Molecular Electron-Transfer Properties of Au₃₈ Clusters

Abstract

The electron transfer (ET) properties of Au38 clusters protected by a phenylethanethiolate monolayer, Au38(SR)24, were studied in N,N-dimethylformamide and dichloromethane. The kinetic parameters of the first oxidation steps (+1/0 and +2/+1) and the first reduction step (0/−1) were obtained by electrochemical methods. The anion electrogenerated from Au38(SR)24 was employed in homogeneous redox catalysis experiments, using diphenyl disulfide and benzyl bromide as the acceptors. Both the heterogeneous and the homogeneous analyses pointed to the fast ET behavior typical for the formation and reactivity of delocalized ionic species with small intrinsic barriers. The results show that Au38 clusters are in all respects efficient redox molecules.