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>Solvent dynamical effects on electronhyphen;transfer kinetics: Influence of electronic coupling on weakhyphen;overlap exchange processes
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Solvent dynamical effects on electronhyphen;transfer kinetics: Influence of electronic coupling on weakhyphen;overlap exchange processes
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机译：Solvent dynamical effects on electronhyphen;transfer kinetics: Influence of electronic coupling on weakhyphen;overlap exchange processes
A numerical integration treatment of the appropriate Kramersrsquo; diffusion equation, involving overdamped solvent motion, is employed to estimate adiabatic barrierhyphen;crossing frequencies ngr;osfor weakhyphen;overlap electronhyphen;exchange processes featuring only outerhyphen;shell (solvent) reorganization as a function of the electronic matrix coupling elementH12. Comparisons are made with estimates of ngr;osobtained from limiting analytical expressions. The competing influence of reaction nonadiabaticity (i.e., electron tunneling) and solvent motion upon the barrierhyphen;crossing frequency is also considered as a function ofH12using a Landaundash;Zener treatment. The results indicate that the dominant influence of overdamped solvent motion on the preexponential factor, that yields the observed inverse correlation between the reaction rate and the solvent longitudinal relaxation time, requires reactions that feature moderate degrees of electronic coupling, aroundH12gsim;0.1 kcalthinsp;molminus;1, in most common polar solvents. These factors are briefly illustrated with reference to recent measurements of the solventhyphen;dependent kinetics of cobalticiniumndash;cobaltocene electrochemical exchange.
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