Interparticle Reactions between Silver Nanoclusters Leading to Product Cocrystals by Selective Cocrystallization

We present an example of an interparticle reaction between atomically precise nanoclusters (NCs) of the same metal resulting in entirely different clusters. In detail, the clusters [Ag-12(TBT)(8)(TFA)(5)(CH3CN)](+) (TBT = tertiarybutylthiolate, TFA = trifluoroacetate, CH3CN = acetonitrile), and [Ag-18(TPP)(10)H-16](2+) (TPP = triphenylphosphine) abbreviated as Ag-12 and Ag-18, respectively, react leading to [Ag-16(TBT)(8)(TFA)(7)(CH3CN)(3)Cl](+) and [Ag-17(TBT)(8)(TFA)(7)(CH3CN)(3)Cl](+), abbreviated as Ag-16 and Ag-17, respectively. The two product NCs crystallize together as both possess the same metal-chalcogenolate shell, composed of Ag16S8, making them indistinguishable. The occupancies of Ag-16 and Ag-17 are 66.66% and 33.33%, respectively, in a single crystal. ESI MS of the reaction product and a dissolved crystal show the population of Ag-16 and Ag-17 NCs to be in 1:1 and 2:1 ratio, respectively, in them. This suggests selective crystallization in the co-crystal. Time-dependent ESI MS was employed to understand the formation of product clusters by monitoring the reaction intermediates formed in the course of the reaction. We present an unprecedented growth mechanism for the formation of silver NCs mediated by silver-thiolate intermediates.