Ion transfer from water to formamide or 1,2-ethanediol studied by polarography at the electrolyte solution dropping electrode

Abstract

Voltammetry for ion transfer at the interface of two immiscible electrolyte solutions was demonstrated to be feasible not only at the aqueous (W) ⋎ organic solution (Org) interface but also at the formamide (FA) ⋎ Org and 1,2-ethanediol (ED) ⋎ Org interfaces. The transfer of alkali metal ions, I −, BF 4 −, ClO 4 −, IO 4 −, PF 6 −, picrate ions and alkylammonium ions has been investigated at the FA ⋎2,6-dimethylnitrobenzene (DNB) and ED ⋎ DNB interfaces. Standard Gibbs energies of ion transfer ⋎ gD G tr 0 ⋎ from W to FA or ED were evaluated from the differences in the half-wave potentials at the FA ⋎ DNB, ED ⋎ DNB and W ⋎ DNB interfaces. The values of Δ G tr 0 were used as the basis of a discussion of features of the salvation of ions in FA, ED and W, taking into account the electrostatic, non-electrostatic and short-range ion-solvent interactions.