Free Energy Contribution Due to the Specific Solvation of Anions. A Comparison of "Pure" Acidity Solvent Scales

Four "pure" acidity solvent parameters (i.e. assumed to be free from non-specific solvation) proposed in the literature on quite different basis: E of Koppel and Palm [1], EN of Krygowski et al. [2], _ of Taft and Kamlet [3,4] and SAof Catalán and Díaz [5] gave the same contribution of the specific solvation of chloride ion to its standard molar free energy of transfer between a given solvent and water, as expected for "pure" scales.