Probing the surface-active sites of metal nanoclusters with atomic precision: a case study of AuAg.

The determination of surface-active sites in metal nanoclusters is of great significance for the in-depth understanding of structural evolutions and physicochemical property mechanisms. In this work, the surface-active sites of the AuAg(DMBT)(DPPOE) cluster template towards metal-/ligand-exchange reactions were unambiguously identified at the atomic level. The active-site tailoring of this nanocluster gave rise to three derivative nanoclusters, AuAgCu(DMBT)(DPPOE), AuAg(DMBT)(DCBT)(DPPOE), and AuAg(DCBT)(DPPOE). The single-crystal structural analysis revealed that all these M (M = Au/Ag/Cu) clusters exhibited almost the same framework. Besides, the surface-active site tailoring contributed to significant changes in optical absorptions and emissions of these metal nanoclusters. The findings in this work not only provide an in-depth understanding of the active-site tailoring of cluster surface structures but also develop an intriguing template that enables us to grasp the structure-property correlations at the atomic level.