Highly ordered bilayer structures of gold(I)–alkanethiolates having two types of alkyl groups

The luminescent gold(I)–alkanethiolates containing two types of alkyl groups, Au(I)–(SR)x(SR′)ys, were synthesized by mixing HAuCl4 with two n-alkanethiols in tetrahydrofuran. Au(I)–(SR)x(SR′)ys have highly ordered bilayer structures and the dominant conformations of the alkyl groups were found to be all-trans from X-ray diffraction and FT-IR spectroscopy studies. The gold nanoparticles stabilized by two types of alkanethiolates could be prepared by reducing the Au(I)–(SR)x(SR′)ys using tetrabutylammonium borohydride (TBABH) as a reducing agent. Elemental analysis results of Au(I)–(SR)x(SR′)ys and gold nanoparticles prepared from Au(I)–(SR)x(SR′)ys indicated that the longer alkanethiols are more reactive for the formation of Au(I)–(SR)x(SR′)ys and also the longer alkylthiolates are preferentially absorbed on the gold particles compared with the shorter ones.