#azo group

• Azo — Containing the azo functional group, which consists of two nitrogen atoms linked by a double bond (-N=N-), each attached to an organic hydrocarbon radical; utilized as an adjective or combining form to designate a broad class of synthetic dyes and aromatic compounds of major industrial importance.
• Azo derivative — A synthetic organic compound derived from a hydrocarbon by replacing hydrogen atoms with the azo functional group (-N=N-), directly bonded to two aromatic or aliphatic organic radicals; these compounds are intensely colored and form the basis for manufacturing most industrial dyes.