Synthesis of Two-Electron Bimetallic Cu-Ag and Cu-Au Clusters by using [Cu₁₃ (S₂ CNⁿ Bu₂ )₆ (C≡CPh)₄ ]⁺ as a Template

Atomically precise Cu-rich bimetallic superatom clusters have been synthesized by adopting a galvanic exchange strategy. [Cu@Cu₁₂ (S₂ CNⁿ Bu₂ )₆ (C≡CPh)₄ ][CuCl₂ ] (1) was used as a template to generate compositionally uniform clusters [M@Cu₁₂ (S₂ CNⁿ Bu₂ )₆ (C≡CPh)₄ ][CuCl₂ ], where M=Ag (2), Au (3). Structures of 1, 2 and 3 were determined by single crystal X-ray diffraction and the results were supported by ESI-MS. The anatomies of clusters 1-3 are very similar, with a centred cuboctahedral cationic core that is surrounded by six di-butyldithiocarbamate (dtc) and four phenylacetylide ligands. The doped Ag and Au atoms were found to preferentially occupy the centre of the 13-atom cuboctahedral core. Experimental and theoretical analyses of the synthesized clusters revealed that both Ag and Au doping result in significant changes in cluster stability, optical characteristics and enhancement in luminescence properties.