Anthracene is a condensed aromatic hydrocarbon containing three rings. The center of the three rings of anthracene is in a straight line, which is the isomer of phenanthrene. The chemical activity of the 9 and 10 positions in the anthracene molecule is relatively high. It is oxidized with nitric acid to generate 9, 10-anthraquinone, which is an important intermediate for the synthesis of anthraquinone dyes. Anthracene can also act as a conjugated diene in a Diels-Alder reaction with maleic anhydride.
Aromatic hydrocarbons are cyclic, planar compounds that resemble benzene in electronic configuration and chemical behavior. Benzene has the molecular formula C6H6 and is the simplest aromatic hydrocarbon. The carbon atoms in benzene are linked by six equivalent σ bonds and six π bonds.