Strengthening gold-gold bonds by complexing gold clusters with noble gases

TL;DR

This study reveals unexpectedly strong chemical bonds between noble gases and gold clusters, showing that noble gas adsorption can enhance gold-gold bonds through electron interactions, supported by computational and experimental evidence.

Contribution

The paper demonstrates that noble gases form surprisingly strong bonds with gold clusters, affecting their electronic structure and stability, a novel insight into gold-noble gas chemistry.

Findings

Noble gases strengthen Au-Au bonds in gold dimers.

Noble gas adsorption influences geometry and vibrational frequencies of gold trimers.

Theoretical results align with experimental infrared dissociation data.

Abstract

We report an unexpectedly strong and complex chemical bonding of rare-gas atoms to neutral gold clusters. The bonding features are consistently reproduced at different levels of approximation within density-functional theory and beyond: from GGA, through hybrid and double-hybrid functionals, up to renormalized second-order perturbation theory. The main finding is that the adsorption of Ar, Kr, and Xe reduces electron-electron repulsion within gold dimer, causing strengthening of the Au-Au bond. Differently from the dimer, the rare-gas adsorption effects on the gold trimer's geometry and vibrational frequencies are mainly due to electron occupation of the trimer's lowest unoccupied molecular orbital. For the trimer, the theoretical results are also consistent with far-infrared multiple photon dissociation experiments.