Core Charge Density Dominated Size-Conversion from Au6P8 to Au8P8Cl2

The stimulus-response of metal nanoclusters is crucial to their applications in catalysis and bio-clinics, etc. However, its mechanistic origin has not been well studied. Herein, the mechanism of the Au^IPPh₃Cl-induced size-conversion from Au₆(DPPP)₄]²⁺ to Au₈(DPPP)₄Cl₂]²⁺ (DPPP is short for 1,3-bis(diphenylphosphino)propane) is theoretically investigated with density functional theory (DFT) calculations. The optimal size-growth pathway, and the key structural parameters were elucidated. The Au−P bond dissociation steps are key to the size-growth, the easiness of which was determined by the charge density of the metallic core of the cluster precursors (i.e., “core charge density”). This study sheds light on the inherent structure–reactivity relationships during the size-conversion, and will benefit the deep understanding on the kinetics of more complex systems.