Does gold behaves as hydrogen? A joint theoretical and experimental study

Abstract

It has been established that the noble-metal-H analogue has been found in a large number of noble-metalligand clusters in view of geometric and electronic structures. Here, we demonstrated a different view of noblemetal-H analogue between noble-metal and hydrogen in M(SCH 3 ) 2 À (M ¼ Cu, Ag, Au and H) systems. Although H(SCH 3 ) 2 À is a typical ion-hydrogen bonding cluster dramatically different from the chemical bonding clusters of M(SCH 3 ) 2 À (M ¼ Cu, Ag and Au), the comparison of the two typical bonding patterns has not yet been fully investigated. Through a series of chemical bonding analyses, it is indicated that the evolution has been exhibited from typical ionic bonding in Cu(SCH 3 ) 2 À to a significant covalent bonding nature in Au(SCH 3 ) 2 À and hydrogen bonding dominating in H(SCH 3 ) 2 À . The comparison of M(SCH 3 ) 2 À (M ¼ Cu, Ag and Au) with H(SCH 3 ) 2 À illustrates the differences in bonding between noble metals and hydrogen, which are mainly related to their diverse atomic orbitals participating in chemical bonding.

Bonding and Electronic Interactions of Hydrogen with Gold Superatoms

“…The Au–H analogy was also verified by the comparable energy gaps between HOMO and the lowest unoccupied molecular orbital (LUMO) and comparable binding energies per atom ( E b ) (Figure a). On the contrary, several reports have claimed that HAu n –1 ( n = 3–8, 20) have a larger adsorption energy of CO and O 2 ( E CO and E O2 , respectively) than those of pristine Au n . ,− Later work by Ghanty and Banerjee demonstrated that this marked difference in E CO and E O2 is due to the usage of significantly different structures of Au n and HAu n –1 in the estimation . Indeed, the E CO and E O2 values calculated for the most stable Au n and HAu n –1 shown in Figure were very similar except for n = 3 (Figure b and c).…”

Recent Advances in Ligand Engineering for Gold Nanocluster Catalysis: Ligand Library, Ligand Effects and Strategies

“…[54] They have been investigated for years in AuNC formation since the 1 s electron of hydrogen can mimic the 6 s electron of gold. [55] Hydrides are found to bridge gold [56] as in [Au 22 H 4 (dppo) 6 ] 2 + (Figure 1 H-2) and in some other cases they simply bind a single gold (Figure 1 H-1). [57] Hydrogen bonds between gold and hydrogen in AuNC systems have also been investigated.…”

“…Hydrogens are not typically considered as functional ligands but they are being more involved in bonding surface metals of metal clusters lately for hydrogenation reactions [54] . They have been investigated for years in AuNC formation since the 1 s electron of hydrogen can mimic the 6 s electron of gold [55] . Hydrides are found to bridge gold [56] as in [Au 22 H 4 (dppo) 6 ] 2+ (Figure 1 H‐2) and in some other cases they simply bind a single gold (Figure 1 H‐1) [57] .…”