The one/two atom size-reduction of [Au 23 SCy 16 ] - induced by the [Au 6 (dppp) 4 ] 2+ cluster.

The recent progress in atomically precise metal (Au, Ag ) nanoclusters has greatly enriched the molecular-level mechanistic understanding of metal nanomaterials. Herein, using two meta-stable (easy formation, easy transformation) clusters, [AuSCy] and [Au(dppp)] (HSCy and dppp denote cyclohexanethiol and 1,3-bis(diphenylphosphino)propane), as the reaction precursors, the etching of Au occurs smoothly, giving the one/two-atom size-reduced [AuSCy(dppp)] and [AuSCy(dppp)] as the major products. Structural analysis and DFT calculations indicate that the active reaction site of Au lies in the core-shell interference of the bi-capped icosahedral Au core and the AuS motifs. The fluorescence, band gap, and thermostability of the Au cluster products are improved compared to that of the Au precursors.