Strong hydrogen bonding between neutral noble-gas molecules (HNgF, Ng=Ar, Kr, and Xe) and hydrogen fluoride: a theoretical study

High-level electronic structure calculation has been performed on the hydrogen-bond complexes of the neutral noble-gas molecules, HArF, HKrF, and HXeF with hydrogen fluoride. Hydrogen bonding from either the hydrogen or the fluorine sides was considered. Very strongly bonding strengths (13–18 kcal/mol) were predicted for the fluorine-side complexes while those of the hydrogen-side complexes were found to be normal for polar neutral molecules. Large increases (409 and 364 cm−1) of the H–Ar and H–Kr stretching frequencies were predicted for HArF⋯HF and HKrF⋯HF complexes. The complexation was found to decrease the dissociation barriers of HNgF along the bending coordinates by approximately 20 kcal/mol.