Metal–Ligand Interface in the Chemical Reactions of Ligand-Protected Noble Metal Clusters

Abstract

We discuss the role of the metal-ligand (M-L) interfaces in the chemistry of ligand protected, atomically precise noble metal clusters, a new and expanding family of nanosystems, in solution as well as in gas phase. A few possible mechanisms in which the structure and dynamics of M-L interfaces could trigger intercluster exchange reactions are presented first. How interparticle chemistry can be a potential mechanism of Ostwald ripening, a well-known particle coarsening process, is also discussed. Reaction of Ag59(2,5-DCBT)32 (DCBT = dichlorobenzenethiol) with 2,4-DCBT leading to the formation of Ag44(2,4-DCBT)30 is presented, demonstrating the influence of the ligand structure in ligand-induced chemical transformations of clusters. We also discuss structural isomerism of clusters such as Ag44(SR)30 (-SR = alkyl/aryl thiolate) in gas phase wherein

Thiolate‐Protected Metal Nanoclusters: Recent Development in Synthesis, Understanding of Reaction, and Application in Energy and Environmental Field

“…Pattern 3 is called a ligand‐exchange‐induced structure transformation (LEIST), which is a reaction that has been widely used for the creation of new metal NCs in recent years. [ 3,158,168,270–300 ] Representative metal NCs synthesized by LEIST are summarized in Table 4 . For this reaction, many studies on the mechanism have been conducted to date.…”

Dynamics of RS-(Au-SR)x Staple Motifs on Metal Surfaces: From Nanoclusters to 2D Surfaces

“…Particularly, step 12b has been also proposed in the formation of AuNC dimers 53 and AgNCs doped with Au atoms. 20 Following step 12c, the thiyl radical can react with excess Au adatoms coming from the cluster and yielding RS-Au…”

Molecular reactivity of thiolate-protected noble metal nanoclusters: synthesis, self-assembly, and applications

“…The significant difference from conventional ligand exchange reactions is that the exchange units in SME are M( i )–SR motifs/complexes, which should be inherently attributed to the dynamic nature of M( i )–SR motifs on the surface of the M(0) core. 112 In metal- cum -ligand exchange reaction, the discovery of M( i )–SR motifs/complexes as the exchanging units can be traced back to 2003, when both metal and ligand exchanges were observed in a two-phase reaction of hexanethiolate-protected Au NCs (∼1.6 nm in the toluene phase) and tiopronin-protected Ag NCs (∼1.6 nm in the aqueous phase). 62 Since the metal and ligand exchange reaction can be almost prohibited under a N 2 environment, the authors proposed a Au( i )–SR complex-assisted mechanism, in which the Au( i )–SR complexes formed by oxidative etching of Au NCs were identified as the “catalysts” that made possible simultaneous exchange of metal and ligand.…”