On the activation energy for hydrogen randomisation in the t-butyl cation

Abstract

The energy required for the loss of methane from the t-butyl cation in the mass spectrometer [1·9 ± 0·3eV; 44 ± 7 kcal mol^–1; (1·8 ± 0·3)× 10² kJ mol^–1] is also sufficient to randomise the hydrogens in the t-butyl cation; the difference in heats of formation of n-butyl and t-butyl cations, calculated on the basis that these ions lose methane by decomposition over the same potential energy surface is 33 ± 9 kcal mol^–1[(1·4 ± 0·4)× 10² kJ mol^–1].