SECONDARY DEUTERIUM-ISOTOPE EFFECTS AND NEIGHBORING GROUP PARTICIPATION REVISITED

Studies on solvolytic reactions proceeding via neighboring group parti cipation by means of secondary deuterium isotope effects are reviewed. The changes in magnitude of secondary KIEs are related to the degree of participation in the reaction transition state and these data are c ompared with other experimental evidence. Supporting information on th e structure of carbocations is obtained by high level ab initio calcul ations. Isotope effect studies turned out to be among the most powerfu l tools available to chemists for elucidating the nature and structure of reaction transition states.