Nonene is an alkene

Alkene

In organic chemistry, an alkene, olefin, or olefine is an unsaturated chemical compound containing at least one carbon-to-carbon double bond...

 with the molecular formula C₉H₁₈. Many structural isomers are possible, depending on the location of the C=C double bond and the branching of the other parts of the molecule. Industrially, the most important nonenes are trimer

Trimer (chemistry)

In chemistry, a trimer is a product derived from three identical precursors. Trimers are typically cyclic. Chemical compounds that often trimerise are aliphatic isocyanates and cyanic acids. Often, trimerization competes with polymerization....

s of propene. This mixture of branched nonenes is used in the alkylation

Alkylation

Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion or a carbene . Alkylating agents are widely used in chemistry because the alkyl group is probably the most common group encountered in...

 of phenol

Phenol

Phenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...

 to produce nonylphenol

Nonylphenol

Nonylphenol is a family of closely related organic compounds, a subset of the alkylphenols. This collection of compounds is a precursor to commercially important detergents...

, a precursor to detergents, which are also controversial pollutants.