HOMOLYTIC AND HETEROLYTIC C-H BOND-DISSOC IATION ENERGIES OF ALPHA-V(OR VI)-GROUP CATION-SUBSTITUTED TOLUENES AND ACETOPHENONES

Eleven alpha-V (or VI)-group cation-substituted toluenes (1) and aceto phenones (2) were synthesized, The equilibrium acidities (pK(a)) of th ese compounds were determined in dimethyl sulfoxide solution by the '' Overlapping Indicator Method'' and the homolytic C-H bond dissociation energies (BDE) were derived from a thermodynamic cycle combining pK, with oxidation potential of carbanion. The effects of the a-positively charged groups on the thermodynamic stabilities of sixteen YIide carb anions and the corresponding Ylide-like radicals and the remote struct ral effect have been discussed.