Tracer Diffusion of a Ligand-Stabilized Two-Shell Gold Cluster

Abstract

Abstract Diffusion coefficients have been measured for the two-shell cluster of Au55(Hdpbs) 12Cl6 (Hdpbs = diphenylphosphino-benzene-3-sulfonic acid) in water at varying ionic strengths. Hydrodynamic radius of the particles are found to be 1.44 nm as calculated from the diffusion coefficient at sufficiently high ionic strengths. This is a little larger than the radius obtained from the AFM image. The diffusion coefficients decrease with decreasing ionic strength, indicating the electrostatic drag due to the ionic atmosphere.