Diisobutene (also known as Diisobutylene and Isooctene) refers to a pair of organic compounds with the overall formula C8H16.
The isomers have the same carbon skeleton but differ in the location of the C=C bond.
These compounds arise via the acid catalyzed dimerization of isobutene, a reaction that proceeds via the carbocation (CH3)3C+.
[1] Hydrogenation is performed at a significant scale to give isooctane, which is an important fuel additive.
Diisobutene is used as precursors to isononylol and octylphenols by hydroformylation/hydrogenation and phenol alkylation, respectively.