Electrochemical Evaluation of the Number of Au Atoms in Polymeric Gold Thiolates by Single Particle Collisions.

Polymeric gold thiolates, [Au(I)SR] n, are common synthetic intermediate precursors of gold nanoclusters and larger nanoparticles. The size and dispersity of the precursors strongly influence the properties of the synthesis products. Evaluating the size of the precursors is not straightforward because they are irregularly shaped (nonspherical) and hard to isolate from solution. Herein, we propose an effective method for determining the number of Au atoms in polymeric thiolate particles from current transients resulting from single precursor collisions, where individual [Au(I)SR] n species are electrochemically reduced at the collector ultramicroelectrode. The developed approach can lead to a better control over the mean size and dispersity of colloidal metal nanoclusters and nanoparticles.