In chemistry, amines are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Formally, amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines, trimethylamine, and aniline. Inorganic derivatives of ammonia are also called amines, such as monochloramine.
Petrochemicals are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as maize, palm fruit or sugar cane.
Aniline is an organic compound with the formula C6H5NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine. It is an industrially significant 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 ignites readily, burning with a smoky flame characteristic of aromatic compounds. It is toxic to humans.
Mauveine, also known as aniline purple and Perkin's mauve, was one of the first synthetic dyes. It was discovered serendipitously by William Henry Perkin in 1856 while he was attempting to synthesise the phytochemical quinine for the treatment of malaria. It is also among the first chemical dyes to have been mass-produced.
Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology, in cytology, and in the medical fields of histopathology, hematology, and cytopathology that focus on the study and diagnoses of diseases at the microscopic level. Stains may be used to define biological tissues, cell populations, or organelles within individual cells.
In organic chemistry, an aryl halide is an aromatic compound in which one or more hydrogen atoms, directly bonded to an aromatic ring are replaced by a halide. Haloarenes are different from haloalkanes because they exhibit many differences in methods of preparation and properties. The most important members are the aryl chlorides, but the class of compounds is so broad that there are many derivatives and applications.
Azo compounds are organic compounds bearing the functional group diazenyl.
New fuchsine is an organic compound with the formula [(H2N(CH3)C6H3)3C]Cl. It is a green-colored solid that is used as a dye of the triarylmethane class. It is one of the four components of basic fuchsine, and one of the two that are available as single dyes. The other is pararosaniline. It is prepared by condensation of ortho-toluidine with formaldehyde. This process initially gives the benzhydrol 4,4'-bis(dimethylamino)benzhydrol, which is further condensed to give the leuco (colorless) tertiary alcohol [(H2N(CH3)C6H3)3COH, which is oxidized in acid to give the dye.
Nitrosylsulfuric acid is the chemical compound with the formula HSO4NO. It is a colourless solid that is used industrially in the production of caprolactam, and was formerly part of the lead chamber process for producing sulfuric acid. The compound is the mixed anhydride of sulfuric acid and nitrous acid.
Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group [R−N+≡N]X− where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halide. The parent compound where R is hydrogen, is diazenylium.
In organic chemistry, an azo coupling is an reaction between a diazonium compound and another aromatic compound that produces an azo compound. In this electrophilic aromatic substitution reaction, the aryldiazonium cation is the electrophile, and the activated carbon, serves as a nucleophile. Classical coupling agents are phenols and naphthols. Usually the diazonium reagent attacks at the para position of the coupling agent. When the para position is occupied, coupling occurs at a ortho position, albeit at a slower rate.
Phenazine is an organic compound with the formula (C6H4)2N2. It is a dibenzo annulated pyrazine, and the parent substance of many dyestuffs, such as the toluylene red, indulines, and safranines (and the closely related eurhodines). Phenazine crystallizes in yellow needles, which are only sparingly soluble in alcohol. Sulfuric acid dissolves it, forming a deep-red solution.
Induline is a dye of blue, bluish-red or black shades. Induline consists of a mixture of several intensely colored species, so the name is often indulines. It was one of the first synthetic dyes, discovered in 1863 by J. Dale and Heinrich Caro. The main components of induline are various substituted phenazines. Although induline no longer in use, the related dye nigrosin is still produced commercially.
Bismarck brown Y also called C.I. 21000 and C.I. Basic Brown 1, is a diazo dye with the idealized formula [(H2N)2C6H3N2]2C6H4. The dye is a mixture of closely related compounds. It was one of the earliest azo dyes, being described in 1863 by German chemist Carl Alexander von Martius. It is used in histology for staining tissues.
The Herz reaction, named after the chemist Richard Herz, is the chemical conversion of an aniline to the benzodithiazolium salt by its reaction with disulfur dichloride. The salt is called a Herz salt. Hydrolysis of this Herz salt give the corresponding sodium thiolate, which can be further converted to the 2-aminothiophenol.
The formazans are compounds of the general formula [R-N=N-C(R')=N-NH-R"], formally derivatives of formazan [H2NN=CHN=NH], unknown in free form.
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.
1-Naphthylamine is an aromatic amine derived from naphthalene. It can cause bladder cancer. It crystallizes in colorless needles which melt at 50 °C. It possesses a disagreeable odor, sublimes readily, and turns brown on exposure to air. It is the precursor to a variety of dyes.
Electrophilic aromatic substitution (SEAr) is an organic reaction in which an atom that is attached to an aromatic system is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic nitration, aromatic halogenation, aromatic sulfonation, alkylation Friedel–Crafts reaction and acylation Friedel–Crafts reaction.
A colorant is any substance that changes the spectral transmittance or reflectance of a material. Synthetic colorants are those created in a laboratory or industrial setting. The production and improvement of colorants was a driver of the early synthetic chemical industry, in fact many of today's largest chemical producers started as dye-works in the late 19th or early 20th centuries, including Bayer AG(1863). Synthetics are extremely attractive for industrial and aesthetic purposes as they have they often achieve higher intensity and color fastness than comparable natural pigments and dyes used since ancient times. Market viable large scale production of dyes occurred nearly simultaneously in the early major producing countries Britain (1857), France (1858), Germany (1858), and Switzerland (1859), and expansion of associated chemical industries followed. The mid-nineteenth century through WWII saw an incredible expansion of the variety and scale of manufacture of synthetic colorants. Synthetic colorants quickly became ubiquitous in everyday life, from clothing to food. This stems from the invention of industrial research and development laboratories in the 1870s, and the new awareness of empirical chemical formulas as targets for synthesis by academic chemists. The dye industry became one of the first instances where directed scientific research lead to new products, and the first where this occurred regularly.
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