Crystal structure of Au₂₅(SePh)₁₈ nanoclusters and insights into their electronic, optical and catalytic properties

Abstract

The crystal structure of selenolate-capped Au25(SePh)18(-) nanoclusters has been unambiguously determined for the first time, and provides a solid basis for a deeper understanding of the structure-property relationships. The selenolate-capped Au25 cluster shows noticeable differences from the previously reported Au25(SCH2CH2Ph)18(-) counterpart, albeit both share the icosahedral Au13 core and semi-ring Au2(SeR)3 or Au2(SR)3 motifs. Distinct differences in the electronic structure and optical, catalytic and electrochemical properties are revealed by the coupling experiments with density functional theory (TD-DFT) calculations. Overall, the successful determination of the Au25(SePh)18(-) structure removes any ambiguity about its structure, and comparison with the thiolated Au25 counterpart helps us to further understand how the ligands affect the properties of the nanocluster.

Atomically Precise Gold Nanoclusters Accelerate Hydrogen Evolution over MoS2 Nanosheets: The Dual Interfacial Effect

“…To further probe the interfacial effect, we used two types of atomically precise Au 25 nanoclusters protected by thiolate (SCH 2 CH 2 Ph) and selenolate (SePh), respectively. The synthesis of Au 25 (SePh) 18 followed a literature procedure, and Figure S2 (Supporting Information) shows UV–vis and MALDI‐MS spectra as well as its X‐ray crystal structure. The Au 25 (SR) 18 and Au 25 (SePh) 18 nanoclusters possess the same atomic packing structure, i.e., an Au 13 icosahedral core protected by six Se(R)AuSe(R)AuSe(R) dimeric staple motifs (Figures S1 and S2, Supporting Information).…”

Bonding properties of thiolate-protected gold nanoclusters and structural analogs from X-ray absorption spectroscopy

“…To date, icosahedral, face-centered-cubic (FCC)-ordered and smaller Au core ( < 13 Au atoms) structures have been reported crystallographically for various Au n (SR) m sizes [19,[21][22][23][24][25][26][27][28][29][30]. A couple of selenolate-protected Au NCs have also been recently elucidated with icosahedral or small Au 8 core structures [31,32]. In the last few years, a number of surface structures in addition to the monomeric and dimeric staple-like motifs were identified such as a trimeric staple-like motif [28], tetrameric staple-like motif [29,30], μ 3 sulfide coordination [25], bridging thiolate motif [24], and ring-like motifs (long Au-SR oligomers) [27,33].…”

“…Figure 1 presents the diversity of thiolate-protected Au NC structures. Currently, only the dimeric staple-like motif and ring-like motif have been confirmed to exist in structurally analogs selenolate-protected Au NCs [31,32].…”

Chiral Gold Nanoclusters: Atomic Level Origins of Chirality

“…The second method is to directly fabricatec hiral nanostructures by templated deposition or growth, [44,45,53] and the third is to assemble achiral Au nanoparticles into chiral assemblies (e.g.,d iscrete oligomers of nanoparticleso rl arge-scale assemblies) with the aid of chiral templates. [65][66][67][68][69][70][71][72][73][74][75][76][77][78][79] More importantly,t he atomic structures of some nanoclusters have been unambiguously mapped out by using single-crystal X-ray crystallography, [64,65,[80][81][82][83][84][85][86][87][88][89][90] and thust he structures have explicitly revealed the atomic-level origin of chirality in the nanoclusters. [1,2,7] Ar ange of atomically precise sizes of gold nanoclusters have recently become assessable, particularly the thiolate-protected ones (denoted Au n (SR) m ,i nw hich n represents the precise number of gold atoms and m is the precise number of surfacet hiolate ligands).…”