Preferential solvation and the composition of the solvation shell of (dimethyl sulphoxide)penta-amminechromium( III ) ion in dimethyl sulphoxide–water mixtures

The number of solvent molecules in the solvation shell of the title complex ion has been found to be 10, the stepwise equilibrium constants for the replacement of the 10 water molecules by 10 dimethyl sulphoxide molecules have been obtained, and the free energy increment per replacement step has been found to be ∼+1.42 kJ mol–1.