Exchange Reactions of the t-Butyl Cation

Abstract

The exchange reaction between t-butyl cation and isobutane in sulfur dioxide solution is first order in both species with Ea = 3.6 kcal/mole and ΔS*298 = −27 e.u. No reaction is observed, under these conditions, between the t-butyl cation and n-butane or neopentane. In a similar system the isopropyl chloride – arsenic pentafluoride complex reacts rapidly with n-butane to yield propane and the t-butyl cation, but does not react with neopentane or cyclopropane. An exchange reaction was also observed between the isopropyl chloride – arsenic pentafluoride complex and propane.