Correlation of the rates of solvolysis of (arylmethyl)methylphenylsulfonium ions†

Abstract

The specific rates of solvolysis of the benzylmethylphenylsulfonium ion (prepared as the trifluoromethanesulfonate salt) and five benzylic ring-substituted derivatives can be satisfactorily correlated using N_T solvent nucleophilicity values. Addition of a secondary term, governed by the aromatic ring parameter (I), shows the sensitivities towards changes in this parameter to fall and those towards changes in N_T to rise with increasing electron-withdrawing ability of the substituent. The Hammett ρ values with electron-withdrawing substituents (based on σ⁺ values) vary from –0.9 in 95% acetone to –1.8 in 97% 2,2,2-trifluoroethanol. These Grunwald–Winstein and Hammett analyses are compared to those previously reported, with essentially the same solvents and substituents, for solvolyses of arylmethyl p-toluenesulfonates.