"Visualizing" the partially reversible conversion of gold nanoclusters via the Au₂₃(S-c-C₆H₁₁)₁₇ intermediate

Transformation chemistry of atomically precise metal nanoclusters has emerged as a novel strategy for fundamental research on the structure-property correlations of nanomaterials. However, a thorough understanding of the transformation mechanism is indeed necessary to understand the structural growth patterns and corresponding property evolutions in nanoclusters. Herein, we present the ligand-exchange-induced transformation of the [Au₂₃(SR)₁₆]^- (8e^-) nanocluster to the [Au₂₅(SR')₁₈]^- (8e^-) nanocluster, through the Au₂₃(SR)₁₇ (6e^-) intermediate species. Identification of this key intermediate through a partially reversible transformation helped in a detailed investigation into the transformation mechanism with atomic precision. Moreover, photophysical studies carried out on this Au₂₃(SR)₁₇ species, which only differs by a single ligand from that of the [Au₂₃(SR)₁₆]^- nanocluster reveal the property evolutions at the slightest change in the nanocluster structure.