Ligand-protected gold clusters: the structure, synthesis and applications

Structure-conserving spontaneous transformations between nanoparticles

“…Atomically precise nanoparticles of noble metals12345678910, often called nanoclusters, which constitute an exploding discipline in nanomaterials, are promising candidates to explore such transformations because of their well-defined structures and drastic changes in their properties, in comparison to their bulk form, arising due to electronic confinement. Most intensely explored of these properties are optical absorption and emission1112131415; near infrared emission of some of the clusters and their large quantum yields have resulted in new applications1617181920.…”

Activation of atom-precise clusters for catalysis

“…This is likely due to the fact that the trimethylaluminum ALD precursors can anchor to surface carboxylate groups, leading to ALD overlayers on top of the clusters in that system, while for dodecanethiolate stabilized clusters, ALD growth can only occur around the clusters. To study the effect of the thickness of alumina layers on thermal stability, catalysts were synthesized by 5, 10, and 20 cycles of alumina deposition over Au 25 overcoating calcined at 250 C and 650 C was found to be 1.8 AE 0.5 nm and 2.4 AE 0.9 nm respectively. 111…”

“…In recent years, tremendous research has focused on the ability to synthesize monodisperse, atom-precise metal clusters by optimizing the synthesis conditions such as the solvent, metal to thiol ratio, temperature, reducing agent, and purication and separation strategies. [17][18][19][25][26][27][28] Atom-precise clusters are highly monodisperse, stable, structurally well-dened, and generally denoted as M x L y , where x is the number of metal atoms, and y is the number of protecting ligands (L) in the cluster composition. Many reports on the synthesis, characterization and applications of atom-precise thiolate ligand protected Au clusters such as Au 144 (SR) 60 , Au 102 (SR) 44 , Au 38 (SR) 24 , Au 25 (SR) 18 , etc., can be found in the literature.…”

“…Padmos and Zhang showed by XAS that as-synthesized small thiolate protected Ag nanoparticles seem to have Ag cores and Ag 2 S shells, while dialkylsulde-stabilized Ag nanoparticles have pure Ag cores. 44 Recently, Bakr and co-workers reported the successful synthesis and structural elucidation of Ag 25 , where all the twelve nonicosahedral Au atoms occupy the center of the triangular face centers of the Au 13 icosahedral core, the Ag 25 (SR) 18 À cluster has three of the nonicosahedral Ag atoms lying away from the triangular face centers, while the nine remaining nonicosahedral Ag atoms lay on the triangular face centers of the Ag 13 icosahedral core. This kind of atomic arrangement enables Ag to be in the proximity of anchoring S of different v-shaped -S-Ag-S-Ag-Smotifs in the Ag 25 (SR) 18 À clusters and thus facilitates weak intermotif interactions which are absent in Au 25 (SR) 18 À clusters.…”

Chiral Ag and Au Nanomaterials Based Optical Approaches for Analytical Applications

“…Among the reported chiral nanomaterials, chiral Ag and Au nanomaterials are most popular, mainly because of their stability, biocompatibility, and interesting optical properties such as localized surface plasmonic resonance (LSPR). In addition, many preparation and functionalization strategies for achiral Ag and Au nanomaterials are ready for preparation of their chiral counterparts when using chiral compounds as the reducing and/or capping agents 2a,c,7. Moreover, many achiral Ag and Au nanomaterials can possess chirality through conjugation with chiral compounds .…”