Disc-Like Silver Nanocluster Ag-93 Built with Bicapped Hexagonal Prismatic Ag-15 and Ino Decahedral Ag-13 Units

The reduction of alkynyl-silver and phosphine-silver precursors with a weak reducing reagent Ph2SiH2 led to the formation of a novel silver nanocluster [Ag-93(PPh3)(6)(C equivalent to CR)(50)](3+) (R=4-CH3OC6H4), which is the largest structurally characterized cluster of clusters. This disc-shaped cluster has a Ag-69 kernel consisting of a bicapped hexagonal prismatic Ag-15 unit wrapped by six Ino decahedra through edge-sharing. This is the first time that Ino decahedra are used as a building block to assemble a cluster of clusters. Moreover, the central silver atom has a coordination number of 14, which is the highest in metal nanoclusters. This work provides a diverse metal packing pattern in metal nanoclusters, which is helpful for understanding metal cluster assembling mechanisms.