Studies on the bond-breaking reaction of the CH3-X bond for DFT calculations in electron transfer

Density functional theory (DFT) calculations were performed to study a conc erted electron transfer (ET) bond-breaking process in the gas phase. The po tential energy surfaces of the reactants and products are described by Mors e type potential curves, which are obtained by the DFT method. The equilibr ium geometries, dissociation energies and force constants are in good agree ment with the experimental results. There is an excellent agreement between the calculated activation energies and the values obtained by the terms of the quadratic character of the activation-driving force relationship for t he empirical model of bond-breaking in the ET reaction. DFT calculations ar e performed on CH3X and its anion radical. The charge density along with th e reaction path was analyzed, and the bond-breaking in the ET reaction for CH3X is investigated.. B3LYP/6-311 + g** is selected to be the best basis s et for F, Cl and Br, and B3LYP/LANL2DZ for I. (C) 2001 Elsevier Science B.V . All rights reserved.