Co(H_2O)_6~(2 /3 )体系电子转移反应动力学的理论研究

电子转移过程在化学、生命科学、材料科学等领域普遍存在,几十年来一直受到国际学术界的广泛关注，是当前化学研究的前沿课题之一[1－6].过渡金属络合物间的电子转移是一类重要的电子转移过程，其动力学行为是理论和实验研究的热点[7－12].根据过渡态理论，这类自交换反应速率可表示为ket=κeZeffexp(－ΔE/RT)(1)其中，Zeff为核频率因子，对于溶液中的双分子反应其值约为1011dm3·mol－1·s－1[11]；ΔE是活化能；κe称为电子因子，对于绝热反应κe=1.显然，活化能和电子因子是影响电子转移速率的两个关键因素.根据络合物的结构特点，一…

Theoretical Study of Self- Exchange Electron Transfer Reactions for Co(H_2O)_6~(2 /3 ) System

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.