Phenylene group

Not to be confused with phenalene.

In organic chemistry, the phenylene group (−C₆H₄−) is based on a di-substituted benzene ring (arylene). For example, poly(p-phenylene) is a polymer built up from para-phenylene repeating units.^[1] The phenylene group has three structural isomers, based on which hydrogens are substituted: para-phenylene, meta-phenylene, and ortho-phenylene.

Isomer naming convention

The chemical structure of the para-phenylene group.