Hydrogen bond energies of the HF and HCl dimers from absolute infrared intensities

Abstract

The dissociation energies of the hydrogen‐bonded complexes, (HF)2 and (HCl)2, have been obtained from high‐resolution measurements of absolute infrared line strengths at a single temperature and pressure under the assumption of minimally perturbed local‐mode behavior of the outer hydrogen stretch. The zero‐point dissociation energies for the HF and HCl dimers are D 0=1038(+43, −34) and 431(±22) cm− 1, respectively. Estimates of the zero‐point energies of the low frequency intermolecular vibrations enable us to obtain the well depths and equilibrium dissociation energies for comparison to a b i n i t i o calculations and empirical models.