Molecular interpretation of the linear relationship between the entropy and the enthalpy of activation of charge transfer reactions in polar liquids

Abstract

The well-known linear relationship (TΔS^# = αΔH^# + β, where 1 > α > 0, β > 0) between the entropy (ΔS^#) and the enthalpy (ΔH^#) of activation for reactions in polar liquids is investigated by using a molecular theory. An explicit derivation of this linear relation from first principles is presented for an outersphere charge transfer reaction. The derivation offers microscopic interpretation for the quantities α and β. It has also been possible to make connection with and justify the arguments of Bell put forward many years ago.