N.M.R. studies of electrolytes in binary solvent mixtures

An N.M.R. study of AlCl3, TiCl4 and paramagnetic CoCl2 in water and in aqueous mixtures of acetone, acetonitrile, dimethylacetamide, N,N-dimethylformamide, dimethylsulphoxide, dioxane, ethanol, methanol, N-methylformamide, tetrahydrofuran, and tetramethylurea over a solvent range has been completed. The chemical shift results indicate that although water solvates ions extensively in all the mixtures, many of the organic components, particularly DMSO and the amides, compete effectively with water for added electrolyte. The diamagnetic and the paramagnetic solution results indicate that solvating ability decreases in the order DMSO > alcohols, amides > TMU, THF > acetone, acetonitrile, dioxane. This order correlates well with the basicities of these compounds but not with their dipole moments or dielectric constants.