Atomically Precise Alkynyl- and Halide-Protected AuAg Nanoclusters Au78Ag66(CCPh)48Cl8 and Au74Ag60(CCPh)40Br12: The Ligation Effects of Halides

Reported herein are the synthesis and structures of two high-nuclearity AuAg nanoclusters, namely, [Au78Ag66(CCPh)48Cl8] q− and [Au74Ag60(CCPh)40Br12]2–. Both clusters possess a three-concentric-shell Au12@Au42@Ag60 structure. However, the dispositions of the metal atoms, and the ligand coordination modes, of the outermost shells of these clusters are distinctly different. These structural differences reflect the bonding characteristics of the halide ligands. As revealed by density functional theory analysis, these clusters exhibit superatomic electron shell closings at magic numbers of 92 (for q = 4) and 84, respectively, consistent with their spherical shapes. Both clusters exhibit unusual multivalent redox properties.