Nuclear magnetic relaxation study of preferential solvation in diamagnetic electrolyte solutions by use of magnetic ion-solvent interactions

Abstract

Proton magnetic relaxation time measurements are reported in the systems KI + D₂O + CD₃OD + CD₃OH, RbI + D₂O + CD₃OD + CD₃OH, KI + D₂O + CD₃OD + CD₂HOD, RbI + D₂O + CD₃OD + CD₂HOD.

The resulting relaxation rates are extrapolated to zero proton concentration. The extrapolation values contain the ion-nucleus proton intermolecular relaxation rates. Apart from magnetic dipole–dipole interaction there seems to be an electronic interaction causing the relaxation mechanism. The experimental results are evaluated so as to yield information regarding preferential solvation. We find no preferential solvation for I^– but preferential hydration for Rb⁺. The requirements of experimental precision render our results as yet preliminary.