Electron Transfer between [Au25(SC2H4Ph)18]−TOA+ and Oxoammonium Cations
journal contributionposted on 16.12.2015, 19:49 by Zhao Liu, Manzhou Zhu, Xiangming Meng, Guoyong Xu, Rongchao Jin
We report intermolecular electron transfer between 2,2,6,6-tetramethylpiperidin-1-oxoammonium tetrafluoroborate (TEMPO+BF4–) and thiol-stabilized [Au25(SC2H4Ph)18]−TOA+ (abbreviated as Au25–) nanoclusters. The TEMPO+ cations are generated by single electron oxidation of piperidine aminoxyl radical TEMPO (2,2,6,6-tetramethylpiperidinyl-oxy). Cyclic voltammetry (CV) and electron spin resonance (ESR) explicitly indicate that two consecutive single-electron transfer reactions occur between TEMPO+ cations and Au25– nanoclusters. Nuclear magnetic resonance (1H NMR) analysis demonstrates that the methylene proton resonances of the thiolate ligands can also be used to monitor the redox process. UV–vis spectroscopic analysis reveals the changes in the absorption peaks of Au25 nanoclusters upon consecutive single-electron transfers between the nanoclusters and TEMPO+ cations. The ease of control over the redox process involving TEMPO+ allows the preparation of pure Au25(SC2H4Ph)18+ nanoclusters. The interesting electron-donating properties of Au25(SR)18 clusters may find some promising applications in future studies.