Evolution of atomically precise silver clusters to superlattice crystals

Researchers reported about the systematic size evolution of an organic-soluble, atomically precise silver cluster. Evolution of precise silver cluster larger nanoparticles was observed by mass spectrometry, while the formation of nanoparticles and crystals was investigated by electron microscopy. A solid-state route was used to synthesize atomically precise clusters and conduct the investigations. The method involves grinding the precursors in a mortar and pestle to form silver thiolates. Addition of sodium borohydride in the solid state to this mixture with continued grinding produced well-defined clusters that were extracted with suitable solvents. A mixture of AgNO3 and tetraoctyl ammonium bromide (TOABr) was taken in an agate mortar and ground uniformly. The product was extracted in ethanol and centrifuged to remove extra thiol in the supernatant and finally the residue was extracted in toluene, which gave reddish-brown solution.