Kinetics of Cationic-Ligand-Exchange Reactions in Au25 Nanoclusters

摘要

Ligand exchange between different ligand-stabilized nanoclusters has been widely applied to the synthesis and functionalization of nanoclusters for neutral- and anionic-thiolates in Au nanoclusters, however to date there has been no report on cationic-ligand thiolate exchange reaction. In this work, we investigated for the first time the ligand-exchange reaction of Au25PET18 (PET: SCH2CH2Ph) nanoclusters with a cationic thiol, ((11-mercaptoundecyl)-N,N,N-trimethylammonium (SR+ )), which resulted in different populations of the two thiolate ligands (SR0 and SR+ ), i.e., Au25(SR0 )18-x(SR+ )x. The results revealed that the kinetics of the cationic-ligand-exchange process, which is different from a typical neutral-thiol-to-neutral-thiol ligand exchange, is strongly dependent on how the SR+ ligands interact with each other during the ligand-exchange process.