Sulfolane is a member of the class of tetrahydrothiophenes that is tetrahydrothiophene in which the sulfur has been oxidised to give the corresponding sulfone. A colourless, high-boiling (285C) liquid that is miscible with both water and hydrocarbons, it is used as an industrial solvent, particularly for the purification of hydrocarbon mixtures by liquid-vapour extraction. It has a role as a polar aprotic solvent. It is a sulfone and a member of tetrahydrothiophenes. It derives from a hydride of a tetrahydrothiophene.