Nanoparticulated Gold: Syntheses, Structures, Electronics, and Reactivities

Abstract This microreview deals mainly with the synthesis and the electronic and chemical properties of gold nanoparticles. Modern synthetic routes, based on physical and on chemical procedures, as well as structural and optical features, are described. The bulk‐to‐molecule transition is discussed by studying size‐controlled quantum‐size effects, resulting in the determination of discrete electronic energy levels in Au 55 clusters. Conductivity measurements of three‐ and two‐dimensionally organized ligand‐protected Au 55 clusters are described, as well as the current techniques for the generation of ordered monolayers and artificial patterns of quantum dots. Finally, some aspects of the chemical activity of gold nanoparticles are discussed by considering ligand‐exchange processes and, last but not least, the expanding role of gold nanoparticles in catalysis is considered. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)