#double bond

• Alkene — A generic name given to unsaturated acyclic hydrocarbons with linear or branched chains, containing a single covalent carbon-carbon double bond (C=C) and having the general molecular formula CnH2n. Alkenes (historically termed olefins) exhibit a much higher chemical reactivity than alkanes, being capable of participating in addition, polymerization, and oxidation reactions (e.g., ethene, propene, alkene isomers).
• 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.