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

Abstract

This Review presents the current status of the noble gas (Ng)‐noble metal chemistry, which began in 1977 with the detection of AuNe+ through mass spectroscopy and then grew from 2000 onwards; currently, the field is in a somewhat matured state. On one side, modern quantum chemistry is very effective in providing important insights into the structure, stability, and barrier for the decomposition of Ng compounds and, as a result, a plethora of viable Ng compounds have been predicted. On the other hand. experimental achievement also goes beyond microscopic detection and characterization through spectroscopic techniques and crystal structures at ambient temperature; for example, (AuXe4)2+(Sb2F11−)2 have also been obtained. The bonding between two noble elements of the periodic table can even reach the covalent limit. The relativistic effect makes gold a very special candidate to form a strong bond with Ng in comparison to copper and silver. Insertion compounds, which are metastable in nature, depending on their kinetic stability, display an even more fascinating bonding situation. The degree of covalency in Ng–M (M=noble metal) bonds of insertion compounds is far larger than that in non‐insertion compounds. In fact, in MNgCN (M=Cu, Ag, Au) molecules, the M−Ng and Ng−C bonds might be represented as classical 2c–2e σ bonds. Therefore, noble metals, particularly gold, provide the opportunity for experimental chemists to obtain sufficiently stable complexes with Ng at room temperature in order to characterize them by using experimental techniques and, with the intriguing bonding situation, to explore them with various computational tools from a theoretical perspective. This field is relatively young and, in the coming years, a lot of advancement is expected experimentally as well as theoretically.

Not Completely Innocent: How Argon Binding Perturbs Cationic Copper Clusters

“…In a more refined picture, one considers also the spin state of the clusters and takes into account the possibility of forming coordination bonds. 30 − 38 Especially, for cationic noble metal clusters, charge transfer from the noble gas atom to the metal can be significant. An example is the unusually strong interaction of Ar with Au for mixed silver–gold trimer clusters.…”

Protonated and Cationic Helium Clusters

“…This is, as it turns out, only part of the truth. Strongly electronegative ligands, such as O and F atoms, have been found to be able to form neutral, covalently bound structures with Ar, Kr, and Xe, with the latter in particular displaying a rich chemical nature, but neutral compounds containing bound He and Ne have generally not been achieved [1][2][3]. Exotic exceptions to this are compounds formed under extreme pressures [4] or by trapping noble gases in molecular cages [3,5,6].…”

Charge-Shift Bonding in Xenon Hydrides: An NBO/NRT Investigation on HXeY···HX (Y = Cl, Br, I; X = OH, Cl, Br, I, CCH, CN) via H-Xe Blue-Shift Phenomena

“…However, significant progress has been made in noble-gas chemistry during the past 20 years. Besides noble-gas hydrides (Khriachtchev et al, 2009), noble gas-noble metal complexes have been studied for their thermodynamic and kinetic stabilities in theory (Jana et al, 2017(Jana et al, , 2018aPan et al, 2019;Saha et al, 2019). Experimentally, about 30 noble-gas hydrides had been identified by the beginning of 1995 (Pettersson et al, 1995;Räsänen et al, 2000;Lundell et al, 2002;Feldman et al, 2003;Khriachtchev et al, 2003Khriachtchev et al, , 2009Duarte and Khriachtchev, 2017).…”