CHEMISTRY OF AGN AGGREGATES IN AQUEOUS-SOLUTION - NONMETALLIC OLIGOMERIC CLUSTERS AND METALLIC PARTICLES

Abstract

Since the discovery of long-lived oligomeric silver clusters in aqueous polyanion solutions it has become possible to investigate the chemical reactivity of silver aggregates over a wide size range, especially in the range where the transition from the atom to the metal takes place. Both oligomeric and metallic particles react with nucleophilic reagents such as NH3, CN- and SH-. The reactivity is attributed to the coordinative unsaturation of silver surface atoms. In the case of the metallic particles, the changes in the shape of the surface plasmon absorption band can be used to detect the interaction of nucleophilic reagents with surface atoms. A mechanism is proposed for oxidative corrosi..