Intracluster ligand rearrangement: an NMR-based thermodynamic study.

Ligand and metal exchange reactions are powerful methods to tailor the properties of atomically precise metal nanoclusters. Hence, a deep understanding of the mechanisms behind the dynamics that rule the ligand monolayer is crucial for its specific functionalization. Combining variable-temperature NMR experiments and dynamic-NMR simulations, we extract the thermodynamic activation parameters of a new exchange reaction: the intracluster ligand rearrangement between the two symmetry-unique positions in [Ag 25 (DMBT) 18 ] - and [Ag 24 Au(DMBT) 18 ] - clusters. We report for the first time that this peculiar intracluster modification does not seem to proceed via metal-sulphur bond breaking and follows a first-order rate law, being therefore a process independent from the well-described collisional ligand exchange.