799823-45-3Relevant articles and documents
Reactions of tris (1,2-ethanediolato)tungsten (VI) with phenyl acetates. X-ray structures of three products
Lehtonen, Ari,Sillanpaa, Reijo
, p. 175 - 179 (1998)
Tungsten (VI) complex [W(eg)3] (eg=ethanediolate dianion) reacts with phenyl acetates leading to the displacement of one or three diolato ligands Two types of phenoxides[W(O-C6H4R-4)6] (R=HMeCl) and [W(eg)2
Aerosol assisted chemical vapor deposition using nanoparticle precursors: A route to nanocomposite thin films
Palgrave, Robert G.,Parkin, Ivan P.
, p. 1587 - 1597 (2006)
Gold nanoparticle and gold/semiconductor nanocomposite thin films have been deposited using aerosol assisted chemical vapor deposition (CVD). A preformed gold colloid in toluene was used as a precursor to deposit gold films onto silica glass. These nanoparticle films showed the characteristic plasmon absorption of Au nanoparticles at 537 nm, and scanning electron microscopic (SEM) imaging confirmed the presence of individual gold particles. Nanocomposite films were deposited from the colloid concurrently with conventional CVD precursors. A film of gold particles in a host tungsten oxide matrix resulted from co-deposition with [W(OPh)6], while gold particles in a host titania matrix resulted from co-deposition with [Ti(OPr)4]. The density of Au nanoparticles within the film could be varied by changing the Au colloid concentration in the original precursor solution. Titania/gold composite films were intensely colored and showed dichromism: blue in transmitted light and red in reflected light. They showed metal-like reflection spectra and plasmon absorption. X-ray photoelectron spectroscopy and energy-dispersive X-ray analysis confirmed the presence of metallic gold, and SEM imaging showed individual Au nanoparticles embedded in the films. X-ray diffraction detected crystalline gold in the composite films. This CVD technique can be readily extended to produce other nanocomposite films by varying the colloids and precursors used, and it offers a rapid, convenient route to nanoparticle and nanocomposite thin films.
Syntheses and electrochemistry of (p-XC6H4O) 6W (1-X, X = H, CH3, OCH3, Cl, Br, OH, OCH 2Ph) and (p-XC6H4O)5W(OC 6H4OH) (X = H, CH3, OCH3, Cl, Br): An approach to electrocatalytic CH bond activation
Sydora, Orson L.,Goldsmith, Jonas I.,Vaid, Thomas P.,Miller, Abigail E.,Wolczanski, Peter T.,Abru?a, Hector D.
, p. 2841 - 2856 (2008/10/09)
Hexaphenoxides (p-XC6H4O)6W (1-X, X = H, CH3, OCH3, OCH2Ph, Cl, Br) serve as starting materials for (p-XC6H4O)5W(OC6H 4OH) (6-X, X = OH, OMe, Me, H, Br, Cl), whose electrochemical oxidations were studied in reference to CH bond activation. Alcoholysis of W(OMe)6 afforded (p-PhCH2OC6H 4O)6W (1-OCH2Ph), which could be hydrogenated (10% Pd/C, 1 atm H2) to prepare (p-HOC6H 4O)6W (1-OH). Related alcoholyses of WCl6 with HOC6H4-p-X provided the hexaphenoxides (p-XC 6H4O)6W (1-X, X = H, CH3, OCH 3, Cl, Br) through minor modifications of literature procedures. Acid catalyzed treatment of 1-X with p-HOC6H4OCH2Ph provided a mixture of substitution products (p-XC6H 4O)6-xW(OC6H4OCH2Ph) x (x = 1, 5-X) that could be hydrogenated (10% Pd/C, 1 atm H 2) to a mixture of hydroxylated products. Chromatography permitted isolation of (p-XC6H4O)5W(OC6H 4OH) (6-X, X = H, 19%; Me, 29%; OCH3, 19%; Cl, 12%; Br, 11%) in modest yields. Hexaphenoxides 1-X and 6-X manifested two electrochemical reduction waves whose positions were a function of para-substituent. When oxidized, 6-X and 1-OH were proposed to behave as W(V)quinone mimics, albeit at potentials capable of oxidizing hydrocarbons as shown via a thermochemical cycle. If the proposed transients (p-XC6H4O) 5W(OC6H4O) (7-X) were generated, degradation was apparently competitive with CH bond activation. The structure of oligomeric {K[(p-ClC6H4O)6W]}∞ (8-Cl) is addressed, and comments on the nature of radical CH bond activation in this and related systems are presented.
