Statistical Mechanics of Deuterium Exchange Reactions: Recalculation of Thermodynamic Properties of Water-Methanol Reactions

Abstract

Thermodynamic properties of the reactions

CH₃OH+HDO → CH₃D+H₂O

CH₃OH+D₂O → CH₃OD+HDO

in the gas phase are calculated from statistical mechanical equations. Two sets of calculated harmonic frequencies are used: one obtained from an experimental force field and the other from an ab initio force field. Thermodynamic properties of the corresponding liquid-phase reactions are obtained by combining the gas-phase values with vapour-pressure isotope effect results. The calculated properties are compared with published experimental values.