isooktaanin

Isooctane, also known as 2,2,4-trimethylpentane, is a branched-chain alkane with the chemical formula C8H18. It is a colorless liquid at room temperature and is highly flammable. Isooctane is a significant component of gasoline, serving as a reference standard for octane rating. Its stability and resistance to knocking in internal combustion engines make it highly desirable as a fuel additive.

The octane rating system is based on the anti-knock quality of gasoline. Isooctane is assigned a value of 100, while n-heptane, a straight-chain alkane, is assigned a value of 0. The octane rating of a fuel mixture is determined by comparing its knocking characteristics to those of isooctane and n-heptane. Higher octane ratings indicate a greater resistance to knocking.

Beyond its role in gasoline, isooctane is used as a solvent in various applications, including in laboratories for chromatography and as a component in some cleaning agents. It is also employed as a reference fuel in engine performance testing. Its relatively low toxicity compared to some other organic solvents contributes to its widespread use. Isooctane is produced through the alkylation of isobutane with butenes.