Robust Organometallic Gold Nanoparticles

Robust gold–carbon nanoparticles were synthesized by the sodium borohydride reduction of the diazonium tetrachloroaurate­(III) complex [C₈F₁₇-4-C₆H₄NN]­AuCl₄. FT-IR, ¹H NMR, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) of the ruby red gold nanoparticles indicated the absence of the diazonium nitrogen and the presence of the organic shell C₈F₁₇-4-C₆H₄. Temperature-dependent X-ray powder diffraction (TD-XRD) measurements showed intense cubic gold nanoparticle diffraction patterns in the temperature range 300–500 °C. The effective hydrodynamic size measured by a nanoparticle track analyzer (NTA) in ethanol is 45 nm, and the average core size estimated by transmission electron microscopy (TEM) is 3.2 ± 0.2 nm. The core–shell bonding is strong and is able to withstand prolonged sonication in ethanol and acetonitrile and indefinite exposure to ambient conditions in the solid state.