Hydrogen isotope fractionation between methanol and diphenylphosphine or dimethylphosphine in the gas phase and in aprotic solvents

Abstract

D/H fractionation factors between MeOH and Ph2PH in dilute solutions of tetrachloroethylene, benzene, tetrahydrofuran, pyridine, and acetonitrile and T/H fractionation factors between MeOH and Me2PH vapors were measured. The experimental results agree very well with values calculated from the statistical theory of isotope effects formulated by Bigeleisen and Mayer. There are correlations between observed fractionation factors and solvent polarity, and the interaction energy of methanol with the given solvent. Another correlation has been found between enthalpy of the exchange reactions and the interaction energy between methanol and the given solvent. Key words: isotope effects, fractionation factor, diphenylphosphine, methanol.