benzenyl

Benzenyl is the aryl substituent derived from benzene by removing a hydrogen atom, giving the formula C6H5–. In radical form, it is the benzenyl radical, C6H5•. Systematically, the substituent can be named benzen-1-yl; benzenyl is a traditional or alternative label that appears in various chemical texts. In common practice, the term phenyl is frequently used to refer to the same aryl group when it is attached to another atom, though terminology can vary by author.

The benzenyl group originates from benzene and preserves an aromatic ring. When it serves as a substituent, the point of attachment is at carbon 1 of the ring, and the bond to the rest of the molecule is a sigma bond from an sp2-hybridized carbon. The ring’s pi system remains largely delocalized, contributing to the stability and characteristic reactivity of aryl compounds derived from benzenyl.

In chemistry, benzenyl is encountered as a fundamental aryl unit in both organic and organometallic contexts. It appears in a wide range of benzene-derived substituents and serves as a building block in reactions such as aryl coupling and electrophilic aromatic substitution frameworks. The benzenyl radical C6H5• is a reactive intermediate studied in radical chemistry, polymerization, and photochemical processes.

See also: phenyl, aryl group, benzene.