Bonding Nature between Noble Gases and Small Gold Clusters

Area of Science:

• Inorganic Chemistry
• Materials Science
• Physical Chemistry

Background:

• Noble gases are traditionally considered inert elements.
• Gold is recognized as a noble metal, typically unreactive.
• Existing understanding suggests weak dispersion forces govern noble gas-gold interactions.

Purpose of the Study:

• To investigate the bonding nature between small gold clusters (Au_n⁺, n ≤ 4) and noble gas atoms (Ar, Kr, Xe).
• To determine the geometries and quantify the bonding characteristics in Au_nNg⁺ complexes.
• To challenge the conventional view of inert gas and noble metal interactions.

Main Methods:

• Utilized mass spectrometry to identify and characterize complexes.
• Employed infrared spectroscopy to probe vibrational properties and bonding.
• Performed density functional theory (DFT) calculations to determine geometries, adsorption energies, and electron distribution.

Main Results:

• Unambiguously determined the geometries of Au_nNg⁺ complexes.
• Quantitatively revealed covalent bonding between gold clusters and noble gas atoms.
• Observed that bond strength increases with the atomic radius of the noble gas (Ar < Kr < Xe).
• Demonstrated covalent character is limited to atop-coordinated noble gas atoms.

Conclusions:

• Noble gases can form strong covalent bonds with small gold clusters, contrary to expectations.
• The strength of these covalent bonds is influenced by the noble gas's atomic size.
• This study expands the understanding of chemical bonding involving noble gases and noble metals.