Hydrogen and halogen bonding in H2O-HF and H2O-F2 complexes

Abstract

Five-dimensional morphed potentials have been generated for the prototype hydrogen-bonded H2O-HF and halogen-bonded H2O-F2. These determined morphed potentials formed the basis for modeling the dynamics of the complexes and predicting accurate intermolecular rovibrational frequencies. The discrepancy between previous experimental and ab initio predictions for the dissociation energy of the H2O-HF complex is discussed. Predictions based on the morphed potential and application of the Badger-Bauer rule give better estimates for the dissociation energy of the H2O-HF complex, that are in better agreement with the experimental prediction. It is found that the H2O-HF and H2O-F2 complexes have similar equilibrium and ground state geometries. This is in agreement with recent developed canonical approaches to potential energy surfaces, which demonstrated that there are no fundamental distinctions between hydrogen and halogen bonds.