A theoretical scheme is presented which is based on an activation model for calculating the rate of the electron- exchange reaction between transition metal complexes in aqueous solution and applies to electron transfer system.The activation parameter and activation energy of the system are obtained via the activation model. The slopes of the potential energy surfaces (curves) of the reacting system at the separated reactants are calculated from the fitted potential energy curves. The coupling matrix element is determined by using the perturbation theory and numerical integral method. Theoretical rate constants are obtained for the system at both UHF/6- 311G and UMP2/6- 311G levels.The agreement of the theoretical results with experimetal values is excellent.This fact indicates the scheme proposed is feasible and accurate in studying the self- exchange eletron transfer reaction.
The isomerization of singlet, nitryl hydride(HNO2) has beed studied by using abinitio method at MP2 level with 6-31G* basis set. The calculation indicates that the reaction isexothermic by 10.8kJ.mol-1, the energy barrier is 227.9kJ·mol-1, and nitryl hydride is not easilyisomerized to trans-HONO.
The isomerization of singlet difluorosilacyclopropene has been studied by using abinitio method with 6-31G(d ) basis set. The transition state with a 3-member cycle of this reactionhas been obtained, and the intrmsic reaction coordmate (IRC) calculation has been performed.The barrier height is 421 .81 kJ.mol -1 (MP2/6-31G(d)/RHF/6-31G(d)) and the released energyis 52.75 kJ.mol- 1 (MP2/6-31G(d)/RHF/6-31G(d)). The relative structure data of the reactant,transition state and product have been given.
