Combining the Single-Atom Engineering and Ligand-Exchange Strategies: Obtaining the Single-Heteroatom-Doped Au16Ag1(S-Adm)13 Nanocluster with Atomically Precise Structure.

Obtaining cognate single-heteroatom doping is highly desirable but least feasible in the research of nanoclusters (NCs). In this work, we reported a new Au16Ag1(S-Adm)13 NC, which is synthesized by the combination of single-atom engineering and ligand-exchange strategies. This new NC is so far the smallest crystallographically characterized Au-based NC protected by thiolate. The Au16Ag1(S-Adm)13 exhibited a tristratified Au3-Au2Ag1-Au1 kernel capped by staple-like motifs including one dimer and two tetramers. In stark contrast to the size-growth from Au18(S-C6H11)14 to Au21(S-Adm)15 via just the ligand-exchange method, combining single Ag doping on Au18(S-C6H11)14 resulted in the size-decrease from Au17Ag1(S-C6H11)14 to Au16Ag1(S-Adm)13. DFT calculations were performed to both homogold Au18 and single-heteroatom-doped Au17Ag1 to explain the opposite results under the same ligand-exchange reaction. Our work is expected to inspire the synthesis of new cognate single-atom-doped NCs by combining single-atom engineering and ligand-exchange strategies and also shed light on extensive understanding of the metal synergism effect in the NC range.