Perspective: Exchange reactions in thiolate-protected metal clusters

Abstract

Thiolate-protected metal clusters can exchange ligands or metal atoms with other substances such as coexisting ligands, complexes, and metal clusters in solution. Using these reactions, it is possible to synthesize metal clusters with new physical and chemical properties. Although the occurrence of such reactions was recognized nearly 20 years ago, their details were not well understood. In recent years, techniques for the precise synthesis of metal clusters and their characterization have progressed considerably and, as a result, details of these reactions have been clarified. In this perspective, we focus on the most-studied thiolate-protected gold clusters and provide a summary of recent findings as well as future expectations concerning the exchange reactions of these clusters.

Ligand exchange reactions on the chiral Au38 cluster: CD modulation caused by the modification of the ligand shell composition

“…Thus, within TDDFT-TB, the solutions of the approximated Casida equations 54 and the ground-state MOs are used to compute the oscillator strengths 54 and also the rotatory strengths and electric and magnetic transition dipole moments as described in ref. 52 23 (TH4)] model clusters. The scalar-relativistic effects were included in the electronic excitation calculations, which were all performed using the ADF2019.107 version of the ADF program package.…”

“…Although atomically precise gold nanoclusters exhibit pronounced chiroptical properties, high stability and catalytic activity, the latter can further be altered by applying post-syn-thetic functionalization strategies: metal doping and ligand exchange. 23 Among this, ligand exchange reactions are especially useful for modifying the protective ligand shell and surface composition in a controlled manner. 23 The choice of the exchanging ligand plays a crucial role in altering the chiroptical properties, stability and solubility of the resulting reaction products.…”

“…23 Among this, ligand exchange reactions are especially useful for modifying the protective ligand shell and surface composition in a controlled manner. 23 The choice of the exchanging ligand plays a crucial role in altering the chiroptical properties, stability and solubility of the resulting reaction products. Furthermore, it can lead to dramatic changes in the native properties of clusters.…”

Ligand-Protected Gold Clusters

“…Although this type of reaction was discovered nearly 20 years ago [60][61][62][63][64][65], the associated mechanism was not fully understood at that time. Recently, tremendous progress has been made in terms of the precise synthesis and evaluation of metal clusters, and details of these reactions have been elucidated [66,67]. Recent findings regardingthesereactionsarethereforealsoincluded herein.…”

Ligand engineering of immobilized nanoclusters on surfaces: ligand exchange reactions with supported Au11(PPh3)7Br3

“…7 As the clusters' properties, including solubility, 10,11 stability and optical characteristics, not only depend on the Au cluster size (number of atoms), but also strongly on the nature of the protecting ligand, their modification influences the entire cluster. 2,3,[12][13][14][15][16][17][18] Ligand engineering therefore represents a strategy for producing nanoclusters with well-controlled and tunable physicochemical properties, as new functionalities such as solubility, photoluminescence, 19,20 optical activity or chirality [21][22][23] can be selectively introduced.…”