Nuclear magnetic resonance study of ion–molecule interactions. Part 6.—25Mg NMR of magnesium(II) ion solvation in aqueous acetone and aqueous acetonitrile solutions

Abstract

²⁵ Mg NMR spectra of Mg(ClO₄)₂ solution were measured in the mixed solvents water–acetone and water–acetonitrile. The linewidth of the ²⁵Mg resonance in solution was considerably broadened at low water concentration. The concentration equilibrium constants for the solvation and the inherent linewidths of the complexes with various hydration numbers were obtained by analysing the variation of ²⁵Mg linewidths measured for various molar ratios of water : acetone or water : acetonitrile in the two solvents. It was found that the dihydrated Mg ion gives the largest ²⁵Mg linewidth.