The C₂benzenes are a class of organic

aromatic compound Aromatic compounds, also known as "mono- and polycyclic aromatic hydrocarbons", are organic compounds containing one or more aromatic rings. The parent member of aromatic compounds is benzene. The word "aromatic" originates from the past grouping ...

s which contain a

benzene ring 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, ...

and two other carbon atoms. For the

hydrocarbons In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ex ...

with no further unsaturation, there are four isomers. There are three

xylene In organic chemistry, xylene or xylol (; IUPAC name: dimethylbenzene) are any of three organic compounds with the formula . They are derived from the substitution of two hydrogen atoms with methyl groups in a benzene ring; which hydrogens are sub ...

s and one

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 ...

. The substances are:

Xylenes In organic chemistry, xylene or xylol (; IUPAC name: dimethylbenzene) are any of three organic compounds with the formula . They are derived from the substitution of two hydrogen atoms with methyl groups in a benzene ring; which hydrogens are sub ...

* ''o''-xylene (1,2-dimethylbenzene), * ''m''-xylene (1,3-dimethylbenzene) * ''p''-xylene (1,4-dimethylbenzene)

Other

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 ...

(not a true xylene but present in mixtures called "mixed xylenes") *

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 ...

Phenylacetylene Phenylacetylene is an alkyne hydrocarbon containing a phenyl group. It exists as a colorless, viscous liquid. In research, it is sometimes used as an analog for acetylene; being a liquid, it is easier to handle than acetylene gas. Preparation In ...

File:Ortho-Xylol - ortho-xylene 2.svg, 1,2-Dimethylbenzene File:Meta-Xylol - meta-xylene 2.svg, 1,3-Dimethylbenzene File:Para-Xylol - para-xylene 2.svg, 1,4-Dimethylbenzene File:Ethylbenzol.svg, Ethylbenzene File:Styrene.svg, Styrene File:Phenylacetylene.svg, Phenylacetylene {{Hydrocarbons Alkylbenzenes Benzene derivatives