Effect of deuteration on hydrogen bonds

Abstract

A study of the 1 : 1 interaction of CH₃OD and t-C₄H₉OD as well as the corresponding hydroxy derivatives with electron donor molecules has shown that the enthalpies of formation of complexes are generally increased by ∼1 to 2 kJ mol^–1 on deuteration. Enthalpies of dimerization of t-C₄H₉OH and t-C₄H₉OD are comparable. Deuterium bond energies may be lower than hydrogen bond energies only for very short hydrogen bonds. The shift in the O—H stretching frequency Δν_OH is related to Δν_OD by the relation, Δν_OH≈ 1.414 Δν_OD as expected on the basis of mass effect alone.