Transfer and exchange contributions to solvent isotope effects

Abstract

It is shown that the transfer contribution to deuterium solvent isotope effects in water can formally be represented as an exchange effect. The introduction of a solute into water creates a change in solvent structure which can be written as a chemical reaction involving solvent hydrogen nuclei, and the isotope effect on the equilibrium constant of this reaction can then be expressed in terms of deuterium fractionation between different hydrogen sites.