Theoretical prediction of FNgM3–kHk (Ng = Ar, Kr, Xe, and Rn; M = Cu, Ag and Au; k = 0–2) molecules

Abstract

Recent finding on the unprecedented enhancement of noble gas-noble metal bonding strength on hydrogen doping in van der Waals type cationic complexes motivates us to explore the possibility of occurrence of noble gas (Ng) inserted neutral compounds involving prototype noble metal trimeric ions. MP2 and DFT based methods have been employed to investigate the structures, stabilities, energetics, harmonic vibrational frequencies, and charge distribution of the predicted neutral FNgM3, FNgM2H, and FNgMH2 (Ng = Ar, Kr, Xe, Rn; M = Cu, Ag, Au). All the predicted molecules are thermodynamically stable with respect to all plausible 2-body and 3-body dissociation channels, except the global minima products. However, sufficient large barrier heights provide enough kinetic stability to the predicted metastable molecules, which in turn can prevent them to dissociate into their respective global minima products. All the results clearly indicate that Ng–M bond has partial covalent character while an ionic interaction is found between F and Ng atoms in FNgM3−kHk (k = 0−2). Furthermore, the charge distribution and AIM analyses suggest that the predicted metastable FNgM3−kHk molecules should essentially exist in the form of [F]δ−[NgM3−kHk]δ+. All the results emphasise that it might be possible to prepare and characterise these predicted molecules by suitable experimental technique(s). Exploration of noble gas-noble metal bonding strength on neutralisation of prototype NgM3−kHk + (Ng = Ar, Kr, Xe, and Rn; M = Cu, Ag, and Au; k = 0−2) ions by fluoride anions through ab initio quantum chemical calculations.