A theoretical study of stabilities, reactivities and bonding properties of XKrOH (X = F, Cl, Br and I) as potential new krypton compounds using coupled cluster, MP2 and DFT calculations

Abstract

CCSD, CCSD(T), MP2, CAM-B3LYP and WB97XD calculations were employed to disclose the conceivable existence of new noble gas molecules, XKrOH (X = F, Cl, Br and I). The calculations were used to present the optimized geometries, vibrational modes, molecular properties, thermodynamic and kinetic stabilities and atomic descriptions of these molecules. IKrOH and BrKrOH molecules showed two X⁻ and KrOH⁺ parts, while in FKrOH and ClKrOH, they could be presented as XKr⁺ and OH⁻. Two decomposition routes (two-body and three-body) were proposed, showing high exothermic reactions especially for the two-body decomposition. However, their decomposition rate constants were small and all molecules had high kinetic stabilities. Comparing relative stabilities and using heats of formations and isodesmic reactions showed that the FKrOH and IKrOH were the most stable and the least stable structures, respectively. Moreover, natural bond orbital (NBO) calculations were used to obtain atomic charges, hybridizations and intermolecular interactions via second-order perturbation energies and the bonding properties of XKrOH molecules were studied by atom in molecule (AIM) calculations. Both of these calculations confirmed the nature of the ionic parts of the molecules and presented a clear picture of their bonding properties. The reactivity parameters, as obtained from population analyses, also showed that the reactivities were increased and stabilities were decreased from FKrOH to IKrOH.