Application of the competitive preferential solvation theory to coordinative solute–solvent interactions

Abstract

The electronic spectroscopic behaviour of copper chloride and acetate complexes with pyridine derivatives has been investigated in the corresponding pyridine derivative–co-solvent mixtures. The results were interpreted in the light of the competitive preferential solvation (COPS) theory. It is shown that COPS theory can be applied successfully also in cases where the strength of preferential solvation leads to solvent coordination. The obtained solute–solvent affinity constants are transferable, in full agreement with COPS theory. Thier realtive magnitude provides further evidence for the existance of solvent classes. The solute–solvent interaction decreases in the order n-donor solvents > π-donor solvents > hydrocarbon solvents, and it is dominated by specific effects.