versions of Stryker's reagent have been reported. By changing the ligand to e.g. P(O-iPr)3 the selectivity can be improved significantly.Andrejs Pelss, Esa T. T. Kumpulainen and Ari M. P. Koskinen J. Org. Chem.
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4-Aminophenylmercuric acetate (CH3CO2HgC6H4NH2, also known as 4-(Acetoxymercurio)aniline or APMA), is an organomercurial compound and thiol- blocking reagent used in experimental biology and chemistry to activate matrix metalloproteinases and collagenase proteolytic enzymes. The material is highly toxic.
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Synthesis of GSK1360707F: #BOC Protecting group. #Enolization and trapping with triflate group (cf Comins' reagent). #Suzuki reaction #Reduction (only 1 mol eq. LAH because N-BOC can be reduced to N-Me) #Trifluoroacetic acid (TFA) removal of protecting group.
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Trimethylsulfoxonium iodide is a sulfoxonium salt. It is used to generate dimethyloxosulfonium methylide by reaction with sodium hydride. The latter compound is used as a methylene-transfer reagent, and is used to prepare epoxides. This compound is commercially available.
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Iodobenzene dichloride is hydrolyzed by basic solutions to give iodosobenzene (PhIO), and is oxidized by sodium hypochlorite to give iodoxybenzene (PhIO2). In organic synthesis, iodobenzene dichloride is used as a reagent for the selective chlorination of alkenes and alkynes.
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Dimethylphosphite is an organophosphorus compound with the formula (CH3O)2P(O)H. It is a reagent for generating other organophosphorus compounds, exploiting the high reactivity of the P-H bond. The molecule is tetrahedral. It is a colorless liquid.
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About 25% of produced oxalic acid will be used as a mordant in dyeing processes. It is used in bleaches, especially for pulpwood. It is also used in baking powder and as a third reagent in silica analysis instruments.
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M. burtonii ICAT Proteome: Protein extracts from M. burtonii cultures grown at 4 °C and 23 °C were labeled with the ICAT reagent and digested with trypsin. ICAT-labeled peptides were isolated using affinity chromatography. 163 proteins were identified.
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Methyl bromoacetate is an alkylating agent. It has been used to alkylate phenol and amino groups. Moreover, it can be used to make vitamins and pharmaceutical drugs. It is commonly used as a reagent in chemical modification of histidine.
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1-Hydroxy-7-azabenzotriazole (HOAt) is a triazole used as a peptide coupling reagent. It suppresses the racemization. HOAt has a melting point between 213 and 216 degrees Celsius. As a liquid, it is transparent and without any color.
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Metal complexes containing terminal hydrides are common. In bi- and polynuclear compounds, hydrides usually are bridging ligands . Of these bridging hydrides many are oligomeric, such as Stryker's reagent. [(Ph3P)CuH]6 and clusters such as [Rh6(PR3)6H12]2+.
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Ethyl isopropyl ketone (2-methyl-3-pentanone) is an aliphatic ketone with used as a reagent in organic chemistry and as a solvent. Its fully fluorinated analog is known as Novec 1230 and is used in gaseous fire suppression.
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From this basic research, a reagent, Limulus amoebocyte lysate (LAL), was developed that can detect minute amounts of bacterial toxins. The LAL test has resulted in dramatic improvement in the quality of drugs and biological products for intravenous injection.
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The entry on Lawesson's reagent has some details on one sub-class of the phosphorus-based compounds. Some benzodiazepines, e.g. temazepam have an inhibitory effect on cholinesterase. Cholinesterase levels can be used as an indirect marker of arsenic exposure.
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Henry Gilman (May 9, 1893 – November 7, 1986) was an American organic chemist known as the father of organometallic chemistry, the field within which his most notable work was done. He discovered the Gilman reagent, which bears his name.
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Balogh, M. "Copper(II) Nitrate–K10 Bentonite Clay" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. . A related reagent based on montmorillonite has proven useful for the nitration of aromatic compounds.
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The Schlosser base (or Lochmann-Schlosser base), the combination of n-butyllithium and potassium tert-butoxide, is commonly cited as a superbase. n-Butyllithium and potassium tert-butoxide form a mixed aggregate of greater reactivity than either component reagent.
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Yohimbine is a drug used in veterinary medicine to reverse the effects of xylazine in dogs and deer. It is used as a research reagent. In the US, it is prescribed, but now rarely, for erectile dysfunction in men.
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O-Acetylpsilocin is ambiguously legal for use as a lab reagent or research chemical; however, it is an acetate ester of psilocin, meaning it would be considered Schedule I under the Federal Analogue Act if sold for human consumption.
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Trimethylsilane is the organosilicon compound with the formula (CH3)3SiH. It is a trialkylsilane. The Si-H bond is reactive. It is less commonly used as a reagent than the related triethylsilane, which is a liquid at room temperature.
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The first step of the Bouveault aldehyde synthesis is the formation of the Grignard reagent. Upon addition of a N,N-disubstituted formamide (such as dimethylformamide) a hemiaminal is formed, which can easily be hydrolyzed into the desired aldehyde.
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1,1'-Carbonyldiimidazole (CDI) is an organic compound with the molecular formula (C3H3N2)2CO. It is a white crystalline solid. It is often used for the coupling of amino acids for peptide synthesis and as a reagent in organic synthesis.
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Nitroacetic acid is the chemical compound with the formula (NO2)CH2CO2H. This substituted carboxylic acid is used as a potential precursor to nitromethane, commonly used as a fuel in drag racing and as an organic reagent in chemical synthesis.
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N-Iodosuccinimide (NIS) is a reagent used in organic chemistry for the iodination of alkenes and as a mild oxidant. NIS is the iodine analog of N-chlorosuccinimide (NCS) and N-bromosuccinimide (NBS) which are used for similar applications.
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Dimethylthiocarbamoyl chloride is an organosulfur compound with the formula (CH3)2NC(S)Cl. A yellow solid, it is often encountered as a yellow syrup. It is a key reagent in the synthesis of arylthiols via the Newman-Kwart rearrangement.
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FIA is an automated method of chemical analysis in which a sample is injected into a flowing carrier solution that mixes with reagents before reaching a detector. Over past 30 years, FIA techniques developed into a wide array of applications using spectrophotometry, fluorescence spectroscopy, atomic absorption spectroscopy, mass spectrometry, and other methods of instrumental analysis for detection. Automated sample processing, high repeatability, adaptability to micro-miniaturization, containment of chemicals, waste reduction, and reagent economy in a system that operates at microliter levels are all valuable assets that contribute to the application of flow injection to real- world assays. The main assets of flow injection are the well defined concentration gradient that forms when an analyte is injected into the reagent stream (which offers an infinite number of well-reproduced analyte/reagent ratios) and the exact timing of fluidic manipulations (which provide exquisite control over the reaction conditions).
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Simple organoboranes such as triethylborane or tris(pentafluorophenyl)boron can be prepared from trifluoroborane (as the ether complex) and the ethyl or pentafluorophenyl Grignard reagent. The borates (R4B− are generated via addition of R−-equivalents (RMgX, RLi, etc.) to R3B).
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One of the most common CDA is Mosher's acid. Another method involves non-covalent interactions. NMR shift reagents such as EuFOD, Pirkle's alcohol, and TRISPHAT take advantage of the formation of diastereomeric complexes between the shift reagent and the analytical sample.
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2 ml of the freshly prepared FRAP reagent was added to 10 lL of the extract. Then the absorbance was measured at 593 nm against the blank after 10 min at room temperature. The standard curve was constructed using Trolox.
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The spores are cylindrical, hyaline, and smooth, measuring 8–11 by 2.5–3.5 µm. They are unreactive in Melzer's reagent. Oligoporus fragilis is similar in appearance, but can be distinguished microscopically from Amylocystis lapponica by the lack of amyloid cystidia.
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Diethylphosphite is the organophosphorus compound with the formula (C2H5O)2P(O)H. It is a popular reagent for generating other organophosphorus compounds, exploiting the high reactivity of the P-H bond. Diethylphosphite is a colorless liquid. The molecule is tetrahedral.
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Dibutylboron trifluoromethanesulfonate (also called dibutylboron triflate or DBBT) is a reagent in organic chemistry. Its chemical formula is C9H18BF3O3S. It is used in asymmetric synthesis for example in the formation of boron enolates in the aldol reaction.Organic Syntheses, Coll. Vol.
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A common reagent for this purpose is thallium(III) trifluoroacetate. The intermediate arylthallium bisfluoroacetate can be isolated and converted to an aryl halide, aryl cyanide, aryl thiol or nitroarene. An example is the iodination of para- xylene.Organic Syntheses, Coll. Vol.
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The shape of the spores ranges from broadly ellipsoid to egg-shaped to more or less spherical, and measure 4.5–6 by 4–5 µm. They are slightly thick-walled, smooth, hyaline (translucent), and are non-reactive with Melzer's reagent.
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Bromine pentafluoride, BrF5, is an interhalogen compound and a fluoride of bromine. It is a strong fluorination reagent. BrF5 finds use in oxygen isotope analysis. Laser ablation of solid silicates in the presence of bromine pentafluoride releases O2 for subsequent analysis.
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Triethylindium can be prepared in a similar fashion but with the grignard reagent EtMgBr.Main Group compounds in Inorganic Syntheses, vol 31, By Schultz, Neumayer, Marks; Ed., Alan H. Cowley, John Wiley & Sons, Inc., 1997, :{InCl3} + 3LiMe -> {Me3In.OEt2} + 3LiCl :{InCl3} + 3MeMgI -> {Me3In.
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Succinyl chloride is the organic compound with the formula (CH2)2(COCl)2. It is the acyl chloride derivative of succinic acid and a simple diacid chloride. It is a colorless liquid. It used as a reagent in organic synthesis.
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The spore print is white. The spores are elliptical, smooth, with dimensions of 8–11 by 5–7 µm. They are amyloid, meaning they will absorb iodine when stained with Melzer's reagent. The spore-bearing cells (basidia) are 4-spored.
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Many electrophiles are chiral and optically stable. Typically chiral electrophiles are also optically pure. One such reagent is the fructose-derived organocatalyst used in the Shi epoxidation. The catalyst can accomplish highly enantioselective epoxidations of trans-disubstituted and trisubstituted alkenes.
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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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Also, phenolic hydroxy groups in nitrogen- containing aromatics can be converted into the chlorine compounds.W. Kijrungphaiboon et al., Cl3CCN/PPh3 and CBr4/PPh3: two efficient reagent systems for the preparation of N-heteroaromatic halides, Tetrahedron Lett., 53, 674–677 (2006).
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Precipitation in hydrometallurgy involves the chemical precipitation of either metals and their compounds or of the contaminants from aqueous solutions. Precipitation will proceed when, through reagent addition, evaporation, pH change or temperature manipulation, any given species exceeds its limit of solubility.
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The test itself is positive if, after adding only Griess reagent to the second bowl, the solution there remains clear. The convictions of Judith Ward and the Birmingham Six were assisted by Frank Skuse's flawed interpretation of Griess test results.
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Metals are "won" from their oxides by chemical reduction, i.e. by the addition of a chemical reagent. A common and cheap reducing agent is carbon in the form of coke. The most prominent example is that of iron ore smelting.
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Due to the same reason, the pressure within the inert gas system will always remain close to atmospheric. This is a disadvantage when attempting cannula transfers using inert gas pressure to force a liquid reagent into another using a cannula.
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The colours are due to LMCT transitions. Chromium trioxide is the anhydride of molecular chromic acid. It is a Lewis acid and can react with a Lewis base, such as pyridine in a non-aqueous medium such as dichloromethane (Collins reagent).
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Basic fuchsine is a mixture of rosaniline, pararosaniline, new fuchsine and Magenta II.Horobin RW & Kiernan JA 20002. Conn's Biological Stains, 10th ed. Oxford: BIOS, p. 184–191 Formulations usable for making of Schiff reagent must have high content of pararosanilin.
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Thulium(III) bromide is used as a reagent for the complexation of lanthanide bromides with aluminium bromide, and as a reactant for preparing alkali metal thulium bromides. It is also used to create discharge lamps that are free of mercury.
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In the late 1970s, trifluoroacetyl chloride was explored for use as a reagent for nuclear magnetic resonance. It was intended to be used on amines, alcohols, thiols, and phenols. Trifluoroacetyl chloride is typically stored as a liquid under high pressure.
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A further oxidation reaction involves Fehling's reagent as a test. The Cu2+ complex ions are reduced to a red-brick-coloured Cu2O precipitate. If the aldehyde cannot form an enolate (e.g., benzaldehyde), addition of strong base induces the Cannizzaro reaction.
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Neophyl chloride, C6H5C(CH3)2CH2Cl, is a halogenated organic compound with unusual nucleophilic substitution properties. Neophyl chloride is used to form a versatile organolithium reagent, neophyl lithium, by reaction with lithium.Lide, R. D.; CRC Handbook of Chemistry and Physics. 2003, 590.
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Microscopy image of a tooth at 100x magnification, stained with Melzer's reagent Spore deposits are white. Viewed under a light microscope, the spores appear hyaline (translucent), covered with minute wart-like bumps, and are spherical or nearly so, with dimensions of 4.6–5.5 by 4–5 µm. They are amyloid (reacting to Melzer's reagent) and cyanophilous (staining in methyl blue). The basidia (spore-bearing cells of the hymenium) are four-spored with basal clamps, and measure 15–24 by 3–4 µm, and sterigmata (extensions of the basidia that bear the spores) are swollen at the base and roughly 3 µm long.
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Fenton's reagent is basically a mixture of ferrous iron salts as a catalyst and hydrogen peroxide. A similar sort of reaction can be made by mixing hydrogen peroxide with [ferric] iron (Iron III). When the peroxide is catalyzed by soluble iron it forms hydroxyl radicals(·OH) that oxidize contaminants such as chlorinated solvents, fuel oils, and BTEX. Traditional Fenton's reagent usually requires a significant pH reduction of the soils and groundwater in the treatment zone to allow for the introduction and distribution of aqueous iron as iron will oxidize and precipitate at a pH greater than 3.5.
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Sanger's Nobel lecture was also published in Science: Prior to this it was widely assumed that proteins were somewhat amorphous. In determining these sequences, Sanger proved that proteins have a defined chemical composition. To get to this point, Sanger refined a partition chromatography method first developed by Richard Laurence Millington Synge and Archer John Porter Martin to determine the composition of amino acids in wool. Sanger used a chemical reagent 1-fluoro-2,4-dinitrobenzene (now, also known as Sanger's reagent, fluorodinitrobenzene, FDNB or DNFB), sourced from poisonous gas research by Bernhard Charles Saunders at the Chemistry Department at Cambridge University.
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This reaction can be optimized by carefully controlling the amount of organolithium reagent addition, or using trimethylsilyl chloride to quench excess lithium reagent. A more common way to synthesize ketones is through the addition of organolithium reagents to Weinreb amides (N-methoxy-N-methyl amides). This reaction provides ketones when the organolithium reagents is used in excess, due to chelation of the lithium ion between the N-methoxy oxygen and the carbonyl oxygen, which forms a tetrahedral intermediate that collapses upon acidic work up. :Li add to weinreb Organolithium reagents can also react with carbon dioxide to form carboxylic acids.
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First off, a Vilsmeier-Haack reagent is prepared by refluxing paraformaldehyde and dimethylamine hydrochloride in isopentanol at a temperature of 131 °C while removing water from the isopentanol using a Dean-Stark separator. The internal temperature of the reagent is then cooled to 10–15 °C, before adding commercially available boldenone (androsta-1,4-dien-17β-ol-3-one). The reaction mixture is then refluxed for 15 hours to give the 6-methylene derivative, 6-methyleneandrosta-1,4-dien-17β-ol-3-one. Subsequently, Jones oxidation of the derivative in acetone at −10 °C gives exemestane in 79% yield after recrystallization.
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Organolithium reagents were synthesized for the first time in 1917 by Schlenk and Holtz, though these reagents did not see widespread use as metallating agents or reagents in organic synthesis until Karl Ziegler, Henry Gilman, and Georg Wittig — among others — developed synthetic methods that improved upon this initial synthesis. After these improvements in synthesis came to be known, interest in the compounds increased significantly, as they are generally more reactive than organomagnesium compounds. The first use of an organolithium reagent as a metalation reagent occurred in 1928, with Schlenk and Bergmann's metalation of fluorene with ethyllithium.
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These reactions use Umemoto's reagent, a sulfonium salt that serves as an electrophilic source of the trifluoromethyl group and that is precedented to react via a single-electron transfer pathway. Thus, single-electron reduction of Umemoto's reagent releases trifluoromethyl radical, which adds to the reactive olefin. Subsequently, single-electron oxidation of the alkyl radical generated by this addition produces a cation which can be trapped by water, an alcohol, or a nitrile. In order to achieve high levels of regioselectivity, this reactivity has been explored mainly for styrenes, which are biased towards formation of the benzylic radical intermediate.
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Lawesson's reagent is commercially available. It can also be conveniently prepared in the laboratory by heating a mixture of anisole with phosphorus pentasulfide until the mixture is clear and no more hydrogen sulfide is formed, then recrystallized from toluene or xylene. As Lawesson's reagent has a strong and unpleasant smell, it is best to prepare the compound within a fume-hood and to treat all glassware used with a decontamination solution before taking the glassware outside the fume-hood. One common and effective method of destroying the foul smelling residues is to use an excess of sodium hypochlorite (chlorine bleach).
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Dess–Martin periodinane (DMP) is a chemical reagent used in the Dess–Martin oxidation, oxidizing primary alcohols to aldehydes and secondary alcohols to ketones. This periodinane has several advantages over chromium- and DMSO-based oxidants that include milder conditions (room temperature, neutral pH), shorter reaction times, higher yields, simplified workups, high chemoselectivity, tolerance of sensitive functional groups, and a long shelf life. However, use on an industrial scale is made difficult by its cost and its potentially explosive nature. It is named after the American chemists Daniel Benjamin Dess and James Cullen Martin who developed the reagent in 1983.
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The formation of acetals reduces the total number of molecules present (carbonyl + 2 alcohol → acetal + water) and therefore is generally not favourable with regards to entropy. One situation where it is not entropically unfavourable is when a single diol molecule is used rather than two separate alcohol molecules (carbonyl + diol → acetal + water). Another way to avoid the entropic cost is to perform the synthesis by acetal exchange, using a pre-existing acetal-type reagent as the OR'-group donor rather than simple addition of alcohols themselves. One type of reagent used for this method is an orthoester.
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Johann Urban, co-founder of VGF, in 1928 In 1857 the Swiss chemist Matthias Eduard Schweizer (1818–60) found that cotton could be dissolved in a solution of copper salts and ammonia and then regenerated. In 1890 the French chemist Louis Henri Despeissis invented the cuprammonium process for spinning fibers from cotton dissolved in Schweizer's reagent. Despeissis died in 1892 and his patent was not renewed. Max Fremery (1859–1932), a German chemist, and Johann Urban (1863–1940), an Austrian engineer, were manufacturing lamp filaments in Oberbruch near Aachen in 1891 using cotton and Schweizer's reagent.
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Tetraamminediaquacopper(II) hydroxide is known as Schweizer's reagent, and has the remarkable ability to dissolve cellulose. Diamminesilver(I) ([Ag(NH3)2]+) is the active species in Tollens' reagent. Formation of this complex can also help to distinguish between precipitates of the different silver halides: silver chloride (AgCl) is soluble in dilute (2M) ammonia solution, silver bromide (AgBr) is only soluble in concentrated ammonia solution, whereas silver iodide (AgI) is insoluble in aqueous ammonia. Ammine complexes of chromium(III) were known in the late 19th century, and formed the basis of Alfred Werner's revolutionary theory on the structure of coordination compounds.
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In the in situ method, protein synthesis is carried out on a protein array surface that is pre-coated with a protein-capturing reagent or antibody. Once the newly synthesized proteins are released from the ribosome, the tag sequence that is also synthesized at the N- or C-terminus of each nascent protein will be bound by the capture reagent or antibody, thus immobilizing the proteins to form an array. Commonly used tags include polyhistidine (His)6 and glutathione s-transferase (GST). Various research groups have developed their own methods, each differing in their approach, but can be summarized into 3 main groups.
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The Trinder glucose activity test is a diagnostic test used in medicine to determine the presence of glucose or glucose oxidase. The test employs the Trinder reagent, and is a colour change test resulting from the Trinder reaction. The Trinder reagent, named after P. Trinder of the Biochemistry Department of the Royal Infirmary in Sunderland (see the article listed in further reading), comprises an aminoantipyrine (such as 4-aminoantipyrine) and phenol (p-hydroxybenzene). The Trinder reaction is the reaction between hydrogen peroxide and the phenol and aminoantipyrine to form a quinone (quinoneimine), catalyzed by the presence of a peroxidase (such as horseradish peroxidase).
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Oxophilic reagents are often used to extract or exchange oxygen centers in organic substrates, especially carbonyls (esters, ketones, amides) and epoxides. The highly oxophilic reagent generated from tungsten hexachloride and butyl lithium is useful for the deoxygenation of epoxides. Such conversions are sometimes valuable in organic synthesis. In the McMurry reaction, ketones are converted into alkenes using oxophilic reagents: :2 R2CO + "Ti" → R2C=CR2 \+ TiO2 Similarly, Tebbe's reagent is used in olefination reactions: : Cp2TiCH2AlCl(CH3)2 \+ R2C=O → "Cp2TiO" + 0.5 (AlCl(CH3)2)2 \+ R2C=CH2 Oxophilic main group compounds are also well known and useful.
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A byproduct of the reaction is elemental phosphorus (or boron) which is incorporated in the coating. Tollens' reagent is a classical exampleof electroless silver plating. For other metals like gold and copper, the reducing agent is typically a low- molecular-weight aldehydes.
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N-Hydroxysuccinimide (NHS) is an organic compound with the formula (CH2CO)2NOH. It is a white solid that is used as a reagent for preparing active esters in peptide synthesis. It can be synthesized by heating succinic anhydride with hydroxylamine or hydroxylamine hydrochloride.
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Discovered in 1937 by Robin Hill, Hill reagents allowed the discovery of electron transport chains during photosynthesis. These are dyes that act as artificial electron acceptors, changing color when they are reduced. An example of a Hill reagent is 2,6-dichlorophelindophenol (DCPIP).
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It is often preferred to other detection methods because it is fast (24-hour testing), relatively accurate ( <1% false negatives and <5% false positives ) and the result is easy to observe and interpret. The reagent is safe to transport and easy to store.
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Danh, N. C.; Arnaud, C.; Huet, J. Bull. Soc. Chim. Fr. 1974, 1071. On the other hand, use of the bulky reagent LTBA leads to a high yield of the conjugate addition product (Eq. ()).Durand, J.; Anh, N. T.; Huet, J. Tetrahedron Lett.
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The solution of the reagent can be used directly without purification, minimizing contact with the carcinogenic chloromethyl methyl ether. Unlike the classical procedure, which uses formaldehyde and hydrogen chloride as starting materials, the highly carcinogenic side product bis(chloromethyl) ether is not generated.
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Triphosgene is used as a reagent in organic synthesis as a source of CO2+. It behaves like phosgene to which it cracks thermally: :OC(OCCl3)2 → 3 OCCl2 Alcohols are converted to carbonates. Primary and secondary amines are converted to ureas and isocyanate.
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Suberoyl chloride is used as a reagent to synthesize hydroxyferrocifen hybrid compounds that have antiproliferative activity against triple negative breast cancer cells. It is also used as a cross-linking agent to cross-link chitosan membranes, and also improves the membrane's integrity.
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The entire experiment is done at room temperature. The Bradford protein assay can measure protein quantities as little as 1 to 20 μg. It is an extremely sensitive technique. The dye reagent is a stable ready to use product prepared in phosphoric acid.
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Iodine pentafluoride is an interhalogen compound with chemical formula IF5. It is one of the fluorides of iodine. It is a colorless liquid, although impure samples appear yellow. It is used as a fluorination reagent and even a solvent in specialized syntheses.
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Clinical Microbiology Procedures Handbook. American Society for Microbiology; 2004. p. 3.3.2-3.3.2.13 These both catalyze the transport of electrons from donor compounds (NADH) to electron acceptors (usually oxygen). The test reagent, TMPD dihydrochloride acts as an artificial electron donor for the enzyme oxidase.
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This reaction also shows that manganate(VII) can serve as an electron acceptor in addition to its usual role as an oxygen- transfer reagent. Barium manganate, BaMnO4, is generated by the reduction of KMnO4 with iodide in the presence of barium chloride.
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A method for generating trifluoroperacetic acid in situ for use in Baeyer–Villiger oxidations from sodium percarbonate and trifluoroacetic anhydride has been reported; it provides a convenient and cheap approach to this reagent without the need to obtain highly concentrated hydrogen peroxide.
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The method according to Rühlmann employs trimethylchlorosilane as a trapping reagent; by this, competing reactions are efficiently subdued. Generally, yields increase considerably. The hydrolytic cleavage of the silylether gives the acyloin. To achieve a mild cleavage methanol can be used in several cases.
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Vinyl bromide and related alkenyl halides form the Grignard reagent and related organolithium reagents. Alkenyl halides undergo base elimination to give the corresponding alkyne. Most important is their use in cross-coupling reactions (e.g. Suzuki-Miyaura coupling, Stille coupling, Heck coupling, etc.).
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Ethanethiol is a reagent in organic synthesis. In the presence of sodium hydroxide, it gives the powerful nucleophile EtS−. The salt can be generated quantitatively by reaction with sodium hydride. Ethanethiol can be oxidized to ethyl sulfonic acid, using strong oxidizing agents.
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Excited at the prospect of working with a freshly dead specimen, West injects Dr. Halsey's body with his reanimating reagent. Dr. Halsey returns to life, also in a zombie-like state. Megan chances upon the scene, and is hysterical. Dan collapses in shock.
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If the reaction is negative, "check cells"—reagent cells coated with IgG—are added to ensure that the test is working correctly. If the test result is indeed negative, the check cells should react with the unbound anti-human globulin and demonstrate agglutination.
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The method avoids DNA cloning (with the exception of NAPPA) and can quickly convert genetic information into functional proteins by using PCR DNA. The reduced steps in production and the ability to miniaturize the system saves on reagent consumption and cuts production costs.
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Positive and negative ions of the analyte are formed by reactions with this plasma. For example, protonation occurs by :CH4 + e^- -> CH4+ + 2e^- (primary ion formation), :CH4 + CH4+ -> CH5+ + CH3 (reagent ion formation), :M + CH5+ -> CH4 + [M + H]+ (product ion formation, e.g. protonation).
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3-Hexyne is the organic compound with the formula C2H5CCC2H5. This colorless liquid is one of three isomeric hexynes. 3-Hexyne forms with 5-decyne, 4-octyne, and 2-butyne a series of symmetric alkynes. It is a reagent in organometallic chemistry.
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Being a widely available reagent, TsCl has been heavily examined from the perspective of reactivity. It is used in dehydrations to make nitriles, isocyanides and diimides. In an unusual reaction focusing on the sulfur center, zinc reduces TsCl to the sulfinate, CH3C6H4SO2Na.
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Copper(I) t-butoxide is an alkoxide of copper(I). It is a white sublimable solid. It is a reagent in the synthesis of other copper compounds. The compound was originally obtained by salt metathesis from lithium tert-butoxide and copper(I) chloride.
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Silver trifluoromethanesulfonate, or silver triflate is the triflate (CF3SO3−) salt of Ag+. It is a white or colorless solid that is soluble in water and some organic solvents including, benzene. It is a reagent used in the synthesis of organic and inorganic triflates.
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It is also used to introduce the trimethylsilyl protecting group in organic synthesis.Harry Heaney, Jian Cui, “N,O-Bis(trimethylsilyl)acetamide” Encyclopedia of Reagents for Organic Synthesis Copyright © 2007 John Wiley & Sons. . A related reagent is N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA).
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The main purpose of the control line is to indicate a proper migration and reagent color. The typhidot test becomes positive within 2–3 days of infection. Two colored bands indicate a positive test. Single-band of control line indicates a negative test.
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They are smooth and thin-walled, hyaline (translucent), with an allantoid (long with rounded ends) to broadly ellipsoid shape. They are unreactive with Melzer's reagent. The basidia (spore-bearing cells) are thin walled and club shaped, measuring 6–10 by 3–4 µm.
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Phosphorus can reduce elemental iodine to hydroiodic acid, which is a reagent effective for reducing ephedrine or pseudoephedrine to methamphetamine. For this reason, iodine was designated by the United States Drug Enforcement Administration as a List I precursor chemical under 21 CFR 1310.02.
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Many CF3-containing metal complexes have been prepared, and some are useful for trifluoromethylation. The most obvious reagent is CF3Li, which can be generated by lithium-iodide exchange. This compound is however unstable even at low temperatures. It degrades to lithium fluoride and difluorocarbene.
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An elimination reaction regenerates the carbene and releases the product 4. For comparison: in the Baylis-Hillman reaction the same electrophilic β-carbon atom is attacked by a reagent but resulting in the activation of the α-position of the enone as the nucleophile.
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Acetone oxime (acetoxime) is the organic compound with the formula (CH3)2CNOH. It is the simplest example of a ketoxime. It is a white crystalline solid that is soluble in water, ethanol, ether, chloroform, and ligroin. It is used as a reagent in organic synthesis.
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It is prepared by distillation of an equimolar mixture of fluorosulfonic acid and dimethyl sulfate. It was originally produced by the reaction of methanol with fluorosulfonic acid. Methyl fluorosulfonate is a highly electrophilic reagent for methylation. It is ranked as less powerful than methyl trifluoromethanesulfonate.
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Reduced glutathione may be visualized using Ellman's reagent or bimane derivatives such as monobromobimane. The monobromobimane method is more sensitive. In this procedure, cells are lysed and thiols extracted using a HCl buffer. The thiols are then reduced with dithiothreitol and labelled by monobromobimane.
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Aspergillus nuclease S1 is used in the laboratory as a reagent in nuclease protection assays. In molecular biology, it is used in removing single stranded tails from DNA molecules to create blunt ended molecules and opening hairpin loops generated during synthesis of double stranded cDNA.
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The toxicity of triphosgene and phosgene are the same since the trimer decomposes to phosgene on heating and upon reaction with nucleophiles. Trace moisture leads to formation of phosgene. Therefore, this reagent can be safely handled if one takes all the precautions as for phosgene.
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Methional is synthesized commercially by the reaction of methanethiol and acrolein. :CH3SH + CH2=CHCHO → CH3SCH2CH2CHO Using the Strecker synthesis, methional is converted to methionine. For the purpose of animal feed supplements, enantiopure methionine is not required. Methional is a versatile reagent in organic chemistry.
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The reagent is an alkaline solution of potassium permanganate. Reaction with double or triple bonds (-C=C- or -C≡C-) causes the color to fade from purplish-pink to brown. Aldehydes and formic acid (and formates) also give a positive test. The test is antiquated.
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BCl3 is an aggressive reagent that can form hydrogen chloride upon exposure to moisture or alcohols. The dimethyl sulfide adduct (BCl3SMe2), which is a solid, is much safer to use, when possible, but H2O will destroy the BCl3 portion while leaving dimethyl sulfide in solution.
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Hydrobromic acid is mainly used for the production of inorganic bromides, especially the bromides of zinc, calcium, and sodium. It is a useful reagent for generating organobromine compounds. Certain ethers are cleaved with HBr. It also catalyzes alkylation reactions and the extraction of certain ores.
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The Shapiro reaction or tosylhydrazone decomposition is an organic reaction in which a ketone or aldehyde is converted to an alkene through an intermediate hydrazone in the presence of 2 equivalents of organolithium reagent. The reaction was discovered by Robert H. Shapiro in 1967.
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Synthetic antibodies can be used in all applications where traditional monoclonal or polyclonal antibodies are used and offer many inherent advantages over animal-derived antibodies, including comparatively low production costs, reagent reproducibility and increased affinity, specificity and stability across a range of experimental conditions.
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It reacts with nitrobenzene to produce phenazine in the Wohl-Aue reaction. Hydrogenation gives cyclohexylamine. Being a standard reagent in laboratories, aniline is used for many niche reactions. Its acetate is used in the aniline acetate test for carbohydrates, identifying pentoses by conversion to furfural.
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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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Tetrazolium dye assays can also be used to measure cytotoxicity (loss of viable cells) or cytostatic activity (shift from proliferation to quiescence) of potential medicinal agents and toxic materials. MTT assays are usually done in the dark since the MTT reagent is sensitive to light.
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Toluene, benzene, and butenes react only slowly with alkyllithium reagents and not at all with potassium alkoxides, yet they react rapidly with a mixture of the two. Although there are similarities, the reactivities of Schlosser's base and the isolated alkylpotassium reagent are not identical.
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Matthias Eduard Schweizer (8 August 1818 – 23 October 1860) was a Swiss chemist. He is known for his 1857 invention of Schweizer's reagent, in which cellulose can be dissolved for production of artificial silk. He was one of the pioneers of the synthetic textile industry.
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The taste and odor are mild. The spore print is yellow to orange-yellow. The spores are elliptical, wrinkled or slightly warted, and 10–14 by 5–7.5 μm. They are nonamyloid, meaning they have a negative color reaction with the iodine in Melzer's reagent.
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It has a dimitic hyphal system with clamps in the generative hyphae; the skeletal hyphae are thick-walled and have a strong dextrinoid reaction with Melzer's reagent. Spores are more or less spherical to truncate, thick-walled, and measure 5–6 by 3–4 μm.
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"Primer for Municipal Wastewater Treatment Systems." Document no. EPA 832-R-04-001. Because of the large amount of reagent necessary to treat domestic wastewater, preliminary chemical coagulation and flocculation are generally not used, remaining suspended solids being reduced by following stages of the system.
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DABCO (1,4-diazabicyclo[2.2.2]octane) is a bicyclic organic compound with the formula N2(C2H4)3. This colorless solid is a highly nucleophilic tertiary amine base, which is used as a catalyst and reagent in polymerization and organic synthesis.Uppuluri V. Mallavadhani, Nicolas Fleury-Bregeot.
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Because it has no C–H bonds, carbon tetrachloride does not easily undergo free-radical reactions. It is a useful solvent for halogenations either by the elemental halogen or by a halogenation reagent such as N-bromosuccinimide (these conditions are known as Wohl–Ziegler bromination).
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Ball-and-stick model of Ph3P=CH2, as found in the crystal structure The Wittig reagent may be described in the phosphorane form (the more familiar representation) or the ylide form: 300px The ylide form is a significant contributor, and the carbon atom is nucleophilic.
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An example of the use of the Wittig reaction in synthesis, making leukotriene A methyl ester Methoxymethylenetriphenylphosphine is a Wittig reagent for the homologation of aldehydes and ketones. After the Wittig reaction, hydrolysis of the methoxyalkene gives an enol, which tautomerizes to an aldehyde.
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Phenylmagnesium bromide, with the simplified formula , is a magnesium- containing organometallic compound. It is commercially available as a solution in diethyl ether or tetrahydrofuran (THF). Phenylmagnesium bromide is a Grignard reagent. It is often used as a synthetic equivalent for the phenyl "Ph−" synthon.
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This would lead to undesirable side reactions, and thus falsifying a result consumption of bromine. For educational purposes, Simurdiak et al. (2016) suggested the use of pyridinium tribromide as bromination reagent which is more safer in chemistry class and reduces drastically the reaction time.
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One of his papers on the use of the reagent is his most cited article, with 223 citations through September 2014 according to Google Scholar.publication list on Google Scholar Other papers of his on this topic have had as many as 170 and 172 citations.
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Faradaic efficiency of a cell design is usually measured through bulk electrolysis where a known quantity of reagent is stoichiometrically converted to product, as measured by the current passed. This result is then compared to the observed quantity of product measured through another analytical method.
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Reagent compositions and method for forming metal films on a substrate by chemical vapor deposition. USPTO Patent Full-Text and Image Database (retrieved on 15 September 2008) He was married and had two sons, aged 2 and 5 at the time of his death.
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Diketene is an organic compound with the molecular formula C4H4O2, and which is sometimes written as (CH2CO)2. It is formed by dimerization of ketene, H2C=C=O. Diketene is a member of the oxetane family. It is used as a reagent in organic chemistry.
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As catalysts for the polymerization of dienes, vanadium complexes are activated with alkylaluminium chlorides, e.g. diethylaluminium chloride. The organoaluminium reagent installs alkyl groups on the V(III) precatalyst. During catalysis or during catalyst activation, some vanadium(III) is reduced to inactive vanadium(II) derivatives.
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Triphenylcarbethoxymethylenephosphorane is an organophosphorus compound with the chemical formula Ph3PCHCO2Et (Ph = phenyl, Et = ethyl). It is a white solid that is soluble in organic solvents. The compound is a Wittig reagent. It is used to replace oxygen centres in ketones and aldehydes with CHCO2Et.
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Aldehydes are commonly generated by alcohol oxidation. In industry, formaldehyde is produced on a large scale by oxidation of methanol. Oxygen is the reagent of choice, being "green" and cheap. In the laboratory, more specialized oxidizing agents are used, but chromium(VI) reagents are popular.
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The reaction mechanism of the Bartoli indole synthesis is illustrated below using o-nitrotoluene (1) and propenyl Grignard (2) to form 3,7-dimethylindole (13). The mechanism of the Bartoli indole synthesis The mechanism begins by the addition of the Grignard reagent (2) onto the nitroarene (1) to form intermediate 3. Intermediate 3 spontaneously decomposes to form a nitrosoarene (4) and a magnesium salt (5). (Upon reaction workup, the magnesium salt will liberate a carbonyl compound (6).) Reaction of the nitrosoarene (4) with a second equivalent of the Grignard reagent (2) forms intermediate 7. The steric bulk of the ortho group causes a [3,3]-sigmatropic rearrangement forming the intermediate 8.
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The cells often have brown contents, and in the presence of 2% potassium hydroxide (KOH) will appear hyaline (translucent) or vinaceous (red wine-colored); in Melzer's reagent they become pale yellow or brown. The cheilocystidia (cystidia found on the edge of a gill) are 30–60 by 7–10 µm, club-shaped to almost cylindrical, thin-walled, with brown incrusting material at the base, and arranged like a bundle of fibers. In KOH they appear hyaline, and are pale yellow in Melzer's reagent. Caulocystidia (found on the stipe) are 60–90 by 7–9 µm, mostly cylindrical with rounded ends, and arranged in bundles with brown pigment particles at the base.
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Furthermore, particularly with NO+ it is possible to separate and independently quantifiy some isomers. In 2012 a PTR-MS instrument was introduced which extends the selectable reagent ions to Kr+ and Xe+; this should allow for the detection of nearly all possible substances (up to the ionization energy of krypton (14 eV)). Although the ionization method for these additional reagent ions is charge-exchange rather than proton-transfer ionization the instruments can still be considered as "classic" PTR-MS instruments, i.e. no mass filter between the ion source and the drift tube and only some minor modifications on the ion source and vacuum design.
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This reagent is not commercially available due to its short shelf life, so it must be freshly prepared in the laboratory. One common preparation involves two steps. First a few drops of dilute sodium hydroxide are added to some aqueous 0.1 M silver nitrate. The HO− ions convert the silver aquo complex form into silver oxide, Ag2O, which precipitate from the solution as a brown solid: :2 AgNO3 \+ 2 NaOH → Ag2O (s) + 2 NaNO3 \+ H2O In the next step, sufficient aqueous ammonia is added to dissolve the brown silver(I) oxide. The resulting solution contains the [Ag(NH3)2]+ complexes in the mixture, which is the main component of Tollens' reagent.
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A dark glass bottle with ground glass plug. Reagent bottles, also known as media bottles or graduated bottles, are containers made of glass, plastic, borosilicate or related substances, and topped by special caps or stoppers. They are intended to contain chemicals in liquid or powder form for laboratories and stored in cabinets or on shelves. Some reagent bottles are tinted amber (actinic), brown or red to protect light-sensitive chemical compounds from visible light, ultraviolet and infrared radiation which may alter them; other bottles are tinted blue (cobalt glass) or uranium green for decorative purposes -mostly vintage apothecary sets, from centuries in which a doctor or apothecary was a prominent figure.
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Therefore, blood typing using IgG antisera requires incubation at and use of the indirect antiglobulin test to demonstrate IgG bound to red blood cells. To type antigens by the indirect antiglobulin test, antisera against the relevant antigen is added to a suspension of red blood cells, then incubated at , the ideal temperature for reactivity of IgG antibodies. After incubation, the red blood cells are washed with saline to remove unbound antibodies, and anti- human globulin reagent is added. If the IgG antibodies in the reagent have bound to the antigen on the cell surface, anti-human globulin will bind to those antibodies, causing the red blood cells to agglutinate after centrifugation.
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Organometallic compounds are compounds that have a bond between a carbon and a metal atom. The halogen atom of an aryl halide atom could be exchanged for a metal atom using an organometallic reagent. An example of such reaction is the reaction between bromobenzene and an organolithium reagent, where there is a nucleophilic attack of the lithium cation on bromine. The formula to such reaction is: : C6H5Br + C4H10Li → C6H5Li + C4H10Br Reaction of Organolithium and Aryl Halide The reaction is able to occur since benzene has a higher acidity compared to butane, which can be explained by the stability of the carbanion after the molecule loses a proton.
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Sanger's reagent (DNFB), B total acid hydrolysis of the dinitrophenyl peptide Determining which amino acid forms the N-terminus of a peptide chain is useful for two reasons: to aid the ordering of individual peptide fragments' sequences into a whole chain, and because the first round of Edman degradation is often contaminated by impurities and therefore does not give an accurate determination of the N-terminal amino acid. A generalised method for N-terminal amino acid analysis follows: #React the peptide with a reagent that will selectively label the terminal amino acid. #Hydrolyse the protein. #Determine the amino acid by chromatography and comparison with standards.
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In mycology a tissue or feature is said to be amyloid if it has a positive amyloid reaction when subjected to a crude chemical test using iodine as an ingredient of either Melzer's reagent or Lugol's solution, producing a blue to blue-black staining. The term "amyloid" is derived from the Latin amyloideus ("starch-like"). It refers to the fact that starch gives a similar reaction, also called an amyloid reaction. The test can be on microscopic features, such as spore walls or hyphal walls, or the apical apparatus or entire ascus wall of an ascus, or be a macroscopic reaction on tissue where a drop of the reagent is applied.
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Microscopically, the spores have smooth surfaces, measuring 9–11 by 3–4.5 µm; in side profile they have asymmetrical sides and a suprahilar depression (a surface indentation formed where the spore attaches to the basidia), while in face view they appear oblong. The spores are not amyloid, meaning that they do not absorb iodine when stained with Melzer's reagent. The basidia (the spore-bearing cells in the hymenium) are thin- walled, four-spored, and have dimensions of 17–19 by 5–7.8 µm. In the presence of potassium hydroxide, they appear hyaline (translucent), and they become pale yellow to nearly hyaline in Melzer's reagent.
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Another oxidation reaction is the basis of the silver-mirror test. In this test, an aldehyde is treated with Tollens' reagent, which is prepared by adding a drop of sodium hydroxide solution into silver nitrate solution to give a precipitate of silver(I) oxide, and then adding just enough dilute ammonia solution to redissolve the precipitate in aqueous ammonia to produce [Ag(NH3)2]+ complex. This reagent converts aldehydes to carboxylic acids without attacking carbon–carbon double bonds. The name silver-mirror test arises because this reaction produces a precipitate of silver, whose presence can be used to test for the presence of an aldehyde.
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Early 1900s The need for high-quality analytical reagent grade chemicals was recognized by chemists in the early 1900s when variations in the purity of routinely used laboratory chemicals began to produce unacceptable variations in the analytical analysis. 1903 With these concerns in mind, the American Chemical Society took the initiative to create the Committee on the Purity of Reagents, the forerunner of the Committee on Analytical Reagents. 1917 The American Chemical Society established the ACS Committee on Analytical Reagents. This Committee, over the past 100 years, has established specifications for reagent grade chemicals used worldwide. William F. Hillebrand (1853-1925) was appointed the chairman of the committee.
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Thermolysis of iron pentacarbonyl gives triiron dodecacarbonyl, , a with a cluster of three iron atoms at its core. Collman's reagent, disodium tetracarbonylferrate, is a useful reagent for organic chemistry; it contains iron in the −2 oxidation state. Cyclopentadienyliron dicarbonyl dimer contains iron in the rare +1 oxidation state.. A landmark in this field was the discovery in 1951 of the remarkably stable sandwich compound ferrocene , by] Paulson and Kealy and independently by Miller and others, whose surprising molecular structure was determined only a year later by Woodward and Wilkinson and Fischer. Ferrocene is still one of the most important tools and models in this class.
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Potassium thioacetate is an organosulfur compound and a salt with the formula CH3COS−K+. This white, water-soluble solid is used as a reagent for preparing thioacetate esters and other derivatives.Zongjun Qiao and Xuefeng Jiang "Potassium Thioacetate" e-EROS Encyclopedia Of Reagents For Organic Synthesis, 2014.
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Roussoëlla is a genus of fungi in the family Didymosphaeriaceae. The genus is characterized by two-celled ascospores, unitunicate asci with a small spherical apical ring that stains slightly blue with Melzer's reagent, and stromata with several perithecia. The genus was named after Marietta Hannon Rousseau.
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In the case of Ullmann-type reactions (aminations, etherifications, etc. of aryl halides), the reaction involves copper(I) alkoxide, copper(I) amides, copper(I) thiolates. The copper(I) reagent can be generated in situ from the aryl halide and copper metal. Even copper(II) sources are effective.
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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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DMP is used mainly as bifunctional coupling reagent to link proteins. It is often used to prepare antibody affinity columns. The appropriate antibody is first incubated with Protein A or Protein G-agarose and allowed to bind. DMP is then added to couple the molecules together.
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Methyl fluorosulfonate, also known as magic methyl, is the organic compound with the formula FSO2OCH3. It is a colorless liquid that is used as a strong methylating agent in organic synthesis. Because of its extreme toxicity, it has largely been replaced by the related reagent methyl trifluoromethanesulfonate.
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Alkenes undergo hydroalumination in the presence of some alkoxyaluminium hydrides.Ashby, C.; Noding, A. J. Org. Chem. 1980, 45, 1035. In a related application, NaAlH2(OCH2CH2OCH3)2 (sodium bis(methoxyethoxy) aluminium dihydride, SMEAH or Red-Al) reacts with zirconocene dichloride to afford zirconocene chloride hydride (Schwartz's reagent).
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Dibutyltin oxide, or dibutyloxotin, is an organotin compound with the chemical formula (C4H9)2SnO. It is a colorless solid that, when pure, is insoluble in organic solvents. It is used as a reagent and a catalyst.Davies, Alwyn G. "Organotin Chemistry", 2nd Edition, 2004, Wiley-VCH: Weinheim. .
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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 spores are 9–12 × 5–6 µm, ellipsoid, and are not amyloid; their surface is smooth. They are yellow in Melzer's reagent. The basidia have dimension of 46–62 × 7–10 µm, and are tetrasporic with short, stubby sterigmata. They have neither pleurocystidia nor cheilocystidia.
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The Barbier reaction involves nucleophilic addition of a carbanion equivalent to a carbonyl. The conversion is similar to the Grignard reaction. The organozinc reagent is generated via an oxidative addition into the alkyl halide. The reaction produces a primary, secondary, or tertiary alcohol via a 1,2-addition.
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Scientists have reported that exploitation of polluted waters which are rich in algal biomass for biotechnological products could be a feasible proposition and that the Phycobiliproteins from algae could be used as sensitive fluorescent dye, as immunochemical reagent and also as efficient fluorochromes in multiple colour analysis.
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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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2-Methyl-6-nitrobenzoic anhydride is an organic acid anhydride also known as the Shiina reagent, having a structure wherein carboxylic acids undergo intermolecular dehydration condensation. It was developed in 2002 by Prof. Isamu Shiina (Tokyo University of Science, Japan). The compound is often abbreviated MNBA.
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Convenient generation of a directing group on the nitrogen of indoles is possible through treatment with an organolithium reagent and carbon dioxide.Katritzky, A. R.; Akutagawa, K. J. Am. Chem. Soc. 1986, 108, 6808. A similar method can be applied for lateral lithiations of ortho-tolyl anilines.
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The hyphal system in Bjerkandera is monomitic, containing only generative hyphae. These hyphae have clamps, and are thin to thick-walled. Cystidia are absent from the hymenium. The spores of Bjerkandera are smooth with a short cylindrical shape, thin-walled, and do not react in Melzer's reagent.
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In synthetic chemistry, two classes of chlorination are usually of interest: oxidative chlorinations and substitutive chlorinations. Oxidative chlorinations entail the transfer of Cl2 from the reagent to the substrate. Substitutive chlorinations entail replacement of O or OH groups with chloride. PCl5 can be used for both processes.
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HFBA has a variety of niche applications in analytical and synthetic chemistry. It is an ion pair reagent for reverse-phase HPLC. It is used in the sequencing, synthesis, and solubilizing of proteins and peptides. Esters derived from HFBA readily undergo condensation, owing to their electrophilicity.
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Rochelle salt is deliquescent so any transducers based on the material deteriorated if stored in damp conditions. It has been used medicinally as a laxative. It has also been used in the process of silvering mirrors. It is an ingredient of Fehling's solution (reagent for reducing sugars).
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983 Sodium Potassium tartrate is also important in the food industry. It is a common precipitant in protein crystallography and is also an ingredient in the Biuret reagent which is used to measure protein concentration. This ingredient maintains cupric ions in solution at an alkaline pH.
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In 2012 a concise and highly stereoselective total synthesis of PGF2α was described. The synthesis requires only seven steps, a huge improvement on the original 17-steps synthesis of Corey and Cheng, and uses 2,5-dimethoxytetrahydrofuran as a starting reagent, with S-proline as an asymmetric catalyst.
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This method, which is largely obsolete, uses sodium in the presence of proton sources. Especially for fine chemical syntheses, lithium aluminium hydride is used to reduce esters to two primary alcohols. The related reagent sodium borohydride is slow in this reaction. DIBAH reduces esters to aldehydes.
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Nanotubes reacted with the diazonium reagent can be converted back into pristine nanotubes when thermally treated at 300 °C in an atmosphere of inert gas. This cleaves the aryl hydroxyl moieties from the nanotube sidewall and restores the spectroscopic feature (Raman and absorption spectra) of pristine nanotube.
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Such compounds find occasional use as stoichiometric reagents in organic synthesis. "Methyltitanium trichloride", nominally CH3TiCl3, can be prepared by treating titanium(IV) chloride with dimethylzinc in dichloromethane at -78 °C. It delivers a methyl groups to carbonyl compounds and alkyl halides. "Methyltriisopropoxytitanium" is a related reagent.
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It is darkly stained. It depends on acid hydrolysis of DNA, therefore fixating agents using strong acids should be avoided. The specimen is subjected to warm (60 °C) hydrochloric acid, then to Schiff reagent. In the past, a sulfite rinse followed, but this is now considered unnecessary.
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Acetic acid is a chemical reagent for the production of chemical compounds. The largest single use of acetic acid is in the production of vinyl acetate monomer, closely followed by acetic anhydride and ester production. The volume of acetic acid used in vinegar is comparatively small.
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Bjerkandera fumosa has a monomitic hyphal system, containing only generative hyphae. The basidia are club-shaped, measuring 20–22 μm. Spores have the shape of short cylinders, and measure 5.5–7 by 2.5–3.5 μm. They are smooth, hyaline, and do not react with Melzer's reagent.
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Protection Reagent: Phosgene, pyridine, -78 to -23 °C, 0.5 h Deprotection Reagents: Phenyllithium in tetrahydrofuran at -78 °C. Diol 19 (Scheme 3) was protected as a cyclic carbonate ester. This carbonate ester was cleaved by phenyllithium in tetrahydrofuran at -78 °C to give hydroxybenzoate 42 (Scheme 4).
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Diphosgene is a chemical compound with the formula ClCO2CCl3. This colorless liquid is a valuable reagent in the synthesis of organic compounds. Diphosgene is related to phosgene and has comparable toxicity, but is more conveniently handled because it is a liquid, whereas phosgene is a gas.
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The compound has antiseptic properties and can act as a disinfectant. It is also used as a "disappearing" preservative in some brands of eye drops. Sodium perborate is also used as an oxidizing reagent in organic synthesis. For example, it converts thioethers into sulfoxides and sulfones.
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Flow injection analysis (FIA) is an approach to chemical analysis. It is accomplished by injecting a plug of sample into a flowing carrier stream. The principle is similar to that of Segmented Flow Analysis (SFA) but no air is injected into the sample or reagent streams.
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The brick-red color of unreacted chromium trioxide (chromic anhydride). The Sarett reagent was originally prepared in 1953 by addition of chromium trioxide to pyridine. The pyridine must be cooled because the reaction is dangerously exothermic. Slowly, the brick-red CrO3 transform into the bis(pyridine) adduct.
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Professor Ion A. Atanasiu (25 September 1894 - 19 December 1978) was the founder of the Romanian School of Electrochemistry and the first to teach this subject in Romania. He is known as the originator of cerimetry, an analytical method based on Cerium (IV) as titration reagent.
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Typical acids are trifluoro- and trichloroacetic acids. Symmetric anhydrides can thus be formed by replacing this trifluoro- or trichloroacetyl group with the acid that was used to form the original reagent. Another related reaction is the reaction of formic acid with CDI to form the formylized imidazole.
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Instrumentation can be used to read extremely small signals created by secondary reactions linked to the antibody – antigen binding. Instrumentation can control sampling, reagent use, reaction times, signal detection, calculation of results, and data management to yield a cost- effective automated process for diagnosis of infectious disease.
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Spores at 1000x magnification. Each minor division equals 1 µm. When viewed in mass, such as with a spore print, the spores appear to be white. Viewed with a light microscope, the basidiospores are 8–10.5 by 4.5–5.5 µm, ellipsoid, smooth, and yellowish in Melzer's reagent.
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A different type of ring breaking reaction can occur when LR is reacted with a metal compounds such as a platinum dichloride bis-phosphine complex, in this case one molecule of MeOCHP(S)Cl is formed as a side product to the platinum complex ([Pt(SP(S)CHOMe)(PR)]). Lawesson's reagent can be used as a dehydrating reagent, for example it has been used to convert a β-aminoamide into an imidazoline. Another useful reaction of LR is the conversion of a 1,4-diketone into a thiophene ring, this reaction can be done with PS but a much higher temperature would be required to make it work with PS. It was claimed in a German patent that the reaction of 1,3,2,4-dithiadiphosphetane 2,4-disulfides with dialkyl cyanamides formed plant protection agents which contained six-membered (P-N=C-N=C-S-) rings. It has been proven in recent times by the reaction of diferrocenyl 1,3,2,4-dithiadiphosphetane 2,4-disulfide (and Lawesson's reagent) with dimethyl cyanamide that in fact a mixture of several different phosphorus containing compounds is formed.
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2,4-Dinitrophenylhydrazine is commercially available usually as a wet powder. It can be prepared by the reaction of hydrazine sulfate with 2,4-dinitrochlorobenzene: :300px Brady's reagent is prepared by dissolving 2,4-dinitrophenylhydrazine in a solution containing methanol and some concentrated sulfuric acid. The medium should be slightly acidic.
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Ventana Medical Systems, Inc. develops, manufactures, and markets instrument reagent systems that automate tissue and slide staining in anatomic pathology laboratories. These products assist in the diagnosis and treatment of cancer and infectious diseases. Part of the Roche Diagnostics Division, Ventana is a member of the Roche Group.
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The Zwikker reagent is used as a simple spot-test to presumptively identify barbiturates. It is composed of a mixture of two solutions. Part A is 0.5 g of copper (II) sulfate in 100 ml of distilled water. Part B consists of 5% pyridine (v/v) in chloroform.
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Hexachlorodisilane is the inorganic compound with the chemical formula Si2Cl6.Simmler, W. "Silicon Compounds, Inorganic", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH. It is a colourless liquid that fumes in moist air. It has specialty applications in as a reagent and as a volatile precursor to silicon metal.
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The cyano group usually cannot be introduced by nucleophilic substitution of haloarenes, but such compounds can be easily prepared from diazonium salts. Illustrative is the preparation of benzonitrile using the reagent cuprous cyanide: :C6H5N+2 + CuCN -> C6H5CN + Cu+ + N2 This reaction is a special type of Sandmeyer reaction.
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Isopropyl β--1-thiogalactopyranoside (IPTG) is a molecular biology reagent. This compound is a molecular mimic of allolactose, a lactose metabolite that triggers transcription of the lac operon, and it is therefore used to induce protein expression where the gene is under the control of the lac operator.
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In organosulfur chemistry, sulfiding is often called thiation. The preparation of thioamides from amides involves thiation. A typical reagent is phosphorus pentasulfide (P4S10). The idealized equation for this conversion is: :RC(O)NH2 \+ 1/4 P4S10 → RC(S)NH2 \+ 1/4 P4S6O4 The process involves no redox reaction.
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Yet Brown's Ph.D. thesis published in 1939 received little interest. Diborane was too rare to be useful as a synthetic reagent. In 1939, Brown became the research assistant in Schlesinger's laboratory. In 1940, they began to research volatile, low molecular weight uranium compounds for the National Defense Research Committee.
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The carbon attached to magnesium functions as a nucleophile, attacking the electrophilic carbon atom that is present within the polar bond of a carbonyl group. The addition of the Grignard reagent to the carbonyl typically proceeds through a six-membered ring transition state. The mechanism of the Grignard reaction.
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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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Triethyloxonium tetrafluoroborate is the organic oxonium compound with the formula [(CH3CH2)3O]BF4. It is often called Meerwein's reagent or Meerwein's salt after its discoverer Hans Meerwein. Also well known and commercially available is the related trimethyloxonium tetrafluoroborate. The compounds are white solids that dissolve in polar organic solvents.
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Diazonaphthoquinone (DNQ) is a diazo derivative of naphthoquinone. Upon exposure to light, DNQ converts to a derivative that is susceptible to etching. In this way, DNQ has become an important reagent in photoresist technology in the semiconductor industry. Diazonaphthoquinone sulfonic acid esters are components of common photoresist materials.
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Phlebiella species are characterized by pleurobasidia and a lack of cystidia in the hymenium. The genus is otherwise quite variable morphologically; for example, spores range from allantoid (sausage-shaped) to spherical, the surface ornamentation ranges from warted to smooth, and reaction with Melzer's reagent can be amyloid or inamyloid.
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The oxidized reagent forms the colored compound indophenol blue. The cytochrome system is usually only present in aerobic organisms that are capable of using oxygen as the terminal electron acceptor. The end-product of this metabolism is either water or hydrogen peroxide (broken down by catalase).MacFaddin JF, editor.
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Copper hydrides are specialized reagents used occasionally as reducing agent. The best known copper hydride is called Stryker's reagent, a cluster compound with the formula [(PPh3)CuH]6. It reduces the alkene α,β-unsaturated carbonyl compounds. The Buchwald reaction is a copper-catalyzed asymmetric reduction of activated alkenes.
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Bromobimane or monobromobimane is a heterocyclic compound and bimane dye that is used as a reagent in biochemistry. While bromobimane itself is essentially nonfluorescent, it alkylates thiol groups, displacing the bromine and adding the fluorescent tag (λemission = 478 nm) to the thiol. Its alkylating properties are comparable to iodoacetamide.
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G. maritimus forms a more inclusive clade along with the members of spectabilis–imperialis; while it produces the smallest fruit bodies, it shares with the other members strong, sturdy mushrooms, caps with fibrils (sometimes with scales) and large, warty spores that turn red in Melzer's reagent or Lugol's iodine.
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However, the faster rate of cis-trans isomerization in THF results in a loss of stereochemical purity. This is a case where understanding the effect of solvent on the stability of the molecular configuration of a reagent is important with regard to the selectivity observed in an asymmetric synthesis.
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Magnaporthaceae that reproduce sexually, have perithecial ascomata that are immersed in host tissue, frequently with long necks. Asci are cylindrical and stain positive in Meltzer's reagent. Ascospores are curved to sigmoid and contain septa. They show variability in their morphology and can be filiform (Gaeumannomyces) or fusiform (Nakataea = Magnaporthe).
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The main use of sodium nitrite is for the industrial production of organonitrogen compounds. It is a reagent for conversion of amines into diazo compounds, which are key precursors to many dyes, such as diazo dyes. Nitroso compounds are produced from nitrites. These are used in the rubber industry.
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Woollins' reagent is commercially available. It can also be conveniently prepared in the laboratory by heating a mixture of dichlorophenylphosphine and sodium selenide (Na2Se), (itself prepared from reacting elementary selenium with sodium in liquid ammonia). An alternative synthesis is the reaction of the pentamer (PPh)5 with elemental selenium.
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Spores are ellipsoid and smooth. When they are viewed in mass, such as with a spore print, the spores appear white. Observing with a light microscope reveals additional details: spores are ellipsoid, smooth, and measure 6–8 by 3.5–5 μm. They are pale yellow in Melzer's reagent.
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Tropic acid is a chemical with IUPAC name 3-hydroxy-2-phenylpropanoic acid and condensed structural formula HOCH2CHPhCOOH. It is a laboratory reagent used in the chemical synthesis of atropine and hyoscyamine. Tropic acid is a chiral substance, existing as either a racemic mixture or as a single enantiomer.
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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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Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is an organic compound with the chemical formula CH3Cl. One of the haloalkanes, it is a colorless, odorless, flammable gas. Methyl chloride is a crucial reagent in industrial chemistry, although it is rarely present in consumer products.
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EuFOD is the chemical compound with the formula Eu(OCC(CH3)3CHCOC3F7)3, also called Eu(fod)3. This coordination compound is used primarily as a shift reagent in NMR spectroscopy. It is the premier member of the lanthanide shift reagents and was popular in the 1970s and 1980s.
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4-Toluenesulfonyl chloride (p-toluenesulfonyl chloride, toluene-p-sulfonyl chloride) is an organic compound with the formula CH3C6H4SO2Cl. This white, malodorous solid is a reagent widely used in organic synthesis. Abbreviated TsCl or TosCl, it is a derivative of toluene and contains a sulfonyl chloride (−SO2Cl) functional group.
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Synthesis of benzophenone imine assisted by grignard reagent The first report about the preparation of ketimines involved Grignard-nitrile complexes followed by careful hydrolysis, which is known as Moureu-Mignonac ketimine synthesis. Then Pickard and Tolbert improved the preparation by using methanol in the addition of Grignard-nitrile complexes.
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Sulfur chloride pentafluoride (), a useful source of the SF5 group, is prepared from SF4. Hydrolysis of SF4 gives sulfur dioxide: :SF4 \+ 2 H2O → SO2 \+ 4 HF This reaction proceeds via the intermediacy of thionyl fluoride, which usually does not interfere with the use of SF4 as a reagent.
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Lipofectamine is a reagent used in the lab to aid in transfection, allowing foreign DNA to enter the target cell. In a study by Garmann et al. they found that the CCMV viral capsids are very robust, remaining intact even after treatment with RNase in the absence of lipofectamine.
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When heated to over 600 °C niobium trichloride disproportionates to niobium metal and niobium pentachloride. NbCl3(dimethoxyethane) has received significant attention as a reagent for reductive coupling of carbonyls and imines. Niobium(III) chloride forms many molecular complexes with tertiary phosphines. It is sold as a 1,2-dimethoxyethane complex.
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The activity of glutathione reductase is used as indicator for oxidative stress. The activity can be monitored by the NADPH consumption, with absorbance at 340 nm, or the formed GSH can be visualized by Ellman's reagent. Alternatively the activity can be measured using roGFP (redox-sensitive Green Fluorescent Protein).
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Schwartz's reagent is the common name for the organozirconium compound with the formula (C5H5)2ZrHCl, sometimes called zirconocene hydrochloride or zirconocene chloride hydride, and is named after Jeffrey Schwartz, a chemistry professor at Princeton University. This metallocene is used in organic synthesis for various transformations of alkenes and alkynes.
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Hydrozirconation is a form of hydrometalation. Substrates for hydrozirconation are alkenes and alkynes. With terminal alkynes the terminal vinyl zirconium product is predominantly formed. Secondary reactions are nucleophilic additions, transmetalations, conjugate additions,Conjugate Addition Of A Vinylzirconium Reagent: 3-(1-Octen-1-Yl)Cyclopentanone, Organic Syntheses, Coll. Vol.
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When used as a reagent in organic synthesis to convert carboxylic acids to their methyl esters, trimethylsilyldiazomethane undergoes acid-catalysed methanolysis, forming diazomethane in situ. A similar hydrolysis reaction may take place when trimethylsilyldiazomethane comes into contact with water on the surface of a human lung. Trimethylsilyldiazomethane is nonexplosive.
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Common applications include ceramics, pyrotechnics, sports equipment, as a laboratory reagent, as a blowing agent, and as a precursor to porous titanium. When heated as a mixture with other metals in powder metallurgy, titanium hydride releases hydrogen which serves to remove carbon and oxygen, producing a strong alloy.
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Dehydrogenative aromatization is the reverse of arene hydrogenation. As such, hydrogenation catalysts are effective for the reverse reaction. Platinum-catalyzed dehydrogenations of cyclohexanes and related feedstocks are the largest scale applications of this reaction (see above). 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is often the reagent of choice.
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According to theory, permanganate is strong enough to oxidize water, but this does not actually happen to any extent. Besides this, it is stable. It is a useful reagent, though with organic compounds, not very selective. Potassium permanganate is used as a disinfectant and water treatment additive in aquaculture.
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Vanadyl isopropoxide is the metal alkoxide with the formula VO(O-iPr)3 (iPr = CH(CH3)2). A yellow volatile liquid, it is a common alkoxide of vanadium. It is used as a reagent and as a precursor to vanadium oxides. The compound is diamagnetic, with tetrahedral geometry.
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Phenylglyoxal is the organic compound with the formula C6H5C(O)C(O)H. It contains both an aldehyde and a ketone functional group. It is yellow liquid when anhydrous but readily forms a colorless crystalline hydrate. It has been used as a reagent to modify the amino acid, arginine.
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H2SiF6 is a specialized reagent in organic synthesis for cleaving Si–O bonds of silyl ethers. It is more reactive for this purpose than HF. It reacts faster with t-butyldimethysilyl (TBDMS) ethers than triisopropylsilyl (TIPS) ethers. Hexafluorosilicic acid and the salts are used as wood preservation agents.
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2-Chlorobutane, along with other alkyl halides, is a useful intermediate in many different organic reactions. The halogen group is an effective leaving group, leading to its use in both elimination and substitution reactions. In addition, the compound is also a candidate for coupling reactions via a Grignard reagent.
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Tetramethyltin is synthesized by reaction of the Grignard reagent methylmagnesium iodide, with SnCl4, which is synthesized by reacting tin metal with chlorine gas. :4 CH3MgI + SnCl4 → (CH3)4Sn + 4 MgICl In tetramethyltin, the metal surrounded by four methyl groups in a tetrahedral structure is a heavy analogue of neopentane.
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Faiz Muhammad Khan Bahadur, (r.1742–1777) the third Nawab of Bhopal, was the son of Yar Muhammad Khan, the second Nawab of Bhopal (as a reagent), and the stepson of Mamola Bai a very influential Hindu wife of Y Muhammad and a direct descendant of Dost Mohammad Khan.
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Dieterle stain showing Treponema pallidum(in black), the organism that causes syphilis. The Dieterle stain is a way of marking tissue for microscopic examination. The key reagent of Dieterle stain is silver nitrate. It can stain microbes like Treponema pallidum in grey or black and background in yellow.
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A common approach to preparing aluminium sulfacetate is by reaction of aluminium sulfate with lead(II) acetate. The relative amount of each reagent controls the composition of the resulting mixture. When the stoichiometric ratio of lead acetate to aluminium sulfate exceeds 3:1, the process is theoretically driven to completion and aluminium triacetate is the sole product. With less lead acetate, a mixture of aluminium triacetate and aluminium sulfacetate results that becomes increasingly rich in the latter as the reagent mole ratio approaches 2:1. This approach is used to form various mixtures for mordant applications: : \+ 3 -> 2 \+ 3 Basic aluminium sulfacetates can also be prepared, , with hydroxide anions replacing some acetate ions.
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Sven-Olov Lawesson (9 September 1926, in Bräcke, Sweden – 5 March 1985) was a Swedish chemist known for his popularization of Lawesson's reagent within the chemical community. He is also known for his 1982 work exploring the possibility of a connection between recreational use of amyl nitrite and an increased incidence of Kaposi's sarcoma in homosexual men Lawesson obtained his education at Uppsala University. He did most of his work at the University of Aarhus in Denmark and his last paper was published in 1986. After finding that 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide was useful for some reactions, Lawesson undertook a general survey of the reactivity of organic compounds with this reagent.
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Occurrence of cytoplasmic PNGase activity in mammalian cells was first reported in cultured cells. This enzyme differ from other “reagent” PNGases from almond (glycoamidase/PNGase A), or bacteria (N-glycanase/PNGase F), that is often used for structural/functional studies of N-glycans, in several enzymatic properties, including the requirement of a reducing reagent for activity and a neutral pH for optimal activity. The gene encoding the cytoplasmic PNGase was first identified in budding yeast, Saccharomyces cerevisiae and gene orthologues have since been found in wide variety of eukaryotes including mammals. In terms of the tissue distribution of the mouse Ngly1 gene, enzyme activities as well as transcripts were detected in all tissues/organs examined.
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Urinalysis and Body Fluids by Susan King Strasinger and Marjorie Schaub Di Lorenzo Indicator-H+(Yellow) \+ Protein → Indicator(Blue-green) \+ Protein-H+ The major source of error with reagent strips occurs with highly buffered alkaline urine that overrides the acid buffer system, producing a rise in pH and a colour change unrelated to protein concentration. Likewise, a technical error of allowing the reagent pad to remain in contact with the urine for a prolonged period may remove the buffer. False-positive readings are obtained when the reaction does not take place under acidic conditions. Highly pigmented urine and contamination of the container with quaternary ammonium compounds, detergents and antiseptics also cause false-positive readings.
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This reaction has generally good yield and wide scope, although forming the ester from tertiary alcohols when the acid reagent has a relatively acidic α-proton is troublesome, since C-C condensations can occur, though this itself may be a desirable reaction. A similar reaction involving thiols and selenols can yield the corresponding esters. The alcohol reaction can also be used to form glycosidic bonds. Similarly, an acid can be used in the place of an alcohol to form the anhydride, although dicyclohexylcarbodiimide is a more typical reagent. The equilibrium can be shifted in the favor of the anhydride by utilizing an acid in a 2:1 ratio that forms an insoluble salt with the imidazole.
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Chemical ionization was developed in the 1960s. Ionization of sample (analyte) is achieved by interaction of its molecules with reagent ions. The analyte is ionized by ion-molecule reactions during collisions in the source. The process may involve transfer of an electron, a proton or other charged species between the reactants.
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Rhodium is usually supplied commercially in the Rh(III) oxidation state, the main starting reagent being hydrated rhodium trichloride. The latter reacts with olefins and with CO to give organometallic complexes, often concomitant with reduction to Rh(I). Cyclopentadienyl complexes of rhodium include the half- sandwich compound pentamethylcyclopentadienyl rhodium dichloride dimer.
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9-Borabicyclo[3.3.1]nonane or 9-BBN is an organoborane compound. This colourless solid is used in organic chemistry as a hydroboration reagent. The compound exists as a hydride-bridged dimer, which easily cleaves in the presence of reducible substrates. 9-BBN is also known by its nickname 'banana borane'.
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The spores are tear-shaped, and measure 7–10 by 3–4 μm. They are amyloid, meaning they will absorb iodine when stained with Melzer's reagent. The cheilocystidia are flask-shaped to pin-headed, measuring 40 by 5–8 μm. The red pigment will dissolve in a solution of ammonium hydroxide.
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NHS is commonly found in organic chemistry or biochemistry where it is used as an activating reagent for carboxylic acids. Activated acids (basically esters with a good leaving group) can react with amines to form amides for example, whereas a normal carboxylic acid would just form a salt with an amine.
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It is often named after him as Lawesson's reagent. The synthesis of thioketones is his most cited paper. At one point S. O. Lawesson worked with the chemist N. M. Yousif. After Lawesson's death, Yousif has been working in Egypt and has been very active within the phosphorus sulfur chemical community.
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The basidia are club-shaped, four- spored, and have a clamp connection at their bases; they measure 12–18 by 4–6 µm. The thin-walled spores are ellipsoid to somewhat tapered at both ends, hyaline, inamyloid (non-staining in Melzer's reagent), and measure 4.5–5.5 by 2–2.3 µm.
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Monosodium tartrate or sodium bitartrate is a sodium acid salt of tartaric acid. As a food additive it is used as an acidity regulator and is known by the E number E335. As an analytical reagent, it can be used in a test for ammonium cation which gives a white precipitate.
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Oxalic acid is an important reagent in lanthanide chemistry. Hydrated lanthanide oxalates form readily in very strongly acidic solutions in a densely crystalline, easily filtered form, largely free of contamination by nonlanthanide elements. Thermal decomposition of these oxalate gives the oxides, which is the most commonly marketed form of these elements.
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Ethyl chloroformate is the ethyl ester of chloroformic acid. It is a reagent used in organic synthesis for the introduction of the ethyl carbamate protecting groupProtective Groups in Organic Synthesis, Third Edition, Theodora W. Greene and Peter G. M. Wuts, pages 504-506, and for the formation of carboxylic anhydrides.
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Triphenylphosphine oxide (often abbreviated TPPO) is the organophosphorus compound with the formula OP(C6H5)3, also written as Ph3PO or PPh3O (Ph = C6H5). This colourless crystalline compound is a common but potentially useful waste product in reactions involving triphenylphosphine. It is a popular reagent to induce the crystallizing of chemical compounds.
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Morpholinos are synthetic oligonucleotides that can be used to inhibit nuclear RNA splicing or mRNA translation and are the common gene inhibition reagent in Xenopus as neither siRNA or miRNA have yet been shown to reproducibly function in frog embryos.Eisen, J.a.S., J. . (2008). Controlling morpholino experiments: don't stop making antisense.
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Samarium(II) iodide is an inorganic compound with the formula SmI2. When employed as a solution for organic synthesis, it is known as Kagan's reagent. SmI2 is a green solid and its solutions are green as well. It is a strong one- electron reducing agent that is used in organic synthesis.
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The synthesis of isocyanates from amines illustrates the electrophilic character of this reagent and its use in introducing the equivalent of "CO2+": :RNH2 \+ COCl2 → RN=C=O + 2 HCl (R = alkyl, aryl) Such reactions are conducted in the presence of a base such as pyridine that absorbs the hydrogen chloride.
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Hydroalumination of alkynes may be either stereospecifically cis or trans depending on the conditions employed. When a dialkylalane such as di(isobutyl)aluminium hydride (DIBAL-H) is used, the hydrogen and aluminium delivered from the reagent end up cis in the resulting alkenylalane.Wilke, G.; Müller, H. Chem. Ber. 1956, 89, 444.
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Isocyanides have also been shown to be a useful reagent in palladium catalysed reactions with a wide variety of compounds being formed using this method. The α position of isocyanides have substantial acidity. For example, benzyl isocyanide has a pKa of 27.4. In comparison, benzyl cyanide has a pKa of 21.9.
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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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The shelf life for the Acute Reagent is two years and for the solutions is three years when stored properly.“Modern Water Microtox Acute Toxicity Overview”, Modern Water. N.D. Retrieved on 28 May 2014. _Microtox Acute Reagent_ is a freeze-dried culture of Allivibrio fischeri that is reconstituted prior to testing.
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Reversed-phase HPLC plot of separation of phenolic compounds. Smaller natural phenols formed individual peaks while tannins form a hump. Phosphomolybdic acid is used as a reagent for staining phenolics in thin layer chromatography. Polyphenols can be studied by spectroscopy, especially in the ultraviolet domain, by fractionation or paper chromatography.
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This was called the "opium-regime". To distinguish between smuggled and legal opium, a simple reagent was added. After discovery the smuggler could count on a severe punishment. Multatuli wrote Max Havelaar in protest against these colonial policies, but another goal was to seek rehabilitation for his resignation from governmental service.
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2-Aminophenol is an organic compound with the formula C6H7NO. Along with its isomer 4-aminophenol, it is an amphoteric molecule and a reducing agent. It is a useful reagent for the synthesis of dyes and heterocyclic compounds.Mitchell, S.C. & Waring, R.H. "Aminophenols." In Ullmann’s Encyclopedia of Industrial Chemistry; 2002 Wiley-VCH, .
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Diethylzinc (C2H5)2Zn, or DEZ, is a highly pyrophoric and reactive organozinc compound consisting of a zinc center bound to two ethyl groups. This colourless liquid is an important reagent in organic chemistry. It is available commercially as a solution in hexanes, heptane, or toluene, or as a pure liquid.
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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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Ampyrone is a metabolite of aminopyrine with analgesic, anti-inflammatory, and antipyretic properties. Due to the risk of agranulocytosis its use as a drug is discouraged. It is used as a reagent for biochemical reactions producing peroxides or phenols. Ampyrone stimulates liver microsomes and is also used to measure extracellular water.
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Dichloro(1,2-bis(diphenylphosphino)ethane)nickel is a coordination complex with the formula NiCl2(dppe); where dppe is the diphosphine 1,2-bis(diphenylphosphino)ethane. It is used as a reagent and as a catalyst. The compound is a bright orange-red diamagnetic solid. The complex adopts a square planar geometry.
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The Flory-Stockmayer Theory allows for the prediction of when gelation occurs using percent conversion of initial monomer and is not confined to cases of stoichiometric balance. Additionally, the Flory-Stockmayer Theory can be used to predict whether gelation is possible through analyzing the limiting reagent of the step-growth polymerization.
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The addition of small quantities of Cr(acac)3 to an NMR sample can allow for quantitative 13C NMR, i.e. accurate relative integrations of peaks. It achieves this by acting as a paramagnetic relaxation reagent which cancels out the Nuclear Overhauser effect, which can adversely effect the integration of 13C peaks.
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Methyl acrylate is an organic compound, more accurately the methyl ester of acrylic acid. It is a colourless liquid with a characteristic acrid odor. It is mainly produced to make acrylate fiber, which is used to weave synthetic carpets. It is also a reagent in the synthesis of various pharmaceutical intermediates.
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Like other thioesters, it reverts to tert-butylthiol by hydrolysis. Lithium 2-methylpropane-2-thiolate can be prepared by treatment of tert-butylthiol with lithium hydride in an aprotic solvent such as hexamethylphosphoramide (HMPA). The resulting thiolate salt is a useful demethylating reagent. For example, treatment with 7-methylguanosine gives guanosine.
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Protection Reagent: Phosgene, pyridine, dichloromethane, -78 °C to room temperature, 1 h. Deprotection Reagents: deprotected through Chan rearrangement (treatment with lithiumtetramethylpiperidide). The cyclic carbonate ester was removed as a result of the Chan rearrangement in 15, which created a carbon-carbon bond that was part of the Taxol framework (Scheme 2).
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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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The basidia (spore-bearing cells) are arranged in a relatively loose palisade, measuring up to 100 µm long. They usually have two, but sometimes three to four sterigmata. Spores are roughly spherical, smooth, hyaline, and feature a slight wall thickening. They are somewhat cyanophilous, but do not react with Melzer's reagent.
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Hagemann's ester, or ethyl-2-methyl-4-oxo-2-cyclohexenecarboxylate, is an organic compound that was first prepared and described in 1893 by German chemist Carl Hagemann. The compound is used in organic chemistry as a reagent in the synthesis of many important natural products including sterols, trisporic acids, and terpenoids.
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Diborane is a highly reactive and versatile reagent. Its dominating reaction pattern involves formation of adducts with Lewis bases. Often such initial adducts proceed rapidly to give other products. It reacts with ammonia to form the diammoniate of diborane, DADB, with lesser quantities of ammonia borane depending on the conditions used.
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Fourth, the printed slide treated with transfection reagent is placed into a square dish with the printed side facing up. Fifth, the harvested cells are gently poured onto the slides (not on the printed areas). Finally, the dish is placed in a 37°C, 5% CO2 humidified incubator and incubated overnight.
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The properties of a standard solution for titrations are: # Its concentration must remain constant all the time. This is so that there is no need for restandardization. # Its reaction with the analyte must be rapid in order to minimize the waiting period after addition of each reagent. # Its reaction must be reasonably complete.
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Tributyltin azide is synthesized by the salt metathesis reaction of tributyltin chloride and sodium azide. It is a reagent used in the synthesis of tetrazoles, which in turn are used to generate angiotensin II receptor antagonists. In some applications, tributyltin azide has been replaced by the less toxic trioctyltin azide and organoaluminium azides.
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Diethyl chlorophosphate is an organophosphorus compound with the formula (C2H5O)2P(O)Cl. As an reagent in organic synthesis, it is use the convert alcohols to the corresponding diethylphosphate esters. It is a colorless liquid with a fruity odor. It is a corrosive, and as a cholinesterase inhibitor, highly toxic through dermal absorption.
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New Haven: Yale University Press, 1999. p. 216. Following Sanger's initial report of the reagent, the dinitrofluorobenzene method was widely adopted for studying proteins, until it was superseded by other reagents for terminal analysis (e.g., dansyl chloride and later aminopeptidases and carboxypeptidases) and other general methods for sequence determination (e.g., Edman degradation).
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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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It is chosen under the spectrophotometric determination method and used as indicator because the reagent forms different visible color. Bromopyrogallol red forms blue to violet-blue complexes with yttrium and cerium. It also has shows orange yellow in strong acid solution, claret red in nearly neutral solution and blue in alkaline solution.
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In this test, the organism under consideration is grown in peptone water broth. It contains tryptophan, which under the action of enzyme tryptophanase is converted to an Indole molecule, pyruvate and ammonium. The indole is then extracted from the broth by means of xylene. To test the broth for indole production, Kovac's reagent .
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Hexafluoroacetylacetone is the chemical compound with the nominal formula CF3C(O)CH2C(O)CF3 (often abbreviated as hfacH). This colourless liquid is a ligand precursor and a reagent used in MOCVD. The compound exists exclusively as the enol CF3C(OH)=CHC(O)CF3. For comparison under the same conditions, acetylacetone is 85% enol.
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Dimethylcadmium is the organocadmium compound with the formula Cd(CH3)2. It is a colorless highly toxic liquid that fumes in air. It is a linear molecule with C-Cd bond lengths of 213 pm. The compound finds limited use as a reagent in organic synthesis and in metalorganic chemical vapor deposition (MOCVD).
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A common 1,4-dithiol is dithiothreitol (DTT), HSCH2CH(OH)CH(OH)CH2SH, sometimes called Cleland's reagent, for to reduce protein disulfide bonds. Oxidation of DTT results a stable six-membered heterocyclic ring with an internal disulfide bond. Reduction of a typical disulfide bond by DTT via two sequential thiol- disulfide exchange reactions.
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However, SF4 is gaseous at room temperature, and many transformations involving this reagent require elevated temperatures, making handling somewhat difficult. In addition, the reaction generates large amounts of hydrogen fluoride. These concerns have led to the development of safer, more robust fluorinating reagents, such as DAST (diethylaminosulfur trifluoride).Hudlicky, M. Org. React.
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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 type of chemical that is used depends on the material the weapon is made of. These acids can range from Fry's Reagent for a magnetic metal, which is a mixture of hydrochloric acid, cupric chloride, and distilled water, to an acidic ferric chloride solution for a non-magnetic, non-aluminum material.
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A case of a brain metastasis from a giant-cell lung carcinoma (both "pure") tested positive for cytokeratins AE1/AE3, and negative for CK-7, CK-20, TTF-1, and GFAP. GCCL cells often stain intensely by Periodic acid-Schiff reagent, suggesting the presence of significant amounts of glycogen in the cell cytoplasm.
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The resulting solution was stirred at 0 °C for 1 hr and then at room temperature for 1.5 hr. The solvents and excess reagent were removed in vacuo. Tetrahydrofuran (40 ml, freshly distilled from lithium aluminum hydride) and finely divided metallic copper powder (0.67 g) were added to the crude diazo ketone, sequentially.
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In this reaction an aromatic hydroxyl group is converted to the corresponding amine group. This is a reversible reaction. The first step in this reaction is an addition reaction of sodium bisulfite to an aromatic double bond. The Bucherer carbazole synthesis is a related organic reaction that uses sodium bisulfite as a reagent.
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2006, 68, 303. If both the donor and acceptor are sugars, then the product is an oligosaccharide. The reaction requires activation with a suitable activating reagent. The reactions often result in a mixture of products due to the creation of a new stereogenic centre at the anomeric position of the glycosyl donor.
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Clitocybula fruit bodies are small- to medium-sized, with a morphology ranging from clitocyboid, collybioid, mycenoid, pleurotoid, to omphalinoid. Gills are decurrent, and the stipe is cylindrical and equal in width throughout its length. Clitocybula spores are smooth, ellipsoid to roughly spherical in shape, hyaline (translucent), and mostly amyloid (staining with Melzer's reagent).
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Phaeotrametes decipiens has brownish, fan-shaped fruit bodies. It has a trimitic hyphal system–containing generative, skeletal, and binding hyphae. Its spores are large, truncate, and thick-walled, and inamyloid (unreactive with Melzer's reagent). A characteristic feature of Phaeotrametes is the presence of chlamydosporic fruit bodies that occur alongside the normal fruit bodies.
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Phosphorus pentachloride is the chemical compound with the formula PCl5. It is one of the most important phosphorus chlorides, others being PCl3 and POCl3. PCl5 finds use as a chlorinating reagent. It is a colourless, water-sensitive and moisture-sensitive solid, although commercial samples can be yellowish and contaminated with hydrogen chloride.
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The closely related Schweizer's reagent is used for the production of cuprammonium rayon. Most pesticides contain ammonium sulfate. Ammonium sulfate is used as an agricultural spray adjuvant for water-soluble insecticides, herbicides, and fungicides. There, it functions to bind iron and calcium cations that are present in both well water and plant cells.
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Water is a common reagent in enzymatic catalysis. Esters and amides are slow to hydrolyze in neutral water, but the rates are sharply affected by metalloenzymes, which can be viewed as large coordination complexes. Acrylamide is prepared by the enzyme-catalyzed hydrolysis of acrylonitrile. US demand for acrylamide was as of 2007.
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Condensed tannins can be characterised by a number of techniques including depolymerisation, asymmetric flow field flow fractionation or small-angle X-ray scattering. DMACA is a dye used for localization of procyanidin compounds in plant histology. The use of the reagent results in blue staining. It can also be used to titrate procyanidins.
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Figure 4. The Example of Ketonization of the Enol of 4-Phenyl-1-Benzoylcyclohexane. 600px In this example the enol intermediate is generated from either the cis- or the trans-stereoisomer of 1-bromo-1-benzoyl-4-phenylcyclohexane using zinc as the reagent. The endo proton approach is blocked by two axial hydrogens.
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The result is influenced by extrinsic coagulation factors, platelets and fibrinogen. EXTEM is a screening test for the (extrinsic) haemostasis system. This assay is not influenced by heparin (heparin inhibitor included in the EXTEM reagent). It is used for therapeutic decisions regarding the administration of fresh frozen plasma, coagulation factors, fibrinogen or platelets.
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Trimethyl borate is the organoboron compound with the formula B(OCH3)3. It is a colourless liquid that burns with a green flame. It is an intermediate in the preparation of sodium borohydride and is a popular reagent in organic chemistry. It is a weak Lewis acid (AN = 23, Gutmann-Beckett method).
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The method exploits the reactivity of nitrous acid derived from acidification of nitrite. Nitrous acid selectively reacts with aromatic amines to give diazonium salts, which in turn couple with a second reagent to give the azo dye. The detection limit is 0.02 to 2 μM. Methods have been highly adapted to biological samples.
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Deprotonation using LDA . Organometallic compounds of electropositive metals are superbases, but they are generally strong nucleophiles. Examples include organolithium and organomagnesium (Grignard reagent) compounds. Another type of organometallic superbase has a reactive metal exchanged for a hydrogen on a heteroatom, such as oxygen (unstabilized alkoxides) or nitrogen (metal amides such as lithium diisopropylamide).
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Tebbe's reagent, which is used for the methylenation of esters and ketones, is prepared from TMA and titanocene dichloride. In combination with 20 to 100 mol % Cp2ZrCl2 (zirconocene dichloride), the (CH3)2Al-CH3 adds "across" alkynes to give vinyl aluminum species that are useful in organic synthesis in a reaction known as carboalumination.
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Coordinating solvents such as ether or THF, are required to solvate (complex) the magnesium(II) center. The solvent must be aprotic since alcohols and water contain an acidic proton and thus react with phenylmagnesium bromide to give benzene. Carbonyl-containing solvents, such as acetone and ethyl acetate, are also incompatible with the reagent.
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Copper(I) forms only labile complexes with ammonia, including the trigonal planar [Cu(NH3)3]+. Silver gives the diammine complex [Ag(NH3)2]+ with linear coordination geometry. It is this complex that forms when otherwise rather insoluble silver chloride dissolves in aqueous ammonia. The same complex is the active ingredient in Tollen's reagent.
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1,3-Diphenylisobenzofuran is a highly reactive diene that can scavenge unstable and short-lived dienophiles in a Diels-Alder reaction. It is furthermore used as a standard reagent for the determination of singlet oxygen, even in biological systems. Cycloadditions with 1,3-diphenylisobenzofuran and subsequent oxygen cleavage provide access to a variety of polyaromatics.
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CDAs are more widely used than CSAs to determine absolute configurations because the covalent bonding to the substrate and auxiliary reagent produce species with greater conformational rigidity which creates greater differences in the NMR spectra. CDAs and CSAs can be used together to improve chiral recognition, although this is not a common.
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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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The Pyriculariaceae that reproduce sexually form perithecial fruiting bodies (ascomata), which are immersed, black and with long cylindrical necks covered in setae. Asci are subcylindrical, unitunicate, short-stipitate and with a large apical ring staining in Meltzer's iodine reagent. Ascospores are septate and fusiform. Asexual morphs are hyphomycetes with simple, branched conidiophores.
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The tridentate ligand called the Kläui ligand is derived from trimethyl phosphite. The formation of this ligand illustrates the susceptibility of trimethyl phosphite (and metal complexes thereof) to the Arbuzov reaction. Trimethyl phosphite is also used as a mild desulfurization reagent in organic synthesis, for example in the preparation of derivatives of tetrathiafulvalene.
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A drop of dilute potassium hydroxide placed on the cap cuticle will stain dark red to blackish, and orange-yellow on the flesh, while ferrous sulphate solution turns the cuticle yellow and then greenish-yellow. Melzer's reagent will turn the flesh dark blue, after the natural bluing reaction to injury has faded.
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Operando spectroscopy has become a vital tool for surface chemistry. Nanotechnology, used in materials science, involves active catalytic sites on a reagent surface with at least one dimension in the nano-scale of approximately 1–100 nm. As particle size decreases, surface area increases. This results in a more reactive catalytic surface.
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The spore print is white to cream. The oval spores are 5.5–7 by 4–4.5 micrometres (µm), with walls that tend to thicken in age. The spores are cyanophilous, meaning they will readily stain dark blue in methyl blue solution. Staining with Melzer's reagent often produces a dextrinoid (reddish-brown) colour reaction.
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Diisopinocampheylborane is an organoborane that is useful for asymmetric synthesis. This colourless solid is the precursor to a range of related reagents. The compound was reported in 1961 by Zweifel and Brown in a pioneering demonstration of asymmetric synthesis using boranes. The reagent is mainly used for the synthesis of chiral secondary alcohols.
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Commercial applications of arsenic acid are limited by its toxicity. It is a precursor to a variety of pesticides. It has found occasional use as a wood preservative, a broad-spectrum biocide, a finishing agent for glass and metal, and a reagent in the synthesis of some dyestuffs and organic arsenic compounds.
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The easy way to work out the extraction mechanism is to draw graphs and measure the slopes. If for an extraction system the D value is proportional to the square of the concentration of a reagent (Z) then the slope of the graph of log10(D) against log10(Z) will be two.
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Míhuànyàowù ( "psychedelic") combines míhuàn ( "phantasmagoric; surreal; mysterious; psychedelic") and yàowù ( "medicine; pharmaceutical; medicament"). The Chinese technical names for the last two classes of hallucinogens are rare: Yóulíyàopǐn ( "dissociative") compounds yóulí ( "dissociated; drifting") and yàopǐn ( " medicine; chemical reagent; drug"); and Zhìzhānwàngyào ( "deliriant") combines zhì "incur; cause", zhānwàng ( "(medical) delirium"), and yào "medicine; drug".
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Purification involves the addition of an aqueous acid such as saturated ammonium chloride solution. This quenches remaining silyl reagent and protonates amine bases, removing them from the reaction mixture. Following extraction, the product can be purified by flash chromatography. Silyl triflate is more reactive and also converts ketones to silyl enol ethers.
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Freshly distilled germanium tetrachloride in a schlenk tube. Germanium tetrachloride is a colourless, fuming liquid with a peculiar, acidic odour. It is used as an intermediate in the production of purified germanium metal. In recent years, GeCl4 usage has increased substantially due to its use as a reagent for fiber optic production.
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Ammonium hydroxide and potassium hydroxide cause bleaching. Testing with melzer's reagent is negative. The trama hyphae of the upper branches are no bigger than 7 μm in diameter and appear glassy, are hyaline, and lack clamp connections. The areas near the septa are inflated up to 15 μm and are ornamented delicately.
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January 1881), Stanley R. Benedict (March 17, 1884 - December 21, 1936), and Agnes E. Benedict (b. October 1888). Stanley R. Benedict later became a chemist, having earned a B.S. from the University of Cincinnati, and discovered the Benedict's Reagent. Also while in Cincinnati, the Benedict family had a servant named Jessie Taylor (b.
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Reacting trifluoroacetic anhydride with sodium percarbonate, , yields trifluoroperacetic acid and sodium carbonate, obviating the need for an additional buffer. :3 \+ 4 -> 6 \+ 4 \+ 3 Trifluoroperacetic acid can also be generated in situ, allowing it to react promptly with the target substrate rather than pre-synthesizing a batch of the reagent for later use.
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Lawsone shows promise as a reagent for fingerprint detection because of its photoluminescence maximized at 640nm, which is high enough that it avoids background interference common for ninhydrin.Thomas, P.; Farrugia, K. An investigation into the enhancement of fingermarks in blood on paper with genipin and lawsone. Sci. Justice 2013, 53, 315-320.
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Important iron carbonyls are the three neutral binary carbonyls, iron pentacarbonyl, diiron nonacarbonyl, and triiron dodecacarbonyl. One or more carbonyl ligands in these compounds can be replaced by a variety of other ligands including alkenes and phosphines. An iron(-II) complex, disodium tetracarbonylferrate (Na2[Fe(CO)4]), also known as "Collman's Reagent," is prepared by reducing iron pentacarbonyl with metallic sodium. The highly nucleophilic anionic reagent can be alkylated and carbonylated to give the acyl derivatives that undergo protonolysis to afford aldehydes: :LiFe(CO)4(C(O)R) + H+ → RCHO (+ iron containing products) Similar iron acyls can be accessed by treating iron pentacarbonyl with organolithium compounds: :ArLi + Fe(CO)5 → LiFe(CO)4C(O)R In this case, the carbanion attacks a CO ligand.
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In other scientific contexts, the term calorie almost always refers to the small calorie. Even though it is not an SI unit, it is still used in chemistry. For example, the energy released in a chemical reaction per mole of reagent is occasionally expressed in kilocalories per mole. Typically, this use was largely due to the ease with which it could be calculated in laboratory reactions, especially in aqueous solution: a volume of reagent dissolved in water forming a solution, with concentration expressed in moles per litre (1 litre weighing 1 kilogram), will induce a temperature change in degrees Celsius in the total volume of water solvent, and these quantities (volume, molar concentration and temperature change) can then be used to calculate energy per mole.
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While the Kastle–Meyer test has been reported as being able to detect blood dilutions down to 1:107, there are a number of important limitations to the test. Chemical oxidants such as copper and nickel salts will cause the Kastle–Meyer reagent to turn pink before the addition of the hydrogen peroxide, thus it is vitally important to add the reagent first, then wait a few seconds, then add the hydrogen peroxide. The Kastle–Meyer test has the same reaction with human blood as it does with any other hemoglobin-based blood, so a confirmatory test such as the Ouchterlony Test must be performed to definitively conclude from which species the blood originated. Color catalytic tests are very sensitive, but not specific.
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Nephelometry can be used to detect either antigen or antibody, but it is usually run with antibody as the reagent and the patient antigen as the unknown.Clinical Immunology and Seriology 3rd Ed., Stevens, pg 127, F.A. Davis Company In the Immunology Medical Lab, two types of tests can be run: "end point nephelometry" and "kinetic (rate) nephelometry". End point nephelometry tests are run by allowing the antibody/antigen reaction to run through to completion (until all of the present reagent antibodies and the present patient sample antigens that can aggregate have done so and no more complexes can form). However, the large particles will fall out of the solution and cause a false scatter reading, thus kinetic nephelometry was devised.
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Between each step, the plate is typically washed with a mild detergent solution to remove any proteins or antibodies that are non-specifically bound. After the final wash step, the plate is developed by adding an enzymatic substrate to produce a visible signal, which indicates the quantity of antigen in the sample. Of note, ELISA can perform other forms of ligand binding assays instead of strictly "immuno" assays, though the name carried the original "immuno" because of the common use and history of development of this method. The technique essentially requires any ligating reagent that can be immobilized on the solid phase along with a detection reagent that will bind specifically and use an enzyme to generate a signal that can be properly quantified.
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The company is a Cayman Islands corporation, incorporated in 2004,China Medical Technologies, Inc. 20-F; Annual and transition report of foreign private issuer pursuant to Sections 13 or 15(d), filed on 18 July 2011 based in China that purported to develop, manufacture and market advanced in vitro diagnostic ("IVD") products using enhanced chemiluminescence ("ECLIA") technology, fluorescent in-situ hybridization ("FISH") technology, and surface plasmon resonance (“SPR”) technology to detect and monitor various diseases and disorders. The ECLIA business purported to consist of ECLIA analyzer and reagent kits, as an IVD system based on ECLIA technology. The reagent kits were purported to detect various thyroid disorders, diabetes, hepatitis, Down syndrome, liver fibrosis, disorders related to reproduction and growth, and various types of tumors.
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Nitrite is detected and analyzed by the formation of a red pink colour upon treatment of a nitrite-containing sample with the Griess reagent, which consists of two components in an acidic solution: an aniline derivative and a coupling agent. The most common arrangements use sulfanilamide and N-(1-naphthyl)ethylenediamine: a typical commercial Griess reagent contains 0.2% N-(1-naphthyl)ethylenediamine dihydrochloride, and 2% sulfanilamide in 5% phosphoric acid. This diamine is used in place of the simpler and cheaper 1-naphthylamine because the latter is a potent carcinogen and moreover the diamine forms a more polar and hence a much more soluble dye in acidic aqueous medium. Other aniline derivatives that have been used include sulfanilic acid, nitroaniline, and p-aminoacetophenone.
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His forty-years research activity focuses mainly on free-radical chemistry using an original multidisciplinary approach that, informed by structure-reactivity-mechanism studies, led to applications in synthetic and analytical methodologies, materials science, and in life sciences. He is known for free radical chemistry and molecular mechanisms of cellular stress and related biomarkers. His work on free radical properties and synthetic strategies has led to the discovery and development of tris(trimethylsilyl)silane as radical-based reducing agent (Fluka prize “Reagent of the Year 1990”) a breakthrough solution to the health and environmental toxicity of chemical reagents. The start and progress of this reagent in free radical chemistry have been presented from time to time in several reviews and books.
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Owing to its symmetrical structure and reactivity, 1,2,4,5-tetrabromobenzene is a precursor to nematic liquid crystals with crossed mesogens and for columnar (discotic) liquid crystals with an extensive planar, "board-like" tetrabenzoanthracene core. Synthesis of discotic LC from 1,2,4,5-Tetrabromobenzene. In a one-pot reaction, 1,2,4,5-tetrabromobenzene reacts with 4-hydroxybenzaldehyde, the alkylating agent 1-bromopentane, the Wittig reagent methyltriphenylphosphonium iodide, the base potassium carbonate, the phase transfer catalyst tetrabutylammonium bromide, the Heck reagent palladium(II)acetate and the Heck co-catalyst 1,3-bis(diphenylphosphino)propane (dppp) in dimethylacetamide obtaining directly a symmetrical tetraalkoxylstilbene as E-isomer in 17% yield. Synthese eines symmetrischer Tetraalkoxystilbens Due to their pronounced π-conjugation such compounds could be potentially applied as optical brighteners, OLED materials or liquid crystals.
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Digital Microfluidics (DMF) allows for precise manipulation and coordination in small- scale chemical synthesis reactions due to its ability to control micro scale volumes of liquid reagents, allowing for overall less reagent use and waste. This technology can be used in the synthesis compounds such as peptidomimetics and PET tracers. PET tracers require nanogram quantities and as such, DMF allows for automated and rapid synthesis of tracers with 90-95% efficiency compared to conventional macro-scale techniques. Organic reagents are not commonly used in DMF because they tend to wet the DMF device and cause flooding; however synthesis of organic reagents can be achieved through DMF techniques by carrying the organic reagents through an ionic liquid droplet, thus preventing the organic reagent from flooding the DMF device.
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2'-deoxy-2',2'-difluoro-5-ethynyluridine (dF-EdU) binds to Herpes simplex virus thymidine kinase but, because of sterical hindrance, not to human thymidine kinase. This reagent together with a fluorescent azide cause fluorescence of infected cells but not of uninfected cells. Therefore, this substrate analog makes it possible to specifically stain infected cells.
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Because Grignard reagents are so sensitive to moisture and oxygen, many methods have been developed to test the quality of a batch. Typical tests involve titrations with weighable, anhydrous protic reagents, e.g. menthol in the presence of a color-indicator. The interaction of the Grignard reagent with phenanthroline or 2,2'-bipyridine causes a color change.
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Niobocene dichloride is the organometallic compound with the formula (C5H5)2NbCl2, abbreviated Cp2NbCl2. This paramagnetic brown solid is a starting reagent for the synthesis of other organoniobium compounds. The compound adopts a pseudotetrahedral structure with two cyclopentadienyl and two chloride substituents attached to the metal. A variety of similar compounds are known, including Cp2TiCl2.
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Ferrocene undergoes a one-electron oxidation at around 0.5 V versus a saturated calomel electrode (SCE). This reversible oxidation has been used as standard in electrochemistry as Fc+/Fc = 0.40 V versus the standard hydrogen electrode.C. E. Housecroft & A. G. Sharpe, Inorganic Chemistry 4th edition, 2012, p. 925. Ferrocenium tetrafluoroborate is a common reagent.
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The spores are roughly spindle-shaped (i.e., tapering at each end), with dimensions of 9–11 by 3.5–4.5 µm. They are nonamyloid, meaning they do not take up iodine when stained with Melzer's reagent. The spore-bearing cells, the basidia, are club- shaped, four-spored and measure 20–22 by 5–6 µm.
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Difluoroacetic acid is a chemical compound with formula CHF2COOH. It is a dihalogenocarboxylic acid, specifically a structural analog of acetic acid with two of three hydrogen atoms on the alpha carbon replaced with fluorine atoms. In solution, it dissociates to form difluoroacetate ions. Difluoroacetic acid can also be used as direct C-H difluoromethylating reagent.
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Lactarius pyrogalus produces a light ochre spore print; the spores are broadly elliptic, with warts generally joined by a moderately thick ridges in a well- developed network. The spores are 7-8 by 5.5-7 µm in size. The spores are amyloid, meaning they stain dark blue in Melzer's reagent, and feature an incomplete net.
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"Vapor nanobubbles rapidly detect malaria through the skin ", news.rice.edu"Hemozoin-generated vapor nanobubbles for transdermal reagent- and needle-free detection of malaria", Ekaterina Y. L., et. al. DOI: 10.1073/pnas.1316253111 They claim it can be operated by nonmedical personal, produce zero false-positive readings, and it doesn't need a needle or any damage done.
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Bis(benzonitrile)palladium dichloride is the coordination complex with the formula PdCl2(NCC6H5)2. It is the adduct of two benzonitrile (PhCN) ligands with palladium(II) chloride. It is a yellow-brown solid that is soluble in organic solvents. The compound is a reagent and a precatalyst for reactions that require soluble Pd(II).
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The oxidizing nature of many organolead compounds is usefully exploited: lead tetraacetate is an important laboratory reagent for oxidation in organic synthesis. Tetraethyllead, once added to gasoline, was produced in larger quantities than any other organometallic compound. Other organolead compounds are less chemically stable. For many organic compounds, a lead analog does not exist.
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2-Methoxypropene is an ether with the chemical formula C4H8O. It is a reagent used in organic synthesis as a protecting group for alcohols, and the conversion diols to the acetonide group. 2-Methoxypropene can be prepared by the elimination of methanol from dimethoxypropane, or by the addition of methanol to propyne or allene.
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Phorbol 12,13-dibutyrate (PDBu) is a phorbol ester which is one of the constituents of croton oil. As an activator of protein kinase C, it is a weak tumor promoter compared to 12-O-tetradecanoylphorbol-13-acetate. PDBu is widely used as a chemical reagent because of its solubility in water and other organic solvents.
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1955, 88, 742. (3)File:CNAl1.png When neutral, pre-formed dialkylaluminum cyanides are used, both carbonyl activation and nucleophilic attack of cyanide are facilitated by the organoaluminum reagent. 1,2-Addition is rapid in this case but is also reversible, and slow but irreversible 1,4-addition eventually leads to the conjugate addition product.Nagata, W. Proc.
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1: Reagent control: addition of chiral allylmetals to achiral aldehydes Various chiral ligands have been developed to prepare chiral allylmetals for the reaction with aldehydes. H. C. Brown was the first to report the chiral allylboron reagents for asymmetric allylation reactions with aldehydes.Brown, H. C.; Jadhav, P. K. J. Am. Chem. Soc. 1983, 105, 2092.
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The RBCs are washed three or four times with isotonic saline solution and then incubated with antihuman globulin. If antibodies have bound to RBC surface antigens in the first stage, RBCs will agglutinate when incubated with the antihuman globulin (also known Coombs reagent) in this stage, and the indirect Coombs test will be positive.
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I. torosus displays the following characteristic colour changes with tests performed on cut flesh less than 12 hours old: ammonium hydroxide (NH4OH)–yellow centre bordered by a blue circular outer ring; potassium hydroxide (KOH)– deep buff (instantly); ferrous sulphate (FeS04)–no change; Melzer's reagent–dark blue; phenol–blue green (very slow); formalin–mid blue (slow).
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Sodium methylsulfinylmethylide (also called NaDMSO or dimsyl sodium) is the sodium salt of the conjugate base of dimethyl sulfoxide. This unusual salt has some uses in organic chemistry as a base and nucleophile. Since the first publication in 1965 by Corey et al., a number of additional uses for this reagent have been identified.
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Gene knockdown is an experimental technique by which the expression of one or more of an organism's genes is reduced. The reduction can occur either through genetic modification or by treatment with a reagent such as a short DNA or RNA oligonucleotide that has a sequence complementary to either gene or an mRNA transcript.
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The two electrons are supplied by phenolphthalin: : HOOH + 2 e− \+ 2 H+ -> 2 H2O The consumption of protons during the course of the reaction has the effect of raising the pH of the solution, but the amount of base produced is negligible compared to the amount of base already present in the reagent mixture.
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Lineatin is a pheromone produced by female striped ambrosia beetle, Trypodendron lineatum Olivier. These kinds of beetles are responsible for extensive damage of coniferous forest infestation in Europe and North America. Since lineatin can act as lures used for mass-trapping of T. lineatum, it is being studied to apply as a pest control reagent.
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Diethylaluminum cyanide is used for the stoichiometric hydrocyanation of α,β-unsaturated ketones. The reaction is influenced by the basicity of the solvent. This effect arises from the Lewis acidic qualities of the reagent. The purpose of this reaction is to generate alkylnitriles, which are precursors to amines, amides, carboxylic acids esters and aldehydes.
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Unfortunately, the Tsuji–Wilkinson decarbonylation is stoichiometric. The product bis(triphenylphosphine)rhodium carbonyl chloride is not readily converted back to a CO-free reagent. Above 200 °C, carbon monoxide RhCl(CO)(PPh3)2 does decarbonylate, however these high temperatures are often prohibitive. The ideal Tsuji–Wilkinon decarbonylation would be by catalytic near ambient temperatures.
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Diisopropyl azodicarboxylate (DIAD) is the diisopropyl ester of azodicarboxylic acid. It is used as a reagent in the production of many organic compounds. It is often used in the Mitsunobu reaction, where it serves as an oxidizer of triphenylphosphine to triphenylphosphine oxide. It has also been used to generate aza-Baylis-Hillman adducts with acrylates.
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Bromocyclopentane is an alkyl halide with the chemical formula C5H9Br. It is a colorless to light yellow liquid at standard temperature and pressure. Bromocyclopentane is a building block used in the synthesis of filaminast. Bromocyclopentane is reacted with magnesium turnings in dry tetrahydrofuran making cyclopentyl Grignard reagent, a main precursor in the synthesis of Ketamine.
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The iminium cation [(CH3)2NC=HCl]+ is the reactive component of interest. This iminium species is a derivative of the imidoyl chloride CH3N=CHCl. Analogues of this particular reagent are generated when tertiary amides other than DMF are treated with POCl3. The salt is a white solid that is soluble in polar organic solvents.
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Hydroiodic acid (or hydriodic acid) is a highly acidic aqueous solution of hydrogen iodide (H I) (concentrated solution usually 48 - 57% HI). It is the second strongest hydrohalic acid, after hydroastatic acid. Hydroiodic acid is a commonly used chemical reagent and is one of the strong acids that ionize completely in an aqueous solution.
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2628-2633, 2009. of the precursor silver nitrate, AgNO3 using an alginate solution as a stabilizing and reducing agent.H. Wang, X. Qiao, J. Chen and S. Ding, Colloids Surf., A, 2005, 256, 111–115 The carboxyl or hydroxyl groups on the alginate reagent form complexes during the synthesis of the AgNPs that stabilize the reaction.
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Cyclamic acid is a compound with formula C6H13NO3S. It is included in E number "E952". Cyclamic acid is mainly used as catalyst in the production of paints and plastics, and furthermore as a reagent for laboratory usage. The sodium and calcium salts of cyclamic acid are used as artificial sweeteners under the name cyclamate.
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The Wittig reaction or Wittig olefination is a chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide (often called a Wittig reagent) to give an alkene and triphenylphosphine oxide. Wittig Reaction It is widely used in organic synthesis for the preparation of alkenes.Maercker, A. Org. React. 1965, 14, 270–490. (Review)W.
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Sulfur tetrafluoride is the chemical compound with the formula SF4. It is a colorless corrosive gas that releases dangerous HF upon exposure to water or moisture. Despite these unwelcome characteristics, this compound is a useful reagent for the preparation of organofluorine compounds, some of which are important in the pharmaceutical and specialty chemical industries.
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However, it can form artifacts which complicate spectral interpretation. Such artifacts are usually the trimethylsilylmethyl esters, RCO2CH2SiMe3, formed when insufficient methanol is present. Acid-catalysed methanolysis is necessary to achieve near- quantitative yields of the desired methyl esters, RCO2Me. The compound is a reagent in the Doyle-Kirmse reaction with allyl sulfides and allyl amines.
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In chemistry, in situ typically means "in the reaction mixture." There are numerous situations in which chemical intermediates are synthesized in situ in various processes. This may be done because the species is unstable, and cannot be isolated, or simply out of convenience. Examples of the former include the Corey-Chaykovsky reagent and adrenochrome.
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Nylander's test is a chemical test used for detecting the presence of reducing sugars. Glucose or fructose reduces bismuth oxynitrate to bismuth under alkaline conditions. When Nylander's reagent, which consists of bismuth nitrate, potassium sodium tartrate and potassium hydroxide, is added to a solution with reducing sugars, a black precipitate of metallic bismuth is formed.
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Dimethylcarbamoyl chloride (DMCC) is a reagent for transferring a dimethylcarbamoyl group to alcoholic or phenolic hydroxyl groups forming dimethyl carbamates, usually having pharmacological or pesticidal activities. Because of its high toxicity and its carcinogenic properties shown in animal experiments and presumably also in humans, dimethylcarbamoyl chloride can only be used under stringent safety precautions.
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The spores' shape is slimly ellipsoidal or cylindrical. Their surface is smooth and their walls are thin. Although they are colourless and hyaline, the spores are amyloid, meaning they will turn bluish or purple when stained with Melzer's reagent. This characteristic differs from other very similar species, and this gave the genus its name.
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Where desired, it may be inserted into a flask via two septa (one on the tube, one on the flask). Used this way, needle tip fires are eliminated, reducing the obvious hazards. Also, there is a reduced tendency for the needle tip to clog due to the reaction of traces of the reagent with air to give salts.
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Aliquoting principle.Volume metering is a typical function of centrifugal fluidics to reach a certain amount of liquid reagent. It can be achieved by simply connecting an overflow channel to the chamber. Once the liquid is at the level of the overflow channel, the rest of the liquid will be routed into the waste chamber connected to the overflow channel.
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Carbon tetraiodide is used as an iodination reagent, often upon reaction with bases. Ketones are converted to 1,1-diiodoalkenes upon treatment with triphenylphosphine (PPh3) and carbon tetraiodide. Alcohols are converted in and to iodide, by a mechanism similar to the Appel reaction. In an Appel reaction, carbon tetrachloride is used to generate alkyl chlorides from alcohols.
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Second solution, referred as ScaleCUBIC-2, CUBIC-2 or just reagent-2, is composed of urea and sucrose in water. This original protocol is slightly modified in different applications, namely in concentrations, incubation times or some components of solutions. The CUBIC protocol can be also combined with perfusion and provide whole organ and whole body clearing of rodents.
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Amines can also be prepared from alcohols by dehydration using the Mitsunobu reaction.Neelamkavil, Santhosh "Di-tert-butyl-imidocarbonate" e-EROS Encyclopedia of Reagents for Organic Synthesis, 2001, John Wiley & Sons. In the usual implementation the reagent is deprotonated to give the potassium salt, which is N-alkylated. The Boc protecting groups are subsequently removed under acidic conditions.
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Aluminium triethoxide is used as a reducing agent for aldehydes and ketones, and is also used as a polymerization catalyst. Aluminium triethoxide is mainly used in Sol-Gel Process preparation of high purity aluminium sesquioxide, which is a polymerization agent. At the same time, it is used as a reducing reagent, for example, carbonyl compounds that restore to alcohol.
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Oxidants such as permanganate and Fenton's Reagent are delivered as water-based solutions. These substances are injected into the aquifer and then allowed to propagate by gravity and water current. As contaminants are encountered, the substances oxidize them and purify the water. Ozone is delivered (sparged) as a gas in either a dry air or oxygen carrier gas.
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This property is useful synthetically: cyclopropanol can be used as a synthon for the homoenolate of propanal. The chemical is also useful as a reagent to introduce a cyclopropyl group into ester, sulfate, and amine linkages. The resulting cyclopropyl- containing compounds have been used in investigations of potential antiviral drugs and of modulators of protein trafficking.
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Condensed tannins may be characterised by a number of techniques including depolymerisation, asymmetric flow field flow fractionation or small-angle X-ray scattering. DMACA is a dye that is particularly useful for localization of proanthocyanidin compounds in plant histology. The use of the reagent results in blue staining. It can also be used to titrate proanthocyanidins.
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Sodium bismuthate is an inorganic compound, and a strong oxidiser. It is somewhat hygroscopic, but not soluble in cold water, which can be convenient since the reagent can be easily removed after the reaction. It is one of the few water insoluble sodium salts. Commercial samples may be a mixture of bismuth(V) oxide, sodium carbonate and sodium peroxide.
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The compound is prepared by the chlorination of diethylphosphite with carbon tetrachloride (Atherton–Todd reaction). The compound is electrophilic. Controlled hydrolysis gives tetraethyl pyrophosphate. Alcohols react to vie mixed phosphate esters: :(C2H5O)2P(O)Cl + ROH → (C2H5O)2P(O)OR + HCl The reagent is routinely employed in organic synthesis for phosphorylation of carboxylates, alcohols, and amines.
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This protocol is a useful alternative to methods requiring acid or hydrogenolysis (e.g., Pd/C and hydrogen gas). Epoxides are generally attacked by alkoxyaluminium hydrides at the less substituted position. A nearby hydroxyl group may facilitate intramolecular delivery of the hydride reagent, allowing for selective opening of 1,2-disubstituted epoxides at the position closer to the hydroxyl group.
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Fostedil synthesis: #Treatment of benzanilide with phosphorus pentasulfide or Lawesson's reagent gives thioamide. #Oxidative ring formation by reaction with potassium ferricyanide and base (presumably involving a free radical intermediate) constructs the benzothiazole ring. #Bromination of this compound with N-bromosuccinimide produces bromomethyl intermediate. #The synthesis of fostedil concludes with a Michaelis-Arbuzov reaction with triethyl phosphite.
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Titanocene dichloride is the organotitanium compound with the formula (η5-C5H5)2TiCl2, commonly abbreviated as Cp2TiCl2. This metallocene is a common reagent in organometallic and organic synthesis. It exists as a bright red solid that slowly hydrolyzes in air. It shows antitumour activity and was the first non-platinum complex to undergo clinical trials as a chemotherapy drug.
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Short-chain alkyl halides are often carcinogenic. The bromine atom is at the secondary position, which allows the molecule to undergo dehydrohalogenation easily to give propene, which escapes as a gas and can rupture closed reaction vessels. When this reagent is used in base catalyzed reactions, potassium carbonate should be used in place of sodium or potassium hydroxide.
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Titan yellow is a compound with formula C28H19N5Na2O6S4. It is a triazene dye used as a stain and fluorescent indicator in microscopy.Thiazole Yellow G at Sigma-Aldrich It is also used as a reagent for the detection of magnesium. As an acid-base indicator, it changes color from yellow to red between pH 12 and pH 13.
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The Tebbe reagent is synthesized from titanocene dichloride and trimethylaluminium in toluene solution.Straus, D. A., "μ-Chlorobis(cyclopentadienyl)(dimethylaluminium)-μ-methylenetitanium": Encyclopedia of Reagents for Organic Synthesis. John Wiley, London, 2000. ::Cp2TiCl2 \+ 2 Al(CH3)3 → CH4 \+ Cp2TiCH2AlCl(CH3)2 \+ Al(CH3)2Cl After about 3 days, the product is obtained after recrystallization to remove Al(CH3)2Cl.
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It is possible to modify Tebbe's reagent through the use of different ligands. This can alter the reactivity of the complex, allowing for a broader range of reactions. For example, cyclopropanation can be achieved using a chlorinated analogue.Unusual Ambiphilic Carbenoid Equivalent in Amide Cyclopropanation Kuo-Wei Lin, Shiuan Yan, I-Lin Hsieh, and Tu-Hsin Yan Org. Lett.
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Methyl propiolate is an organic compound with the formula HC2CO2CH3. It is the methyl ester of propiolic acid, the simplest acetylenic carboxylic acid. It is a colorless liquid that is miscible with organic solvents. The compound is a reagent and building block for the synthesis of other organic compounds, reactions that exploit the electrophilicity of the alkyne group.
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Ethyl propiolate is an organic compound with the formula HC2CO2C2H5. It is the ethyl ester of propiolic acid, the simplest acetylenic carboxylic acid. It is a colorless liquid that is miscible with organic solvents. The compound is a reagent and building block for the synthesis of other organic compounds, reactions that exploit the electrophilicity of the alkyne group.
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Reagent testing is one of the process used to identify substances contained within a pill, usually illicit substances. With the increased prevalence of drugs being available in their pure forms, the terms "drug checking" or "pill testing" may also be used, although these terms usually refer to testing with a wider variety of techniques covered by drug checking.
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Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula (CH3CO)2O. Commonly abbreviated Ac2O, it is the simplest isolable anhydride of a carboxylic acid and is widely used as a reagent in organic synthesis. It is a colorless liquid that smells strongly of acetic acid, which is formed by its reaction with moisture in the air.
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Biocatalysis makes use of biological compounds, ranging from isolated enzymes to living cells, to perform chemical transformations. The advantages of these reagents include very high e.e.s and reagent specificity, as well as mild operating conditions and low environmental impact. Biocatalysts are more commonly used in industry than in academic research; for example in the production of statins.
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With respect to carboxylic acids, aminosulfuranes and SF4 are complementary: the former gives acid fluorides, while the latter gives trifluoromethyl compounds. Perfluorinated alkylamines, such as Ishikawa's reagent (N,N-diethyl-1,1,2,3,3,3-hexafluoropropylamine),Takaoka, A.; Iwagiri, H.; Ishikawa, N. Bull. Chem. Soc. Jpn. 1979, 52, 3377. are highly selective for hydroxyl groups and do not react with aldehydes and ketones.
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Almost all amine oxides are prepared by the oxidation of either tertiary aliphatic amines or aromatic N-heterocycles. Hydrogen peroxide is the most common reagent both industrially and in academia, however peracids are also important. More specialised oxidising agents can see niche use, for instance Caro's acid or mCPBA. Spontaneous or catalysed reactions using molecular oxygen are rare.
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It was however, inferior in quality, and cost-prohibitive to produce. Adams was concerned because two processes showed an equal potential to emerge as the preferred manner of production. One depended on distilling an additive for reactivity, while the other used a petroleum-based reagent. Adams was hopeful that rubber would come to be polymerized by petrochemical means.
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Another synthetic route uses the Speeter-Anthony tryptamine synthesis starting from 4-hydroxyindole. Psilocin is relatively unstable in solution due to its phenolic hydroxy (-OH) group. In the presence of oxygen it readily forms bluish and dark black degradation products. Similar products are also formed under acidic conditions in the presence of oxygen and Fe3+ ions (Keller's reagent).
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Semicarbazide is used in preparing pharmaceuticals including: nitrofuran antibacterials (furazolidone, nitrofurazone, nitrofurantoin), and dizatrifone. It is also a product of degradations of the blowing agent azodicarbonamide (ADC). Semicarbazide forms in heat-treated flour containing ADC as well as breads made from ADC-treated flour. Semicarbazide is used as a detection reagent in thin layer chromatography (TLC).
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They are hyaline, thin-walled, and smooth, showing no reaction to Melzer's reagent. The fungus grows on angiosperm wood and causes a brown rot. Molecular phylogenetic analysis shows Buglossoporus be closely related to Neolentiporus. This latter genus, however, has a dimitic hyphal system in trama with irregularly thick- walled generative hyphae, and skeletal hyphae that are metachromatic.
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This method was generalized to a route producing biaryls by coupling phenylboronic acid with aryl halides. C-C bond forming processes commonly use phenylboronic acid as a reagent. Alpha-amino acids can be generated using the uncatalyzed reaction between alpha-ketoacids, amines, and phenylboronic acid. Heck-type cross coupling of phenylboronic acid and alkenes and alkynes has been demonstrated.
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The reagent is generated in situ from copper(I) NHC complex. The hydride equivalents are provided by a silane. :Buchwald selective- copper based chemistry Synthesis of Z-Fluoro alkene dipeptide isosteres,.Otaka, A.; Watanabe, H.; Mitsoyama, E.; Yukimasa, A.; Tamamura, H.; Fujii, N. Synthesis of (Z)-fluoroalkene isosteres utilizing organocopper- mediated reduction of gama, gamma- α,β - enoates.
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Borane dimethylsulfide (BMS) is a complexed borane reagent that is widely used for hydroborations. Diborane can be produced in situ by reduction BF3 with NaBH4 (see for Flavopiridol). Usually however, borane dimethylsulfide complex BH3S(CH3)2 (BMS) is used as a source of BH3.See Borane-dimethylsulfide complex It can be obtained in highly concentrated forms.
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Clark, R. D.; Muchowski, J. M.; Fisher, L. E.; Flippin, L. A.; Repke, D. B.; Souchet, M. Synthesis 1991, 871. (7)File:LatLithScope4.png Sulfonamides require two equivalents of an organolithium reagent for lateral lithiation, but represent a useful class of directing groups. Treatment with ketones leads to tertiary alcohols in high yield.Watanabe, H.; Mao, C.-L.
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1976, 41, 1879. A useful indicator for the progress of lateral lithiations is the color of the reaction mixture. Benzyllithium compounds range in color from red to deep purple, and in many cases the lack of a color change upon addition of an organolithium reagent to the substrate may indicate the presence of an undesired proton source in solution.
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When stained in potassium hydroxide, the hyphal contents tend to form beads, while staining in Melzer's reagent causes the pigment to form globules. Cystidia are common in the hymenial tissue; they are swollen at the base and narrow at the apex (lageniform), measuring 30–40 µm long by 7–9 µm thick. Clamp connections are absent in the hyphae.
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They have a clamp connection at base. Pleurocystidia (cystidia on the gill face) are not present in this species. The gill tissue is made of smooth, thin-walled cylindrical to egg-shaped cells, up to 30.4 μm in diameter. The cells are dextrinoid (producing a black to blue-black positive reaction with Melzer's reagent), and reddish brown.
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For example, pyridones and pyrimidones can be converted to chloro- derivatives such as 2-chloropyridines and 2-chloropyrimidines, which are intermediates in the pharmaceutical industry. In the Vilsmeier-Haack reaction, POCl3 reacts with amides to produce a "Vilsmeier reagent", a chloro-iminium salt, which subsequently reacts with electron-rich aromatic compounds to produce aromatic aldehydes upon aqueous work-up.
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Several chemical tests utilize copper sulfate. It is used in Fehling's solution and Benedict's solution to test for reducing sugars, which reduce the soluble blue copper(II) sulfate to insoluble red copper(I) oxide. Copper(II) sulfate is also used in the Biuret reagent to test for proteins. Copper sulfate is used to test blood for anemia.
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They further demonstrated that the levels of skin brightness were improved after treatment of the reagent by 2.49%. Moreover, the number of comedones were decreased 9.59%. Survey analysis showed that the volunteers had high personal satisfaction levels after using the reagents. Collectively, the results indicated that the galactomyces containing essence-formed cosmetics have an improved effect on facial skin.
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On 18 March 2020, Dr. Kalumbi Shangula, on behalf of the Ministry of Health and Social Services, received a donation of 1 000 diagnostic test kits from the Chinese Ambassador Zhang Yiming. This was to increase the testing capacity of COVID-19 in the country. On 28 March, Namibian bank Bank Windhoek donated 500 reagent- and swop testing kits.
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Wortmannin is a commonly used cell biology reagent that has been used previously in research to inhibit DNA repair, receptor-mediated endocytosis and cell proliferation.Liu Y, Shreder KR, Gai W, Corral S, Ferris DK, Rosenblum JS. Wortmannin, a widely used phosphoinositide 3-kinase inhibitor, also potently inhibits mammalian polo-like kinase. Chem Biol. 2005;12:99–107.
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The cap has a cuticle consisting of tightly interwoven pressed-down hyphae that are usually 3–5 μm wide. The hyphae in the epicuticular zone (a waxy layer on the surface of the cuticle) often have fine granular incrustations that can be seen in both KOH and Melzer's reagent. Clamp connections are absent from the hyphae of B. rubroflammeus.
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In the process of oxidizing the organic substances found in the water sample, potassium dichromate is reduced (since in all redox reactions, one reagent is oxidized and the other is reduced), forming Cr3+. The amount of Cr3+ is determined after oxidization is complete, and is used as an indirect measure of the organic contents of the water sample.
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Hydridocopper is a hydrophilic (polar) solute, and so dissolves in polar compounds. As hydridocopper is an electron-deficient compound, its dominant behaviour is to polymerise, first to oligomers, then to copper hydride. A well-known oligomer is octahedro- hexacuprane(6), occurring in Stryker's reagent. Hydridocopper has acidic behavior for the same reason as normal copper hydride.
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53 no. 4 325-329 The Formal method also has the disadvantages of involving the use and disposal of formaldehyde which is a known carcinogenVirginia Tech University "Estimate of FAN by Formol Titration" Adapted from Zoecklein et al., 1999 and Gump, Zoecklein and Fugelsang, 2002. Accessed: March 31st, 2013 and the highly toxic reagent barium chloride.
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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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This technique brings together protein and precipitation solutions without premixing them, but instead, injecting them through either sides of a channel, allowing equilibrium through diffusion. The two solutions come into contact in a reagent chamber, both at their maximum concentrations, initiating spontaneous nucleation. As the system comes into equilibrium, the level of supersaturation decreases, favouring crystal growth.
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Mycena galericulata produces a white spore print. The spores are ellipsoid, 8–10 by 5.5–7 μm, and amyloid—which means they will turn blue-black to black when stained with Melzer's reagent. The basidia (spore-bearing cells) have stout sterigmata, and measure 34–40 by 7–9 μm. They may be either two-spored or four-spored.
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Green Chemistry, volume 19, issue 15, pages 3671-3678. Alessandro Pellis, Fergal P Byrne, James Sherwood, Marco Vastano, James W Comerford, Thomas J Farmer (2019) Safer bio-based solvents to replace toluene and tetrahydrofuran for the biocatalyzed synthesis of polyesters. Green Chemistry, volume 21, issue 7, pages 1686-1694. and as a reagent in chemical synthesis.
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BTMSA is used as a nucleophile in Friedel-Crafts type acylations and alkylations and a precursor to lithium trimethylsilylacetylide. The TMS groups can be removed with tetra-n-butylammonium fluoride (TBAF) and replaced with protons. BTMSA is also a useful reagent in cycloaddition reactions. Illustrating its versatility, BTMSA was used in a concise total synthesis of (±)-estrone.
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Benzotriazole has been known for its great versatility. It has already been used as a restrainer in photographic emulsions and as a reagent for the analytical determination of silver. More importantly, it has been extensively used as a corrosion inhibitor in the atmosphere and underwater. Also, its derivatives and their effectiveness as drug precursors have been drawing attention.
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Skeletal formula of methyl thionobenzoate Thionoesters are isomeric with thioesters. In a thionoester, sulfur replaces the carbonyl oxygen in an ester. Methyl thionobenzoate is C6H5C(S)OCH3. Such compounds are typically prepared by the reaction of the thioacyl chloride with an alcohol, but they can also be made by the reaction of Lawesson's reagent with esters.
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To minimize the chance of contamination, investigators should reserve separate rooms for reagent preparation, the PCR, and analysis of product. Reagents should be dispensed into single-use aliquots. Pipettors with disposable plungers and extra-long pipette tips should be routinely used. Environmental samples that contain humic acids may inhibit PCR amplification and lead to inaccurate results.
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The peptide to be sequenced is adsorbed onto a solid surface. One common substrate is glass fibre coated with polybrene, a cationic polymer. The Edman reagent, phenylisothiocyanate (PITC), is added to the adsorbed peptide, together with a mildly basic buffer solution of 12% trimethylamine. This reacts with the amine group of the N-terminal amino acid.
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It is also used as to form Dragendorff reagent, which is used as a TLC stain. Bismuth nitrate forms insoluble complexes with pyrogallol and cupferron and these have been the basis of gravimetric methods of determining bismuth content.A.I. Vogel,(1951), Quantitative Inorganic analysis, (2d edition), Longmans Green and Co On heating bismuth nitrate can decompose forming nitrogen dioxide, NO2.
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It was used in World War I as a chemical weapon, called BA by British and B-Stoff (Weisskreuz) by Germans. Due to its toxicity, it is not used as a riot control agent anymore. Bromoacetone is a versatile reagent in organic synthesis. It is, for example, the precursor to hydroxyacetone by reaction with aqueous sodium hydroxide.
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In a so-called tandem oxidation- Wittig process the aldehyde is formed in situ by oxidation of the corresponding alcohol. As mentioned above, the Wittig reagent itself is usually derived from a primary alkyl halide. Quaternization of triphenylphosphine with most secondary halides is inefficient. For this reason, Wittig reagents are rarely used to prepare tetrasubstituted alkenes.
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The Minimum Information About a Protein Affinity Reagent has been developed and maintained by the Molecular Interaction worktrack of the HUPO-PSI (www.psidev.info)in conjunction with the HUPO Antibody Initiative and a European consortium of binder producers and seeks to encourage users to improve their description of binding reagents, such as antibodies, used in the process of protein identification.
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Thus, for enolate acylation reactions in which C- vs. O-selectivity is a concern, methyl cyanoformate is often used in place of more common acylation reagent like methyl chloroformate. It is notoriously known for being an ingredient in Zyklon A, a predecessor to Zyklon B, the brand name of a German gas pesticide that was used during the Holocaust.
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A. subrubescens mushrooms are mildly toxic: consumption causes a gastrointestinal illness that usually subsides one to four hours after ingestion. In deposit, the spores are white. The spores are 3.4–4.7 by 2.2–3.4 µm, ellipsoid to ovoid in shape, and amyloid (absorbing iodine when stained with Melzer's reagent). Most have a single large oil drop.
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Dibromochloromethane was formerly used as a flame retardant and as an intermediate in chemicals manufacturing. Today it is used only as a laboratory reagent. Dibromochloromethane is also a disinfection byproduct, formed by the reaction of chlorine with natural organic matter and bromide ions in the raw water supply. As a result, it is commonly found in chlorinated drinking water.
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Selenium tetrafluoride (SeF4) is an inorganic compound. It is a colourless liquid that reacts readily with water. It can be used as a fluorinating reagent in organic syntheses (fluorination of alcohols, carboxylic acids or carbonyl compounds) and has advantages over sulfur tetrafluoride in that milder conditions can be employed and it is a liquid rather than a gas.
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Trimethyl phosphite is an organophosphorus compound with the formula P(OCH3)3, often abbreviated P(OMe)3. It is a colorless liquid with a highly pungent odor. It is used as a ligand in organometallic chemistry and as a reagent in organic synthesis. The molecule features a pyramidal phosphorus(III) center bound to three methoxy groups.
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The flesh is pallid but soon pale cinnamon-buff. The odor and taste are not distinctive. A drop of FeSO4 solution (a reagent commonly used in mushroom identification) applied to the surface of the cap will turn olive-green. The gills are pinkish-buff when young (in unopened caps), dull cinnamon-brown at maturity when the spores mature.
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Hygrophoropsis is a saprophytic genus that causes brown rot in the wood it colonises. The fruit bodies grow on the ground in woodlands, on moss, peat, and on woodchips. They are convex to infundibuliform (funnel-shaped) and have decurrent, forked brightly colored gills. The spores are dextrinoid, meaning that they stain reddish-brown in Melzer's reagent.
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The spore print colour ranges from whitish to cream. Microscopically, Hygrophoropsis lacks cystidia and has spores that are dextrinoid, meaning that they stain reddish-brown in Melzer's reagent. Clamp connections are present in the hyphae. With respect to overall appearance, Hygrophoropsis species closely resemble those in genus Cantharellula; the latter genus, however, has amyloid rather than dextrinoid spores.
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To form kaitocephalin's pyrrolidine core, a stereoconvergent cyclization reaction was discovered. A mixture of anti and syn isomers that undergoes this reaction will favor the trans product, regardless of the initial ratios used. This removes the need for an additional chiral reagent to obtain the desired stereochemistry. The mechanism for this cyclization is not yet understood.
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Tungsten hexachloride is the chemical compound of tungsten and chlorine with the formula WCl6. This dark violet blue species exists as a volatile solid under standard conditions. It is an important starting reagent in the preparation of tungsten compounds.. Other examples of charge-neutral hexachlorides are ReCl6 and MoCl6. The highly volatile WF6 is also known.
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Like the gills, the top of the stem is often beaded with drops of translucent liquid in moist weather. The spores are ellipsoid, smooth, and measure 7–9 by 4.5–5 µm. They are yellowish when stained with Melzer's reagent. The basidia (spore-bearing cells in the hymenium) are four-spored, and measure 40–54 by 6–8 µm.
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The reagent can be modified to effect partial reductions. SMEAH in toluene under reflux has been used to reduce aliphatic p-toluenesulfonamides (TsNR2) to the corresponding free amines and is one of the few reagents that can carry out this challenging reduction in general settings. Notably, LiAlH4 does not reduce this functional group unless forcing conditions are used.
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Environmentally beneficial, low-cost substitutes for rigid thermoplastic and fired ceramic are made using s as a chemical reagent. The s in these processes is reacted with the alkaline components of fully hardened hydraulic cement or gypsum plaster to form various carbonates. The primary byproduct is water. Supercritical carbon dioxide is used in the foaming of polymers.
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Other technologies mix and dose into the water body using a mobile water based floating system. The technology must be selected carefully based on the application and the reagent selected. For example for the treatment of turbidity the flocculant must be evenly dispensed over the surface of the water body to allow it to settle through creating flocs.
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Most glucometers today use an electrochemical method. Test strips contain a capillary that sucks up a reproducible amount of blood. The glucose in the blood reacts with an enzyme electrode containing glucose oxidase (or dehydrogenase). The enzyme is reoxidized with an excess of a mediator reagent, such as a ferricyanide ion, a ferrocene derivative or osmium bipyridyl complex.
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One of the simplest examples of an organic compound of zinc is the acetate (). Organozinc compounds are those that contain zinc–carbon covalent bonds. Diethylzinc () is a reagent in synthetic chemistry. It was first reported in 1848 from the reaction of zinc and ethyl iodide, and was the first compound known to contain a metal–carbon sigma bond.
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