JOURNAL OF NANOPARTICLE RESEARCH, vol.11, no.5, pp.1099-1105, 2009 (SCI-Expanded)
Preparation of gold nanoparticles, particularly gold nanorods, by wet chemistry processes involves gold seeds, an Au(III) salt, structure directing surfactants, and metal ion additives in the growth solution into which a weak reducing agent is added. The most commonly employed weak reducing agent is l-ascorbic acid (vitamin C) which is known to reduce many metal ions in the solution phase and form complexes with relatively low stability constants. A purple-gray gold-ascorbate compound, obtained from the reaction of sodium tetrachloroaurate(III) with sodium ascorbate, is now reported. The compound possesses the expected structural features of vitamin C-metal complexes as verified by its C-13 CP-MAS NMR spectrum. A discussion is also presented on the possibility of gold-ascorbate complexation operating in gold nanoparticle formation.