PREFERENTIAL SOLVATION OF IONS IN BINARY MIXED-SOLVENTS - NMR AND SIMULATION DATA

The quadrupole relaxation rate of the Li-7+ and Na-23+ nuclei in a var iety of binary solvents was measured to investigate the influence of d ifferent factors on the preferential solvation phenomenon of these ion s. Structural and dynamic properties of solvation shells of the Na+ an d Cl- ions in an aqueous solution and in a mixture of water with hexam ethylphosphoric triamide, as well as ion pair formation in water and i on-molecule pair formation (preferential solvation) in the mixture wer e studied by means of molecular dynamics simulations. A long-lived wat er separated sodium ion-organic molecule pair was found and its struct ural and dynamic properties were compared in detail with those of a wa ter separated Na+ - Cl- ion pair.