Tailoring the Structure of 58-Electron Gold Nanoclusters: Au₁₀₃S₂(S-Nap)₄₁ and Its Implications

Abstract

We report the synthesis and crystal structure determination of a gold nanocluster with 103 gold atoms protected by 2 sulfidos and 41 thiolates (i.e., 2-naphthalenethiolates, S-Nap), denoted as AuS(S-Nap). The crystallographic analysis reveals that the thiolate ligands on the nanocluster form local tetramers by intracluster interactions of C-H···π and π···π stacking. The herringbone pattern formation via intercluster interactions is also observed, which leads to a linearly connected zigzag pattern in the single crystal. The kernel of the nanocluster is a Marks decahedron of Au, which is the same as the kernel of the previously reported Au(pMBA) (pMBA = -SPh-p-COOH); this is a surprise given the much bulkier naphthalene-based ligand than pMBA, indicating the robustness of the decahedral structure as well as the 58-electron configuration. Despite the same kernel, the surface structure of Au is quite different from that of Au, indicating the major role of ligands in constructing the surface structure. Other implications from Au and Au include (i) both nanoclusters show similar HOMO-LUMO gap energy (i.e., E ≈ 0.45 eV), indicating the kernel is decisive for E while the surface is less critical; and (ii) significant differences are observed in the excited-state lifetimes by transient absorption spectroscopy analysis, revealing the kernel-to-surface relaxation pathway of electron dynamics. Overall, this work demonstrates the ligand-effected modification of the gold-thiolate interface independent of the kernel structure, which in turn allows one to map out the respective roles of kernel and surface in determining the electronic and optical properties of the 58e nanoclusters.

Formation of an Alkynyl‐Protected Ag112 Silver Nanocluster as Promoted by Chloride Released In Situ from CH2Cl2

“…The number of free electrons for Ag 112 was calculated to be 58e (112−6−51+3), which indicates shell closing in a spherical structure. Gold or bimetallic nanoclusters (Au 102 , Au 103 , Au 80 Ag 30 , and Au 57 Ag 53 ) have been reported to be 58 e systems, but no other silver clusters with 58 e are known.…”

Metal Nanoclusters: New Paradigm in Catalysis for Water Splitting, Solar and Chemical Energy Conversion

“…Kernel represents the core of metal atoms usually surrounded by organic moieties (ligands) to form an organic shell around the metal core that also defines their surface properties. The coupling of metal core and organic shell dictates the final structure of the nanocluster, which makes it difficult to determine which component predominantly gives rise to the material properties. Moreover, it cannot be excluded that not only the pure organic ligands have capped the NCs but also that support materials and the cage‐like supramolecular architecture can induce the same properties especially when considering solution‐based chemistry .…”

“…Recently, Higaki et al. synthesized Au 103 S 2 (S‐Nap) 41 (S‐Nap=2‐naphtalenethiolate) using also the ligand‐exchange method and determined its structure by means of crystallography …”

Templated Growth of InP Nanocrystals with a Polytwistane Structure

“…Thea bility to define structure at the nascent stage of nanocrystal (NC) nucleation has enabled the synthesis of awide variety of non-thermodynamic structures,including Al, Ge,and Au clusters, [1][2][3][4][5] metal chalcogenide superlattices, [6][7][8][9] allotropic phases such as e-Co, [10] and molecule-like crystals of InP and CdSe, [11][12][13][14] many of which exhibit unique surface chemistry and optical properties,a nd all of which redefine the classical ideas of material phase and crystal synthesis.Controlling the synthesis of these non-thermodynamic materials using soft-chemical methods presents ap articular challenge.E fforts in the field of semiconductor NC synthesis have revealed colloidal routes to,for example,new allotropes of Si [15] as well as metastable phases of CuInSe 2 [16] and SnS. Thea bility to define structure at the nascent stage of nanocrystal (NC) nucleation has enabled the synthesis of awide variety of non-thermodynamic structures,including Al, Ge,and Au clusters, [1][2][3][4][5] metal chalcogenide superlattices, [6][7][8][9] allotropic phases such as e-Co, [10] and molecule-like crystals of InP and CdSe, [11][12][13][14] many of which exhibit unique surface chemistry and optical properties,a nd all of which redefine the classical ideas of material phase and crystal synthesis.Controlling the synthesis of these non-thermodynamic materials using soft-chemical methods presents ap articular challenge.E fforts in the field of semiconductor NC synthesis have revealed colloidal routes to,for example,new allotropes of Si [15] as well as metastable phases of CuInSe 2 [16] and SnS.…”