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 ΔV_OH is related to ΔV_OD by the relation, ΔV_OH≈1.414 ΔV_OD as expected on the basis of mass effect alone.