Ligand-protected silver-sulfur and cadmium-sulfur clusters: structures and transformations

Silver-sulfur (Ag-S) and cadmium-sulfur (Cd-S) clusters, serving as critical bridges linking simple chalcogenides to semiconductor nanoparticles, have emerged as research hotspots in nanomaterials due to their unique optoelectronic properties, atomically precise structures, and controllable functionality. This review systematically summarizes the structural characteristics and transformation mechanisms of ligand-protected Ag-S and Cd-S clusters. Structurally, both are zero-dimensional semiconductor nanomaterials with specific metal-sulfur stoichiometries and 4d¹⁰ electron configurations, yet they exhibit significant differences in metal ion characteristics, bonding interactions, and symmetry. Ligands regulate cluster size, stability, and optoelectronic properties through coordination. Regarding transformation mechanisms, structural transitions in Ag-S clusters can be achieved via electrochemical driving, ligand mediation, and sulfur source modulation, while Cd-S clusters primarily undergo transformations through ion exchange, temperature/ligand-induced isomerization, and ligand treatment. These findings provide key theoretical foundations for understanding nucleation mechanisms in semiconductor nanomaterials and designing functional cluster materials. Their application potential in optoelectronics, catalysis, bioimaging, and related fields further lays the groundwork for developing next-generation functional nanomaterials.