Cocrystallization-driven Formation of fcc-based Ag₁₁₀ Nanocluster with Chinese Triple Luban Lock Shape

Luban locks with mortise and tenon structure have structural diversity and architectural stability, and it is extremely challenging to synthesize Luban lock-like structures at the molecular level. In this work, we report the cocrystallization of two structurally related atom-precise fcc silver nanoclusters Ag₁₁₀(SPhF)48(PPh3)12 (Ag₁₁₀) and Ag14(μ6-S)(SPhF)12(PPh3)8 (Ag₁₄). It is worth noting that the Ag₁₁₀ cluster is the first compound to simulate the complex Luban lock structure at the molecular level. Meanwhile, Ag₁₁₀ is the largest known fcc-based silver nanocluster, so far, there is no precedent for fcc silver nanocluster with more than 100 silver atoms. DFT calculations show that Ag₁₁₀ is a 58-electron superatom with an electronically closed shell1S21P61D102S21F142P61G18. Ag₁₁₀⋅Ag₁₄ can rapidly catalyze the reduction of 4-nitrophenol within 4 minutes. In addition, Ag₁₁₀ presents clear structural evidence to reveal the critical size and mechanism of the transformation of metal core from fcc stacking to quasi-spherical superatom. This research work provides an important structural model for studying the nucleation mechanism and structural assembly of silver nanoclusters.