New approach for the evaluation of single-ion conductances in pure and mixed non-aqueous solvents

Abstract

The Zwanzig theory of dielectric friction on the moving ion has been critically examined for Et₄N⁺, Pr₄N⁺ and Bu₄N⁺ ions in a number of non-aqueous solvents. The theory applies satisfactorily only to Et₄N⁺ in acetonitrile, N,N-dimethylformamide and acetone and to Bu₄N⁺ in methanol, but it fails in all of the other cases. However, the empirically modified form of Stokes's law which was recently proposed from this laboratory has been found to be applicable (within an average uncertainty of ±2%) for all these ions in pure solvents. This empirically modified equation predicts ionic conductances for Et₄N⁺, Pr₄N⁺ and Bu₄N⁺ ions in quantitative agreement with the experimental values in mixed solvents and so provides a new method for the evaluation of single ion conductances.