Combining the Single-Atom Engineering and Ligand-Exchange Strategies: Obtaining the Single-Heteroatom-Doped...

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.