Aromatic hydrocarbon

The aromatic hydrocarbons, also benzenoid hydrocarbons, named according to IUPAC arenes are cyclic, planar hydrocarbons with aromatic system. Due to their delocalized π - electron system they are energetically more favorable than their non- aromatic Mesomeric and therefore chemically stable. Aromatic hydrocarbons can be divided into mono- ( mAh) or polycyclic aromatic hydrocarbons ( PAHs).

Like all pure hydrocarbons are aromatic hydrocarbons nonpolar lipophilic compounds. Since the IUPAC definition aromatic compounds are compared with the aliphatic carbon compounds and therefore defined by a negation, this means, conversely, that all non-aliphatic organic compounds are aromatic. Classification of organic compounds in aliphatic and aromatic compounds is carried out by the aromaticity.

History

The first was the benzene aromatic discovered in 1825 by Michael Faraday found in coal gas ( C6H6). Soon substances have been discovered with similar properties that show a different construction. We quickly realized that this formally unsaturated compounds were not easy to move, despite the double bonds to addition reactions.

Examples

( Alkylbenzenes )

( Polyarylalkanes )

(PAH)

Benzene

Toluene    Xylenes (o -, m-, p- xylene)   ethylbenzene cumene

Diphenylmethane triphenylmethane

Naphthalene anthracene phenanthrene pyrene

Annulenes, that cyclic hydrocarbons having conjugated double bonds may have aromaticity. After benzene - annulene is the smallest aromatic annulene, also are aromatic annulenes with 18 and 22 carbon atoms.

Occurrence and extraction

Aromatic hydrocarbons are found in the petroleum. There arenes are found that have the structural elements of indane, tetrahydronaphthalene, fluorene, biphenyl, and acenaphthene, and arenes with isoprenoid structure. The majority of industrially important compounds are synthesized by petrochemical processes. In the coke plant fall aromatics as by- product and can be found in coal tar and coke oven gas. Important mass products are benzene, toluene, the xylenes and ethylbenzene (BTEX aromatics). You yourself are the raw materials for plastics and other bulk chemicals. PAHs are important naphthalene and anthracene, which are derived from coal tar and petroleum.

Derivatives

Aromatic hydrocarbons can form complexes with organic or non- organic substituent derivatives.