On Earth, naphthalene and biphenyl are considered toxic and are used moth balls and citrus fruit wrappings, respectively.
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The sample cylinders made with urea and naphthalene could hold the heavy weights and retain a mostly stable shape.
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Often, it contains small amounts of volatile, toxic, organic compounds such as benzene, formaldehyde, butadiene, carbon tetrachloride, naphthalene and chloroform.
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Other common plasticizers, like naphthalene and polycarboxylate, were also mixed with regolith and printed in the same way for comparison.
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The embossed and slightly rusty letters warned residents not to place "carpet sweepings containing naphthalene or camphor balls" into the incinerator.
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Pollutants, including pentacholorphenol, benzene naphthalene, toluene, and phenol, have migrated from the ponds, contaminating the shallow ground water beneath the site and the Laramie River.
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It's not only designed to capture particular matter, like smoke, dust, and pollen, but now is also capable of trapping harmful gases like formaldehyde, benzene, toluene, and naphthalene, Dyson claims.
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The team inserted grains of naphthalene and biphenyl, compounds that are likely to exist on Titan, into a modified tumbler device and rotated them for 20 minutes in a nitrogen-rich environment.
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In 66.43, the EPA looked into community concerns that excavation during GEO Group's expansion of the center to house 553 more people might have exposed workers and detainees to contamination from mercury and naphthalene vapors.
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Avian choreographed that production with Michael Bennett; Ms. Lee played Connie in it.) The now classic designs (sets by Robin Wagner, costumes by Theoni V. Aldredge, lighting by Tharon Musser) appear to have been retrieved from storage; you can almost smell the naphthalene wafting from the ultra-'70s woolens.
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Most naphthalene is derived from coal tar. From the 1960s until the 1990s, significant amounts of naphthalene were also produced from heavy petroleum fractions during petroleum refining, but today petroleum-derived naphthalene represents only a minor component of naphthalene production. Naphthalene is the most abundant single component of coal tar. Although the composition of coal tar varies with the coal from which it is produced, typical coal tar is about 10% naphthalene by weight.
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Naphthalene poisoning (or mothball poisoning) is a form of poisoning that occurs when naphthalene is ingested. Severe poisoning can result in haemolytic anaemia. Naphthalene was introduced in 1841 by Rossbach as an antiseptic to counteract typhoid fever. Although naphthalene was widely used industrially, only nine cases of poisoning have been reported since 1947.
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Other names in common use include naphthalene dioxygenase, and naphthalene oxygenase. This enzyme participates in 4 metabolic pathways: 1- and 2-methylnaphthalene degradation, naphthalene and anthracene degradation, fluorene degradation, and ethylbenzene degradation. It employs one cofactor, iron.
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There are two methods explored to synthesize michellamines A and B. The first one, originally synthesized in 1994, is a retrosynthesis that leads to a biomimetic pathway that uses the construction of naphthalene/isoquinoline bonds before the naphthalene/naphthalene axis. The second method, originally synthesized only a few montes after the first method, is a complementary pathway that would use the naphthalene/naphthalene axis after it is created and add the two isoquinoline moieties.
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1,8-Bis(dimethylamino)naphthalene is an organic compound with the formula CH(NMe) (Me = methyl). It is classified as a peri-naphthalene, i.e. a 1,8-disubstituted derivative of naphthalene. Owing to its unusual structure, it exhibits exceptional basicity.
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Naphthalene exposure is usually insignificant unless exposed to large amounts of naphthalene within production or being near proximity of a product that contains naphthalene. Naphthalene levels within an area are very unstable and frequently change over time and space. Due to this variance, sampling protocols must be conducted carefully and are usually analysed using different analytical methods.
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Experimental set up for the sublimation reaction of naphthalene Solid naphthalene sublimes and form the crystal-like structure at the bottom of the watch glass Solid compound of naphthalene sublimed to form a crystal-like structure on the cool surface.
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Naphthalene locomotive, 1913 A Naphthalene locomotive was tested in France in 1913. It was built by Schneider-Creusot for use in their own plant.
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The industrial synthesis involves aerobic oxidation of naphthalene over a vanadium oxide catalyst: :CH + 3/2 O → CHO + HO In the laboratory, naphthoquinone can be produced by the oxidation of a variety of naphthalene compounds. An inexpensive route involves oxidation of naphthalene with chromium trioxide.
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Tobacco is also a source of exposure, creating an estimated range of 0.3 to 4 micrograms of naphthalene inhalation per cigarette that is consumed. A regular pack a day smoker on average would be inhaling amounts of 6-80 micrograms of naphthalene daily, which is a small and negligible amount of naphthalene, and is similar in magnitude to normal exposure near highways and areas where car exhaust is frequently inhaled or consumed. The naphthalene within cigarettes is different to other sources of naphthalene. The naphthalene that is produced in cigarette smoke is bound to other particles and is not presented as a free vapour, meaning the exposure is small.
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Naphthalene has also been found to be secreted by termites in order to protect their nests. The termites use naphthalene to repel ants and any intruders who try to invade their nests. This naphthalene produced is not only toxic for the insects but can also affect humans in the same way. Naphthalene poisoning via termite nest was featured in the eleventh episode of the first season of the American television medical drama House, "Detox", where the final diagnosis ended up as acute naphthalene poisoning as a result of a termite nest being contained within the walls of the patient's bedroom, leading him to inhale naphthalene in his sleep and becoming sick.
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In electrophilic aromatic substitution reactions, naphthalene reacts more readily than benzene. For example, chlorination and bromination of naphthalene proceeds without a catalyst to give 1-chloronaphthalene and 1-bromonaphthalene, respectively. Likewise, whereas both benzene and naphthalene can be alkylated using Friedel–Crafts reactions, naphthalene can also be easily alkylated by reaction with alkenes or alcohols, using sulfuric or phosphoric acid catalysts. In terms of regiochemistry, electrophiles attack at the alpha position.
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1,2-dihydroxynaphthalene dioxygenase (, 1,2-DHN dioxygenase, DHNDO, 1,2-dihydroxynaphthalene oxygenase, 1,2-dihydroxynaphthalene:oxygen oxidoreductase) is an enzyme with systematic name naphthalene-1,2-diol:oxygen oxidoreductase. This enzyme catalyses the following chemical reaction : naphthalene-1,2-diol + O2 \rightleftharpoons 2-hydroxy-2H-chromene-2-carboxylate This enzyme is involved in naphthalene degradation.
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This diketone (an ortho-quinone) is a metabolite of naphthalene. It arises from the naphthalene-1,2-oxide. It is also found in diesel exhaust particles. The accumulation of this toxic metabolite in rats from doses of naphthalene has been shown to cause eye damage, including the formation of cataracts.
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A railway locomotive using solid naphthalene was built by Schneider-Creusot in France in 1913. It was a 70 bhp petrol-paraffin engine, but using solid naphthalene rather than paraffin, simply as a cheaper fuel. The naphthalene was melted and vaporised by a water jacket, heated by the engine.
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According to the International Agency for Research on Cancer, naphthalene is possibly carcinogenic to humans (Group 2B), as there is inadequate evidence in humans for the carcinogenicity of naphthalene, however there is sufficient evidence in experimental animals for the carcinogenicity of naphthalene. The carcinogenicity was tested on rats in mice, via intraperitoneal administration and subcutaneous administration, of newborns and adult rats, providing evidence of tumours. The IARC also discovered that naphthalene toxicity also had potential to cause cataracts in humans, rats, rabbits and mice, however the tests were considered inefficient to substantiate a diagnosis resulting in naphthalene as a potential carcinogen classification. Likewise, the European Chemical agency classified naphthalene as Group C, a possible human carcinogen.
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The first rylenes, with an example of a diimide derivative at bottom-left. A rylene dye is a dye based on the rylene framework of naphthalene units linked in peri-positions. In homologues additional naphthalene units are added, forming compounds — or poly(peri-naphthalene)s — such as perylene, terrylene and quarterrylene.
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Several peri-naphthalenes are prepared via nitrations. Dinitration of naphthalene gives 1,8-dinitronaphthalene, which undergoes hydrogenation to the diamine. The diamine can also be produced by reaction of the 1,8-diol with ammonia at high temperatures. The peri- naphthalene 1-amino-naphthalene-8-sulfonic acid is a precursor to other peri- naphthalenes.
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In enzymology, a cis-1,2-dihydro-1,2-dihydroxynaphthalene dehydrogenase () is an enzyme that catalyzes the chemical reaction :cis-1,2-dihydronaphthalene-1,2-diol + NAD+ \rightleftharpoons naphthalene-1,2-diol + NADH + H+ Thus, the two substrates of this enzyme are cis-1,2-dihydronaphthalene-1,2-diol and NAD+, whereas its 3 products are naphthalene-1,2-diol, NADH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is cis-1,2-dihydronaphthalene-1,2-diol:NAD+ 1,2-oxidoreductase. Other names in common use include (+)-cis-naphthalene dihydrodiol dehydrogenase, naphthalene dihydrodiol dehydrogenase, and cis-dihydrodiol naphthalene dehydrogenase. This enzyme participates in 1- and 2-methylnaphthalene degradation and naphthalene and anthracene degradation.
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Naphthalene is used mainly as a precursor to other chemicals. The single largest use of naphthalene is the industrial production of phthalic anhydride, although more phthalic anhydride is made from o-xylene. Many azo dyes are produced from naphthalene, and so is the insecticide 1-naphthyl-N- methylcarbamate (carbaryl). Other useful agrichemicals include naphthoxyacetic acids.
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In industrial practice, distillation of coal tar yields an oil containing about 50% naphthalene, along with twelve other aromatic compounds. This oil, after being washed with aqueous sodium hydroxide to remove acidic components (chiefly various phenols), and with sulfuric acid to remove basic components, undergoes fractional distillation to isolate naphthalene. The crude naphthalene resulting from this process is about 95% naphthalene by weight. The chief impurities are the sulfur-containing aromatic compound benzothiophene (< 2%), indane (0.2%), indene (< 2%), and methylnaphthalene (< 2%).
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The first proposed mechanism for a thermal rearrangement of an aromatic compound was for the automerization of naphthalene. It was suggested that the rearrangement of naphthalene occurred due to reversibility of the isomerization of azulene to naphthalene. This mechanism would therefore involve an azulene intermediate and is depicted below: upright=2 Subsequent work showed that the isomerization of azulene to naphthalene is not readily reversible ( the free energy of a naphthalene to azulene isomerization was too high - approximately 90 kcal/mol). A new reaction mechanism was suggested that involved a carbene intermediate and consecutive 1,2-hydrogen and 1,2-carbon shifts across the same C-C bond but in opposite directions.
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Santucci, K; Shah, B. (January 2000). "Association of naphthalene with acute hemolytic anemia". Academic Emergency Medicine. 7(1):42-7. IARC classifies naphthalene as possibly carcinogenic to humans and other animals (see also Group 2B).
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Naphtholactam is an organic compound derived from naphthalene. It is a tricyclic species consisting of a naphthalene core fused with a lactam (NH- CO-) at the 1,8-positions. The N-alkyl derivatives are commercially important.
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Petroleum-derived naphthalene is usually purer than that derived from coal tar. Where required, crude naphthalene can be further purified by recrystallization from any of a variety of solvents, resulting in 99% naphthalene by weight, referred to as 80 °C (melting point). Approximately 1.3M tons are produced annually.. In North America, the coal tar producers are Koppers Inc., Ruetgers Canada Inc.
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Aside from coal tar, trace amounts of naphthalene are produced by magnolias and some species of deer, as well as the Formosan subterranean termite, possibly produced by the termite as a repellant against "ants, poisonous fungi and nematode worms." Some strains of the endophytic fungus Muscodor albus produce naphthalene among a range of volatile organic compounds, while Muscodor vitigenus produces naphthalene almost exclusively.
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It is prepared by disulfonation of naphthalene with oleum: :C10H8 \+ 2 SO3 → C10H6(SO3H)2 Further sulfonation gives The 1,3,5-trisulfonic acid derivative.Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. .
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Naphthalene is used in engineering to study heat transfer using mass sublimation.
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Naphthalene on oxidation with potassium permanganate or potassium dichromate gives phthalic acid.
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Naphthalene, an organic compound commonly found in pesticides such as mothballs, sublimes easily because it is made of non- polar molecules that are held together only by van der Waals intermolecular forces. Naphthalene is a solid that sublimes at standard atmospheric temperature with the sublimation point at around 80°C or 176°F. At low temperature, its vapour pressure is high enough, 1mmHg at 53°C, to make the solid form of naphthalene evaporate into gas. On cool surfaces, the naphthalene vapours will solidify to form needle-like crystals.
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The electronegativity of the atoms of this ring system and conjugation cause a ring current resulting in a quadrupole. For naphthalene, this quadrupole manifests in a δ- and δ+ accumulating within and outside the ring system, respectively. Naphthalene assembles through the coordination of δ- of one molecules to the δ+ of another molecule. This results in 1D columns of naphthalene in a herringbone configuration.
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Molten naphthalene provides an excellent solubilizing medium for poorly soluble aromatic compounds. In many cases it is more efficient than other high-boiling solvents, such as dichlorobenzene, benzonitrile, nitrobenzene and durene. The reaction of C60 with anthracene is conveniently conducted in refluxing naphthalene to give the 1:1 Diels–Alder adduct. The aromatization of hydroporphyrins has been achieved using a solution of DDQ in naphthalene.
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Both naphthalene and 1,4-dichlorobenzene undergo sublimation, meaning that they evaporate from a solid state directly into a gas; this gas is toxic to moths and moth larvae. Naphthalene and 1,4-dichlorobenzene should not be used together because the mixture may cause damage to items being preserved. Due to the health risks of 1,4-dichlorobenzene, and flammability of naphthalene, other substances like camphor are sometimes used.
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A bathochromic shift of about 100 nm is recorded per additional naphthalene unit.
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Brillié designed an experimental Naphthalene locomotive, which was built by Schneider in 1913.
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Treatment is in the form of bathing in this special grade of warm crude oil. Doctors in Azerbaijan have claimed that Naftalan crude baths can cure more than 70 diseases, including skin, joint, and neurological ailments, even though Western Medicine experts have rebutted this claim and stated that the Naftalan crude ingredient naphthalene is possibly carcinogenic. Crude naphthalene (obtained directly from production wells); purified naphthalene (with various additives to increase its density); naphthalene cleaned from resin; naphthenic hydrocarbons; and naphthalene mastic (which consists of naftalan, paraffin, wax, ceresin, and camphor) are all used in these treatments. The Duzdag Hotel in Nakhchivan, Istisu Masalli, and the Qalaalti Hotel & Spa in Shabran region have been cited as some of the most popular health resorts in the world.
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1-Naphthyl isothiocyanate is a chemical compound which is an isothiocyanate derivative of naphthalene.
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Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley- VCH, Weinheim. .
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He discovered and synthesized the first lactones and investigated structures of piperine naphthalene and fluorene.
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A railway locomotive using solid naphthalene was built by Schneider-Creusot in France in 1913. This had no relation to the naphtha engine. It was a 70 bhp internal combustion engine, similar to a petrol-paraffin engine, which operated as a petrol engine and once started and warmed up could be switched to naphthalene simply as a cheaper fuel. The naphthalene was melted and vaporised by a water jacket, heated by the engine.
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Naphthalene has been tentatively detected in the interstellar medium in the direction of the star Cernis 52 in the constellation Perseus. \- This spectral assignment has not been independently confirmed, and is described by the authors as "tentative" (page L58). More than 20% of the carbon in the universe may be associated with polyaromatic hydrocarbons, including naphthalene. Protonated cations of naphthalene () are the source of part of the spectrum of the Unidentified Infrared Emissions (UIRs).
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1-Lithionaphthalene can be further lithiated to give 1,8-dilithionaphthalene, a precursor to peri-naphthalene compounds.
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Heilbronner, E.; Plattner, P. A.; Wieland, K. Rearrangement of Azulene to Naphthalene. Experientia 1947, 3, 70–71. Since then, many other isomerizations have been recorded, however the rearrangement of azulene to naphthalene has received the most attention. Likewise, since the characterization of the automerization of naphthalene by Scott in 1977, similar atom scramblings of other aromatic hydrocarbons such as pyrene,Scott, L. T.; Kirms, M. A.; Berg, A.; Hansen, P. E. Automerization of Pyrene a Test for the Mechanism of Naphthalene Automerization. Tetrahedron Letters 1982, 23 (18), 1859–1862. DOI: 10.1016/S0040-4039(00)87204-4 azulene, benz[a]anthraceneScott, L. T.; Tsang, T.-H.
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For example, Pseudomonas fluorescens has been genetically engineered to be capable of degrading salicylate and naphthalene, and is used as a biosensor to assess the bioavailability of salicylate and naphthalene. Biosensors can also be used as an indicator of cellular metabolic activity and to detect the presence of pathogens.
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Since naphthalene, at ordinary temperature and pressure, is in a solid state, the engine was started with petrol or benzene. The naphthalene tank was enclosed in a water jacket, which was heated to boiling point by engine exhaust. Once the naphthalene (melting point 80°C) had liquified, it could be used as a fuel. British patent 26541 awarded to Gaston Paul Jean Lion and Eugène Brillié in 1907, describes a fuel melting system but it differs from that described above.
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Naphthalene is a precursor in the production of phthalic anhydride. This application has been displaced by alternative technologies.
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Nadoxolol is a beta blocker. Hydrogenation of naphthalene gives tetralin, which is used as a hydrogen-donor solvent.
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This enzyme participates in naphthalene and anthracene degradation. It has 4 cofactors: FAD, Iron, Sulfur, and Iron-sulfur.
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Elbs however did not correctly interpret the reaction product due to a lack of knowledge about naphthalene structure.
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In enzymology, a naphthalene 1,2-dioxygenase () is an enzyme that catalyzes the chemical reaction :naphthalene + NADH + H+ \+ O2 \rightleftharpoons (1R,2S)-1,2-dihydronaphthalene-1,2-diol + NAD+ The 4 substrates of this enzyme are naphthalene, NADH, H+, and O2, whereas its two products are (1R,2S)-1,2-dihydronaphthalene-1,2-diol and NAD+. This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with NADH or NADPH as one donor, and incorporation of two atoms o oxygen into the other donor. The systematic name of this enzyme class is naphthalene,NADH:oxygen oxidoreductase (1,2-hydroxylating).
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General structure of polychlorinated naphthalenes Structure of 2,3,6,7-Tetrachloronaphthalene Polychlorinated naphthalene (PCN) are the products obtained upon treatment of naphthalene with chlorine. The generic chemical formula is C10H8−(m+n)Cl(m+n). Commercial PCNs are mixtures of up to 75 components and byproducts.van de Plassche, E.; Schwegler, A. (2002).
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Naphthalene's minimum odor threshold is 0.084 ppm for humans. Mothballs and other products containing naphthalene have been banned within the EU since 2008. In China, the use of naphthalene in mothballs is forbidden. Danger to human health and the common use of natural camphor are cited as reasons for the ban.
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1-Fluornaphthalene is an organofluorine chemical compound from the group of naphthalene derivatives and fluoroaromatics. Its chemical formula is .
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It is used on a large scale to prepare naphthalene dicarboxylic anhydride, which is a precursor to dyes and optical brighteners. Naphthalene dicarboxylic anhydride is the precursor to perylenetetracarboxylic dianhydride, precursor to several commercial pigments and dyes.K. Hunger. W. Herbst "Pigments, Organic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2012.
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With alkali metals, naphthalene forms the dark blue-green radical anion salts such as sodium naphthalenide, Na+C10H. The naphthalenide salts are strong reducing agents. Naphthalene can be hydrogenated under high pressure in the presence of metal catalysts to give 1,2,3,4-tetrahydronaphthalene(), also known as tetralin. Further hydrogenation yields decahydronaphthalene or decalin ().
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The New England Journal of Medicine. July 27, 2006. Mothballs containing naphthalene have been banned within the EU since 2008.
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Flange connections were essential as blockages from naphthalene or pitchy deposits were likely to occur. The condensed liquids flowed down the sloping pipes in the same direction as the gas. As long as gas flow was slow, this was an effective method for the removal of naphthalene. Vertical air condensers had gas and tar outlets.
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This device injected a fine mist of naphtha into the outgoing gas so as to avoid the crystallization of naphthalene in the mains, and their consequent blockage. Naphtha was found to be a rather effective solvent for these purposes, even in small concentrations. Where troubles with naphthalene developed, as it occasionally did even after the introduction of this minor carburettor, a team of workers was sent out to blow steam into the main and dissolve the blockage; still, prior to its introduction, naphthalene was a very major annoyance for the gasworks.
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Naphthalene sulfonic acids are used in the manufacture of naphthalene sulfonate polymer plasticizers (dispersants), which are used to produce concrete and plasterboard (wallboard or drywall). They are also used as dispersants in synthetic and natural rubbers, and as tanning agents (syntans) in leather industries, agricultural formulations (dispersants for pesticides), dyes and as a dispersant in lead–acid battery plates. Naphthalene sulfonate polymers are produced by treating naphthalenesulfonic acid with formaldehyde, followed by neutralization with sodium hydroxide or calcium hydroxide. These products are commercially sold as superplasticizers for the production of high strength concrete.
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Exposure to large amounts of naphthalene may damage or destroy red blood cells, most commonly in people with the inherited condition known as glucose-6-phosphate dehydrogenase (G6PD) deficiency, which over 400 million people suffer from. Humans, in particular children, have developed the condition known as hemolytic anemia, after ingesting mothballs or deodorant blocks containing naphthalene. Symptoms include fatigue, lack of appetite, restlessness, and pale skin. Exposure to large amounts of naphthalene may cause confusion, nausea, vomiting, diarrhea, blood in the urine, and jaundice (yellow coloration of the skin due to dysfunction of the liver).
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3-Benzoxepin is a bright yellow solid that crystallizes in platelets, with a smell similar to naphthalene. The material is soluble in apolar, organic solvents. Like naphthalene, it can be purified through sublimation. The solid is relatively acid-resistant, only under refluxing in concentrated, acidic alcohol solutions an unsaturated aldehyde is formed (likely an indene-3-aldehyde).
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Yus, M.; Ramón, D. Arene-catalysed lithiation reactions with lithium at low temperature, Chem. Comm. 1991, 398-400. The major drawback of using lithium naphthalene catalysts is that it is hard to separate from the reaction mixture because naphthalene adsorbs on surface of arene substrates. In polymer chemistry, sodium metal has been used for dehalogenation process.
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1-Naphthol, or α-naphthol, is a fluorescent organic compound with the formula C10H7OH. It is a white solid. It is an isomer of 2-naphthol differing by the location of the hydroxyl group on the naphthalene ring. The naphthols are naphthalene homologues of phenol, with the hydroxyl group being more reactive than in the phenols.
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1-Naphthol is prepared by two main routes. In one method, naphthalene is nitrated to give 1-nitronaphthalene, which is hydrogenated to the amine followed by hydrolysis: : C10H8 \+ HNO3 → C10H7NO2 \+ H2O : C10H7NO2 \+ 3 H2 → C10H7NH2 \+ 2 H2O : C10H7NH2 \+ H2O → C10H7OH + NH3 Alternatively, naphthalene is hydrogenated to tetralin, which is oxidized to 1-tetralone, which undergoes dehydrogenation.
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The general reaction schemes of the two types are illustrated in Figure 1. This class of reactions was uncovered through studies on the automerization of naphthalene as well as the isomerization of unsubstituted azulene, to naphthalene. Research on thermal rearrangements of aromatic hydrocarbons has since been expanded to isomerizations and automerizations of benzene and polycyclic aromatic hydrocarbons.
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It is used in pyrotechnic special effects such as the generation of black smoke and simulated explosions. It is used to create artificial pores in the manufacture of high-porosity grinding wheels. In the past, naphthalene was administered orally to kill parasitic worms in livestock. Naphthalene and its alkyl homologs are the major constituents of creosote.
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2-Naphthol, or β-naphthol, is a fluorescent colorless (or occasionally yellow) crystalline solid with the formula C10H7OH. It is an isomer of 1-naphthol, differing by the location of the hydroxyl group on the naphthalene ring. The naphthols are naphthalene homologues of phenol, but more reactive. Both isomers are soluble in simple alcohols, ethers, and chloroform.
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Dialin (1,2-dihydronaphthalene) is a hydrocarbon with the chemical formula C10H10. It is similar to naphthalene but one ring is partially saturated.
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This complication resulted with an increased use of Camphor as a moth repellent. Camphor is frequently used in place of naphthalene in Asia.
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Naphthalene metabolites of 1,2-hydroxynaphthalene has also been found to be a mechanism of oxidative DNA damage within humans. In the presence of the reduced form of nicotinamide adenine dinucleotide (NADH).The damaging activity of the DNA of the activity of 1,2-hydroxynaphthalene was observed at much larger levels. 1,2-hydroxynaphthalene is reduced by NADH to be formed as a part of the redox cycle, resulting in the speeding up of DNA damage, however, this is only presented within larger prolonged exposure to naphthalene, values that are unrealistic for any individual not working near a place where naphthalene production occurs.
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In organic chemistry, peri-naphthalenes are particular derivatives of naphthalene with the formula C10H6-1,8-X2. Owing to the rigidity of the naphthalene skeleton, these substituents on the 1- and 8-positions are constrained to be relatively close 2.5 Å, which is within the van der Waals radius for many atoms. In contrast, ortho-substituents pendant from a benzene ring are separated by about 3.3 Å.Kilian, P.; Knight, F. R.; Woollins, J. D., "Synthesis of ligands based on naphthalene peri-substituted by Group 15 and 16 elements and their coordination chemistry", Coordination Chemistry Reviews 2011, volume 255, 1387-1413.
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Benzene is oxidized by the enzyme Cytochrome P450 to benzene oxide. In chemistry, an arene oxide is an epoxide of an arene. Two important families of arene oxides are benzene oxides and naphthalene oxides as these are intermediates in the oxidative degradation of benzene and naphthalene, two common pollutants. Benzopyrene is also converted to an epoxide, (+)-benzo[a]pyrene-7,8-epoxide.
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Until the late 1950s coal tar was the principal source of naphthalene. From 1981 to 1983 the U.S. National Institute for Occupational Safety and Health found over 100,000 workers were potentially exposed to toxic levels of naphthalene, working primarily for major industrial and agricultural businesses. Exposure may often be a result of oral ingestion, inhalation, or through prolonged skin exposure.
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Naphthalene is a major component of some mothballs. It repels moths as well as some animals. Since mothballs that contain naphthalene are considered hazards, safer alternatives have been developed, such as the use of 1,4-dichlorobenzene, however, 1,4-dichlorobenzene has been declared as a potential neurotoxin. 1,4-dichlorobenzene has been linked to potentially causing depression as a form of encephalopathy.
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The intermediate naphtyl methyl radical was formed during the reaction of sulfate radical anion with NAA.Naduvilpurakkal B. Shibin, Radhakrishnan Sreekanth, Usha K. Aravind, Kadavilpparampu M. Afsal Mohammed, Narayana V. Chandrashekhar, Jayan Joseph, Sisir K. Sarkar, Devidas B. Naik and Charuvila T. Aravindakumar. Radical chemistry of glucosamine naphthalene acetic acid and naphthalene acetic acid: a pulse radiolysis study. J. Phys. Org. Chem.
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There was also interest in the use of naphthalene as a motor fuel in the United Kingdom. In 1917, the Commercial Motor reported on experiments conducted by J.H. Willis and G.G. Wilson, of Birmingham Corporation Gas Works, using naphthalene fuel in a 10 hp motor boat engine. The tests were hailed as a success but nothing further seems to have been done.
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2-Chloronaphthalene is an organochlorine chemical compound, a chlorinated derivative of naphthalene. Its chemical formula is . The compound is an isomer for 1-chloronaphthalene.
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The peripheral protons around the ring are deshielded while the methylene bridge nuclei are strongly shielded. Its resonance energy is smaller than that of naphthalene.
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Graphene is an example of two-dimensional metallic bonding. Its metallic bonds are similar to aromatic bonding in benzene, naphthalene, anthracene, ovalene, and so on.
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The dipole-dipole and other intermolecular interactions align to minimize energy in the solid state and determine the crystal lattice structure. thumb A quadrupole, like a dipole, is a permanent pole but the electric field of the molecule is not linear as in acetone, but in two dimensions. Examples of molecular solids with quadrupoles are octafluoronaphthalene and naphthalene. Naphthalene consists of two joined conjugated rings.
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Phthalic anhydride was first reported in 1836 by Auguste Laurent. Early procedures involved liquid- phase mercury-catalyzed oxidation of naphthalene. The modern industrial variant process instead uses vanadium pentoxide (V2O5) as the catalyst in a gas-phase reaction with naphthalene using molecular oxygen. The overall process involves oxidative cleavage of one of the rings and loss of two of the carbon atoms as carbon dioxide.
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Acute exposure to naphthalene is unlikely to cause toxicity and must be ingested unless prolonged contact is provided along the skin or eyes. After ingestion of mothballs containing naphthalene, symptoms of haemolytic anaemia are presented and treated normally through the use of methylene blue and regular blood transfusions, and patients are usually released after 6-10 days depending on their haemoglobin levels. Repeated naphthalene exposure has also been found to potentially cause airway epithelial damage, aberrant repair, and inflammation. Greater numbers of peribronchial Mac-3-positive macrophages and CD3-positive T-cells were observed throughout the airways which displays acute inflammation within the airways.
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1,2-Dihydroxynaphthalene has been used as a potential biomarker of excessive exposure to naphthalene levels and was tested on smokers and those exposed to naphthalene among the working population. After collecting the urine samples of multiple workers, Median 1,2-Dihydroxynaphthalene values were 1012 micrograms per litre for those exposed to naphthalene and 8 micrograms per litre for those who were in the control group indicating that it is useful as a biomarker for exposure within humans. The median results for the concentrations of 1,2-Dihydroxynaphthalene were about ten times the amount of the standard markers of 1-naphthol and 2-naphthol within human urine.
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Fagopyrum tataricum contains aromatic substances. The most important difference when compared to the aroma of Fagopyrum esculentum is the absence of salicylaldehyde and presence of naphthalene.
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Initiation of styrene polymerization with sodium naphthalene proceeds by electron transfer from the naphthalene radical anion to the monomer. The resulting radical dimerizes to give a dilithio compound, which then functions as the initiator. Polar solvents are necessary for this type of initiation both for stability of the anion-radical and to solvate the cation species formed. The anion-radical can then transfer an electron to the monomer.
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Symmetrical naphthalene diimides are synthesized by the condensation reaction of primary amines and the dianhydride. Unsymmetrical derivatives, i.e. those derived from two different amines, are obtained by hydrolysis of one of the two anhydride groups prior to the condensation with the first amine. These diimides are members of a broader class of compounds called rylenes, oligomers of naphthalene with bonds between the 1 and 1' and 8 and 8' positions.
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2-Naphthalenethiol is an organosulfur compound with the formula C10H7SH. It is a white solid. It is one of two monothiols of naphthalene, the other being 1-naphthalenethiol.
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Naphthalenetetracarboxylic diimide (NTCDI) is a solid organic compound and one of the simplest naphthalenediimides (NDIs). NTCDI is produced from the parent naphthalene via an intermediate compound naphthalenetetracarboxylic dianhydride.
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After Barnes left Princeton for American Cyanamid, he directed funding to Brattain and others to study the infrared absorption spectra of organic compounds such as benzene, toluene, and naphthalene.
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Traditional lignosulfonate and naphthalene sulfonate-based plasticisers disperse the flocculated gypsum particles through a mechanism of electrostatic repulsion (see Colloid). In normal plasticisers, the active substances are adsorbed on to the gypsum particles, giving them a negative charge, which leads to repulsion between particles. Lignin and naphthalene sulfonate plasticizers are organic polymers. The long molecules wrap themselves around the gypsum particles, giving them a highly negative charge so that they repel each other.
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1, p. 1142. It was the German chemist Karl Gräbe who, in 1869, first used the prefixes ortho-, meta-, para- to denote specific relative locations of the substituents on a di-substituted aromatic ring (viz, naphthalene).Graebe (1869) "Ueber die Constitution des Naphthalins" (On the structure of naphthalene), Annalen der Chemie und Pharmacie, 149 : 20-28 ; see especially p. 26. In 1870, the German chemist Viktor Meyer first applied Gräbe's nomenclature to benzene.
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Many naphthalenesulfonic acids and sulfonates are useful. Alkyl naphthalene sulfonate are surfactants, The aminonaphthalenesulfonic acids, naphthalenes substituted with Etherss and sulfonic acids, are intermediates in the preparation of many synthetic dyes. The hydrogenated naphthalenes tetrahydronaphthalene (tetralin) and decahydronaphthalene (decalin) are used as low-volatility solvents. Naphthalene sulfonic acids are also used in the synthesis of 1-naphthol and 2-naphthol, precursors for various dyestuffs, pigments, rubber processing chemicals and other chemicals and pharmaceuticals.
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This compound is a diamine in which the two dimethylamino groups are attached on the same side (peri position) of a naphthalene ring. This molecule has several very interesting properties; one is its very high basicity; another is its spectroscopic properties. With a pK of 12.34 for its conjugate acid in aqueous solution, 1,8-bis(dimethylamino)naphthalene is one of the strongest organic bases. However, it only absorbs protons slowly—hence the trade name.
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IARC points out that acute exposure causes cataracts in humans, rats, rabbits, and mice. Chronic exposure to naphthalene vapors is reported to also cause cataracts and retinal hemorrhage. Under California's Proposition 65, naphthalene is listed as "known to the State to cause cancer".Proposition 65 , Office of Environmental Health Hazard Assessment Research at the University of Colorado at Boulder revealed a probable mechanism for the carcinogenic effects of mothballs and some types of air fresheners.
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It is prepared by nitration of naphthalene-1-sulfonic acid followed by reduction. Diazotization followed by loss of N2 gives the naphthosultone. This species reacts with NaOH to give sequentially 1-hydroxynaphthalene-8-sulfonic acid and then the 1,8-diol.. Four peri- naphthalene derivatives. Certain perinaphthalene derivatives can be prepared from 1,8-dilithionaphthalene, which in turn is generated by dilithiation of 1-bromonaphthalene: :C10H7Br + BuLi → C10H7Li + BuBr :C10H7Li + BuLi → C10H6Li2 \+ BuH The deprotonation requires tmeda.
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Melatonin (top) vs. agomelatine (bottom) The chemical structure of agomelatine is very similar to that of melatonin. Where melatonin has an indole ring system, agomelatine has a naphthalene bioisostere instead.
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Others include benzene, toluene, xylenes, cumenes, coumarone, indene, benzofuran, naphthalene and methyl-naphthalenes, acenaphthene, fluorene, phenol, cresols, pyridine, picolines, phenanthracene, carbazole, quinolines, fluoranthene. Many of these constituents are known carcinogens.
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Bacterial biosensor systems offer the potential for cheap, robust detection systems that are selective and highly sensitive. One developed system uses Pseudomonas fluorescens HK44 to quantitatively assay for naphthalene using bioluminescence.
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It is prepared via the Bucherer reaction of 2-hydroxynaphthalene-1-sulfonic acid with ammonia and ammonium sulfite.Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. .
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Traditional lignosulfonate-based plasticisers, naphthalene and melamine sulfonate-based superplasticisers disperse the flocculated cement particles through a mechanism of electrostatic repulsion (see colloid). In normal plasticisers, the active substances are adsorbed on to the cement particles, giving them a negative charge, which leads to repulsion between particles. Lignin, naphthalene, and melamine sulfonate superplasticisers are organic polymers. The long molecules wrap themselves around the cement particles, giving them a highly negative charge so that they repel each other.
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Figure 1. Top) Thermal isomerization of azulene to naphthalene; Bottom) Thermal automerization of naphthalene. Thermal rearrangements of aromatic hydrocarbons are considered to be unimolecular reactions that directly involve the atoms of an aromatic ring structure and require no other reagent than heat. These reactions can be categorized in two major types: one that involves a complete and permanent skeletal reorganization (isomerization), and one in which the atoms are scrambled but no net change in the aromatic ring occurs (automerization).
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Creosote, pentachlorophenol (PCP), polyaromatic hydrocarbons (PAHs), and dioxin are the main contaminants found on the site (1). Properties adjacent to the site include residential lands where PAH and dioxin contamination attributable to the site has been identified (1). Primary contaminants in the ground water are PCP and naphthalene (1). Dangerous levels of other toxic wastes at ETC include arsenic, benzo(a)pyrene, dieldrin, naphthalene, toluene, xylene, benzene, copper, chromium, and more, as well as asbestos and PCB's (3).
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The molecule is planar, like benzene. Unlike benzene, the carbon–carbon bonds in naphthalene are not of the same length. The bonds C1−C2, C3−C4, C5−C6 and C7−C8 are about 1.37 Å (137 pm) in length, whereas the other carbon–carbon bonds are about 1.42 Å (142 pm) long. This difference, established by X-ray diffraction, is consistent with the valence bond model in naphthalene and in particular, with the theorem of cross-conjugation.
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Azulene is an organic compound and an isomer of naphthalene. Whereas naphthalene is colourless, azulene is dark blue. Two terpenoids, vetivazulene (4,8-dimethyl-2-isopropylazulene) and guaiazulene (1,4-dimethyl-7-isopropylazulene), that feature the azulene skeleton are found in nature as constituents of pigments in mushrooms, guaiac wood oil, and some marine invertebrates. Azulene has a long history, dating back to the 15th century as the azure-blue chromophore obtained by steam distillation of German chamomile.
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In the reaction of phthalic anhydride with sodium tetracarbonylferrate, only one of the carboxyl groups is reduced to the aldehyde, the second remains unchanged. Synthese von 2-Carboxybenzaldehyd aus Phthalsäureanhydrid This gives 2-carboxybenzaldehyde in a yield of 61%. In a laboratory procedure, the oxidation of naphthalene with alkaline potassium permanganate is given, which, however, yields only a yield of 39% 2-carboxybenzaldehyde. Also the oxidation of naphthalene with ozone to 2-formylbenzoic acid offers no significant advantages.
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Tetralin (1,2,3,4-tetrahydronaphthalene) is a hydrocarbon having the chemical formula C10H12. It is a partially hydrogenated derivative of naphthalene. It is a colorless liquid that is used as a hydrogen-donor solvent.
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Azorubine is an azo dye consisting of two naphthalene subunits. It is a red solid. It is mainly used in foods that are heat-treated after fermentation. It has E number E122.
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Acenaphthene is a polycyclic aromatic hydrocarbon (PAH) consisting of naphthalene with an ethylene bridge connecting positions 1 and 8. It is a colourless solid. Coal tar consists of about 0.3% of this compound.
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Tetralin is produced by the catalytic hydrogenation of naphthalene. 440px Although nickel catalysts are traditionally employed, many variations have been evaluated. Over hydrogenation converts tetralin into octahydronaphthalene (decalin). Rarely encountered is dihydronaphthalene (dialin).
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Ascorbic acid is used to treat methemoglobinemia, a symptom of naphthalene poisoning and is used when methylene blue is not available, or in conjunction with methylene blue in order to restore haemoglobin count.
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Muscodor vitigenus is an endophytic fungus which colonizes Paullinia paullinioides, a liana of the Peruvian Amazon rainforests. It has the unusual property of, under certain circumstances, producing near-pure naphthalene, an insect repellent.
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1-Naphthaleneacetic acid (NAA) is an organic compound with the formula C10H7CH2CO2H. This colorless solid is soluble in organic solvents. It features a carboxylmethyl group (CH2CO2H) linked to the "1-position" of naphthalene.
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Sprouting can be inhibited by preharvest spraying with maleic hydrazide, treatment of tubers with methyl ester of naphthalene acetic acid (MENA) in acetone on paper spread between tubers and 0.5-4.0% thiourea solution.
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White phosphorus is reduced by sodium-potassium alloy: : P4 \+ 12 Na → 4 Na3P Phosphorus reacts with sodium in an autoclave at 150 °C for 5 hours to produce Na3P. Alternatively the reaction can be conducted at normal pressures but using a temperatures gradient to generate nonvolatile NaxP phases (x < 3) that then react further with sodium. In some cases, an electron-transfer agent, such as naphthalene, is used. In such applications, the naphthalene forms the soluble sodium naphthalenide, which reduces the phosphorus.
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This was a period rich in the development of structural theory and nomenclature, and Gräbe is known for introducing the "ortho", "meta" and "para" nomenclature for naphthalene ring substitution.In 1869, Gräbe first used the prefixes ortho-, meta-, para- to denote specific relative locations of the substituents on a di-substituted aromatic ring (viz, naphthalene): Graebe (1869) "Ueber die Constitution des Naphthalins" (On the structure of naphthalene), Annalen der Chemie und Pharmacie, 149 : 20–28 ; see especially p. 26. In 1870, the German chemist Viktor Meyer first applied Gräbe's nomenclature to benzene: Victor Meyer (1870) "Untersuchungen über die Constitution der zweifach-substituirten Benzole" (Investigations into the structure of di-substituted benzenes), Annalen der Chemie und Pharmacie, 156 : 265–301 ; see especially pp. 299–300. See also: Hermann von Fehling, ed.
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Bertram Philipp, Peter Stevens: Grundzüge der Industriellen Chemie, VCH Verlagsgesellschaft mbH, 1987, S. 179, . Parallels exist with the production of phthalic anhydride: While older methods use naphthalene, modern methods use o-xylene as feedstock.
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Cis-3,4-dihydrophenanthrene-3,4-diol dehydrogenase is an enzyme that uses (+)-cis-3,4-dihydrophenanthrene-3,4-diol and NAD+ to produce phenanthrene-3,4-diol, NADH and H+. This enzyme participates in naphthalene and anthracene degradation.
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Polyethylene naphthalate (poly(ethylene 2,6-naphthalate) or PEN) is a polyester derived from naphthalene-2,6-dicarboxylic acid and ethylene glycol. As such it is related to poly(ethylene terephthalate), but with superior barrier properties.
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2-Chloronaphthalene is obtained directly by chlorination of naphthalene, with the formation of more highly substituted derivatives such as dichloro- and trichloronaphthalenes, in addition to the two monochlorinated isomeric compounds: 1-chloronaphthalene and 2-chloronaphthalene.
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0]decapentaene is a structural isomer with a fused 4–8 ring system and azulene is another, with a fused 5-7 ring system. Bicyclo[6.2.0]decapentaene The point group symmetry of naphthalene is D2h.
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Pronethalol (Alderlin, Nethalide) was an early non-selective beta blocker clinical candidate. It was never used clinically due to carcinogenicity in mice, which was thought to result from formation of a carcinogenic naphthalene epoxide metabolite.
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1-Chloronaphthalene is obtained directly by chlorination of naphthalene, with the formation of more highly substituted derivatives such as dichloro- and trichloronaphthalenes in addition to the two monochlorinated isomeric compounds: 1-chloronaphthalene and 2-chloronaphthalene.
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Living polymerization was demonstrated by Michael Szwarc in 1956 in the anionic polymerization of styrene with an alkali metal / naphthalene system in tetrahydrofuran (THF). Szwarc showed that electron transfer occurred from radical anion of naphthalene to styrene. The initial radical anion of styrene converts to a dianion (or equivalently disodio-) species, which rapidly added styrene to form a "two – ended living polymer." An important aspect of his work, Szwarc employed the aprotic solvent tetrahydrofuran, which dissolves but is otherwise unreactive toward the organometallic intermediates.
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In stages B and D the aryl can rotate with respect to the naphthalene with steric interactions preventing the aryl from passing the naphthalene. The rotary cycle consists of four chemically induced steps which realize the conversion of one stage into the next. Steps 1 and 3 are asymmetric ring opening reactions which make use of a chiral reagent in order to control the direction of the rotation of the aryl. Steps 2 and 4 consist of the deprotection of the phenol, followed by regioselective ring formation.
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Naphthalene-M4L6 cluster Based on a predictive strategy, the Raymond group has developed several self-assembled, metal-ligand clusters of high symmetry. Some of these clusters, including the naphthalene-M4L6 workhorse cluster (see image), have a cavity within the cluster that can encapsulate a variety of guest molecules. In collaboration with Robert G. Bergman, the unique reaction chemistry of these host–guest assemblies has been explored. Recent work on this project, which led to a paper in Science,Raymond, K. N. Science 2007, 316 (5821), 85–88.
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Resveratrol Photoisomerization: An Integrative Guided-Inquiry Experiment Elyse Bernard, Philip Britz-McKibbin, Nicholas Gernigon Vol. 84 No. 7 July 2007 Journal of Chemical Education 1159. :Resveratrol photoisomerization Thermal rearrangement of azulene to naphthalene has been observed.
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Substances found, according to the reports, are naphthol, naphthalene, Sevin, tarry residues, alpha naphthol, mercury, organochlorines, chromium, copper, nickel, lead, hexachlorethane, hexachlorobutadiene, pesticide HCH (BHC), volatile organic compounds and halo-organics.Stringer et al. (2002).Srishti (2002).
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Other names in common use include phenol hydroxylase, and phenol o-hydroxylase. This enzyme participates in 3 metabolic pathways: gamma- hexachlorocyclohexane degradation, toluene and xylene degradation, and naphthalene and anthracene degradation. It employs one cofactor, FAD.
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It is prepared by treatment of naphthalene with bromine:H. T. Clarke and M. R. Brethen "α-Bromonaphthalene" Org. Synth. 1921, volume 1, 35. :C10H8 \+ Br2 → C10H7Br + HBr The compound exhibits many reactions typical of aryl bromides.
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Proposed early steps in vanadium-catalyzed oxidation of naphthalene to phthalic anhydride, with V2O5 represented as a molecule vs its true extended structure. Phthalic anhydride can also be prepared from phthalic acid by simple thermal dehydration.
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Confluentimicrobium naphthalenivorans is a Gram-negative, aerobic, naphthalene-degrading, moderately halophilic and motile bacterium from the genus of Confluentimicrobium with a single flagellum which has been isolated from tidal flat sediments from the South Sea in Korea.
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Novosphingobium naphthalenivorans is a Gram-negative and strictly aerobic bacterium from the genus of Novosphingobium which has been isolated from soil which was contaminated with polychlorinated-dioxin in Japan. Novosphingobium naphthalenivorans has the ability to degrade naphthalene.
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Celeribacter naphthalenivorans is a Gram-negative, naphthalene-degrading, moderately halophilic, aerobic and motile bacterium from the genus of Celeribacter with a polar flagellum which has been isolated from tidal flat sediments from the South Sea in Korea.
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This was classified due to lack of evidence of naphthalene alone causing carcinogenic properties in rats, and limited human contact with naphthalene within industrial environments. Haemolysis occurs either through haemoglobin defects, such as formation of Heinz bodies, or cell membrance defects, especially those with glucose-6-phosphate dehydrogenase deficiency and a low tolerance to oxidative stress. This haemolysis is usually accompanied by neurological effects such as vertigo, lethargy and convulsions, usually caused by cerebral edema. Gastrointestinal bleeding may also appear as a symptom after ingestion of mothballs, especially for those who are younger.
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After World War I, William T. Badham established a small chemical business, Naphthalene Products Company, using the naphthalene gas from coke ovens in Birmingham to manufacture items which included mothballs and insecticides. A brigadier general during World War II, he served with the U.S. 8th Air Force in England and the Middle East. Drawing since he was ten years old, painting became an increasingly serious aspect of his life. By the age of fifty with his business successful, he was able to devote most of his time to painting while traveling over Europe and Mexico.
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A naphthalene molecule can be viewed as the fusion of a pair of benzene rings. (In organic chemistry, rings are fused if they share two or more atoms.) As such, naphthalene is classified as a benzenoid polycyclic aromatic hydrocarbon (PAH). The eight carbons that are not shared by the two rings carry one hydrogen atom each. For purpose of the standard IUPAC nomenclature of derived compounds, those eight atoms are numbered 1 through 8 in sequence around the perimeter of the molecule, starting with a carbon adjacent to a shared one.
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The selectivity for alpha over beta substitution can be rationalized in terms of the resonance structures of the intermediate: for the alpha substitution intermediate, seven resonance structures can be drawn, of which four preserve an aromatic ring. For beta substitution, the intermediate has only six resonance structures, and only two of these are aromatic. Sulfonation gives the "alpha" product naphthalene-1-sulfonic acid as the kinetic product but naphthalene-2-sulfonic acid as the thermodynamic product. The 1-isomer forms predominantly at 25 °C, and the 2-isomer at 160 °C.
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The US National Toxicology Program (NTP) held an experiment where male and female rats and mice were exposed to naphthalene vapors on weekdays for two years. Both male and female rats exhibited evidence of carcinogenesis with increased incidences of adenoma and neuroblastoma of the nose. Female mice exhibited some evidence of carcinogenesis based on increased incidences of alveolar and bronchiolar adenomas of the lung, while male mice exhibited no evidence of carcinogenesis. The International Agency for Research on Cancer (IARC) classifies naphthalene as possibly carcinogenic to humans and animals (Group 2B).
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The IARC also points out that acute exposure causes cataracts in humans, rats, rabbits, and mice; and that hemolytic anemia (described above) can occur in children and infants after oral or inhalation exposure or after maternal exposure during pregnancy. Under California's Proposition 65, naphthalene is listed as "known to the State to cause cancer".Proposition 65 , Office of Environmental Health Hazard Assessment A probable mechanism for the carcinogenic effects of mothballs and some types of air fresheners containing naphthalene has been identified."Scientists May Have Solved Mystery Of Carcinogenic Mothballs", Physorg.
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The stability gain from aromaticity is estimated to be half that of naphthalene. Its dipole moment is , in contrast with naphthalene, which has a dipole moment of zero. This polarity can be explained by regarding azulene as the fusion of a 6 π-electron cyclopentadienyl anion and a 6 π-electron tropylium cation: one electron from the seven-membered ring is transferred to the five-membered ring to give each ring aromatic stability by Hückel's rule. Reactivity studies confirm that seven-membered ring is electrophilic and the five-membered ring is nucleophilic.
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Naphthalenetetracarboxylic dianhydride (NTDA) is an organic compound related to naphthalene. The compound is a beige solid. NTDA is most commonly used as a precursor to naphthalenediimides (NDIs) (such as napthalenetetracarboxylic diimide), a family of compounds with many uses.
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Phosphonic acid-terminated polyethers are effective superplasticizers. Traditional plasticizers are lignosulphonates as their sodium salt. Superplasticizers are synthetic polymers. Compounds used as superplasticizers include sulfonated naphthalene formaldehyde condensate, sulfonated melamine formaldehyde condensate, acetone formaldehyde condensate and polycarboxylate ethers.
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1-Naphthol is a metabolite of the insecticide carbaryl and naphthalene. Along with TCPy, it has been shown to decrease testosterone levels in adult men. It biodegrades via formation of 1-naphthol-3,4-oxide, which converts to 1,4-naphthoquinone.
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In 2017, Wang published a simpler method to break the C-C bond in naphthalene and its derivatives to transform them into benzoborepin. This method of synthesis helps make new borepin systems applicable in the field of organic materials.
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The publication of the NAPAP-fIIa crystal structure triggered many researches on thrombin inhibitors. NAPAP is an active site thrombin inhibitor. It fills the S3 and S2 pockets with its naphthalene and piperidine groups. AstraZeneca used the information to develop melagatran.
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1-Naphthylamine is an aromatic amine derived from naphthalene. It can cause bladder cancer (transitional cell carcinoma). It crystallizes in colorless needles which melt at 50 °C. It possesses a disagreeable odor, sublimes readily, and turns brown on exposure to air.
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Other names in common use include salicylate hydroxylase, salicylate 1-hydroxylase, salicylate monooxygenase, and salicylate hydroxylase (decarboxylating). This enzyme participates in 3 metabolic pathways: 1- and 2-methylnaphthalene degradation, naphthalene and anthracene degradation, and fluorene degradation. It employs one cofactor, FAD.
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Acenaphthylene, a polycyclic aromatic hydrocarbon is an ortho- and peri-fused tricyclic hydrocarbon. The molecule resembles naphthalene with positions 1 and 8 connected by a -CH=CH- unit. It is a yellow solid. Unlike many polycyclic aromatic hydrocarbons, it has no fluorescence.
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One bicyclic pyrylium ion is called benzopyrylium ion (IUPAC: chromenylium ion) (Formula: , molar mass: 131.15 g/mol, exact mass: 131.04968983). It can be seen as a charged derivative of 2H-1-benzopyran (IUPAC: 2H-chromene) (), or a (charged) substituted heterocyclic derivative of naphthalene ().
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The structure of two fused benzene rings was proposed by Emil Erlenmeyer in 1866, and confirmed by Carl Gräbe three years later.C. Graebe (1869) "Ueber die Constitution des Naphthalins" (On the structure of naphthalene), Annalen der Chemie und Pharmacie, 149 : 20–28.
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The naphthalene anion initiate polymerization by reducing styrene to its radical anion, which dimerizes to the dilithiodiphenylbutane, which then initiates the polymerization. These experiments relied on Szwarc's ability to control the levels of impurities which would destroy the highly reactive organometallic intermediates.
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2-Naphthoic acid is an organic compound of the formula C10H7CO2H. It is one of two isomeric carboxylic acid derivatives of naphthalene, the other one being 1-naphthoic acid. It can be prepared by carboxylation of 1-chloronaphthalene. Its pKa is 4.2.
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Oxidation with chromate affords perinaphthenone and then naphthalene-1,4,5,8-tetracarboxylic acid. It undergoes a series of hydrogenation reactions, and it is susceptible to halogenation, Diels-Alder additions, and nitration, all with varying degrees of selectivity. Bromination occurs at one of the 3-positions.
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Polaromonas naphthalenivorans is a Gram-negative, oxidase- and catalase- positive, non-spore-forming, nonmotile bacterium from the genus Polaromonas, which was isolated from coal-tar contaminated freshwater sediment. P. naphthalenivorans has the ability to degrade naphthalene. Its colonies have a smooth and glistening surface.
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Fluorene , or 9H-fluorene is an organic compound with the formula (C6H4)2CH2. It forms white crystals that exhibit a characteristic, aromatic odor similar to that of naphthalene. It has a violet fluorescence, hence its name. For commercial purposes it is obtained from coal tar.
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Armstrong's acid (naphthalene-1,5-disulfonic acid) is a fluorescent organic compound with the formula C10H6(SO3H)2. It is one of several isomers of naphthalenedisulfonic acid. It a colorless solid, typically obtained as the tetrahydrate. Like other sulfonic acids, it is a strong acid.
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Since liquid ammonia has to be condensed into the flask and has to evaporate overnight after the reaction is complete, the whole procedure can be quite troublesome and time-consuming. However, alternative solvents have been employed, such as THF as well as a mixture of n-propylamine and ethylenediamine, both with comparable results. The latter one actually is a modification of the Benkeser reaction, which in its original forms tends to reduce naphthalene all the way to octahydro- and decahydronaphthalene. :Modified Benkeser reduction This reduction of naphthalene to isotetralin (1,4,5,8-tetrahydronaphthalene) produces some tetralin (1,2,3,4-tetrahydronaphthalene) as byproduct, as is the case with the regular Birch reduction.
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Laurdan is composed of a chain of lauric fatty acid (hydrophobic) with a naphthalene molecule linked by an ester bond (hydrophilic).S. A. Sanchez, M.A.Tricerri, G. Gunther and E.Gratton, Lurdan GP:frm cuvette to mycroscope Because of a partial charge separation between the 2-dimethylamino and the 6-carbonyl residues, the naphthalene moiety has a dipole moment, which increases upon excitation and causes the reorientation of the surrounding solvent dipoles. This causes its fluorescence and explains its importance in electronic microscopy. leftThe solvent’s reorientation requires energy. This energy requirement decreases the energy state of the excited probe, which is reflected in a continuous red shift in the probe’s emission spectrum.
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An alternative process involves oxidation of the two methyl groups of o-xylene, a more atom-economical process. This reaction is run at about 320–400 °C and has the following stoichiometry: :C6H4(CH3)2 \+ 3 O2 → C6H4(CO)2O + 3 H2O The reaction proceeds with about 70% selectivity. About 10% of maleic anhydride is also produced: :C6H4(CH3)2 \+ 7.5 O2 → C4H2O3 +4 H2O + 4 CO2 Phthalic anhydride and maleic anhydride are recovered by distillation by a series of switch condensers. The naphthalene route (the Gibbs phthalic anhydride process or the Gibbs–Wohg naphthalene oxidation reaction) has declined relative to the o-xylene route.
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Sodium also reacts with polycyclic aromatic hydrocarbons via one-electron reduction. With solutions of naphthalene, it forms the deeply coloured radical sodium naphthalenide, which is used as a soluble reducing agent: :C10H8 \+ Na -> Na+[C10H8]−• The related anthracene as well as potassium derivatives are well known.
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Hg(II) can be alkylated by treatment with diazonium salts in the presence of copper metal. In this way 2-chloromercuri-naphthalene has been prepared. Phenyl(trichloromethyl)mercury can be prepared by generating dichlorocarbene in the presence of phenylmercuric chloride. A convenient carbene source is sodium trichloroacetate.
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Bicyclo[6.2.0]decapentaene is a bicyclic organic compound and an isomer of naphthalene and azulene. Whether this substance is an aromatic compound is of interest to researchers. Both the component cyclobutadiene and cyclooctatetraene component rings are antiaromatic, but when fused together the rings counteract each other.
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Oxidation with in the presence of vanadium pentoxide as catalyst gives phthalic anhydride: :C10H8 \+ 4.5 O2 → C6H4(CO)2O + 2 CO2 \+ 2 H2O This reaction is the basis of the main use of naphthalene. Oxidation can also be effected using conventional stoichiometric chromate or permanganate reagents.
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Naphthylvinylpyridine (NVP) is a naphthalene derivative that possesses anticholinergic activity similar to that of atropine. However, NVP's method of acetylcholine (ACh) antagonism involves inhibiting the enzyme choline acetyltransferase. Several NVP derivatives have been synthesized and evaluated for their ability to inhibit choline acetyltransferase and protect against nerve toxins.
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IAEDANS is an organic fluorophore (fluorescent molecule). It stands for 5-({2-[(iodoacetyl)amino]ethyl}amino)naphthalene-1-sulfonic acid. It is widely used as a marker in fluorescence spectroscopy. 1,5-IAEDANS has a peak excitation wavelength of 336 nm and a peak emission wavelength of 490 nm.
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A plastic scintillator based on PMMA in this way boasts transparency to its own radiation, helping to ensure uniform collection of light. Other common bases include polyvinyl xylene (PVX) polymethyl, 2,4-dimethyl, 2,4,5-trimethyl styrenes, polyvinyl diphenyl, polyvinyl naphthalene, polyvinyl tetrahydronaphthalene, and copolymers of these and other bases.
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The observed mass shift indicates that it is likely that hydroxylation occurs in both the naphthalene and indole portions of the molecule. Human metabolites were similar although most metabolism took place on the indole ring and pentyl side chain, and the hydroxylated metabolites were extensively conjugated with glucuronide.
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It is prepared by reduction of 1,5-dinitronaphthalene, which in turn is obtained with the 1,8-isomers by nitration of 1-nitronaphthalene. It can also be prepared by treatment of 1,5-dihydroxynaphthalene with ammonium sulfite. It is a precursor to naphthalene-1,5-diisocyanate, a precursor to specialty polyurethanes.
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Poisoning of river Elbe by the company Draslovka Kolin a.s., a Responsible Care certified company or hiding of 20 metric tons leakage of naphthalene by the company Deza, also a Responsible Care company, questions whether the Responsible Care brings any real improvement or is just a marketing tool.
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The feasibility of vaporization of THC has been demonstrated in a series of laboratory studies involving different vaporizer designs. An electric vaporizer was shown to release substantial amounts of the THC while producing no measurable amounts of benzene, toluene, and naphthalene, which are generated when marijuana is smoked.
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Fluids with increased conductivity more readily dissipate static charges to mitigate the risk of explosions or fires due to Static Discharge Ignitions Dinonylnaphthylsulfonic acid by itself does not function as an anti- static additive. Dinonylnaphthylsulfonic acid is prepared by reaction of naphthalene with nonene, yielding diisononylnaphthalene. Diisononylnaphthalene then undergoes sulfonation.
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Organic scintillators are aromatic hydrocarbon compounds which contain benzene ring structures interlinked in various ways. Their luminescence typically decays within a few nanoseconds. Some organic scintillators are pure crystals. The most common types are anthracene (, decay time ≈30 ns), stilbene (, 4.5 ns decay time), and naphthalene (, few ns decay time).
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Analogous to the synthesis of phenyllithium is the conversion of 1-bromonaphthalene to 1-lithionaphthalene, a lithium-halogen exchange: :C10H7Br + BuLi → C10H7Li + BuBr The resulting lithionaphthalene undergoes a second lithiation, in contrast to the behavior of phenyllithium. These 1,8-dilithio derivatives are precursors to a host of peri-naphthalene derivatives.
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Benzothiophene is an aromatic organic compound with a molecular formula C8H6S and an odor similar to naphthalene (mothballs). It occurs naturally as a constituent of petroleum-related deposits such as lignite tar. Benzothiophene has no household use. In addition to benzo[b]thiophene, a second isomer is known: benzo[c]thiophene.
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Benzene oxide (C6H6O) exists as an equilibrium mixture with the seven-membered ring oxepin, which has three double bonds. They are valence isomers and in equilibrium via disrotatory 6π ring closing and opening. 200px Arene oxides are highly reactive. Benzene oxide and naphthalene-1,2-oxide hydrate to give dihydroxydihydrobenzene and 1,2-dihydroxydihydronaphthalene, respectively.
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Smoke contains ethylene, and once this was realized the smoke was replaced with ethephon or naphthalene acetic acid, which induce ethylene production.Annual Plant Reviews, Plant Hormone Signaling. Peter Hedden, Stephen G. Thomas. John Wiley & Sons, Apr 15, 2008 In 1901, a Russian scientist named Dimitry Neljubow showed that the active component was ethylene.
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2, pp. l-70; Wiley, New York (1968) The term polycyclic is used when more than one ring appears in a single molecule. Naphthalene is formally a polycyclic compound, but is more specifically named as a bicyclic compound. Several examples of macrocyclic and polycyclic structures are given in the final gallery below.
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Cashmeran was discovered by International Flavors and Fragrances in the 1970s by John Hall.US Patent 3,773,836 Nov 20, 1973 Its invention came about researching inexpensive chemical transformations from ingredients from the pentamethyl indane and tetramethyl naphthalene structures. As a result, Cashmeran, an unsaturated ketone, was identified as an important new fragrance ingredient.
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Second generation proton sponges are known with even higher basicity. 1,8-bis(hexamethyltriaminophosphazenyl)naphthalene or HMPN is prepared from 1,8-diaminonaphthalene by reaction with tris(dimethylamino)bromophosphonium bromide in the presence of triethylamine. HMPN has a pK of 29.9 in acetonitrile which is more than 11 orders of magnitude higher than Proton Sponge.
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1-Naphthoic acid is an organic compound of the formula C10H7CO2H. It is one of two isomeric monocarboxylic acids of naphthalene, the other one being 2-naphthoic acid. 1-Naphthoic acid is a frequent substrate for C-H activation reactions. In general the hydroxynaphthoic acids are far more useful than the parent.
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Arene oxides are intermediates in the oxidation of arenes by cytochrome P450. For prochiral arenes (naphthalene, toluene, benzoates, benzopyrene), the epoxides are often obtained in high enantioselectivity. Chiral epoxides can often be derived enantioselectively from prochiral alkenes. Many metal complexes give active catalysts, but the most important involve titanium, vanadium, and molybdenum.
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Proposed early steps in the vanadium-catalyzed oxidation of naphthalene to phthalic anhydride, with V2O5 represented as a molecule vs its true extended structure. Maleic anhydride is produced by the V2O5-catalysed oxidation of butane with air: :C4H10 \+ 4 O2 → C2H2(CO)2O + 8 H2O Maleic anhydride is used for the production of polyester resins and alkyd resins.. Phthalic anhydride is produced similarly by V2O5-catalysed oxidation of ortho-xylene or naphthalene at 350–400 °C. The equation is for the xylene oxidation: :C6H4(CH3)2 \+ 3 O2 → C6H4(CO)2O + 3 H2O Phthalic anhydride is a precursor to plasticisers, used for conferring pliability to polymers. A variety of other industrial compounds are produced similarly, including adipic acid, acrylic acid, oxalic acid, and anthraquinone.
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This theorem would describe naphthalene as an aromatic benzene unit bonded to a diene but not extensively conjugated to it (at least in the ground state), which is consistent with two of its three resonance structures. :Resonance structures of naphthalene Because of this resonance, the molecule has bilateral symmetry across the plane of the shared carbon pair, as well as across the plane that bisects bonds C2-C3 and C6-C7, and across the plane of the carbon atoms. Thus there are two sets of equivalent hydrogen atoms: the alpha positions, numbered 1, 4, 5, and 8, and the beta positions, 2, 3, 6, and 7. Two isomers are then possible for mono-substituted naphthalenes, corresponding to substitution at an alpha or beta position. Bicyclo[6.2.
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The Li-arene reacted with water or deuterium to produce the dehalogenated product.Ramón, D.; Yus, M. Masked lithium bishomoenolates: Useful intermediates in organic synthesis, J. Org. Chem. 1991, 56, 3825-3831.Guijarro, A.; Ramón, D.; Yus, M. Naphthalene- catalysed lithiation of functionalized chloroarenes: regioselective preparation and reactivity of functionalized lithioarenes, Tetrahedron, 1993, 49, 469-482.
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Trans-o-hydroxybenzylidenepyruvate hydratase-aldolase (, 2'-hydroxybenzalpyruvate aldolase, NsaE, tHBPA hydratase-aldolase) is an enzyme with systematic name (3E)-4-(2-hydroxyphenyl)-2-oxobut-3-enoate hydro- lyase. This enzyme catalyses the following chemical reaction : (3E)-4-(2-hydroxyphenyl)-2-oxobut-3-enoate + H2O \rightleftharpoons salicylaldehyde + pyruvate This enzyme is involved in naphthalene degradation.
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A cooling curve of naphthalene from liquid to solid. A cooling curve is a line graph that represents the change of phase of matter, typically from a gas to a solid or a liquid to a solid. The independent variable (X-axis) is time and the dependent variable (Y-axis) is temperature.Garland, Nibler, and Shoemaker.
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Direct Blue 15 is an organic compound that is classified as an azo dye. It is a dark blue water soluble solid. It is a popular substantive dye, which means that it useful for dying cotton and related cellulosic materials. It is produced by azo coupling of o-dianisidine with the appropriate naphthalene disulfonate..
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These mutants reflect the importance of ABA in seed germination and early embryo development. Pyrabactin (a pyridyl containing ABA activator) is a naphthalene sulfonamide hypocotyl cell expansion inhibitor, which is an agonist of the seed ABA signaling pathway. It is the first agonist of the ABA pathway that is not structurally related to ABA.
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Henry Edward Armstrong FRS FRSE(Hon) (6 May 1848 – 13 July 1937) was a British chemist. Although Armstrong was active in many areas of scientific research, such as the chemistry of naphthalene derivatives, he is remembered today largely for his ideas and work on the teaching of science. Armstrong's acid is named for him.
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It is more acidic than phenol or naphthol. The pKa of 6-hydroxyazulenes in water is 7.38 making it also more acidic than phenol or naphthol. In naphth[a]azulene, a naphthalene ring is condensed at the 1,2-positions of azulene. In one such system deformation from planarity is found similar to that of tetrahelicene.
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HDEP-28 or ethylnaphthidate is a piperidine based stimulant drug, closely related to ethylphenidate, but with the benzene ring replaced by naphthalene. It is even more closely related to HDMP-28, which acts as a potent serotonin–norepinephrine–dopamine reuptake inhibitor with several times the potency of methylphenidate and a short duration of action.
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Juglone is derived by oxidation of the nontoxic hydrojuglone, 1,5-dihydroxynaphthalene, after enzymatic hydrolysis.Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley- VCH, Weinheim. . It can also be obtained by oxidations of 5,8-dihydroxy-1-tetralone with silver oxide (Ag2O), manganese dioxide (MnO2), or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ).
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Cross- linked melamine- or naphthalene-sulfonates, referred to as PMS (polymelamine sulfonate) and PNS (polynaphthalene sulfonate), respectively, are illustrative. They are prepared by crosslinking of the sulfonated monomers using formaldehyde or by sulfonating the corresponding crosslinked polymer. Idealized structure of naphthalenesulfonate/formaldehyde polymer used as a superplasticizer. Polycarboxylate displacement on a multi-phase suspension.
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Because of this unusual structural feature, many unusual compounds are derived from peri-naphthalenes. One example is 1,8-bis(dimethylamino)naphthalene, known as proton sponge because of its high affinity for protons. Its ammonium derivative has a pKa of 12.7.Alexander F. Pozharskii and Valery A. Ozeryanskii "Proton sponges and hydrogen transfer phenomena" Mendeleev Commun.
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1,4-Naphthoquinone or para-naphthoquinone is an organic compound derived from naphthalene. It forms volatile yellow triclinic crystals and has a sharp odor similar to benzoquinone. It is almost insoluble in cold water, slightly soluble in petroleum ether, and more soluble in polar organic solvents. In alkaline solutions it produces a reddish-brown color.
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Naphthalene (the chemical used in mothballs) is considered more effective, but there are concerns over its effects on human health. Moth larvae may be killed by freezing the items which they infest for several days at a temperature below .Choe, D.-H. "Clothes Moths" in How to Manage Pests: Pests of Homes, Structures, People, and Pets.
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For example, the methanol radical cation fragments into a methenium cation CH3+ and a hydroxyl radical. In naphthalene the unfragmented radical cation is by far the most prominent peak in the mass spectrum. Secondary species are generated from proton gain (M+1) and proton loss (M-1). Some compounds containing the dioxygenyl cation can be prepared in bulk.
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PAHs (according to EPA 610) in the exhaust gas of rotary kilns usually appear at a distribution dominated by naphthalene, which accounts for a share of more than 90% by mass. The rotary kiln systems of the cement industry destroy virtually completely the PAHs input via fuels. Emissions are generated from organic constituents in the raw material.
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An Oxyliquit, also called liquid air explosive or liquid oxygen explosive, is an explosive material which is a mixture of liquid oxygen (LOX) with a suitable fuel, such as carbon (as lampblack), or an organic chemical (e.g. a mixture of soot and naphthalene), wood meal, or aluminium powder or sponge. It is a class of Sprengel explosives.
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Vat Red 29 typical example of a structure with a perylene core The perylene molecule consists of two naphthalene molecules connected by a carbon-carbon bond at the 1 and 8 positions on both molecules. All of the carbon atoms in perylene are sp2 hybridized. The structure of perylene has been extensively studied by X-ray crystallography.
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2,6-Dimethylnaphthalene (2,6-DMN) is a polycyclic aromatic hydrocarbon. It is one of the ten dimethylnaphthalene isomers, which are derived from naphthalene by the addition of two methyl groups. 2,6-DMN is of commercial importance as a starting material for high-performance polyester fibers and films. Polyethylene naphthalate (PEN) is made from the product of oxidation 2,6-DMN.
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EDANS (5-((2-Aminoethyl)amino)naphthalene-1-sulfonic acid) is a donor for FRET-based nucleic acid probes and protease substrates. EDANS is often paired with DABCYL or DABSYL. The combination can be used in enzyme assays. When the two compounds are in close proximity, most of the energy emitted from EDANS will be quenched by DABCYL.
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7,16-Bis(tris(trimethylsilyl)silylethynyl)heptacene was synthesized in 2005. This compound is stable in the solid state for a week but decomposes in contact with air. Its synthesis started from anthraquinone and naphthalene-2,3-dicarboxaldehyde. More stable substituted heptacenes have been reported: with stabilizing p-(t-butyl)thiophenyl substituents and with phenyl and triisopropylsilylethynyl groups.
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The di-anion has its two negative charges in one ring, converting that ring into a 10-pi electron aromatic system similar to the di-anion of cyclooctatetraene. In the 18-pi electron tetra-anion, both rings effectively have access to 10 pi electrons, leading to a planar, bicyclic aromatic structure analogous to that of naphthalene.
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1,1'-Binaphthyl is an organic compound with the formula (CH). It is one of the dimers of naphthalene (or literally: dimers of naphthyl). A colorless solid, it has attracted some attention because the atropisomers can be isolated due in part to hindered rotation between the two naphthyl subunits. The halflife of the racemization is 14.5 min.
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At further heating to phase II can be handled safely in an ambient environment. The metal reacts with the silica gel in an exothermic reaction in which Na4Si4 nanoparticles are formed. The powder reacts with water to form hydrogen. Compounds such as biphenyl and naphthalene are reduced by the powder and form highly coloured radical anions.
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Naphthionic acid is an organic compound with the formula C10H6(SO3H)(NH2). It is one of several aminonaphthalenesulfonic acids, derivatives of naphthalene containing both amine and sulfonic acid functional groups. It is a white solid, although commercial samples can appear gray.4-Amino-1-naphthalenesulfonic acid; MSDS No. 250619; Sigma–Aldrich Chemie GmbH: Steinheim, 29 Dec 2011.
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Hexabenzocoronene is a large polycyclic aromatic hydrocarbon. Polycyclic aromatic hydrocarbons (PAHs) are aromatic hydrocarbons that consist of fused aromatic rings and do not contain heteroatoms or carry substituents. Naphthalene is the simplest example of a PAH. PAHs occur in oil, coal, and tar deposits, and are produced as byproducts of fuel burning (whether fossil fuel or biomass).
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Many important chemical compounds are derived from benzene by replacing one or more of its hydrogen atoms with another functional group. Examples of simple benzene derivatives are phenol, toluene, and aniline, abbreviated PhOH, PhMe, and PhNH2, respectively. Linking benzene rings gives biphenyl, C6H5–C6H5. Further loss of hydrogen gives "fused" aromatic hydrocarbons, such as naphthalene, anthracene, phenanthrene, and pyrene.
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It is named after its discoverer, Roland Scholl, a Swiss chemist. The Scholl reaction In 1910 Scholl reported the synthesis of a quinone Scholl, R. and Mansfeld, J. (1910), meso- Benzdianthron (Helianthron), meso-Naphthodianthron, und ein neuer Weg zum Flavanthren. Ber. Dtsch. Chem. Ges., 43: 1734–1746. and of perylene from naphthalene Scholl, R., Seer, Chr.
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Decalin (decahydronaphthalene, also known as bicyclo[4.4.0]decane and sometimes decaline), a bicyclic organic compound, is an industrial solvent. A colorless liquid with an aromatic odor, it is used as a solvent for many resins or fuel additives. It is the saturated analog of naphthalene and can be prepared from it by hydrogenation in the presence of a catalyst.
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Urinal deodorizer blocks are tablets (usually cylindrical in shape). The chemicals composing the block may vary. The original formulations were of naphthalene and later para-dichlorobenzene (pDCB), both now known to be hazardous to health by inhalation. In some areas, the use of para-dichlorobenzene toilet blocks has been banned; in other areas para-dichlorobenzene blocks or "para blocks" are still used.
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The synthesis of suramin itself and structural analogs is by successive formation of the amide bonds from their corresponding amine (aniline) and carboxyl (as acyl chloride) components. Various routes to these compounds have been developed, including starting from separate naphthalene structures and building towards an eventual unification by formation of the urea or starting with a urea and appending successive groups.
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The alkali metal naphthalenides are prepared by stirring the metal with naphthalene in an ethereal solvent, usually as tetrahydrofuran or dimethoxyethane. The resulting salt is dark green. The anion is a radical, giving a strong EPR signal near g = 2.0, with a reduction potential near -2.5 V vs NHE. Its deep green color arises from absorptions centered at 463, 735 nm.
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"Organometallics in Organic Synthesis", Schlosser, M., Ed, Wiley: New York, 1994. The reduction proceeds via a radical pathway. Below is an example of the preparation of a functionalized lithium reagent using reduction with lithium metal. Sometimes, lithium metal in the form of fine powders are used in the reaction with certain catalysts such as naphthalene or 4,4’-di-t- butylbiphenyl (DTBB).
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Similar to sodium sulfide, anhydrous caesium sulfide can be produced by reacting caesium and sulfur in THF. It needs ammonia or naphthalene to react. : 2Cs + S → Cs2S By dissolving hydrogen sulfide into caesium hydroxide solution, it will produce caesium bisulfide, then it will produce caesium sulfide too.Wilhelm Blitz, Ernst Wilke-Dörfurt: "Über Sulfide des Rubidiums und Cäsiums" in Zeitschr. f. anorg. Chem. 1906.
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Traditional mothballs deter adult moths with strong-smelling naphthalene; modern ones use volatile repellents such as 1,4-Dichlorobenzene. Moth larvae can be killed with insecticides such as permethrin or pyrethroids. However, insecticides cannot safely be used in food storage areas; alternative treatments include freezing foods for four days at or baking for half an hour at to kill any insects present.
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The coal tar activities at Uithoorn continued after 1997 as Cindu Chemicals, (50% owned by Koninklijke Hoogovens), as well as the joint venture Nevcin Polymers. In 2001 a storage tank for Naphthalene cracked; the resultant odor brought complaints about the odor of (moth balls), which was reported as far away as England. In 2010 the plant was sold to Koppers Inc..
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After the creation of and successful research surrounding xDNA, more forms of expanded nucleotides were investigated. yDNA is a second, similar system of nucleotides which uses a benzene ring to expand the four natural bases. xxDNA and yyDNA use naphthalene, a polycyclic molecule consisting of two hydrocarbon rings. The two rings expand the base even wider, further altering its chemical properties.
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1-Naphthol is a precursor to a variety of insecticides including carbaryl and pharmaceuticals including nadolol as well as for the antidepressant sertraline and the anti-protozoan therapeutic atovaquone. It undergoes azo coupling to give various azo dyes, but these are generally less useful than those derived from 2-naphthol.Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. .
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It can also be reacted with iron pentacarbonyl (Fe(CO)5) in isooctane at 150 °C to yield a solid organoarsenic compound with the formula C34H25As,Fe(CO)3. Reacting pentaphenylarsole with metallic lithium or potassium yields 1,2,3-triphenyl naphthalene. Reaction of phenylarsenous dichloride with linear diphenyls results in 1,2,5-triphenylarsole (see below), a solid with a melting point of about 170 °C.
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The resulting materials have rigidly planar, highly conjugated cores. They exhibit good processing characteristics for fabrication of soft electronic devices. Aside from the NDIs, other members include the diimide derivatives of perylene-3,4:9,10-tetracarboxylic dianhydride and terrylene-3,4:11,12-tetracarboxylic dianhydride. Synthesis of symmetric and unsymmetric NDIs Naphthalene diimides (NDIs) are often fluorescent, although the intensity is sensitive to substituents.
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Naphthalene is an organic compound with formula . It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings. It is best known as the main ingredient of traditional mothballs.
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An experiment was carried out by Schneider-Creusot. The Schneider establishment consisted of two distinct areas that were connected to each other by a rail link running through a tunnel. Steam traction was in use and the tunnel was filled with smoke from the locomotives. Following experiments carried out on a Renault car, it was decided to build a small naphthalene-powered locomotive.
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The idea seems to re-surface periodically. A 1997 patent of Luis Cisneros Zazueta claims: "The invention can be used for all type of four-cycle gasoline engines operating under the Jammes Otto thermodynamic cycle, which comprise a carburator or a fuel injection system, the number of cylinders being unimportant. Naphthalene low cost and efficiency make the use of this device inexpensive".
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The extent of the aromaticity of the compound was examined by comparison with naphthalene, which allowed the conclusion that it behaved as a 10-electron system in which the sulfur atom contributed its lone pair to the resonance structures, in accordance with Hückel's rule. However, 1,2,3-benzothiadiazole is much less reactive than naphthalene in its electrophilic aromatic substitution chemistry, for example only forming nitro derivatives under forcing conditions. For that reason, many of its simple derivatives have been made either from already-substituted 2-aminothiophenols or by the Herz reaction in which a substituted aniline is treated with disulfur dichloride and the intermediate 1,3,2-benzothiazathiolium salt is diazotised to complete the formation of a 1,2,3-benzothiadiazole. The parent system cannot be made this way, since the use of aniline in this reaction leads to formation of the 6-chloro derivative.
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In enzymology, a 4-(2-carboxyphenyl)-2-oxobut-3-enoate aldolase () is an enzyme that catalyzes the chemical reaction :(3Z)-4-(2-carboxyphenyl)-2-oxobut-3-enoate + H2O \rightleftharpoons 2-formylbenzoate + pyruvate Thus, the two substrates of this enzyme are (3Z)-4-(2-carboxyphenyl)-2-oxobut-3-enoate and H2O, whereas its two products are 2-formylbenzoate and pyruvate. This enzyme participates in naphthalene and anthracene degradation.
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2-Naphthylamine is one of two isomeric aminonaphthalenes, compounds with the formula C10H7NH2. It is a colorless solid, but samples take on a reddish color in air because of oxidation. It was formerly used to make azo dyes, but it is a known carcinogen and has largely been replaced by less toxic compounds.Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. .
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Chemical structure of 12-phthaloperinone, a derivative of 1,8-diaminonaphthalene It is prepared by reduction of 1,8-dinitronaphthalene, which in turn is obtained as a mixture of isomers by nitration of 1-nitronaphthalene. Upon treatment with phthalic anhydride derivatives, the diamine converts to phthaloperinones. The derivative from phthalic anhydride itself, Solvent Orange 60, is a useful orange pigment. It is a precursor to 1,8-bis(dimethylamino)naphthalene.
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Polycyclic aromatic hydrocarbons (PAHs) can be generated from the pyrolysis of different solid waste fractions, such as hemicellulose, cellulose, lignin, pectin, starch, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET). PS, PVC, and lignin generate significant amount of PAHs. Naphthalene is the most abundant PAH among all the polycyclic aromatic hydrocarbons. When the temperature is increased from 500 to 900 °C, most PAHs increase.
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Simple aromatic rings can be heterocyclic if they contain non-carbon ring atoms, for example, oxygen, nitrogen, or sulfur. They can be monocyclic as in benzene, bicyclic as in naphthalene, or polycyclic as in anthracene. Simple monocyclic aromatic rings are usually five-membered rings like pyrrole or six-membered rings like pyridine. Fused aromatic rings consist of monocyclic rings that share their connecting bonds.
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2-hydroxychromene-2-carboxylate isomerase (, HCCA isomerase, 2HC2CA isomerase, 2-hydroxychromene-2-carboxylic acid isomerase) is an enzyme with systematic name 2-hydroxy-2H-chromene-2-carboxylate---(3E)-4-(2-hydroxyphenyl)-2-oxobut-3-enoate isomerase. This enzyme catalyses the following chemical reaction : 2-hydroxy-2H-chromene-2-carboxylate \rightleftharpoons (3E)-4-(2-hydroxyphenyl)-2-oxobut-3-enoate This enzyme is involved in naphthalene degradation.
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Pseudomonas balearica is a Gram-negative, rod-shaped, nonfluorescent, motile, and denitrifying bacterium. It is an environmental bacterium that has been mostly isolated from polluted environments all over the world. Many of the isolates have demonstrated capabilities to degrade several compounds. Some of the strains are naphthalene degraders and one strain isolated in New Zealand has demonstrated the potential to oxidize inorganic sulfur compounds to tetrathionate.
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Divinylbenzene (DVB) consists of a benzene ring bonded to two vinyl groups. It is related to styrene (vinylbenzene) by the addition of a second vinyl group.CRC Handbook of Chemistry and Physics 65Th Ed. It is a colorless liquid manufactured by the thermal dehydrogenation of isomeric diethylbenzenes. Under synthesis conditions, o-divinylbenzene converts to naphthalene and thus is not a component of the usual mixtures of DVB.
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The European Union enforced a ban on the distribution and production of mothballs containing naphthalene in 2008, as a part of the new regulations of the Registration, Evaluation and Authorisation of Chemicals (REACH), regulating chemical use within its representative countries. In 2014, New Zealand banned the distribution of mothballs. Mothballs are restricted within Australia, only being distributed in forms that prevent them from being ingested.
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Treatment of naphthalene toxicity usually follows the same treatments involved for haemolytic anaemia, which involves a series of blood transfusions, in order to restore healthy levels of haemoglobin. This may include intravenous methylene blue and ascorbic acid. The methylene blue allows the methaemoglobin to be converted to haemoglobin. Supportive treatment is also usually provided, depending on the severity of the toxicity, that resulted in the anaemia.
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Methamnetamine (also known as methylnaphetamine, MNA, MNT and PAL-1046) is a triple monoamine releasing agent and N-methyl analog of the non-neurotoxic experimental drug naphthylaminopropane and the naphthalene analog of methamphetamine. It has been sold online as a designer drug. It acts as a releasing agent of serotonin, norepinephrine, and dopamine, with EC50 values of 13 nM, 34 nM, and 10 nM, respectively.
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A large scale industrial application of quinones is for the production of hydrogen peroxide. 2-Alkylanthraquinones are hydrogenated to the corresponding hydroquinones (quinizarins), which then transfer to oxygen: : dihydroanthraquinone + → anthraquinone + in this way, several billion kilograms of are produced annually.Gustaaf Goor, Jürgen Glenneberg, Sylvia Jacobi "Hydrogen Peroxide" in Ullmann's Encyclopedia of Industrial Chemistry 2007, Wiley-VCH, Weinheim. . 1,4-Naphthoquinone, derived by oxidation of naphthalene with chromium trioxide.
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Quinones are commonly named with a prefix that indicates the parent aromatic hydrocarbon ("benzo-" for benzene, "naphtho-" for naphthalene, "anthra-" for anthracene, etc.) and the "-quinone" suffix. Infix multipliers "-di-", "-tri-", "-tetra-" (etc.) are used when there are 4, 6, 8 (etc.) carbonyls. The position of the carbonyl groups can be indicated before the prefix (as in "1,4,5,8-naphthodiquinone") or after it ("anthra-1,4-quinone").
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The powder can also be introduced in a column chromatography setup and eluted with organic reactants in order to probe the reducing power. The powder is mixed with additional (wet) silica gel which provides additional hydrogen. A Birch reduction of naphthalene takes 5 minutes elution time. The column converts benzyl chloride to bibenzyl in a Wurtz coupling and in a similar fashion dibenzothiophene is reduced to biphenyl.
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It is used in the synthesis of azo dyes such as Rocceline (a. k. a. Solid Red A), during which the amino group of the acid (in the form of a salt) is diazotated and then coupled with, in the case mentioned, β-naphthol. It is prepared by treating 1-aminonaphthalene with sulfuric acid.Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. .
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The final Sampling and Analysis Plan was approved in June 2001 (2). EPA has found that the ETC plume of contamination contains elevated levels of dioxin, pentachlorophenol (PCP),naphthalene, dioxin and a number of other organic contaminants (3). The dioxin findings are particularly troubling because EPA is ignoring dioxin in its Mt. Dioxin groundwater cleanup planning (3). The plume usually flows ESE toward upper Bayou Texar (3).
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Alkyl naphthalene sulfonates (ANS) are used in many industrial applications as nondetergent wetting agents that effectively disperse colloidal systems in aqueous media. The major commercial applications are in the agricultural chemical industry, which uses ANS for wettable powder and wettable granular (dry-flowable) formulations, and the textile and fabric industry, which utilizes the wetting and defoaming properties of ANS for bleaching and dyeing operations.
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The blue color of the mushroom Lactarius indigo is due to the azulene derivative (7-isopropenyl-4-methylazulen-1-yl)methyl stearate.Azulene is usually viewed as resulting from fusion of cyclopentadiene and cycloheptatriene rings. Like naphthalene and cyclodecapentaene, it is a 10 pi electron system. It exhibits aromatic properties: (i) the peripheral bonds have similar lengths and (ii) it undergoes Friedel-Crafts-like substitutions.
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Polycyclic aromatic hydrocarbons are molecules containing two or more simple aromatic rings fused together by sharing two neighboring carbon atoms (see also simple aromatic rings). Examples are naphthalene, anthracene, and phenanthrene. In fused aromatics, not all carbon–carbon bonds are necessarily equivalent, as the electrons are not delocalized over the entire molecule. The aromaticity of these molecules can be explained using their orbital picture.
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Picene is a hydrocarbon found in the pitchy residue obtained in the distillation of peat tar and of petroleum. This is distilled to dryness and the distillate repeatedly recrystallized from cymene. It may be synthetically prepared by the action of anhydrous aluminium chloride on a mixture of naphthalene and 1,2-dibromoethane, or by distilling a-dinaphthostilbene. It crystallizes in large colorless plates which possess a blue fluorescence.
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Sodium etching of fluoropolymers has been used for decades to enhance bondability of PTFE. It is performed by immersion of the PTFE in a solution containing sodium followed by rinsing in alcohol and water. The process was originally performed by dissolving sodium metal in liquid ammonia. An alternative method was to form a complex with naphthalene, which was then dissolved in an ether such as tetrahydrofuran (THF).
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Rogers Corporation, a manufacturer of PTFE printed circuit board laminates, refers to Poly-Etch and FluoroEtch etchants in its Fabrication Guidelines, "Bonding PTFE Materials for Microwave Stripline Packages and Other Multilayer Circuits". Poly-Etch is a sodium naphthalene complex in tetraglyme, while Fluoro-Etch is a sodium naphthalide complex in diglyme Matheson, the manufacturer of Poly-Etch, also manufactures a monoglyme-based etchant called Poly-Etch W.
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The physical characteristics of decaborane(14) resemble those of naphthalene and anthracene, all three of which are volatile colorless solids. Sublimation is the common method of purification. Decaborane is highly flammable, but, like other boron hydrides, it burns with a bright green flame. It is not sensitive to moist air, although it hydrolyzes in boiling water, releasing hydrogen and giving a solution of boric acid.
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Traditionally, 2-naphthol is produced by a two-step process that begins with the sulfonation of naphthalene in sulfuric acid:. :C10H8 \+ H2SO4 → C10H7SO3H + H2O The sulfonic acid group is then cleaved in molten sodium hydroxide: :C10H7(SO3H) + 3 NaOH → C10H7ONa + Na2SO3 \+ 2 H2O Neutralization of the product with acid gives 2-naphthol. 2-Naphthol can also be produced by a method analogous to the cumene process.
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Nasutes have lost their mandibles through the course of evolution and must be fed by workers. A wide variety of monoterpene hydrocarbon solvents have been identified in the liquids that nasutes secrete. Similarly, Formosan subterranean termites have been known to secrete naphthalene to protect their nests. Soldiers of the species Globitermes sulphureus commit suicide by autothysis – rupturing a large gland just beneath the surface of their cuticles.
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The Buck igniter was a small can of thin, corrugated aluminium. This contained a glass ampule of sulfuric acid, surrounded by flash powder that included powdered naphthalene. The can crushed when subjected to a pressure of around , shattering the ampule and causing the acid to mix with the powder. The resulting chemical reaction produced a flash that ignited the detonator of the main explosive charge.
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In the first step of the reaction mechanism a proton adds to a carbon atom with high electron density therefore by preference to C2 or C4 of naphthol (1). This leads to resonance stabilized adducts 1a-1e. De- aromatization of the first ring of the naphthalene system occurs at the expense of 25 kcal/mol. In the next step a bisulfite anion adds to C3 through 1e.
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A polycyclic aromatic hydrocarbon (PAH) is a hydrocarbon—a chemical compound containing only carbon and hydrogen—that is composed of multiple aromatic rings. The group is a major subset of the aromatic hydrocarbons. The simplest of such chemicals are naphthalene, having two aromatic rings, and the three- ring compounds anthracene and phenanthrene. The terms polyaromatic hydrocarbon or polynuclear aromatic hydrocarbon are also used for this concept.
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At the beginning of the twentieth century, steam locomotives continued to dominate the railways but alternatives were being considered. One of the problems to be solved was that of finding a cheap fuel. Liquid fuels, such as naphtha, petrol, benzole and alcohol had all been tried, but were expensive. Naphthalene seemed attractive because of its low cost, due to its origin from coal tar.
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Commercial manganese powder is not suited for the synthesis of organomanganese compounds. In 1996 Rieke introduced activated manganese (see Rieke metal) obtained by reaction of anhydrous manganese(II) chloride with lithium metal in a solution of a catalytic amount of naphthalene in THF. Other reducing agents are potassium graphite and magnesium. Activated manganese facilitates the Mn version of the Barbier reaction and the pinacol coupling.
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Adding an excessive amount of plasticizer will result in excessive segregation of concrete and is not advisable. Depending on the particular chemical used, use of too much plasticizer may result in a retarding effect. Plasticizers are commonly manufactured from lignosulfonates, a by-product from the paper industry. Superplasticizers have generally been manufactured from sulfonated naphthalene condensate or sulfonated melamine formaldehyde, although newer products based on polycarboxylic ethers are now available.
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When Laurdan is located in the cell membrane its emission maximum is centered at 440 nm in gel-phase, and at 490 nm in liquid-phase. This spectral shift is the result of the dipolar relaxation of Laurdan on the lipidic environment, namely, the reorientation of solvents caused by Laurdan’s excitation. Particularly, due to some water molecules located at the level of the glycerol backbone, where the naphthalene moiety residesT.
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Third-hand smoking (THS) consists of residual tobacco smoke pollutants that remain on surfaces and in dust after tobacco has been smoked, are re-emitted into the gas phase, or react with oxidants and other compounds in the environment to yield secondary pollutants. Chemicals of tobacco smoking include nicotine, 3-ethenylpyridine (3-EP), phenol, cresols, naphthalene, formaldehyde, and tobacco-specific nitrosamines (including some not found in freshly-emitted tobacco smoke).
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The reagent removes pairs of H atoms from organic molecules. The stoichiometry of its action is illustrated by the conversion of tetralin to naphthalene: :2 C6Cl2(CN)2O2 \+ C10H12 → 2 C6Cl2(CN)2(OH)2 \+ C10H8 The resulting hydroquinone is poorly soluble in typical reaction solvents (dioxane, benzene, alkanes), which facilitates workup. Solutions of DDQ in benzene are red, due to the formation of a charge-transfer complex.
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A major research goal is to determine the microbial chemistry of the anaerobic pathways of naphthalene, methylnaphthalene and phenanthrene. She was one of the first researchers to use stable isotope labeled compounds to decipher the mechanism of attack of hydrocarbons by anaerobes. This approach is now being widely used. By understanding the anaerobic biodegradation pathways, Young's group has developed methods to improve or enhance natural rates of biodegradation in the environment.
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Tobias acid (2-amino-1-naphthalenesulfonic acid) is an organic compound with the formula C10H6(SO3H)(NH2). It is one of several aminonaphthalenesulfonic acids, which are derivatives of naphthalene containing both amine and sulfonic acid functional groups. It is a white solid, although commercial samples can appear otherwise. It is used in the synthesis of azo dyes such as C.I. Acid Yellow 19 and C.I. Pigment Red 49.
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Graebe (1869) "Ueber die Constitution des Naphthalins" (On the structure of naphthalene), Annalen der Chemie und Pharmacie, 149 : 20–28; see especially p. 26. In 1870, the German chemist Viktor Meyer first applied Gräbe's nomenclature to benzene.Victor Meyer (1870) "Untersuchungen über die Constitution der zweifach-substituirten Benzole" (Investigations into the structure of di-substituted benzenes), Annalen der Chemie und Pharmacie, 156 : 265–301; see especially pp. 299–300.
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2-Methylnaphthalene is a component of crude oil and is "structurally related to naphthalene, an ingredient in mothballs and toilet-deodorant blocks" that the EPA considers a possible human carcinogen. Kellogg's offered consumers refunds in the meantime. Only products with the letters "KN" following the use-by date were included in the recall. The products were distributed throughout the U.S. and began arriving in stores in late March 2010.
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In enzymology, a 1-hydroxy-2-naphthoate 1,2-dioxygenase () is an enzyme that catalyzes the chemical reaction :1-hydroxy-2-naphthoate + O2 \rightleftharpoons (3Z)-4-(2-carboxyphenyl)-2-oxobut-3-enoate Thus, the two substrates of this enzyme are 1-hydroxy-2-naphthoate and O2, whereas its product is (3Z)-4-(2-carboxyphenyl)-2-oxobut-3-enoate. This enzyme participates in naphthalene and anthracene degradation. It employs one cofactor, iron.
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The phase I cytochrome P450 enzyme systems of C. elegans has been implicated in the neutralization of numerous polycyclic aromatic hydrocarbons (PAH). It can degrade molecules such as anthracene, 7-methylbenz[a]anthracene and 7-hydroxymethylbenz[a]anthracene, phenanthrene, acenaphthene, 1- and 2-methylnaphthalene, naphthalene, fluorene or benzo(a)pyrene. In the case of phenanthrene, C. elegans produces a glucoside conjugate of 1-hydroxyphenanthrene (phenanthrene 1-O-beta-glucose).
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The sugars, chelating agents in lignosulfonates such as aldonic acids and extractive compounds are mainly responsible for set retardation. These low range water reducing dispersants are commonly manufactured from lignosulfonates, a by-product from the paper industry. High range superplasticizers (dispersants) have generally been manufactured from sulfonated naphthalene condensate, although polycarboxylic ethers represent more modern alternatives. Both of these high range water reducers are used at 1/2 to 1/3 of the lignosulfonate types.
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Cetane is the chemical compound with chemical formula n-C16H34, today named hexadecane according to IUPAC rules. It is an unbranched alkane, a saturated hydrocarbon chain with no cycles. Cetane ignites very easily under compression, so it was assigned a cetane number of 100, while alpha-methyl naphthalene was assigned a cetane number of 0. All other hydrocarbons in diesel fuel are indexed to cetane as to how well they ignite under compression.
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Zethrene (dibenzo[de,mn]naphthacene) is a polycyclic aromatic hydrocarbon consisting of two phenalene units fused together. According to Clar's rule, the two exterior naphthalene units are truly aromatic and the two central double bonds are not aromatic at all. For this reason the compound is of some interest to academic research. Zethrene has a deep-red color and it is light sensitive - complete decomposition under a sunlight lamp occurs within 12 hours.
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Indications of thermal rearrangements of aromatic hydrocarbons were first noted in the early 20th century by natural products chemists who were working with sesquiterpenes. At the time, they noticed the automerization of a substituted azulene shown below, but no further structural or mechanistic investigations were made. upright=1.5 The oldest characterized thermal rearrangement of an aromatic compound was that of the isomerization of azulene to naphthalene by Heilbronner et al. in 1947.
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The compound is easily prepared by the ring closure of 2,5-dimethylhexane-2,5-diol using acid catalysts. Zeolites have been shown to be particularly high yielding but sulfuric acid can also be used. TMTHF reacts with benzene in the presence of triflic acid to form 1,1,4,4-dimethyltetralin and symmetric tetramethyloctahydroanthracene. This and other similar reactions can be used for the selective preparation of derivatives of naphthalene, anthracene, and tetracene, and other fused-ring aromatic hydrocarbons.
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The crystal structure of the hydroxylase component of naphthalene 1,2-dioxygenase from Pseudomonas has been determined. The protein is an (αβ)3 hexamer. The β-subunit belongs to the α+β class. It has no prosthetic groups and its role in catalysis is unknown. The α-subunit can be divided into two domains: a Rieske domain that contains the [Fe2S2] center and the catalytic domain that contains the active site mononuclear iron.
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For transport without contact. There are three different approaches. Transport by gravity using an upright microscope (called GAM, gravity-assisted microdissection) or transport by laser pressure catapult; the most recent generation utilizes a technology based on laser induced forward transfer (LIFT). With cut-and-capture, a cap coated with an adhesive is positioned directly on the thinly cut (5-8 μm) tissue section, the section itself resting on a thin membrane (polyethylene naphthalene).
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As discussed in more detail at Tineola bisselliella, alternatives to mothballs to control clothes moths include dry cleaning, freezing, thorough vacuuming, and washing in hot water. Camphor is also used as a moth repellent, particularly in China. Unlike naphthalene and dichlorobenzene, camphor has medicinal applications and is not regarded as a carcinogen, though it is toxic in large doses. Pheromone traps are also an effective tool used when attempting to protect valuable clothing.
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Calconcarboxylic acid (IUPAC name 3-hydroxy-4-[(2-hydroxy-4-sulfonaphthalen-1-yl)diazenyl]naphthalene-2-carboxylic acid; commonly called Patton and Reeder's Indicator) is an azo dye (chemical formula CH3CHOHCH3) which is used as an indicator for complexometric titrations of calcium with ethylenediaminetetraacetic acid (EDTA) in the presence of magnesium. Structurally, it is similar to eriochrome blue black R, which is obtained from calconcarboxylic acid by decarboxylation and reaction with sodium hydroxide.
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In some PAHs, like naphthalene, anthracene, and coronene, all carbon and hydrogen atoms lie on the same plane. This geometry is a consequence of the fact that the σ-bonds that result from the merger of sp2 hybrid orbitals of adjacent carbons lie on the same plane as the carbon atom. Those compounds are achiral, since the plane of the molecule is a symmetry plane. However, some other PAHs are not planar.
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2,3-Butanediol is prepared by hydrolysis of 2,3-epoxybutane:Heinz Gräfje, Wolfgang Körnig, Hans-Martin Weitz, Wolfgang Reiß, Guido Steffan, Herbert Diehl, Horst Bosche, Kurt Schneider and Heinz Kieczka "Butanediols, Butenediol, and Butynediol" in Ullmann's Encyclopedia of Industrial Chemistry, 2000, Wiley-VCH, Weinheim. :(CH3CH)2O + H2O → CH3(CHOH)2CH3 The isomer distribution depends on the stereochemistry of the epoxide. The meso isomer is used to combine with naphthalene-1,5-diisocyanate. The resulting polyurethane is called "Vulkollan".
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In 1924, when only a few crystal structures had been determined throughout the world, Banerjee's work on the determination of atomic arrangements in crystalline naphthalene and anthracene received international attention. Banerjee was awarded the DSc degree of the University of Calcutta in 1930"Dr. Shekhar Mande, DG CSIR of India's reporting article, Early developments in crystallography stated that Professor Banerjee a eminent contributor to the crystallography of India". This article of Dr. Shekhar Mande, at present DG, CSIR, Govt.
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The production of iron from its ores involves powerful reduction reactions in blast furnaces. Cooling waters are inevitably contaminated with products especially ammonia and cyanide. Production of coke from coal in coking plants also requires water cooling and the use of water in by-products separation. Contamination of waste streams includes gasification products such as benzene, naphthalene, anthracene, cyanide, ammonia, phenols, cresols together with a range of more complex organic compounds known collectively as polycyclic aromatic hydrocarbons (PAH).
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In 2007 Cindu's output included Naphthalene, Creosote, Carbon black and Pitch used for the production of carbon electrodes, and also bitumen emulsions for road construction. The primary process carried out the site was by distillation at 350C, in addition to further purification processes. The primary source of raw material (tar) was Koninklijke Hoogovens, tar from the plant was shipped by barge to Uithoorn. As of 2012 the plant had a capacity to process 140000t of tar per year.
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Upon exposure to a parasite, group members must both evaluate the threat it poses and the current level of colony infection in order to respond appropriately. Mechanisms of social immunity are often categorized by the stage of the parasite attack on a group of organisms they target. Some mechanisms are prophylactic (e.g. burying beetles smearing their carcasses with antimicrobials or termites fumigating their nests with naphthalene) whilst others are activated in response to a parasite challenge (e.g.
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In one of the breakthrough events in the field of polymer science, Szwarc elucidated that electron transfer occurred from radical anion of naphthalene to styrene. The results in the formation of a dianion (or equivalently disodio-) species, which rapidly added styrene to form a "two – ended living polymer." An important aspect of his work, Szwarc employed the aprotic solvent tetrahydrofuran. Being a physical chemist, Szwarc elucidated the kinetics and the thermodynamics of the process in considerable detail.
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Meanwhile, group 1 metals such as lithium, sodium, and potassium, and their organic compounds (e.g. sodium naphthalene) serve as effective anionic initiators. In both anionic and cationic polymerization, each charged chain end (negative and positive, respectively) is matched by a counterion of opposite charge that originates from the initiator. Because of the charge stability necessary in ionic polymerization, monomers which may be polymerized by this method are few compared to those available for free radical polymerization.
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For the next five years, she was used as a general cargo freighter in the North Atlantic. On 21 December 1951, under the command of Henrik Kurt Carlsen, she left Hamburg, Germany bound for the USA. Among her cargo was of pig iron and of coffee, rags, peat moss, twelve Volkswagen cars, antiques and antique musical instruments, typewriters, of naphthalene as well as ten passengers. There is speculation that the cargo also included gold and zirconium.
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The Haworth reaction is a classic method for the synthesis of 1-tetralone. In this reaction, benzene is reacted with succinic anhydride, the intermediate product is reduced and a second FC acylation takes place with addition of acid.Li, Jie Jack (2003) Name Reactions: A Collection of Detailed Reaction Mechanisms, Springer, , p. 175. :Haworth reaction In a related reaction, phenanthrene is synthesized from naphthalene and succinic anhydride in a series of steps which begin with FC acylation.
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A mechanistic rational for the thermal rearrangement of azulene to naphthalene is included below. Homolysis of the weakest bond in azulene occurs, followed by a hydrogen shift and ring closure so as to retain the aromaticity of the molecule. upright=2 Benzene ring contractions are the last two mechanisms that have been suggested, and they are currently the preferred mechanisms. These reaction mechanisms proceed through the lowest free energy transition states compared to the diradical and dyotropic mechanisms.
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SDB-005 is an indazole-based synthetic cannabinoid that has been sold online as a designer drug. It is presumed to be an agonist of the CB1 and CB2 cannabinoid receptors. SDB-005 is the indazole core analog of PB-22 where the 8-hydroxyquinoline has also been replaced with a naphthalene group. The code number SDB-005 was originally used for a different compound, the N-phenyl instead of N-benzyl analogue of SDB-006.
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As an example, a residual quantity of a highly volatile contaminant (such as trichloroethene) in a homogeneous sand with high permeability and low carbon content (i.e., low/negligible adsorption) will be readily treated with SVE. In contrast, a heterogeneous vadose zone with one or more clay layers containing residual naphthalene would require a longer treatment time and/or SVE enhancements. SVE effectiveness issues include tailing and rebound, which result from contaminated zones with lower air flow (i.e.
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The US Department of Health and Human Services (DHHS) has determined that 1,4-dichlorobenzene "may reasonably be anticipated to be a carcinogen". This has been indicated by animal studies, although a full-scale human study has not been done. The National Toxicology Program (NTP), the International Agency for Research on Cancer (IARC) and the state of California consider 1,4-dichlorobenzene a carcinogen. Exposure to naphthalene mothballs can cause acute hemolysis (anemia) in people with glucose-6-phosphate dehydrogenase deficiency.
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Excavation showing soil contamination at a disused gasworks in England. Soil contamination or soil pollution as part of land degradation is caused by the presence of xenobiotics (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons (such as naphthalene and benzo(a)pyrene), solvents, pesticides, lead, and other heavy metals.
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They are named ansamycins (from the Latin ansa, handle) because of their unique structure, which consists of an aromatic moiety bridged by an aliphatic chain. The main difference between various derivatives of ansamycins is the aromatic moiety, which can be a naphthalene ring or a naphthoquinone ring as in rifamycin and the naphthomycins. Another variation consists of benzene or a benzoquinone ring system as in geldanamycin or ansamitocin. Ansamycins were first discovered in 1959 by Sensi et al.
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The molecular formula of suramin is C51H40N6O23S6. It is a symmetric molecule in the center of which lies a urea (NH–CO–NH) functional group. Suramin contains six aromatic systems - four benzene rings, sandwiched by a pair of naphthalene moieties - plus four amide functional groups (in addition to the urea) and six sulfonic acid groups. When given as a medication, it is usually delivered as the sodium sulfonate salt as this formulation is water-soluble, though it does deteriorate rapidly in air.
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Cytochrome P450 2F1 is a protein that in humans is encoded by the CYP2F1 gene. This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum and is known to dehydrogenate 3-methylindole, an endogenous toxin derived from the fermentation of tryptophan, as well as xenobiotic substrates, such as naphthalene and ethoxycoumarin.
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2,6-Dimethylnaphthalene is mainly used for the preparation of 2,6-naphthalenedicarboxylic acid by oxidation of 2,6-dimethylnaphthalene in the liquid phase. 2,6-Naphthalenedicarboxylic acid is a monomer for the production of high-performance polymers, in particular poly (ethylene-2,6-naphthalene dicarboxylate) or shorter polyethylene naphthalate (PEN), a polyester which is stronger and has a higher thermal resistance than the frequently used polyethylene terephthalate (PET). However, 2,6-DMN is a more expensive intermediate than terephthalic acid that is used for PET.
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The quinones are a class of organic compounds that are formally "derived from aromatic compounds [such as benzene or naphthalene] by conversion of an even number of –CH= groups into –C(=O)– groups with any necessary rearrangement of double bonds", resulting in "a fully conjugated cyclic dione structure". The archetypical member of the class is 1,4-benzoquinone or cyclohexadienedione, often called simply "quinone" (thus the name of the class). Other important examples are 1,2-benzoquinone (ortho-quinone), 1,4-naphthoquinone and 9,10-anthraquinone.
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Older mothballs consisted primarily of naphthalene, but due to naphthalene's flammability, many modern mothball formulations instead use 1,4-dichlorobenzene. The latter formulation may be somewhat less flammable, although both chemicals have the same NFPA 704 rating for flammability. The latter chemical is also variously labeled as para-dichlorobenzene, p-dichlorobenzene, pDCB, or PDB, making it harder to identify unless all these acronyms are known to a potential purchaser. Both of these formulations have the strong, pungent, sickly-sweet odor often associated with mothballs.
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More recently, glycol ethers (known as glymes) have come into use as carriers for the sodium naphthalene complex for PTFE etching. These glymes are ethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether (diglyme), and tetraethylene glycol dimethyl ether (tetraglyme). Glymes pose minimal or no health risks to the user, and the solutions do not require special storage conditions. When using glyme- based etchants, it is recommended that the etching process be performed at moderately elevated temperatures, about 50 °C.
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The main effect of sodium etching is defluorination of the PTFE, stripping the fluorine molecules from the carbon backbone of the polymer. The fluorine-to-carbon atomic ratio (F/C ratio) is reduced from PTFE's theoretical ratio of 2.0 to 0.2 or less, after exposure to sodium naphthalene for 1 minute. The fluorine atoms are replaced with hydroxyl, carbonyl, and other functional groups which can form hydrogen bonds. Topographically, chemical etching of PTFE with sodium results in a highly porous defluorinated layer.
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Rylene diimides are, as said, one of the two main subclasses which are a basis for acceptor-molecules in modern NFA-OSCs. Rylene diimides are industrial dyes and can be divided into, once again, two subclasses: Perylene Diimides (PDIs) and Naphthalene Diimides (NDIs). Rylene diimides consist of a planar rylene framework and numerous constructions can be made by attaching certain subgroups and by using more PDI molecules in one acceptor. The mono- PDI molecule is shown in the figure on the right.
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BioPerformance is a multi-level marketing company that sells fuel additives, often in the form of "gas pills", which are claimed to increase fuel efficiency in automobiles. The company was founded in 2006. Research has concluded that the "gas pills" are not effective with regard to fuel efficiency. It has also been claimed that BioPerformance made other false claims, such as that its pills are non-toxic (they are made primarily of naphthalene, a toxic chemical also found in mothballs).
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The liquid was forced by a small pump into the carburettor. The calorific value of naphthalene is about 8,765 calories/kg (36.6 MJ/kg) compared to normal gasoline, which is approx. 11,400 cal/kg (44.8 MJ/kg). From 1911 the de Mesmay company also used the 'Abeille' engine to power a four-wheel drive light agricultural tractor, the 'Tracteur FT'. With a plough permanently fitted underneath, between the front and rear wheels and weighing about 1,050 kg, it was sold as the 'Houe-tracteur'.
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For diatomic molecules, a systematic study using a minimum basis set and the first calculation with a larger basis set were published by Ransil and Nesbet respectively in 1960. The first polyatomic calculations using Gaussian orbitals were performed in the late 1950s. The first configuration interaction calculations were performed in Cambridge on the EDSAC computer in the 1950s using Gaussian orbitals by Boys and coworkers. By 1971, when a bibliography of ab initio calculations was published, the largest molecules included were naphthalene and azulene.
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The use of genetic engineering to create organisms specifically designed for bioremediation is under preliminary research. Two category of genes can be inserted in the organism: degradative genes which encode proteins required for the degradation of pollutants, and reporter genes that are able to monitor pollution levels. Numerous members of Pseudomonas have also been modified with the lux gene, but for the detection of the polyaromatic hydrocarbon naphthalene. A field test for the release of the modified organism has been successful on a moderately large scale.
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Germabenzene (C5H6Ge) is the parent representative of a group of chemical compounds containing in their molecular structure a benzene ring with a carbon atom replaced by a germanium atom. Germabenzene itself has been studied theoretically, and synthesized with a bulky 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl or Tbt group. Also, stable naphthalene derivatives do exist in the laboratory such as the 2-germanaphthalene-containing substance represented below. The germanium to carbon bond in this compound is shielded from potential reactants by a Tbt group.
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Sulfonamides (such as sulfanilamide, sulfamethoxazole, and mafenide), thiazolesulfone, methylene blue, and naphthalene should also be avoided by people with G6PD deficiency as they antagonize folate synthesis, as should certain analgesics (such as phenazopyridine and acetanilide) and a few non-sulfa antibiotics (nalidixic acid, nitrofurantoin, isoniazid, dapsone, and furazolidone).A comprehensive list of drugs and chemicals that are potentially harmful in G6PD deficiency can be found in . Henna has been known to cause hemolytic crisis in G6PD- deficient infants. Rasburicase is also contraindicated in G6PD deficiency.
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In a condensed phase, the carbocation can also gain an electron from surrounding molecules, thus becoming an electrically neutral radical. For example, in crystalline naphthalene, a molecule with tritium substituted for hydrogen in the 1 (or 2) position will be turned by decay into a cation with a positive charge at that position. That charge will however be quickly neutralized by an electron transported through the lattice, turning the molecule into the 1-naphthyl (or 2-naphthyl) radical; which are stable, trapped in the solid, below .
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Heteroaromatic analogues of the biphenyl compounds also exist, where hindered rotation occurs about a carbon-nitrogen or a nitrogen-nitrogen bond. Others are dimers of naphthalene derivatives such as 1,1'-bi-2-naphthol. In a similar way, aliphatic ring systems like cyclohexanes linked through a single bond may display atropisomerism provided that bulky substituents are present. The use of axially chiral biaryl compounds such as BINAP, QUINAP and BINOL, have been found to be useful in the area of asymmetric catalysis as chiral ligands.
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The isomerization of unsubstituted azulene to naphthalene was the first reported thermal transformation of an aromatic hydrocarbon, and has consequently been the most widely studied rearrangement. However, the following mechanisms are generalized to all thermal isomerizations of aromatic hydrocarbons. Many mechanisms have been suggested for this isomerization, yet none have been unequivocally determined as the only correct mechanism. Five mechanisms were originally considered: a reversible ring-closure mechanism, which is shown above, a norcaradiene- vinylidene mechanism, a diradical mechanism, a methylene walk mechanism, and a spiran mechanism.
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As early as 1909, the dimerization of anthracene into dianthracene was investigated as a means of storing solar energy, as well as the photodimerization of the naphthalene series., p. 235-237 In the 70’s and 80’s a fuel had been made from another reversible chemical, the norbornadiene to quadricyclane transformation cycle, but this failed because the reversal process had a low potential. Ruthenium-based molecules were also attempted, but this was dismissed because ruthenium is both rare and too heavy of a material.
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Pure crystalline naphthalene is a moderate insulator at room temperature, with resistivity of about 1012 Ω m. The resistivity drops more than a thousandfold on melting, to about 4 × 108 Ω m. Both in the liquid and in the solid, the resistivity depends on temperature as ρ = ρ0 exp(E/(k T)), where ρ0 (Ω m) and E (eV) are constant parameters, k is Boltzmann's constant (8.617×10−5 eV/K), and T is absolute temperature (K). The parameter E is 0.73 in the solid.
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US government agencies have set occupational exposure limits to naphthalene exposure. The Occupational Safety and Health Administration has set a permissible exposure limit at 10 ppm (50 mg/m3) over an eight-hour time- weighted average. The National Institute for Occupational Safety and Health has set a recommended exposure limit at 10 ppm (50 mg/m3) over an eight-hour time-weighted average, as well as a short-term exposure limit at 15 ppm (75 mg/m3).CDC - NIOSH Pocket Guide to Chemical Hazards.
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The work with Riverkeeper had led Kennedy to decide on environmental law as a career, and he resolved to identify all the polluters along the creek and sue them. He and Cronin hiked along the lower seven miles (11 km) of the creek, taking notes and photos wherever they could. They dived and swam into ponds to collect samples, exposing themselves to raw sewage and many toxins such as naphthalene in the process. They snuck onto company roofs late at night to find illegal pipes.
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In enzymology, a salicylaldehyde dehydrogenase () is an enzyme that catalyzes the chemical reaction :salicylaldehyde + NAD+ \+ H2O \rightleftharpoons salicylate + NADH + 2 H+ The 3 substrates of this enzyme are salicylaldehyde, NAD+, and H2O, whereas its 3 products are salicylate, NADH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is salicylaldehyde:NAD+ oxidoreductase. This enzyme participates in naphthalene and anthracene degradation.
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Some common polynuclear aromatic compounds that are functionalized with hydrophilic or hydrophobic moieties are used to solubilize carbon nanotubes into organic or aqueous solvents. Some of these amphiphiles are phenyl, naphthalene, phenanthrene, pyrene and porphyrin systems. The greater π-π stacking of aromatic amphiphiles such as pyrene amphiphiles had the best solubility compared to phenyl amphiphiles with the worse π-π stacking, lead to more solubility in water. These aromatic systems can be modified with amino and carboxylic acid groups prior to functionalizing the carbon nanotubes.
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The latter compound can be synthesized from α,α′-dibromodimethyl ether (bis(bromomethyl)ether or BBME) which is accessible from hydrobromic acid, paraformaldehyde, and triphenylphosphine. The reaction is performed in dry methanol with sodium methoxide, and the product is obtained in 55% yield. :Synthesis from 3-benzoxepin according to K. Dimroth The compound can also be obtained through UV-irratiation of certain naphthalene derivatives such as 1,4-epoxy-1,4-dihydronaphthalene. :3-Benzoxepin from UV-irradiation from epoxydihydronaphthaline It can also be obtained by photooxidation of 1,4-dihydronaphthalene, followed by pyrolysis of the formed hydroperoxides.
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The study with Q8 demonstrated that the bacterium could degrade nearly all naphthalene and pyrene with 1–2 weeks, indicating that Q8 can grow in the presence of and rapidly degrade PAHs. Q8 can also significantly reduce the viscosity of oil, making it more soluble in water and easier to utilize by other bacteria in a process known as petroleum bioremediation. Other Gordonia have been used to remove boat lubricants from water using a similar mechanism. The process of PAH degradation by Q8 results in products including benzene, hydroxyl and methyl groups, and oxidized oil.
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His investigations on Perkin's reaction led him to an explanation of its mechanism which appeared to be more in accordance with the facts. The question, however, is one of much difficulty, and the exact course of the reaction appears to await solution. These researches incidentally solved the constitution of coumarin, the odoriferous principle of woodruff. Fittig and Erdmann's observation that γ-phenyl structural analog of isocrotonic acid readily yielded α-naphthol by loss of water was of much importance, since it afforded valuable evidence as to the constitution of naphthalene.
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Aromatic compounds, such as benzene, are considered to be environmental pollutants despite their natural prevalence in nature. Strain P16 of P. stutzeri is a polycyclic aromatic hydrocarbon (PAH) degrading bacterium that was isolated from creosote-contaminated soil via a phenanthrene enrichment culture. As the sole carbon and energy source, strain P16 is able to grow using phenanthrene, fluorene, naphthalene, and methylnaphthalenes. In conjunction with the anionic surfactant Tergitol NP10 and phenanthrene, strain P16 has been proposed to be a model for looking at the effects of surfactants on non-aqueous hydrocarbon bioavailability.
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This bacterium has been isolated from oil-contaminated soil and marine water/sediment samples. While most Pseudomonas strains that have been isolated from marine environments are eventually transferred to another genus after classification, P. stutzeri is one of the few strains that has not. This strain meets the requirements of being able to tolerate NaCl and it is found in water columns in the Pacific Ocean and sediments in the Mediterranean. These marine strains have many ecological roles including naphthalene degradation, sulfur oxidation, and most importantly denitrification and diazotrophy (nitrogen fixation).
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Hugo Wilhelm Traugott Erdmann (8 May 1862 – 25 June 1910) was the German chemist who discovered, together with his doctoral advisor Jacob Volhard, the Volhard-Erdmann cyclization. In 1898 he was the first who coined the term noble gas (the original noun is in German). Erdmann invented the name Thiozone in 1908, hypothesizing that S3 made up a large proportion of liquid sulfur. In collaboration with Rudolph Fittig, Erdmann found that dehydration of γ-phenyl structural analog of isocrotonic acid produced α-naphthol, an observation that provided evidence in understanding the nature of naphthalene.
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Antonio Berlese described this method of dynamic sampling in 1905 with a hot water jacket as heat source. In 1918 Albert Tullgren described a modification, where the heating came from above by an electric bulb and the heat gradient was increased by an iron sheet drum around the soil sample. Today's extraction funnels of this type usually combine elements from both publications and thus should be referred to as Berlese-Tullgren funnel. A variation of the Berlese funnel uses naphthalene flakes or similar aromatic mothballs in place of the heat source to drive organisms downward.
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The safety data sheet for a 2003 Texan unleaded gasoline shows at least 15 hazardous chemicals occurring in various amounts, including benzene (up to 5% by volume), toluene (up to 35% by volume), naphthalene (up to 1% by volume), trimethylbenzene (up to 7% by volume), methyl tert-butyl ether (MTBE) (up to 18% by volume, in some states) and about ten others.Material safety data sheet Tesoro petroleum Companies, Inc., U.S., 8 February 2003 Hydrocarbons in gasoline generally exhibit low acute toxicities, with LD50 of 700–2700 mg/kg for simple aromatic compounds.Karl Griesbaum et al.
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1,4-Dichlorobenzene (1,4-DCB, p-DCB, or para-dichlorobenzene, sometimes abbreviated as PDB or para) is an organic compound with the formula C6H4Cl2. This colorless solid has a strong odor. The molecule consists of a benzene ring with two chlorine atoms (replacing hydrogen atoms) on opposing sites of the ring. It is used as a disinfectant, pesticide, and deodorant, most familiarly in mothballs in which it is a replacement for the more traditional naphthalene because of naphthalene's greater flammability (though both chemicals have the same NFPA 704 rating).
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He was the first to suggest, in 1862, that double and triple bonds could form between carbon atoms, and he made other important contributions to the development of theories of molecular structure. In 1863 he became associate professor at the University of Heidelberg. In 1868 he was hired as full professor in Munich to take charge of the laboratories of the new Munich Polytechnic School, a post which he held until his retirement from teaching in 1883. His work mostly focused on theoretical chemistry, where he suggested the formula for naphthalene.
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Hunt A, Cities of Science Subsequently, the GLCC decided that it would carry out the processing of by-products itself, rather than sell them to independent chemical companies. A purpose-built chemical works, Beckton Products Works, was constructed in 1879. It was the largest tar and ammonia by-products works in the UK, possibly in the world. Besides millions of gallons of road tar, products included phenol, the cresols and xylenols, naphthalene, pyridine bases, creosote, benzene, toluene, xylene, solvent naphtha, ammonium sulphate and ammonia solution, sulphuric acid, picolines, quinoline, quinaldine, acenaphthene, anthracene and dicyclopentadiene.
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The reason for this large difference is that when one proton is removed from the cis isomer (maleic acid) a strong intramolecular hydrogen bond is formed with the nearby remaining carboxyl group. This favors the formation of the maleate H+, and it opposes the removal of the second proton from that species. In the trans isomer, the two carboxyl groups are always far apart, so hydrogen bonding is not observed. Section 6-2: Structural Effects on Acidity and Basicity Proton sponge, 1,8-bis(dimethylamino)naphthalene, has a pKa value of 12.1.
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As of May 2007, the company still does not take credit cards and is still selling a naphthalene-based product. The headquarters is no longer in Texas, and the company no longer ships to Texas, where the owners were sued and ultimately gave over $7,000,000 to the Office of the Attorney General. Nor did they issue refunds or ship over 10,000 cases of product, although complaints arrived from all over the nation. To date, over $6.5 million in refund requests have been processed by the Texas Attorney General's Office.
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Para- dichlorobenzene and naphthalene blocks do not readily dissolve in water or urine, but easily sublime into the air, creating a sickly-sweet odor and anti- mould and disinfectant effects. Many urinal blocks are now para- dichlorobenzene-free, water-soluble alternative blocks made from surfactants, which offer some active cleaning efficacy. The new water-soluble blocks improve the cleaning of the pipes to remove some of the cause of odor problems. Some recent formulations also include bacterial spores which, coupled with the surfactant cleaning power, can more completely eradicate odors and blockages caused by the buildup of solids in the traps and pipes.
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Prodan is a fluorescent dye (a naphthalene derivative) used as a membrane probe with environment-sensitive coloration, as well as a non-covalently bonding probe for proteins. Prodan was proposed as a membrane dye by Weber and Farris in 1979. Since then, multiple deivatives have been introduced, such as lypophilic Laurdan (derivative of lauric acid) and thiol-reactive Badan (bromoacetic acid derivative) and Acrylodan. Being a push-pull dye, Prodan has a large excited-state dipole moment and consequently high sensibility to the polarity of its environment (solvent or cell membrane, including the physical state of surrounding phospholipids).
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Abeilles were available with different bodies ranging from 2-seater runabouts to Landaulettes, limousines and Double-Phaetons. 'Abeille' marine engines were available in 1, 2 and various 4-cylinder configurations. The 4-cylinder T-5 of about 30 hp was chosen by the French Navy to power armed patrol boats ('vedettes-canonniers') for export to a foreign navy. At the Paris General Agricultural Exhibition in 1910, the firm exhibited a motor powered by naphthalene. Granules of naphthlene were heated to a liquid state (around 79 °C) by a pipe through which the hot exhaust gas was drawn.
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The Benkeser reduction reaction is the hydrogenation of polycyclic aromatic hydrocarbons, especially naphthalenes using lithium or calcium metal using low molecular weight alkyl amines as the solvent and, in part, as a source of protons. This reaction is a modification of the Birch reduction, where ammonia is the solvent. It offers the advantage that the reactions can be conducted at temperatures higher than the boiling point of ammonia (−33 °C).Institute of Chemistry, Skopje, Macedonia For the reduction naphthalene with lithium in a mixed ethylamine-dimethylamine solution, the principal products are bicyclo[3.3.0]dec-(1,9)-ene, bicyclo[3.3.
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The specific pollutants discharged by organic chemical manufacturers vary widely from plant to plant, depending on the types of products manufactured, such as bulk organic chemicals, resins, pesticides, plastics, or synthetic fibers. Some of the organic compounds that may be discharged are benzene, chloroform, naphthalene, phenols, toluene and vinyl chloride. Biochemical oxygen demand (BOD), which is a gross measurement of a range of organic pollutants, may be used to gauge the effectiveness of a biological wastewater treatment system, and is used as a regulatory parameter in some discharge permits. Metal pollutant discharges may include chromium, copper, lead, nickel and zinc.
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This genetic and catabolic diversity is not only due to the large bacterial chromosome, but also to the presence of three large linear plasmids. Rhodococcus is also an experimentally advantageous system owing to a relatively fast growth rate and simple developmental cycle, but is not well characterized. Another important application of Rhodococcus comes from bioconversion, using biological systems to convert cheap starting material into more valuable compounds, such as its ability to metabolize harmful environmental pollutants, including toluene, naphthalene, herbicides, and PCBs. Rhodococcus species typically metabolize aromatic substrates by first oxygenating the aromatic ring to form a diol (two alcohol groups).
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Q8 was chosen for study as a bioremediator due to its ability to grow on media which includes the polycyclic aromatic hydrocarbons (PAHs) naphthalene and pyrene. PAHs are the products of incomplete combustion of fossil fuels and are considered toxic and carcinogenic, in particular to aquatic organisms. Sixteen PAHs are listed as priority pollutants by the U.S. Environmental Protection Agency because of their association with cancer in aquatic animals and increased mutagenicity of sediments. PAH-degrading microorganisms are commonly found in polluted areas such as oil wells, where they utilize PAHs as their sole carbon and energy source.
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Modification of these residues in turn can allow tryptophan to adopt different spatial orientations that would offer alternative regioselectivities. Naturally occurring tryptophan 7-halogenase isolated from Lechevalieria aerocolonigenes was shown to be able to halogenate naphthalene derivatives, albeit only at activated positions, revealing that certain strains of tryptophan 7-halogenase are fairly wide in substrate scope. Free enzyme is precipitated then treated with a cross-linking agent to synthesize CLEAs Following design of a suitable enzyme, a cross-linked enzyme aggregate is used for larger-scale reaction. The enzyme by itself faces stability issues, but immobilization through CLEA circumvents this problem.
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JWH-250 or (1-pentyl-3-(2-methoxyphenylacetyl)indole) is an analgesic chemical from the phenylacetylindole family that acts as a cannabinoid agonist at both the CB1 and CB2 receptors, with a Ki of 11 nM at CB1 and 33 nM at CB2. Unlike many of the older JWH series compounds, this compound does not have a naphthalene ring, instead occupying this position with a 2'-methoxy- phenylacetyl group, making JWH-250 a representative member of a new class of cannabinoid ligands. Other 2'-substituted analogues such as the methyl, chloro and bromo compounds are also active and somewhat more potent.The Cannabinoid Receptors.
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In the aftermath of Hurricane Isaac, it was discovered that Stolthaven LLC's terminal in Braithwaite, Louisiana (near New Orleans) terminal leaked thousands of gallons of hazardous material. In addition there were several railroad tankers that were full of hazardous material and left at the plant for the duration of the hurricane. Many of the rail cars were overturned and potentially leaked hazardous material. On 11 September 2012 Stolthaven reported to the Louisiana Department of Environmental Quality that it had potentially leaked 97.3 gallons of benzene, 177,568 gallons of diethylethanolamine, 97.3 gallons of naphthalene, and large amounts of various other hazardous chemicals.
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JWH-015 has been shown in vitro to be metabolized primarily by hydroxylation and N-dealkylation, and also by epoxidation of the naphthalene ring, similar to the metabolic pathways seen for other aminoalkylindole cannabinoids such as WIN 55,212-2. Epoxidation of polycyclic aromatic hydrocarbons (see for example benzo(a)pyrene toxicity) can produce carcinogenic metabolites, although there is no evidence to show that JWH-015 or other aminoalkylindole cannabinoids are actually carcinogenic in vivo. A study published in the British Journal of Cancer shows that JWH-015 may signal certain cancers to shrink through a process called apoptosis.
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M-SG reductions: benzyl chloride reduction to bibenzyl, dibenzothiophene reduction to biphenyl and naphthalene reduction to dihydronaphthalene In M-SG an alkali metal is absorbed into silica gel at elevated temperatures. The resulting black powder material is an effective reducing agent and safe to handle as opposed to the pure metal. The material can also be used as a desiccant and as a hydrogen source.Alkali Metals Plus Silica Gel: Powerful Reducing Agents and Convenient Hydrogen Sources James L. Dye, Kevin D. Cram, Stephanie A. Urbin, Mikhail Y. Redko, James E. Jackson, and Michael Lefenfeld J. Am. Chem. Soc.
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This led to the suggestion that alizarin was a derivative of naphthalene, a C10 hydrocarbon, although Schunck pointed out that this did not explain the reactions of alizarin. He was vindicated when Graebe and Liebermann (1868) distilled alizarin with zinc dust to give anthracene, a C14 hydrocarbon, and subsequently (1869) synthesised alizarin from anthraquinone. Schunck showed that alizarin was not the major colour precursor component of fresh madder root, but it was a yellow, bitter, water-soluble component, which he called rubian. Rubian was obtained from the water extract of madder root by adding bone–charcoal and extracting the bone–charcoal with ethanol.
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The difference between the two ring contractions is minute however, so it has not been determined which is favored over the other. Both mechanisms are shown as follows for the ring contraction of biphenylene: upright=2 The first involves a 1,2-hydrogen shift to a carbene followed by a 1,2-carbon shift on the same C-C bond but in opposite directions. The second differs from the first only by the order of the 1,2-shifts, with the 1,2-carbon shift preceding the 1,2-hydrogen shift. The four described mechanisms would all result in the isomerization from azulene to naphthalene.
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It was determined that spent hydrocarbons buried at the landfill disposal site included not only chlorobenzene, hexachlorobutadiene, hexachloroethane, hexachloronorbornadiene, naphthalene, tetrachloroethylene, toluene, hexachlorocyclopentadiene, and benzene, but also the known carcinogens carbon tetrachloride and chloroform. The drums and cartons containing these chemicals were deposited in trenches that were deep and 12 to wide and covered with approximately of soil. Velsicol took no precautions to insure the drums from bursting and, invariably, some of the drums would leak their contents into the soil. Furthermore, the trenches were neither lined nor covered with any impermeable material to prevent the chemical waste from leaking into the soil.
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In enzymology, a cis-3,4-dihydrophenanthrene-3,4-diol dehydrogenase () is an enzyme that catalyzes the chemical reaction :(+)-cis-3,4-dihydrophenanthrene-3,4-diol + NAD+ \rightleftharpoons phenanthrene-3,4-diol + NADH + H+ Thus, the two substrates of this enzyme are (+)-cis-3,4-dihydrophenanthrene-3,4-diol and NAD+, whereas its 3 products are phenanthrene-3,4-diol, NADH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (+)-cis-3,4-dihydrophenanthrene-3,4-diol:NAD+ 3,4-oxidoreductase. This enzyme participates in naphthalene and anthracene degradation.
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The 25-NB compounds are mostly N-benzylphenethylamines, though in some cases the phenyl ring of the N-benzyl group is replaced by other heterocycles such as thiophene, pyridine, furan, tetrahydrofuran, benzodioxole or naphthalene, among others. Generally speaking, they have methoxy groups at the 2 and 5 positions of the phenyl ring, a substitution such as a halogen or alkyl group at the 4 position of the phenyl ring, and a methoxy or other substitution (e.g., hydroxyl, fluoro) at the 2 position of the N-benzyl ring. More rarely, other substitution patterns may be present (see e.g.
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His main field of research was physicochemical fundamentals of chemical technology. He was researching contact oxidation of ammonia, naphthalene and anthracene, mechanism of ammonia oxidation on platinum at low temperatures, reduction of iron dioxide by a methane, methods of obtaining aluminium oxide from Polish kaolinite and aluminosilicate, use of Polish anhydrite and gypsum deposit to production sulfuric acid and cementum, kinematics of thermal dissociation. Under the German occupation of Poland during World War II, he was involved in the clandestine operation of the Warsaw University of Technology. Together with Marceli Struszyński, Zawadzki analyzed captured German V-2 rocket for its fuel composition.
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In some cases, the non- planarity may be forced by the topology of the molecule and the stiffness (in length and angle) of the carbon-carbon bonds. For example, unlike the coronene, corannulene adopts a bowl shape in order to reduce the bond stress. The two possible configurations, concave and convex, are separated by a relatively lowenergy barrier (about 11 kcal/mol)Marina V. Zhigalko, Oleg V. Shishkin, Leonid Gorb, and Jerzy Leszczynski (2004): "Out-of-plane deformability of aromatic systems in naphthalene, anthracene and phenanthrene". Journal of Molecular Structure, volume 693, issues 1–3, pages 153-159.
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Pyrene and its derivatives are used commercially to make dyes and dye precursors, for example pyranine and naphthalene-1,4,5,8-tetracarboxylic acid. It has strong absorbance in UV-Vis in three sharp bands at 330 nm in DCM. The emission is close to the absorption, but moving at 375 nm. The morphology of the signals change with the solvent. Its derivatives are also valuable molecular probes via fluorescence spectroscopy, having a high quantum yield and lifetime (0.65 and 410 nanoseconds, respectively, in ethanol at 293 K). Pyrene was the first molecule for which excimer behavior was discovered.
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Two different ways are usual: chemical doping by mixing with free radicals and creation of F-centers by irradiation in an intensive electron beam. Commonly used target materials are butanol, ammonia , lithium hydrides and their deuterated counterparts. A very interesting material is hydrogen deuteride, because it has the maximal content of polarizable nucleons. High proton polarizations have been reached in a large naphthalene single crystal using optically excited triplet states of fully deuterated pentacene guest molecules at temperatures around 100 K and magnetic field of 0.3 T. Hyperpolarized carbon-13 has been studied for medical imaging applications .
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Each of the torches contained a solid fuel tablet made of hexamine and 6% naphthalene (following torch running tests in May 1947) that fuelled the flame itself. The solid fuel increased the distance each runner could run to over flat terrain, decreasing the number of torches needed to be produced, which in turn reduced the cost of the relay. There were eight tablets loaded into each torch, with the bottom tablets pushed up by the use of a spring. The design increased the burning time of each torch up to around fifteen minutes, an increase from the four-minute torches of the 1936 Olympics.
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When the probe is in an apolar solvent the shift emission is blue, and a red-shifted emission is observed in polar solvents. Due to its structure and its fluorescence characteristics, Laurdan is very useful in studies about lipid bilayer dynamics, more particularly about cell's plasmatic membrane's dynamics. The hydrophobic tail of the fatty acid allows the solubilization of the dye in the lipid bilayer, while the naphthalene moiety of the molecule stays at the level of the glycerol backbones of the membrane’s phospholipids. This means that the fluorescent part of the molecule is located towards the aqueous environment, which makes the reorientation of the solvent dipoles by Laurdan’s emission possible.
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BjF consists of two naphthalene-like structures which are fused by a cyclopentane structure. This cyclopentane is not included in the aromaticity of the molecule. BjF can be obtained when either 2-(1-chloroethenyl)benzo[c]phenanthrene or 6-(1-chloroethenyl)chrysene is treated by flash vacuum thermolysis (FVT) at high temperatures (above 900 °C) followed by ring rearrangements (ring contraction/expansion) to selectively yield BjF.M. Sarobe et al. (1 January 1997) "High temperature gas phase syntheses of C20H12 cyclopenta-fused polycyclic aromatic hydrocarbons: benz[l]acephenanthrylene and benz[j]acephenanthrylene and their selective rearrangement to benzo[j]fluoranthene" Journal of the Chemical Society, Perkin Trans.
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In 1982 tubewells in the vicinity of the UCIL factory had to be abandoned and tests in 1989 performed by UCC's laboratory revealed that soil and water samples collected from near the factory and inside the plant were toxic to fish. Several other studies had also shown polluted soil and groundwater in the area. Reported polluting compounds include 1-naphthol, naphthalene, Sevin, tarry residue, mercury, toxic organochlorines, volatile organochlorine compounds, chromium, copper, nickel, lead, hexachloroethane, hexachlorobutadiene, and the pesticide HCH. In order to provide safe drinking water to the population around the UCIL factory, Government of Madhya Pradesh presented a scheme for improvement of water supply.
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They exhibited electrostatic, hydrophobic, and hydrogen-bonding interactions with key amino acids within the binding pocket with binding interaction profiles similar to AR-A014418 (the known inhibitor). The negative charges of the carboxylic acid groups in both drugs interact electrostatically with the positively charged guanidine group of Arg141. Moreover, the hydrogen bonding interactions between carboxylic acid moieties of cromolyn and the ammonium groups of Lys183 and Lys60, in addition to π-stacking of the naphthalene ring system of naproxen with the phenolic ring of Tyr134. Antidiabetic effects of naproxen and cromolyn: In normal animal models, both drugs have showed dose-dependent reduction in blood glucose levels and rise in glycogen levels.
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The stability of halocarbons tended to encourage beliefs that they were mostly harmless, although in the mid-1920s physicians reported workers in polychlorinated naphthalene manufacturing suffering from chloracne , and by the late 1930s it was known that workers exposed to PCNs could die from liver disease and that DDT would kill mosquitos and other insects . By the 1950s, there had been several reports and investigations of workplace hazards. In 1956, for example, after testing hydraulic oils containing PCBs, the U.S. Navy found that skin contact caused fatal liver disease in animals and rejected them as "too toxic for use in a submarine" . Atmospheric concentration of several halocarbons, years 1978-2015.
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Phthalate esters are the dialkyl or alkyl aryl esters of phthalic acid (also called 1,2-benzenedicarboxylic acid, not be confused with the structurally isomeric terephthalic or isophthalic acids ); the name "phthalate" derives from phthalic acid, which itself is derived from the word "naphthalene". When added to plastics, phthalates allow the long polyvinyl molecules to slide against one another. The phthalates have a clear syrupy liquid consistency and show low water solubility, high oil solubility, and low volatility. The polar carboxyl group contributes little to the physical properties of the phthalates, except when R and R' are very small (such as ethyl or methyl groups).
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The extent of the aromaticity of the compound was examined by a study of its proton NMR spectrum and comparison with naphthalene, which allowed the conclusion that it and related oxygen and selenium heterocycles did behave as 10-electron systems in which the 2-heteroatom contributed its lone pair to the ring current, in accordance with Hückel's rule. As a result, 2,1,3-benzothiadiazole undergoes the standard chemistry of aromatic compounds, for example readily forming nitro and chloro derivatives. The chemistry of this heterocycle and its simple derivatives has been reviewed. Under reducing conditions, 2,1,3-benzothiadiazoles can be converted back to the 1,2-diaminobenzene compounds from which they were prepared.
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S. METHANE 'HOT SPOT' BIGGER THAN EXPECTED NASA, 9 Oct. 2014. Other concerns are related to emissions from the hydraulic fracturing chemicals and equipment such as volatile organic compound (VOC) and ozone. In 2008, ozone concentrations in ambient air near drilling sites in Sublette County, Wyoming were frequently above the National Ambient Air Quality Standards (NAAQS) of 75 ppb and have been recorded as high as 125 ppb. In DISH, Texas, elevated levels of disulfides, benzene, xylenes and naphthalene have been detected in the air, emitted from compressor stations. In Garfield County, Colorado, an area with a high concentration of drilling rigs, VOC emissions increased 30% between 2004 and 2006.
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His most convincing work was done on the camphoraceous odor, for which he posited a hemispherical socket in which spherical molecules, such as camphor, cyclooctane, and naphthalene could bind. When Linda Buck and Richard Axel published their Nobel Prize winning research on the olfactory receptors in 1991, they identified in mice 1,000 G-protein-coupled receptors used for olfaction. Since all types of G-protein receptors currently known are activated through binding (docking) of molecules with highly specific conformations (shapes) and non-covalent interactions, it is assumed that olfactory receptors operate in a similar fashion. Further research on human olfaction systems identified 347 olfactory receptors.
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1\. Li, H.; Kim, F. S.; Ren, G.; Jenekhe, S. A. “High Mobility n-Type Conjugated Polymers for Organic Electronics,” J. Am. Chem. Soc. 2013, 135, 14920-14923. DOI:10.1021/ja407471b. 2\. Earmme, T.; Hwang, Y. J.; Murari, N. M.; Subramaniyan, S.; Jenekhe, S. A. “All-Polymer Solar Cells with 3.3% Efficiency Based on Naphthalene Diimide- Selenophene Copolymer Acceptor,” J. Am. Chem. Soc. 2013, 135, 14960-14963. DOI: 10.1021/ja4085429. 3\. Richards, J. J.; Rice, A. H.; Nelson, R. M.; Kim, F. S.; Jenekhe, S. A.; Luscombe, C. K.; Pozzo, D. C. “Modification of PCBM crystallization via incorporation of C60 in polymer/fullerene solar cells,” Adv. Funct. Mater.
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Induline is a derivative of the eurhodines (aminophenazines, aminonaphthophenazines). By means of their diazo derivatives can be de-amidated, yielding in this way azonium salts; consequently they may be considered as amidated azonium salts. The first reaction giving a clue to their constitution was the isolation of the intermediate azophenin by O. Witt, which was proved by Fischer and Hepp to be dianilidoquinone dianil, a similar intermediate compound being found shortly afterwards in the naphthalene series. Azophenin, C30H24N4, is prepared by warming quinone dianil with aniline, by melting together quinone, aniline and aniline hydrochloride, or by the action of aniline on para-nitrosophenol or para-nitrosodiphenylamine.
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The Model C unsuccessfully attempted to address this problem by reducing the amount of explosives and increasing the thickness of the concrete. The Model D reduced the amount of explosive once again and increased the thickness of the concrete but the explosive charge was now too small. The Model E increased the amount of explosives back up to the amount used by the Model C, the internal metal container was eliminated, and the concrete was now cast around a rebar framework. The early models were filled with TNT but later models were filled with naphthalene a lower grade explosive that may have been used to promote fragmentation.
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In 2008 rural residents 5 miles east-northeast of complained of discolored water, foul smells and illness that they suspected was due to fracking, and the EPA opened an investigation.Abrahm Lustgarten, "Feds Warn Residents Near Wyoming Gas Drilling Sites Not to Drink Their Water" ProPublica (September 1, 2010). Retrieved May 19, 2011Nicholas Kusnetz, "Wyoming Fracking Rules Would Disclose Drilling Chemicals" ProPublica (September 14, 2010). Retrieved May 19, 2011 In 2010, the EPA investigators warned the affected rural residents not to drink their water after finding benzene, naphthalene, phenols, and metals in the water and recommended that the affected rural residents use fans while bathing or washing clothes to avoid the risk of explosion.
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A black drongo in a typical "anting" posture The use of millipedes in self-anointing by birds has been reported for the strong-billed woodcreeper (Xiphocolaptes promeropirhyncus) in Belize, the little shrike-thrush (Colluricincla megarhyncha parvula) in Australia, the black-throated shrikebill (Clytorhynchus nigrogularis) and the jungle mynah (Acridotheres fuscus) in the Fiji Islands, the European robin (Erithacus rubecula) in England and the grey- winged trumpeter (Psophia crepitans) and the pale-winged trumpeter (P. leucoptera) in northern South America. In one study, mothballs (which contain naphthalene) were placed in a flowerbed. A common grackle picked one out, extended its left wing and rubbed the mothball up and down the length of the shaft of each of the secondary feathers.
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As an example, it was still taught as a useful analytic procedure in Cohen's Practical Organic Chemistry of 1910, in which the molar mass of naphthalene is determined using a Beckmann freezing apparatus. Freezing-point depression can also be used as a purity analysis tool when analyzed by differential scanning calorimetry. The results obtained are in mol%, but the method has its place, where other methods of analysis fail. This is also the same principle acting in the melting-point depression observed when the melting point of an impure solid mixture is measured with a melting-point apparatus since melting and freezing points both refer to the liquid-solid phase transition (albeit in different directions).
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Produced water spills and subsequent contamination of groundwater also presents a risk for exposure to carcinogens. Research that modeled the solute transport of BTEX (benzene, toluene, ethylbenzene, and xylene) and naphthalene for a range of spill sizes on contrasting soils overlying groundwater at different depths found that benzene and toluene were expected to reach human health relevant concentration in groundwater because of their high concentrations in produced water, relatively low solid/liquid partition coefficient and low EPA drinking water limits for these contaminants. Benzene is a known carcinogen which affects the central nervous system in the short term and can affect the bone marrow, blood production, immune system, and urogenital systems with long term exposure.
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As of 2004, this process had yet to be rendered asymmetric, but the products could be separated through chiral HPLC. Cyclisation carried out with a diyne and a separate alkyne affords greater control. Using commercially available cyclopentadienylcobalt dicarbonyl, CpCo(CO)2, as catalyst, bis(trimethylsilyl)acetylene (BTMSA) will react with a diyne-1,2-disubstituted benzene to form an anthroquinone aromatic system: :500px Benzyne, generated in situ from a benzene ring bearing ortho- distributed triflate and trimethylsilyl substituents, can be used to generate an aryne in place of an acetylene and combined with a suitable diyne. Such a benzene derivative reacts with 1,7-octadiyne in the presence of a suitable catalyst to generate a naphthalene system.
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These highly soluble versions of Lawesson's reagent are created by the reaction of PS with aryl ethers which are different from anisole. For instance butoxybenzene and 2-tert-butylanisole have both been reacted to form more soluble thionation reagents of the 1,3,2,4-dithiadiphosphetane 2,4-disulfide class. The general structure of a 1,3,2,4-dithiadiphosphetane 2,4-disulfide and the reversible generation of the dithiophosphine ylides An important subclass of these compounds are the naphthalen-1,8-diyl 1,3,2,4-dithiadiphosphetane 2,4-disulfides; these are intellectually interesting because the two dithiophosphine ylides are fixed together in space by the rigid naphthalene unit. The reactivity of these compounds is very different from that of 1,3,2,4-dithiadiphosphetane 2,4-disulfides.
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While strychnine has been suggested as the poison that killed Johnson, at least one scholar has disputed the notion. Tom Graves, in his book Crossroads: The Life and Afterlife of Blues Legend Robert Johnson, relies on expert testimony from toxicologists to argue that strychnine has such a distinctive odor and taste that it cannot be disguised, even in strong liquor. Graves also claims that a significant amount of strychnine would have to be consumed in one sitting to be fatal, and that death from the poison would occur within hours, not days. In their 2019 book Up Jumped the Devil, Bruce Conforth and Gayle Dean Wardlow suggest that the poison was naphthalene, from dissolved mothballs.
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Chem-Dyne is a hazardous waste dump site located on the east side of Hamilton. In 1982, the Justice Department disclosed that the hazardous chemicals at the dump included arsenic, benzene, cyanides, vinyl chloride, naphthalene, chloroform, polychlorinated biphenyls, trichloroethylene and the pesticides aldrin and dieldrin. The Justice Department filed a lawsuit against Chem-Dyne and asked the court to issue an injunction requiring the defendants to help with cleanup as well as to reimburse the government for clearing and safeguarding the site, which the department said had already cost $826,000. The defendants were alleged to have violated the Resource Conservation and Recovery Act and the Superfund Act established to help pay for cleaning up hazardous waste sites.
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In a reverse tracking shot, Fellini reveals the stupendous behind-the-scenes of his floating opera of a movie - giant hydraulic jacks (constructed by Oscar- winning set designer, Dante Ferretti) that created the ship's rolling sea movements, along with acres of plastic ocean, an army of technicians burning naphthalene for the smoke of disaster effect, and, finally, an enigmatic figure that may be Orlando or Fellini intentionally hiding behind his own camera filming the main camera filming himself. The main camera then tracks forward to a final shot of Orlando in a lifeboat with the rhinoceros happily munching on hay. "Did you know," confides Orlando, "that a rhinoceros gives very good milk?" Laughing, he once again mans the oars to disappear on a vast plastic ocean.
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The most common bases used in plastic scintillators are the aromatic plastics, polymers with aromatic rings as pendant groups along the polymer backbone, amongst which polyvinyltoluene (PVT) and polystyrene (PS) are the most prominent. While the base does fluoresce in the presence of ionizing radiation, its low yield and negligible transparency to its own emission make the use of fluors necessary in the construction of a practical scintillator. Aside from the aromatic plastics, the most common base is polymethylmethacrylate (PMMA), which carries two advantages over many other bases: high ultraviolet and visible light transparency and mechanical properties and higher durability with respect to brittleness. The lack of fluorescence associated with PMMA is often compensated through the addition of an aromatic co-solvent, usually naphthalene.
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Prof. Young's research focuses on anaerobic microorganisms that degrade harmful organic contaminant chemicals like pesticides and benzene, toluene and xylene (BTX-compounds) from gasoline and other petroleum compounds such as naphthalene, phenanthrene and hexadecane. The microorganisms in the environment are essentially carrying out oxidation and reduction reactions, namely, oxidation of the organic contaminant coupled to the reduction of inorganic electron acceptors. The mechanism by which these bacteria (mainly denitrifiers, iron reducers, sulfidogens and methanogens, respectively) degrade the contaminants is different from aerobic bacteria because they cannot use oxygen to activate the stable hydrocarbon molecules. In contrast to humans, these bacteria are not dependent on oxygen as an electron acceptor for cellular respiration, but use molecules like nitrate, iron, sulfate and carbonate.
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For example, a very polar (hydrophilic) solute such as urea is very soluble in highly polar water, less soluble in fairly polar methanol, and practically insoluble in non-polar solvents such as benzene. In contrast, a non-polar or lipophilic solute such as naphthalene is insoluble in water, fairly soluble in methanol, and highly soluble in non-polar benzene. Dissolution of sodium chloride in water. In even more simple terms a simple ionic compound (with positive and negative ions) such as sodium chloride (common salt) is easily soluble in a highly polar solvent (with some separation of positive (δ+) and negative (δ-) charges in the covalent molecule) such as water, as thus the sea is salty as it accumulates dissolved salts since early geological ages.
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Ed. 2013, 52, 5513-5517. 10\. Hwang, Y. J.; Murari, N. M.; Jenekhe, S. A. “New n-Type Polymer Semiconductors Based on Naphthalene Diimide and Selenophene Derivatives for Organic Field-Effect Transistors,” Polym. Chem. 2013, 4, 3187-3195. 11\. Earmme, T.; Jenekhe, S. A. “Improved electron injection and transport by use of baking soda as a low-cost, air-stable, n-dopant for solution-processed phosphorescent organic light-emitting diodes,” Appl. Phys. Lett. 2013, 102, 233305/1-4. 12\. Shoaee, S.; Subramaniyan, S.; Xin, H.; Keiderling, C.; Tuladhar, P. S.; Jamieson, F.; Jenekhe, S. A.; Durrant, J. R. “Charge photogeneration for a series of thiazolo-thiazole donor polymers blended with the fullerene electron acceptors PCBM and ICBA,” Adv. Funct. Mater. 2013, 23, 3286-3298.
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Shimomura was one of the earliest workers on ammonium sulphate to produce it on a large scale and put it on the market as a fertilizer in the days when its superiority to sodium nitrate in Japanese soils was not very well recognized. He was not an expert in tar distillation and was among the first to produce naphthalene in powder, balls and cakes at a time when its smell was objected to as something unbearable. He was the first to put up a plant to extract benzene from coke-oven gas, when it was thought that it would not sell. This fear was subsequently contradicted by increased demand for benzene as solvent, motor oil and also an important raw material for dyestuffs.
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Kedareswar Banerjee (15 September 1900 – 30 April 1975) was an X-ray crystallographer and director of the Indian Association for the Cultivation of Science, Kolkata. “K Banerjee was Reader, University of Dacca; Mahendra Lal Sircar Professor (1943-52), Indian Association for the Cultivation of Science (IACS), Kolkata; Professor & Head, Department of Physics, University of Allahabad (1952-59); and Director, IACS (1959)”. Professor Banerjee Director at Indian Association of Cultivation of Science"K Banerjee Birth Centenary Celebration Committee, Indian Association for the Cultivation of Science (IACS)". Prof. K Banerjee was a pioneer in X-Ray Crystallography Research in India Early in his career he determined the structures of naphthalene and anthracene. In 1931, he worked with Sir William Henry Bragg and developed one of the first direct methods of crystal structure determination.
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A strong driving force for the [4+2] cycloaddition of such species is a result of the establishment (or reestablishment) of aromaticity. Common methods for generating o-quinodimethanes include pyrolysis of benzocyclobutenes or the corresponding sulfone, 1,4-elimination of ortho benzylic silanes or stannanes, and reduction of α,α'-ortho benzylic dibromides. in situ generation of o-quinodomethanes On the contrary, stable dienes are rather unreactive and undergo Diels–Alder reactions only at elevated temperatures: for example, naphthalene can function as a diene, leading to adducts only with highly reactive dienophiles, such as N-phenyl- maleimide. Anthracene, being less aromatic (and therefore more reactive for Diels–Alder syntheses) in its central ring can form a 9,10 adduct with maleic anhydride at 80 °C and even with acetylene, a weak dienophile, at 250 °C.
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Bellows-driven instruments – such as the accordion, concertina, melodeon and (Irish) Uilleann bagpipes – reportedly need less frequent cleaning and maintenance as a result of the Irish smoke-free law. "Third-hand smoke", solid particulates from secondhand smoke that are adsorbed onto surfaces and later re-emitted as gases or transferred through touch, are a particular problem for musicians. After playing in smoky bars, instruments can emit nicotine, 3-ethenylpyridine (3-EP), phenol, cresols, naphthalene, formaldehyde, and tobacco-specific nitrosamines (including some not found in freshly emitted tobacco smoke), which can enter musicians' bodies through the skin, or be re-emitted as gases after they have left the smoky environment. Concern about third-hand smoke on instruments is one of the reasons many musicians, represented by the New Orleans Musicians' Clinic, supported the smoking ban there.
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These transformations effectively turn the Yalkowsky log-linear model into a predictive model, where a researcher can predict with fair accuracy the cosolvent concentration for solubilization of a compound using only aqueous solubility data. For a more in-depth discussion of cosolvent modeling systems, the reader is directed to reviews by Jouyban (2008), Smith and Mazo (2008), and for biochemical context, Canchi and Garcia (2013). A simpler view at choosing cosolvents involves looking at measureable properties of varying cosolvent systems and making a determination from empirical evidence. Researchers from the University of Arizona and the University of Wisconsin-Madison review a selection of parameters in an Environmental Toxicology and Chemistry paper,Li, A., Andren, A.W., Yalkowsky, S.H. Choosing a cosolvent: solubilization of naphthalene and cosolvent property. Environ. Toxicol. Chem. 1996, 15, 2233-2239.
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In enzymology, a cis-1,2-dihydrobenzene-1,2-diol dehydrogenase () is an enzyme that catalyzes the chemical reaction :cis-1,2-dihydrobenzene-1,2-diol + NAD+ \rightleftharpoons catechol + NADH + H+ Thus, the two substrates of this enzyme are cis-1,2-dihydrobenzene-1,2-diol and NAD+, whereas its 3 products are catechol, NADH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is cis-1,2-dihydrobenzene-1,2-diol:NAD+ oxidoreductase. Other names in common use include cis-benzene glycol dehydrogenase, cis-1,2-dihydrocyclohexa-3,5-diene (nicotinamide adenine, and dinucleotide) oxidoreductase. This enzyme participates in 4 metabolic pathways: gamma-hexachlorocyclohexane degradation, toluene and xylene degradation, naphthalene and anthracene degradation, and styrene degradation.
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Relative to untreated PTFE, the sodium etching process has been well-documented to increase PTFE bond strengths significantly regardless of the test method (tensile, peel, lap shear) used to evaluate samples bonded with epoxy. Virtually all sodium etching bond strengths reported in academic journals predate the advent of glymes as carriers for sodium naphthalene complex. In adhesion tests per ASTM D4541, in which an aluminum stud is bonded to the test surface and the stud is pulled in the direction normal to the surface, both surfaces of the failure interface were analyzed by X-ray photoelectron spectroscopy (XPS). F/C ratio was used as an indicator of the failure mode: F/C of zero corresponds to failure in the epoxy, while an F/C ratio near 2.0 indicates failure in the bulk PTFE.
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In 1830 he became an assistant to Eilhard Mitscherlich at Berlin, subsequently receiving his doctorate with a thesis on pollen, Dissertatio de plantarum polline (1833). In 1844 he became an associate professor in St. Petersburg, where in 1852 he attained a full professorship.ADB: Fritzsche, Karl Julius at Allgemeine Deutsche BiographieGoogle Books Berichte der Deutschen Chemischen Gesellschaft, Volume 5 In his studies of anthracene, he discovered that "paranthracene" was an isomeric modification of anthracene when anthracene was exposed to sunlight. Also, he was able to obtain the crystalline compounds of picric acid with hydrocarbons (benzene, naphthalene, etc.)A Dictionary of Chemistry and the Allied Branches of Other Sciences, Volume 4 by Henry Watts In addition, he studied the nature of murexide and recognized it as the ammonium salt of purpuric acid.
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The organic contaminant guidelines also appeared to be very accurate for all classes of polycyclic aromatic hydrocarbons (PAHs) and most of the individual PAHs. The incidence of effects was 25% or below when the concentrations were below the respective ERL value, with only (fluorene as an exception, while the incidence of effects was 75% or greater at concentrations above the respective ERM, excepting dibenzo(a,h)anthracene, p,p’-DDE, total dichlorodiphenyltrichloroethane (DDT), and total Polychlorinated biphenyls (PCBs). Importantly, one hundred percent effects were seen in concentrations above the ERM for acenaphthylene, 2-methyl naphthalene, and low-molecular weight PAHs, and ninety percent or greater effects in this range were seen for chromium, lead, silver, benz(a)anthracene, and fluoranthene. Contaminants that were reported as having low accuracies included nickel, mercury, chromium, total PCBs, p,p’-DDE, and total DDT.
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In addition to such obvious dangers as insecticides and weed killers, other common household substances that should be used with caution in areas where cats may be exposed include mothballs and other naphthalene products, as well as phenol-based products often used for cleaning and disinfecting near cats' feeding areas or litter boxes, such as Pine-Sol, Dettol (Lysol), hexachlorophene, etc. which, although they are widely used without problem, have been sometimes seen to be fatal. Essential oils are toxic to cats and there have been reported cases of serious illnesses caused by tea tree oil and tea tree oil-based flea treatments and shampoos.TEA TREE OIL - TOXIC TO CATSBe Wary of Aromatherapy Claims for Cats Many human foods are somewhat toxic to cats; theobromine in chocolate can cause theobromine poisoning, for instance, although few cats will eat chocolate.
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One hundred Wabamun Lake residents took part in a five-hour blockade of the CN tracks in protest against what they felt was insufficient action by the railway in cleaning up the spill. The province of Alberta then issued an environmental protection order to ensure that the cleanup proceed. It was not until four days after the derailment that CN revealed that a "hazardous chemical" had spilled into the lake in addition to the bunker C fuel oil. Residents were told to stop cleaning wildlife and to completely avoid all lake water and well water, even for watering gardens and lawns. The 88,000 litres (19,000 Imp gal/23,000 US gal) of pole treating oil that had escaped from a ruptured, derailed tank car contained naphthalene and other polycyclic aromatic hydrocarbons listed as "highly toxic" and suspected of being carcinogens.
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The molecule is chiral and the separate enantiomers have been isolated. Certain barrelenes have been used as a monomer in a ring opening metathesis polymerization :Synthesis of Poly(1,4-naphthylenevinylenes): Metathesis Polymerization of Benzobarrelenes Lin Pu, Michael W. Wagaman, and Robert H. Grubbs Macromolecules; 1996; 29(4) pp 1138 - 1143; (Article) Synthesis of Organic and Water Soluble Poly(1,4-phenylenevinylenes) Containing Carboxyl Groups: Living Ring-Opening Metathesis Polymerization (ROMP) of 2,3-Dicarboxybarrelenes Michael W. Wagaman, and Robert H. Grubbs Macromolecules; 1997; 30(14) pp 3978–3985; (Article) :Benzobarrelene polymerization The catalyst is a Fischer carbene (a molybdenum bis-(hexafluoro-tert-butoxy) carbene catalyst) and the long alkyl chain attached to the monomer is required for solubility. Oxidation of the polymer with DDQ affords the naphthalene pendant of poly(p-phenylene vinylene). Isopentane solutions of barrelene undergo photolytic isomerisation when acetone is added as a photosensitizer to produce semibullvalene.
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X-ray crystallography has led to a better understanding of chemical bonds and non-covalent interactions. The initial studies revealed the typical radii of atoms, and confirmed many theoretical models of chemical bonding, such as the tetrahedral bonding of carbon in the diamond structure, the octahedral bonding of metals observed in ammonium hexachloroplatinate (IV), and the resonance observed in the planar carbonate group and in aromatic molecules. Kathleen Lonsdale's 1928 structure of hexamethylbenzene established the hexagonal symmetry of benzene and showed a clear difference in bond length between the aliphatic C–C bonds and aromatic C–C bonds; this finding led to the idea of resonance between chemical bonds, which had profound consequences for the development of chemistry. Her conclusions were anticipated by William Henry Bragg, who published models of naphthalene and anthracene in 1921 based on other molecules, an early form of molecular replacement.
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Similarly, spectra of weakly trapped molecular excitons are also strongly influenced by adjacent exciton bands. It is an important property of typical molecular crystals with two or more symmetrically-equivalent molecules in the elementary cell, such as benzine and naphthalene, that their exciton absorption spectra consist of doublets (or multiplets) of bands strongly polarized along the crystal axes as was demonstrated by Antonina Prikhot'ko. This splitting of strongly polarized absorption bands that originated from the same molecular level and is known as the 'Davydov splitting' is the primary manifestation of molecular excitons. If the low-frequency component of the exciton multiplet is situated at the bottom of the exciton energy spectrum, then the absorption band of an impurity exciton approaching the bottom from below is enhanced in this component of the spectrum and reduced in two other components; in the spectroscopy of molecular excitons this phenomenon is sometimes referred to as the 'Rashba effect'.
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In this case, the terminal carbon is a reactant that produces a primary addition product instead of a secondary addition product, in the case of propene. A new method of anti-Markovnikov addition has been described by Hamilton and Nicewicz, who utilize aromatic molecules and light energy from a low-energy diode to turn the alkene into a cation radical. Anti-Markovnikov behaviour extends to more chemical reactions than additions to alkenes. Anti- Markovnikov behaviour is observed in the hydration of phenylacetylene by auric catalysis, which gives acetophenone; although with a special ruthenium catalystcatalyst system based on in-situ reaction of ruthenocene with Cp and naphthalene ligands and a second bulky pyridine ligand it provides the other regioisomer 2-phenylacetaldehyde: Anti-Markovnikov hydration Anti-Markovnikov behavior can also manifest itself in certain rearrangement reactions. In a titanium(IV) chloride-catalyzed formal nucleophilic substitution at enantiopure 1 in the scheme below, two products are formed – 2a and 2b.
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After a string of breakdowns in the 2010s, including renewal of the lease of the Gabala Radar Station to Russia, and the consequent constructions of the a new station in Russia's own Krasnodar Region, the decision by Russia to stop transit of Azeri oil via the Baku-Novorossiysk pipeline, the holding of the Azerbaijani tanker "Naphthalene" in Dagestan on suspicion of hauling contraband and the Federal Lezgian National and Cultural Autonomy movement's announcement that Lezgians were be in August 2013. The discussions involved the issue of regulation of Nagorno-Karabakh, the Caspian Sea legal regime and cooperation in energy. Additionally, an agreement on cooperation and terms for oil supply was signed by the State Oil Company of Azerbaijan Republic (SOCAR) and Rosneft; while there was also an agreement on the construction of a new automobile bridge across the Samur River, on the joint border. The visit took on added importance as it was read as leveraging Armenia–Azerbaijan relations in a warning in light of Armenia considering signing an Association Agreement with the European Union.
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Electron transfer mechanism of Rieske dioxygenases A catalytically-competent Rieske dioxygenase has three components: an NADH-dependent FAD reductase, a ferredoxin with two [2Fe-2S] Rieske clusters, and an α3β3 oxygenase with each α-subunit containing a mononuclear iron center and a [2Fe-2S] Rieske cluster. Within each α-subunit, the iron-sulfur cluster and mononuclear iron center are separated by a distance of some ~43 Å, much too far for efficient electron transfer to occur. Instead, it is proposed electron transfer is mediated through these two centers in adjacent subunits, that the iron-sulfur cluster of one subunit transfers electrons to the mononuclear iron center of the adjacent subunit which is conveniently separated by ~12 Å. While this distance would appear optimal for efficient electron transfer, replacement of the bridging aspartate residue causes a loss of enzyme function, suggesting that electron transfer instead proceeds through the hydrogen-bonding network held in place by this aspartate residue. Active site of Rieske dioxygenase (naphthalene 1,2-dioxygenase from Rhodococcus sp.) (PDB 2B1X) The mechanistic picture for this class of dioxygenases is not yet clear, but there is evidence supporting an iron(III) hydroperoxy intermediate in the reaction pathway.
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To create such methods, the scientist synthesized the total mellitic acid anhydride, which was found to form orange-red crystals with naphthalene, dark blue with anthracene, brown-red with phenanthrene, and light brown with veratrole. The scientist isolated the crystals of all these compounds and found that, in all cases, the molecular relation of their components was 1 : 1. Then, Mustafin presented a summary table of colors of solutions of mellitic acid trianhydride in 62 organic solvents and proposed original procedures for determining mellitic acid and some other organic compounds. During these years the young organic chemist fell in love with analytical chemistry. Then the Second World War started and Mustafin joined the army, taking with him his laboratory journal and the first volume of Mendeleyev’s “Principles of Chemistry.” After returning from the army to the university, Mustafin started his work at the division of analytical chemistry headed by the famous analyst Leonid Markovich Kul’berg. In those years the “advanced” topic in analytical chemistry was the application of organic reagents to analysis. Being on the border of organic, inorganic, and physical chemistry, this field grew with the most interesting results, stimulating the further development of spectroscopic, potentiometric, luminescent, and other methods of analysis.
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