Gold Deassembly: From Au44(SPh-tBu)28to Au36(SPh-tBu)24Nanocluster through Dynamic Surface Structure Reconstruction

Abstract

Molecular level understanding of the structural growth patterns and property evolution in nanoclusters (NCs) is crucial for the design and rational synthesis of clusters for specific properties and applications. In this regard, transformation has always been a versatile approach to achieve atomic precision with atomic purity and a deeper understanding of the growth mechanisms of noble metal NCs. To the latter end, we have demonstrated a structural transformation of Au44(SPh-tBu)28 to Au36(SPh-tBu)24 NC, which occurred through the deassembly of an Au8(SPh-tBu)4 fragment. Kinetic studies conducted on the transformation showed that it follows zero-order kinetics with a low activation energy pathway. Theoretical studies demonstrated that this process happens via surface restructuring of the core-ligand interface, which was found to be the rate-determining step of this transformation. Based on this, a plausible mechanistic pathway for the transformation have been proposed which we envision, will provide useful insights into NC structure evolution. © 2021 American Chemical Society.