Aromatic Hydrocarbons


Also found in: Dictionary, Thesaurus, Medical.
Related to Aromatic Hydrocarbons: benzene

Aromatic Hydrocarbons

 

organic compounds of carbon and hydrogen, containing a benzene ring.

The simplest and most important representative of aromatic hydrocarbons is benzene (I) and such homologues as methylbenzene, or toluene (II), and dimethylbenzene, or xylene. Aromatic hydrocarbons also include derivatives of benzene with unsaturated side chains—for example, styrene (III). There are also many aromatic hydrocarbons having several benzene rings per molecule—for example, diphenylmethane (IV) and diphenyl C6H5—C6H5, in which both benzene rings are directly connected to one another; in naphthalene (V) both rings share two carbon atoms. These hydrocarbons are called aromatics with condensed rings.

The basic source of aromatics are products of coking coal. On the average, one ton of coal resin yields 3.5 kg of benzene, 1.5 kg of toluene, and 2 kg of naphthalene. Of great importance is the production of aromatics from liquid petroleum hydrocarbons. For certain aromatics purely synthetic methods are practical. Thus ethylbenzene, produced from benzene and ethylene, is condensed to yield styrene:

The chemical properties of aromatic hydrocarbons differ sharply from those of the unsaturated alicyclics. They are relegated to a separate large class of chemical compounds. When aromatic compounds are treated with sulfuric acid, nitric acid, halogen, and other reagents, hydrogen atoms are replaced, and aromatic sulfo acids, nitrogen compounds, and halogen benzenes are formed. These compounds serve as intermediary products in the manufacture of dyes and pharmaceuticals. Styrene easily forms the useful and important polymer polystyrene. During the oxidation of naphthalene, phthalic acid o-C6H4(COOH)2 is formed; it serves as a raw material in the production of many dyes, alkyd resins, and phenolphthalein.

REFERENCE

Iukel’son, I. I. Tekhnologiia osnovnogo organicheskogo sinteza. Moscow, 1968.

IA. F. KOMISSAROV

References in periodicals archive ?
Though we haven't yet observed polycyclic aromatic hydrocarbons directly, we understand their chemistry quite well.
MT-TNO research into the biodegradation of soils and sediments contaminated with oils and polycyclic aromatic hydrocarbons (PAHs).
For Neanderthals, inhaling smoke and eating charcoal-broiled meat, they would be exposed to multiple sources of polycyclic aromatic hydrocarbons," co-author Gary Perdew from the Pennsylvania State University said in the statement.
Up till now, around 30 compounds and many other derivatives of polycyclic aromatic hydrocarbons have been discovered having carcinogenic and mutagenic properties which make them largest class of carcinogens ever known (Bjorseth and Ramdahl, 1985).
The concentration levels, spatial distributions of resolved aliphatics, total aromatic hydrocarbons in addition to unresolved complex mixture in surface sediment samples from Jeddah coast were detected.
Hidrocarburos Aromaticos Policiclicos (HAPs) (polycyclic aromatic hydrocarbons, PAHs).
In present study the hydrocarbon degrading bacterial strains were isolated from petrol contaminated soil of Karachi and the isolated bacterial strains were identified and checked for their biodegradation capabilities for aromatic hydrocarbons (xylene, phenanthrene, naphthalene, biphenyl and anthracene) which are deleterious for both biotic and abiotic flora by means of enumeration using spread plate method.
100% of the main process equipment was delivered to the aromatic hydrocarbons production complex at Atyrau refinery in 2013.
Fetal window of vulnerability to airborne polycyclic aromatic hydrocarbons on proportional intrauterine growth restriction.
Polycyclic aromatic hydrocarbons are a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances and can cause cancer.
Polycyclic aromatic hydrocarbons are known carcinogens and have been linked to developmental problems.