TEMPERATURE-DEPENDENCE OF THE TRANSFER-COEFFICIENT OF SIMPLE ELECTROCHEMICAL REDOX REACTIONS DUE TO SLOW SOLVENT DYNAMICS

It is shown that for simple electrochemical redox reactions in which b oth outer- and inner-sphere modes are reorganized, the transfer coeffi cient alpha may decrease with increasing temperature if the solvent dy namics along the outer-sphere coordinate is sufficiently slow. A simil ar trend is observed for the activation energy, The effect is due to a change in the most effective reaction path with temperature and is in timately related to the phenomenon of saddle-point avoidance. It is al so shown that the effect enhances the potential dependence of the tran sfer coefficient.