Recent studies of supported vanadium oxide catalysts have revealed that the vanadium oxide component is present as a twodimensional metal oxide overlayer on oxide supports (i.e., A1203, TiO2) (1-9). These surface vanadium oxide species are generally more selective and active than bulk, crystalline V205 for the partial oxidation of hydrocarbons (3, 5, 10, 11). The molecular structures of these s...

We report for the first time on the redox multiphoton polymerization of an organic-inorganic composite material, in which one of the components, a vanadium metallo-organic complex, initiates the polymerization. The composite employs multiphoton absorption to self-generate radicals by photoinduced reduction of the metal species from vanadium (V) to vanadium (IV). We exploit this material for the...

Various combinations of density functionals and pseudopotentials with associated valence basis-sets are compared for reproducing the known solid-state structure of [V 2O 2(OO) 2 l-lact 2] (2-) cis . Gas-phase optimizations at the B3LYP/SBKJC level have been found to provide a structure that is close to that seen in the solid state by X-ray diffraction. Although this may result in part from erro...

A simple and highly selective spectrophotometric method has been developed for the determination of trace amounts of V (V) using newly synthesized reagent 5-bromo salicylaldehyde isonicotinoyl hydrazone (5BrSAINH) in aqueous DMF medium. Vanadium (V) forms a brown colored soluble complex with 5-BrSAINH in the pH range 1.0-5.0. The complex shows maximum absorbance at 400nm in the pH range 4.5-5.5...

Vanadium haloperoxidases catalyse the oxidation of halides leading to halogenation of substrates or, in the absence of suitable substrates, to oxidation of hydrogen peroxide into singlet oxygen and water. Furthermore, V-haloperoxidases are capable to give enantioselective sulfoxidation under the appropriate conditions. The most interesting model compounds that have been synthesised and studied ...

The microstructure of a Cu/V nanocomposite wire processed by cold drawing was investigated by high resolution transmission electron microscopy and atom probe tomography. The experimental data clearly reveal some deformation induced interfacial mixing where the vanadium filaments are nanoscaled. The mixed layer is a 2nm wide vanadium gradient in the fcc Cu phase. This mechanical mixing leads to ...

Vanadium is an important metal used almost exclusively in ferrous and non-ferrous alloys due to its physicochemical and mechanical properties such as grain refinement, high tensile strength, hardness and fatigue resistance; it has a wide range of uses in the metallurgical and chemical sectors [1–3]. There are mainly three kinds of raw materials, bone coal, vanadium slag and waste vanadium catal...

V₂O₅-TiO₂ mixed oxide nanotube (NT) layers were successfully prepared via the one-step anodization of Ti-V alloys. The obtained samples were characterized by scanning electron microscopy (SEM), UV-Vis absorption, photoluminescence spectroscopy, energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (DRX), and micro-Raman spectroscopy. The effect of the applied voltage (30-50 V), vanadium...

The aim of this thesis is the investigation of the spectroscopic properties and the electronic structure of vanadium in minerals with a geological and/or technological interest. V K-edge HERFD-XAS experiments were combined with a theoretical determination of the measured spectra. Two approaches were complementary used to calculate the spectra: an ab initio approach and a multielectronic one. Th...