Determination of ionization energies by the thermokinetic method

Charge transfer reactions of the type M.+ + B --> B.+ + M have been studied in order to test the applicability of the "thermokinetic" method to the de termination of ionization energies (IEs). Three examples are presented with M=benzene, cyclopentanone, and vinyl alcohol. The correlation observed bet ween the bimolecular rate constants and IE(B) allows the determination of I E(M) with a mean deviation of similar to0.02 eV with respect to spectroscop ic values. One other advantage of the method is to provide ionization energ ies of unstable neutrals, The role of various corrective terms, and of poss ible geometry changes during charge transfer reactions are discussed. (C) 2 001 Elsevier Science B.V.