The C₂benzenes are a class of organic aromatic compounds which contain a benzene ring and two other carbon atoms. For the hydrocarbons with no further unsaturation, there are four isomers. There are three xylenes and one ethylbenzene. The substances are:

Xylenes

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

Other

• Ethylbenzene (not a true xylene but present in mixtures called "mixed xylenes")
• Styrene
• Phenylacetylene

• 
  1,2-Dimethylbenzene
• 
  1,3-Dimethylbenzene
• 
  1,4-Dimethylbenzene
• 
  Ethylbenzene
• 
  Styrene
• 
  Phenylacetylene