To achieve better control of the formation of silver sulfide (Ag_2S) nanoparticles, ultrasmall Ag nanoclusters protected by thiolate ligands (Ag_(44)(SR)_(30) and Ag_(16)(GSH)_9) are used as precursors, which, via delicate chemistry, can be readily converted to monodisperse Ag_2S nanoparticles with controllable sizes (4–16 nm) and switchable solvent affinity (between aqueous and organic solvents). This new synthetic protocol makes use of the atomic monodispersity and rich surface chemistry of Ag nanoclusters and a novel two-phase protocol design, which results in a well-controlled reaction environment for the formation of Ag_2S nanoparticles
