Solvation effects of H2O and DMSO on the O-H bond dissociation energies of substituted phenols

Solvation effects on the O-H homolytic bond dissociation energies (BDEs) of substituted phenols were studied. It was demonstrated that the BDEs measured in solution in general do not equal the BDEs in the gas phase. Detailed theoretical analyses indicated that a long-range solvation effect (i.e. the interaction between the solvent and the overall dipole moment of the solute) and a short-range solvation effect (i.e. the hydrogen bonding between the solute and solvent) were both important for the O-H BDEs in water and in DMSO. Neither one of these two factors by itself could fully explain the experimentally observed solvation effect. However, a combination of these two factors, estimated through a semi-continuum solvation model, was shown to be reasonably successful in explaining the experimental results. Copyright (C) 2004 John Wiley Sons, Ltd.