Benzene

Other names: phenyl hydride

C₆H₆

3/50 common

Benzene is the simplest aromatic hydrocarbon. Often depicted in organic chemistry in its theoretical resonance isomer as a 1,3,5-cyclohexatriene, the π bonds in benzene in reality form a single continuous ring in which all carbon-carbon bonds are equivalent. This representation of benzene is occasionally known as the Kekulé structure, after the German organic chemist who proposed it after being inspired by a daydream of a snake eating its own tail (an ouroboros). Prior to Kekulé's epiphany, many competing structures were proposed for benzene, several of which have since been synthesized as highly unstable isomers of benzene (including prismane and Dewar benzene). The conjugated ring is itself a capable donor orbital for the formation of organometallic "sandwich complexes" such as bis(benzene)chromium.