Unprecedented Enhancement of Noble Gas–Noble Metal Bonding in NgAu₃⁺(Ng = Ar, Kr, and Xe) Ion through Hydrogen Doping

Abstract

Behavior of gold as hydrogen in certain gold compounds and a very recent experimental report on the noble gas-noble metal interaction in Ar complexes of mixed Au-Ag trimers have motivated us to investigate the effect of hydrogen doping on the Ng-Au (Ng = Ar, Kr, and Xe) bonding through various ab initio based techniques. The calculated results show considerable strengthening of the Ng-Au bond in terms of bond length, bond energy, stretching vibrational frequency, and force constant. Particularly, an exceptional enhancement of Ar-Au bonding strength has been observed in ArAuH species as compared to that in ArAu system, as revealed from the CCSD(T) calculated Ar-Au bond energy value of 32 and 72 kJ mol for ArAu and ArAuH, respectively. In the calculated IR spectra, the Ar-Au stretching frequency is blue-shifted by 65% in going from ArAu to ArAuH species. Similar trends have been obtained in the case of all Ar, Kr, and Xe complexes with Ag and Cu trimers. Among all the NgMH complexes (where k = 0-2), the strongest binding in NgMH complex is attributed to significant enhancement in the covalent characteristics of the Ng-M bond and considerable increase in charge-induced dipole interaction, as shown from the topological analysis.

Noble‐Noble Strong Union: Gold at Its Best to Make a Bond with a Noble Gas Atom

“…For a given Ng, it also varies similarly as that for bond dissociation energy. In a further work on such trinuclear system, Ghosh and Ghanty explored the effect of the replacement of Au in NgAu 3 + by isolobal H atom on the Ng−Au bond strength. They achieved a sharp enhancement in binding strength by this treatment.…”

“…For a given Ng, it also varies similarly as that for bond dissociation energy. In a further work on such trinuclear system, Ghosh and Ghanty [76] [M(BiPy)] + (M=Cu, Ag, Au) is known to make complex with different ligands. Jana et al [77] studied whether Ng can also act as a weak ligand towards [M(BiPy)] + .…”

On the stability and chemical bond of noble gas halide cations NgX+ (Ng = He – Rn; X = F – I)

“…Subsequently, on a laboratory scale, a variety of compounds possessing Ng‐Halogen, [ 2,11–14 ] ‐oxygen, [ 15 ] ‐sulfur, [ 16 ] ‐nitrogen, [ 17–21 ] among others, [ 22,23 ] bonds have been obtained at extreme conditions, and theoretically studied through high‐level calculations. [ 24–31 ] Those findings were even more surprising when it was realized that these compounds can form covalent bonds with other atoms, going contrary to what has been believed about the noble gas behavior. Recently, interest has grown in the study of Ng‐compounds because they were found in the interstellar medium.…”

Helium Droplet Mass Spectrometry

“…Two years later, Seidel and Seppelt attempted to produce AuF, but the reaction unexpectedly produced AuXe 4 2+ as AuXe 4 2+ -(Sb 2 F 11 − ) 2 crystals instead [321]. Relatively strong interactions between coinage metal atom clusters and rare gas atoms have also been found in neutral Au n and mixed Au n Ag m clusters complexed with a few Ar and Kr atoms [322][323][324][325][326][327] and cationic CuNe m + and CuAr m + complexes [315]. Martini et al recently published a mass spectrometric study of cationic atomic gold ions complexed with all non-radioactive rare gases by analyzing the abundance distributions of AuRg m + (Rg = He-Xe), supported by CCSD(T)/def2-TZVPP ab initio calculations [314].…”