2,2-Dimethylbutane, trivially known as neohexane at William Odling's 1876 suggestion,[1] is an organic compound with formula C6H14 or (H3C-)3-C-CH2-CH3. It is therefore an alkane, indeed the most compact and branched of the hexane isomers — the only one with a quaternary carbon and a butane (C4) backbone.
Butlerov's student V. Goryainov originally discovered neohexane in 1872 by cross-coupling of zinc ethyl with tert-butyl iodide.[2]
2,2-Dimethylbutane can be synthesised by the hydroisomerisation of 2,3-dimethylbutane using an acid catalyst.[3]
It can also be synthesised by isomerization of n-pentane in the presence of a catalyst containing combinations of one or more of palladium, platinum, rhodium and rhenium on a matrix of zeolite, alumina, silicon dioxide or other materials. Such reactions create a mixture of final products including isopentane, n-hexane, 3-methylpentane, 2-methylpentane, 2,3-dimethylbutane and 2,2-dimethylbutane. Since the composition of the final mixture is temperature dependant the desired final component can be obtained choice of catalyst and by combinations of temperature control and distillations.[4] [5] [6]
Neohexane is used as a high-octane anti-knock additive in gasoline and in the manufacture of agricultural chemicals.[7] It is also used in a number of commercial, automobile and home maintenance products, such as adhesives, electronic contact cleaners and upholstery polish sprays.[8]
In laboratory settings, it is commonly used as a probe molecule in techniques which study the active sites of metal catalysts. Such catalysts are used in hydrogen-deuterium exchange, hydrogenolysis, and isomerization reactions. It is well suited to this purpose as 2,2-dimethylbutane contains both an isobutyl and an ethyl group.[9]