Theoretical predictions of the spectroscopic parameters in noble-gas molecules: HXeOH and its complex with water

Abstract

We employ state-of-the-art methods and basis sets to study the effect of inserting the Xe atom into the water molecule and the water dimer on their NMR parameters. Our aim is to obtain predictions for the future experimental investigation of novel xenon complexes by NMR spectroscopy. Properties such as molecular structure and energetics have been studied by supermolecular approaches using HF, MP2, CCSD, CCSD(T) and MP4 methods. The bonding in HXeOH⋯H₂O complexes has been analyzed by Symmetry-Adapted Perturbation Theory to provide the intricate insight into the nature of the interaction. We focus on vibrational spectra, NMR shielding and spin–spin coupling constants—experimental signals that reflect the electronic structures of the compounds. The parameters have been calculated at electron-correlated and Dirac–Hartree–Fock relativistic levels. This study has elucidated that the insertion of the Xe atom greatly modifies the NMR properties, including both the electron correlation and relativistic effects, the ¹²⁹Xe shielding constants decrease in HXeOH and HXeOH⋯H₂O in comparison to Xe atom; the ¹⁷O, as a neighbour of Xe, is deshielded too. The HXeOH⋯H₂O complex in its most stable form is stabilized mainly by induction and dispersion energies.