How a Single Electron Affects the Properties of the “Non-Superatom” Au₂₅ Nanoclusters

Abstract

In this study, we successfully synthesized the rod-like [Au 25 (PPh 3 ) 10 (SePh) 5 Cl 2 ] q (q = +1 or +2) nanoclusters through kinetic control. The single crystal X-ray crystallography determined their formulas to be [Au 25 (PPh 3 ) 10 (SePh) 5 Cl 2 ]-(SbF 6 ) and [Au 25 (PPh 3 ) 10 (SePh) 5 Cl 2 ](SbF 6 )(BPh 4 ), respectively. Compared to the previously reported Au 25 coprotected by phosphine and thiolate ligands (i.e., [Au 25 (PPh 3 ) 10 (SR) 5 Cl 2 ] 2+ ), the two new rod-like Au 25 nanoclusters show some interesting structural differences. Nonetheless, each of these three nanoclusters possesses two icosahedral Au 13 units (sharing a vertex gold atom) and the bridging "Au−Se(S)−Au" motifs. The compositions of the two new nanoclusters were characterized with ESI-MS and TGA. The optical properties, electrochemistry, and magnetism were studied by EPR, NMR, and SQUID. All these results demonstrate that the valence character significantly affects the properties of the "non-superatom" Au 25 nanoclusters, and the changes are different from the previously reported "superatom" Au 25 nanoclusters. Theoretical calculations indicate that the extra electron results in the half occupation of the highest occupied molecular orbitals in the rod-like Au 25 + nanoclusters and, thus, significantly affects the electronic structure of the "non-superatom" Au 25 nanoclusters. This work offers new insights into the relationship between the properties and the valence of the "non-superatom" gold nanoclusters.

Metal Nanoclusters Stabilized by Selenol Ligands

“…The rod‐like [Au 25 (SePh) 5 (PPh 3 ) 10 Cl 2 ] q ( q = +1 or +2) nanoclusters were controllably synthesized and structurally determined by Song et al Different with the thiolated analogues (i.e., Au 25 (SR) 5 (PPh 3 ) 10 Cl 2 ) that only presented the “+2” overall charge, the “+1” charged Se‐Au 25 was novel. The rod‐like Se‐Au 25 nanoclusters were prepared by reacting the Au m (PPh 3 ) n nanoclusters with PhSeH ligands in different reaction conditions .…”

Electron localization in rod-shaped triicosahedral gold nanocluster

“…Ligand-protected, atomically precise metal nanoclusters have emerged as a model system for investigating the correlation between structure and electronic properties of nanostructures (6,7). Among the nanoclusters with known structures, a unique type is comprised of small building blocks, that is, the "clusters of clusters" (8), such as the rod-shaped Au 25 nanocluster made up of two Au 13 units via vertex sharing (9)(10)(11), as well as the Au 28 (SR) 20 , Au 36 (SR) 24 , Au 44 (SR) 28 , and Au 52 (SR) 32 nanoclusters built up by doublehelical assembly of Au 4 tetrahedral units (12). Some of these gold nanoclusters retain the electronic properties of the building blocks while new electronic transition emerges due to "conjugation" of Au 13 units (10,(13)(14)(15).…”

Ligand-Protected Gold Clusters

“…For these reasons, SR ligands have become the most common choice for use with gold clusters . Recently, the synthesis of gold clusters protected by other chalcogenates (selenolate (SeR) or tellurolate (TeR); Figure 1(c)) [41][42][43][44][45][46][47][48][49][50][51], by alkynes [52][53][54], or by two kinds of ligand ( Figure 1(d)) [55][56][57][58][59] has also been reported. In this chapter, we focus on gold clusters protected by chalcogenates (Au n (XR) m ; XR = SR, SeR, or TeR) and describe the synthetic procedures, geometric/electronic structures, and physical and chemical properties of these compounds.…”