Thermal behavior of gold(I)-thiolate complexes and their transformation into gold nanoparticles under heat treatment process

The structural and thermal behavior of photoluminescent Au(I)-alkanethiolate was investigated by using differential scanning calorimetry, spectrofluorophotometer, FT-IR spectroscopy, NMR spectroscopy, X-ray diffraction, and transmission electron microscopy. Upon heating the sample, the conformation of the alkyl groups in Au(I)-alkanethiolate changed from the initial all-trans state at room temperature to the gauche containing disorder state along with the decrease of emission intensity, and then Au(I)-alkanethiolate changed to a mixture of di-n-alkyl disulfide, di-n-alkyl sulfide, and gold nanoparticles stabilized by the n-alkanethiolates. Carboxylic acid and ester functionalized gold nanoparticles can be easily obtained from this simple one-step heating process, using the corresponding functionalized Au(I)-thiolates without any solvent, surfactants, or chemical reagents. © 2008 American Chemical Society.