Mechanistic insights into Ag + induced size-growth from [Au 6 (DPPP) 4 ] 2+ to [Au 7 (DPPP) 4 ] 2+ clusters.

The size conversion of atomically precise metal nanoclusters lays the foundation to elucidate the inherent structure-activity correlations on the nanometer scale. Herein, the mechanism of the Ag + -induced size growth from [Au 6 (dppp) 4 ] 2+ to [Au 7 (dppp) 4 ] 3+ (dppp is short for 1,3-bis(diphenylphosphino)propane) is studied via density functional theory (DFT) calculations. In the absence of extra Au sources, the one "Au + " addition was found to be regulated by the Ag + doping induced Au-activation, i.e. , the formation of formal Au(i) blocks via the Ag + alloying processes. The Au(i) blocks could be extruded from the core structure in the formed Au-Ag alloy clusters, triggering a facile Au + migration to the Au 6 precursor to form the Au 7 product. This study sheds light on the structural and stability changes of gold nanoclusters upon the addition of Ag + and will hopefully benefit the development of more metal ion-induced size-conversion of metal nanoclusters.