Ion Solvation in Non-aqueous and Mixed Solvents

Abstract

The structure and stability of a metal ion solvate depend on the steric demands of the solvent molecule upon coordination. Water is a small molecule without steric demands, and the coordination number of metal ion hydrates is given by the number of oxygen atoms able to cluster around a metal ion with a given ionic radius. Some solvent molecules as tetramethyl- and dimethylpropyleneurea and hexamethylphosphoramide have methyl groups close to the oxygen donor atom, which make them require much more space upon coordination. The structures and physico-chemical properties of metal ion solvates with and without steric demands upon coordination, and thereby different crowdedness in the solvation sphere, are discussed in addition to selective solvation in mixed solvents.