Temperature coefficients of electrode potentials and Gibbs energies, entropies and enthalpies of transfer of Ag+, Na+ and Tl+ from N,N-dimethylformamide to its mixtures with N,N-dimethylthioformamide and with water

Abstract

Gibbs energies of transfer for Ag⁺, Na⁺ and Tl⁺ from N,N-dimethylformamide (DMF) into its mixtures with N,N-dimethylthioformamide (DMTF) and with water were derived from electrochemical measurements on the basis of the bis(biphenyl)chromium assumption. Transfer entropies were obtained from the temperature coefficients of the half-wave potentials or electrode potentials employing the assumption of a negligible thermal-diffusion potential. Gibbs energies and entropies of transfer were used to calculate transfer enthalpies.

The Gibbs energies of Ag⁺, Na⁺ and Tl⁺ into these two solvent mixtures are interpreted on the basis of hard and soft solvent donor properties. The entropies were influenced by the structure of the solvents. The transfer enthalpies were affected by both the solvent donor properties and the solvent structure.