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Disodium 4,4'-dinitrostilbene-2,2'-disulfonate
Disodium 4,4′-dinitrostilbene-2,2′-disulfonate is an organic compound with the formula (O2NC6H3(SO3Na)CH)2. This salt is a common precursor to a variety of textile dyes and optical brighteners Preparation and reactions The synthesis of disodium 4,4′-dinitrostilbene-2,2′-disulfonate begins with sulfonation of 4-nitrotoluene. This reaction affords 4-nitrotoluene-2-sulfonic acid. Oxidation of this species with sodium hypochlorite yields the disodium salt of 4,4′-dinitrostilbene-2,2′-disulfonic acid. The product is useful as its reaction with aniline derivatives results in the formation of azo dyes. Commercially important dyes derived from this compound include Direct Red 76, Direct Brown 78, and Direct Orange 40. Reduction gives 4,4′-diamino-2,2′-stilbenedisulfonic acid, which is a common optical brightener. History Arthur Green and André Wahl first reported the formation of disodium 4,4'-dinitrostilbene-2,2'-disulfonate using sodium hypochlorite.{{cite journa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Living t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Brightener
Optical brighteners, optical brightening agents (OBAs), fluorescent brightening agents (FBAs), or fluorescent whitening agents (FWAs), are chemical compounds that absorb light in the ultraviolet and violet region (usually 340-370 nm) of the electromagnetic spectrum, and re-emit light in the blue region (typically 420-470 nm) through the phenomenon of fluorescence. These additives are often used to enhance the appearance of color of fabric and paper, causing a "whitening" effect; they make intrinsically yellow/orange materials look less so, by compensating the deficit in blue and purple light reflected by the material, with the blue and purple optical emission of the fluorophore. Properties The most common classes of compounds with this property are the stilbenes, e.g., 4,4′-diamino-2,2′-stilbenedisulfonic acid. Older, non-commercial fluorescent compounds include umbelliferone, which absorbs in the UV portion of the spectrum and re-emit it in the blue portion of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfonation
Aromatic sulfonation is an organic reaction in which a hydrogen atom on an arene is replaced by a sulfonic acid functional group in an electrophilic aromatic substitution. Aryl sulfonic acids are used as detergents, dye, and drugs. Stoichiometry and mechanism Typical conditions involve heating the aromatic compound with sulfuric acid: :C6H6 + H2SO4 → C6H5SO3H + H2O Sulfur trioxide or its protonated derivative is the actual electrophile in this electrophilic aromatic substitution. To drive the equilibrium, dehydrating agents such as thionyl chloride can be added. :C6H6 + H2SO4 + SOCl2 → C6H5SO3H + SO2 + 2 HCl Chlorosulfuric acid is also an effective agent: :C6H6 + HSO3Cl → C6H5SO3H + HCl In contrast to aromatic nitration and most other electrophilic aromatic substitutions this reaction is reversible. Sulfonation takes place in concentrated acidic conditions and desulfonation is the mode of action in a dilute hot aqueous acid. The reaction is very useful in protecting the a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-Nitrotoluene
4-Nitrotoluene or ''para''-nitrotoluene is an organic compound with the formula CH3C6H4NO2. It is a pale yellow solid. It is one of three isomers of nitrotoluene. Synthesis and reactions Together with other isomers, 4-nitrotoluene is prepared by nitration of toluene, commonly using titanium(IV) nitrate. It undergoes the reactions typical for nitrobenzene derivatives, e.g. hydrogenation gives ''p''-toluidine. Oxidation of the methyl substituent of 4-nitrotoluene has been extensively investigated. Depending on the conditions, oxidation yields 4-nitrobenzaldehyde diacetate, 4-nitrobenzenoic acid, and 4,4'-dinitrobibenzyl. Treatment of 4-nitrotoluene with bromine gives the 4-nitrobenzyl bromide. Applications The principal application involves its sulfonation to give the 4-nitrotoluene-2-sulfonic acid (with the –SO3H group adjacent to methyl). This species can be oxidatively coupled to produce stilbene derivatives, which are used as dyes. Representative derivatives include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Hypochlorite
Sodium hypochlorite (commonly known in a dilute solution as bleach) is an Inorganic chemistry, inorganic chemical compound with the chemical formula, formula NaOCl (or NaClO), comprising a sodium cation () and a hypochlorite anion (or ). It may also be viewed as the sodium salt (chemistry), salt of hypochlorous acid. The anhydrous Chemical compound, compound is unstable and may decompose explosively. It can be crystallized as a hydrate, pentahydrate ·5, a pale greenish-yellow solid which is not explosive and is stable if kept refrigerated. Sodium hypochlorite is most often encountered as a pale greenish-yellow dilute solution referred to as liquid bleach, which is a household chemical widely used (since the 18th century) as a disinfectant or a bleaching agent. In solution, the compound is unstable and easily decomposes, liberating chlorine, which is the active principle of such products. Sodium hypochlorite is the oldest and still most important chlorine-releasing compounds, chl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt (chemistry)
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions. The component ions in a salt compound can be either inorganic, such as chloride (Cl−), or organic, such as acetate (). Each ion can be either monatomic, such as fluoride (F−), or polyatomic, such as sulfate (). Types of salt Salts can be classified in a variety of ways. Salts that produce hydroxide ions when dissolved in water are called ''alkali salts'' and salts that produce hydrogen ions when dissolved in water are called ''acid salts''. ''Neutral salts'' are those salts that are neither acidic nor basic. Zwitterions contain an anionic and a cationic centre in the same molecule, but are not considered salts. Examples of zwitterions are amino acids, many metabolites, peptid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aniline
Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine In organic chemistry, an aromatic amine is an organic compound consisting of an aromatic ring attached to an amine. It is a broad class of compounds that encompasses aniline Aniline is an organic compound with the formula C6 H5 NH2. Consi .... It is an industrially significant Commodity chemicals, commodity chemical, as well as a versatile starting material for fine chemical synthesis. Its main use is in the manufacture of precursors to polyurethane, dyes, and other industrial chemicals. Like most volatile amines, it has the odor of rotten fish. It Combustion, ignites readily, burning with a smoky flame characteristic of aromatic compounds. It is toxic to humans. Relative to benzene, it is electron-rich. It thus participates more rapidly in electrophilic aromatic substitution reactions. Likewise, it is also prone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azo Dye
Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl and substituted aryl groups. They are a commercially important family of azo compounds, i.e. compounds containing the C-N=N-C linkage. Azo dyes are synthetic dyes and do not occur naturally. Most azo dyes contain only one azo group, but some dyes called "disazo dyes" contain two azo groups, some dyes called "trisazo dyes" contain three azo groups and are or more. Azo dyes comprise 60-70% of all dyes used in food and textile industries. Azo dyes are widely used to treat textiles, leather articles, and some foods. Chemically related derivatives of azo dyes include azo pigments, which are insoluble in water and other solvents. Classes Many kinds of azo dyes are known, and several classification systems exist. Some classes include disperse dyes, metal-complex dyes, reactive dyes, and substantive dyes. Also called direct dyes, substantive dyes are employed for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ullmann's Encyclopedia Of Industrial Chemistry
''Ullmann's Encyclopedia of Industrial Chemistry'' is a major reference work related to industrial chemistry by Chemist Fritz Ullmann, first published in 1914, and exclusively in German as "Enzyklopädie der Technischen Chemie" until 1984. History Ullmann's Encyclopedia of Industrial Chemistry is a major reference work related to industrial chemistry by chemist Fritz Ullmann. Its 1st edition was published in German by Fritz Ullmann in 1914. The 4th edition, published 1972 to 1984, already contained 25 volumes. The 5th edition, published 1985 to 1996, was the first version available in English. In 1997, the first online version was published. 2014 marked its centenary. As of 2016, Ullmann's Encyclopedia was in its 7th edition, in 40 volumes including one index volume and more than 1,050 articles (200 more than the 6th edition), approx. 30,000 pages, 22,000 images, 8,000 tables, 19,000 references and 85,000 indices. Editions * 1914–1922: 1st edition in 12 volumes, which can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wiley-VCH
Wiley-VCH is a German publisher owned by John Wiley & Sons. It was founded in 1921 as Verlag Chemie (meaning "Chemistry Press": VCH stands for ''Verlag Chemie'') by two German learned societies. Later, it was merged into the German Chemical Society (GDCh). In 1991, VCH acquired Akademie Verlag :''There also were unrelated publishing houses in Stuttgart and in (East-)Berlin, and there is the (JAVG).'' Akademie Verlag (AV) is a German scientific and academic publishing company, founded in 1946 in the Soviet-occupied eastern part .... It has been owned by John Wiley & Sons since 1996. The humanities section of Akademie Verlag and the Akademie brand were sold in 1997 to R. Oldenbourg Verlag, while VCH retained the natural sciences catalog. References External links * Wiley (publisher) Publishing companies of Germany Publishing companies established in 1921 Weinheim German companies established in 1921 {{publish-company-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4,4′-Diamino-2,2′-stilbenedisulfonic Acid
4,4′-Diamino-2,2′-stilbenedisulfonic acid is the organic compound with the formula (H2NC6H3SO3H)2C2H2. It is a white, water-soluble solid. Structurally, it is a derivative of trans-stilbene, containing amino and sulfonic acid functional groups on each of the two phenyl rings. The compound is a popular optical brightener for use in laundry detergent Laundry detergent is a type of detergent (cleaning agent) used for cleaning dirty laundry (clothes). Laundry detergent is manufactured in powder (washing powder) and liquid form. While powdered and liquid detergents hold roughly equal share o ...s. It is produced by reduction of 4,4′-dinitro-2,2′-stilbenedisulfonic acid with iron powder.P. F. Vogt, J. J. Gerulis, "Amines, Aromatic" in ''Ullmann’s Encyclopedia of Industrial Chemistry'', 2005, Wiley-VCH, Weinheim. References {{DEFAULTSORT:Diamino-2,2'-stilbenedisulfonic acid, 4,4'- Benzenesulfonic acids Cleaning product components Luminescence Stilbenoids [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
