Diethylbenzene (DEB) refers to any of three
isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers.
Iso ...
s with the formula C
6H
4(C
2H
5)
2. Each consists of a
benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...
ring and two
ethyl
Ethyl may refer to:
Arts and entertainment
* Cold Ethyl, a Swedish rock band
*Ethyl Sinclair, a character in the ''Dinosaurs'' television show
Science and technology
* Ethyl group, an organic chemistry moiety
* Ethyl alcohol (or ethanol)
* E ...
substituents. The meta and para have the greater commercial significance. All are colorless liquids.
Nomenclature
*
''Ortho'': known as 1,2-diethylbenzene and ''o''-diethylbenzene.
*
''Meta'': known as 1,3-diethylbenzene and ''m''-diethylbenzene.
*
''Para'': known as 1,4-diethylbenzene and ''p''-diethylbenzene.
Production and applications
Diethylbenzenes arise as side-products of the alkylation of benzene with ethylene, which can described as two steps. The first step is the industrial route to
ethylbenzene
Ethylbenzene is an organic compound with the formula . It is a highly flammable, colorless liquid with an odor similar to that of gasoline. This monocyclic aromatic hydrocarbon is important in the petrochemical industry as an reaction intermediat ...
, which is produced on a large scale as a precursor to
styrene
Styrene () is an organic compound with the chemical formula C6H5CH=CH2. This derivative of benzene is a colorless oily liquid, although aged samples can appear yellowish. The compound evaporates easily and has a sweet smell, although high concen ...
.
:C
6H
6 + C
2H
4 → C
6H
5C
2H
5
The diethylbenzene is an inadvertent side product.
:C
6H
5C
2H
5 + C
2H
4 → C
6H
4(C
2H
5)
2
Using shape-selective
zeolite
Zeolites are microporous, crystalline aluminosilicate materials commonly used as commercial adsorbents and catalysts. They mainly consist of silicon, aluminium, oxygen, and have the general formula ･y where is either a metal ion or H+. These pos ...
catalysts, the para isomer can be produced in high selectivity.
Much diethylbenzene is recycled by
transalkylation
In organic chemistry, transalkylation is a chemical reaction involving the transfer of an alkyl group from one organic compound to another. The reaction is used for the transfer of methyl and ethyl groups between benzene rings. This is of particul ...
to give ethylbenzene:
[
: C6H4(C2H5)2 + C6H6 → 2 C6H5C2H5
]
Uses
Diethylbenzene is used in a mixture with methyl and/or ethyl biphenyls as a low temperature heat transfer fluid.
Diethylbenzene is dehydrogenated to give divinylbenzene
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 ...
(DVB):
: C6H4(C2H5)2 → C6H4(C2H3)2 + 2 H2
DVB is used in the production of crosslinked polystyrene.
References
{{reflist
Alkylbenzenes