Solvent‐Induced Cluster‐to‐Cluster Transformation of Homoleptic Gold(I) Thiolates between Catenane and Ring‐in‐Ring Structures

Supramolecular ensembles adopting ring‐in‐ring structures are less developed compared with catenanes featuring interlocked rings. While catenanes with inter‐ring closed‐shell metallophilic interactions, such as d 10 –d 10 Au I –Au I interactions, have been well‐documented, the ring‐in‐ring complexes featuring such metallophilic interactions remain underdeveloped. Herein is described an unprecedented ring‐in‐ring structure of a Au I ‐thiolate Au 12 cluster formed by recrystallization of a Au I ‐thiolate Au 10 [2]catenane from alkane solvents such as hexane, with use of a bulky dibutylfluorene‐2‐thiolate ligand. The ring‐in‐ring Au I ‐thiolate Au 12 cluster features inter‐ring Au I –Au I interactions and underwent cluster core change to form the thermodynamically more stable Au 10 [2]catenane structure upon dissolving in, or recrystallization from, other solvents such as CH 2 Cl 2 , CHCl 3 , and CH 2 Cl 2 /MeCN. The cluster‐to‐cluster transformation process was monitored by 1 H NMR and ESI‐MS measurements. Density functional theory (DFT) calculations were performed to provide insight into the mechanism of the “ring‐in‐ring⇌ [2]catenane” interconversions.