Molar Gibbs energies of transfer for Cu2+, Zn2+, Cd2+ and Pb2+

Abstract

Gibbs energies of transfer for Cu²⁺, Zn²⁺, Cd²⁺ and Pb²⁺ derived from the bis(biphenyl)chromium assumption are given for the transfer from N,N-dimethylformamide into 32 non-aqueous solvents. Plots of these data versus the Gibbs energies of transfer of Ag⁺ allowed a classification of the interactions of a given solvent with any of these four divalent cations into soft–soft- or hard–hard-type interactions. Furthermore, these data lead to an ordering of soft solvents according to the degree of softness exhibited. The degree of response of these cations to changes in the nature of solvents and their relation to solvent parameters is discussed.