Estimation of the rate constant for electron transfer in room temperature ionic liquids

► The electron transfer system considered is the oxidation of ferrocene. ► The parameters estimated include the outer sphere Gibbs activation energy for electron transfer, the longitudinal relaxation time, and the standard rate constant. ► The longitudinal relaxation time increases with increase in the length of the alkyl chain. ► As a result the standard rate constant for oxidation of ferrocene decreases as the cation in the ionic liquid is made longer.