Alkanethiolate-protected gold clusters generated from sodium S-dodecylthiosulfate (Bunte salts)

A new synthesis for alkanethiolate-functionalized gold clusters derived from sodium S-dodecylthiosulfate is presented. The new clusters are analytically characterized by H-1 NMR spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA), and UV-vis absorption spectroscopy. These monolayer-protected clusters (MPCs) are indistinguishable in composition, monolayer architecture, and Au-sulfur bonding from those previously prepared from dodecanethiol using the Brust synthesis. One difference is that, for syntheses run under identical conditions, the average core dimensions for MPC products from sodium S-dodecylthiosulfate are somewhat larger. The average core size of MPCs synthesized from sodium S-dodecylthiosulfate is somewhat solvent-dependent, being smaller when they are made using toluene/H2O rather than THF/H2O.