From Ligand-Stabilized Gold Nanoparticles to Hybrid Organic-Inorganic Superstructures

Gold nanoparticles (Au NPs) have many potential applications including nanoelectronics, catalysts andsensors. These future devices depend on stable and monodisperse NPs and their directed assembly. Herein wereview our efforts to develop oligomeric thioether ligands able to direct the synthesis of Au NPs and their surfacefunctionalization. A screening of different oligomeric thioethers indicates that the NPs become more stable andmonodisperse with increasing length of the thioether oligomer. The heptameric benzylic thioether 4 stabilizesmonodisperse NPs with a diameter of 1 nm and excellent long-term stability in solution. It is further monofunctionalizedwith a central protected acetylene. After NP formation in the presence of the ligands we utilize theperipheral functionality to interlink the NPs. A mild oxidative diacetylene coupling protocol is used to covalentlybind these ‘artificial molecules’. This wet-chemical procedure leads to the formation of hybrid organic–inorganicsuperstructures.