Self-assembly of organometallic clusters onto the surface of gold

We report the preparation and characterization of thin films generated via the solution-phase self-assembly of organometallic chalcogen-containing cluster compounds onto the surface of gold. The following anionic complexes were used as thin film precursors: [Fe 3(CO) 9E] 2− and [HFe 3(CO) 9E] −, where E=S, Se, and Te. The films were prepared by adsorption from organic solvents (i.e. methanol, acetonitrile, acetone, and dicholoromethane) onto evaporated gold and were characterized by ellipsometry, polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS), X-ray diffraction (XRD), atomic force microscopy (AFM), quartz crystal microbalance (QCM) and X-ray photoelectron spectroscopy (XPS). The data demonstrate that the clusters strongly attach to gold and that the films most likely exist as bilayers rather than monolayers.