As a test of our earlier interpretations of the 13C kinetic isotope effects found for alcoholysis of 1-phenyl-1-bromoethane, we have examined the effect of the p-methyl and p-bromo substituents on the 13C fractionations in ethanol and methanol. Isotopic fractionation at the α- carbon is found to be substituent dependent, and the observed trend is consistent with the proposal that stabilization of the cationic center by the phenyl ring is a major factor ...
