VOCl3 Research Articles

Synthetic, spectral, and antimicrobial aspects of biologically relevant coordination compounds of dioxomolybdenum(VI) and oxovanadium(V)

Heterocyclic ketimines, 5-nitro-3-(indolin-2-one)hydrazinecarbothioamide (L1H), 5-nitro-3-(indolin-2-one)hydrazinecarboxamide (L2H), 6-nitro-3-(indolin-2-one)hydrazinecarbo-thioamide (L3H), and 6-nitro-3-(indolin-2-one) hydrazinecarboxamide (L4H), were prepared by the condensation of thiosemicarbazide and semicarbazide hydrochloride (in the presence of sodium acetate) in ethanol with the respective ketones. The dioxomolybdenum(VI) complexes and oxovanadium(V) complexes have been prepared by mixing dioxobis(2,4-pentanedinato)molybdenum(VI) in 1: 2 molar ratios and vanadium oxytrichloride in 1: 1 and 1: 2 molar ratios with monobasic bidentate ketimines. The resulting complexes have been characterized by elemental analysis, conductance measurements, and spectral studies, including IR, 1H NMR, and UV spectra. The ketimines and their corresponding metal complexes have been tested on a number of pathogenic bacteria and fungi in order to assess their growth inhibition potency at different concentrations.

Enthalpy of solution of VOCl3 in dilute sodium hydroxide solutions and the standard enthalpy of formation of the HVO 4 2− ion

The calorimetric enthalpies of solution of liquid vanadium oxytrichloride in dilute sodium hydroxide solutions were measured at 298.15 K and ionic strengths I = 0.5, 1.0, or 1.5 (NaClO4). The standard enthalpy of formation of the HVO42− ion was calculated from the measured data.

Synthesis of oxide nanoparticles via microwave plasma decomposition of initial materials

Vanadium pentoxide (V 2O 5) and zinc oxide (ZnO) powders were synthesized by making use of an atmospheric microwave plasma torch. Zn granules for ZnO and vanadium oxytrichloride (VOCl 3) in liquid for V 2O 5 were used as initial materials. A sample for V 2O 5 consisted of nano- and micro-structured particles aligned with the plasma reactor structure. A sample for ZnO was typical nanorods with 100–200 nm in length. The V 2O 5 and ZnO samples were characterized by XRD, SEM, and TEM.

Production of vanadium nitride nanopowders from gas-phase VOCl 3 by making use of microwave plasma torch

Vanadium nitride (VN) nanopowders were directly prepared via decomposition of gas-phase vanadium oxytrichloride (VOCl 3) in N 2/Ar/H 2 microwave plasma generated at the atmospheric pressure. The dark greenish black powders were deposited on the inner wall of the quartz tube in the microwave plasma torch. The synthesized samples were taken from two regions of the plasma reactor and analyzed by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and transmission electron microscope (TEM). All the samples taken from two regions consisted of typical nanoparticles, containing a large amount of VN and a little bit of V 2O 3. The TEM images show that the nanoparticles have sphere-shapes and well-defined planes formed by ordered stackings with d-spacings of 0.17 and 0.21 nm.

Nucleophilic Acyl Substitutions of Esters with Protic Nucleophiles Mediated by Amphoteric, Oxotitanium, and Vanadyl Species.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Nucleophilic Acyl Substitutions of Esters with Protic Nucleophiles Mediated by Amphoteric, Oxotitanium, and Vanadyl Species

[reaction: see text] A diverse array of oxometallic species were examined as catalysts in nucleophilic acyl substitution (NAS) reactions of methyl (or ethyl) esters with protic nucleophiles. Among them, oxotitanium acetylacetonate (TiO(acac)(2)) and vanadyl chloride (VOCl(2)-(THF)(x)()) served as the most efficient and water-tolerant catalysts. Transesterifications of methyl and/or ethyl esters with functionalized (including acid- or base-sensitive) 1 degrees and 2 degrees alcohols can be carried out chemoselectively in refluxed toluene or xylene in a 1:1 substrate stoichiometry using 1 mol % catalyst loading. The resultant products were furnished in 85-100% yields by simple aqueous workup to remove water-soluble catalysts. The new NAS protocol is also amenable to amines and thiols in 74-91% yields, albeit with higher loading (2.5 equiv) of protic nucleophiles. Representative examples of commercial interests such as Padimate O and antioxidant additives for plastics were also examined to demonstrate their practical applications. A 1:1 adduct between TiO(acac)(2) and a given 1-octadecanol was identified as (C(18)H(37)O)(2)Ti(acac)(2) and was responsible for its subsequent NAS of methyl esters.

Intramolecular Biaryl Oxidative Coupling of Stilbenes by Vanadium Oxytrichloride (VOCl3): Facile Synthesis of Substituted Phenanthrene Derivatives

Vanadium oxytrichloride (VOCl3) has proven to be a highly efficient reagent for intramolecular biaryl oxidative coupling reaction of electron‐rich stilbenes. Accordingly, a mild and efficient route to phenanthrene derivatives from stilbenes oxygenated is developed.

Surface structure and thermal oxidative degradation of the reaction products of polyethylene with PCl3 and VOCl3 vapors

Reaction products of phosphorus(III) chloride and vanadium(V) oxychloride with low-density polyethylene were studied by chemical analysis and physicochemical (IR spectroscopy and atomic-force microscopy) methods. Thermaloxidative transformations of the initial and modified samples were studied by differential thermal analysis.

Intramolecular Biaryl Oxidative Coupling of Stilbenes by Vanadium Oxytrichloride (VOCl3): Facile Synthesis of Substituted Phenanthrene Derivatives.

Abstract Vanadium oxytrichloride (VOCl3) has proven to be a highly efficient reagent for intramolecular biaryl oxidative coupling reaction of electron‐rich stilbenes. Accordingly, a mild and efficient route to phenanthrene derivatives from stilbenes oxygenated is developed.

Building block syntheses of site-isolated vanadyl groups in silicate oxidesElectronic supplementary information (ESI) available: summary of experimental procedures, 51V NMR collection parameters, BET, IR and Raman data. See http://www.rsc.org/suppdata/cc/b3/b316184f/

Cross-linking of the cubic silicate building block, Si8O20 with vanadyl chloride leads to porous solids in which a homogeneous dispersion of isolated vanadyl groups is maintained throughout the matrix even at high loadings of vanadium.

Gas-phase infrared spectrum of vanadium (III) oxyfluoride, OVF: theoretical and experimental investigations

The gas phase infrared spectrum of vanadium (III) oxyfluoride, OVF has been recorded. The molecule was generated for the first time by an on-line process using vanadium oxychloride, OVCl, as a precursor passed over heatedsodium fluoride at about 570°C. The infrared spectrum shows two bands centred at 1028, and 807 cm - 1 , which are assigned to ν 3 (O=V stretch) and ν 2 (V-F stretch), respectively. Ab initio self-consistent-field (SCF) molecular orbital (MO) calculations were performed to determine the geometry, total energy and the vibrational frequencies of OVF.

Theoretical and Experimental Investigations of Vanadium (III) Oxychloride

An attempt has been made to produce vanadium (III) oxychloride, (OVCl) by an on-line process for the first time using vanadium oxytrichloride, VOCl3 as a precursor passed over heated silver wool at about 930°C. The vapour products have been characterised by their infrared spectra; values for ν3 of 1010 cm−1 (O=V stretch) and for ν2 of 420 cm−1 (V-Cl stretch) were obtained. Ab initio self-consistent-field molecular orbital calculations were performed to determine the geometry, total energy and the vibrational frequencies of OVCl.

Synthesis and characterization of V 2O 5-doped SnO 2 nanocrystallites for oxygen-sensing properties

V 2O 5-doped SnO 2 nanocrystalline powders were synthesized by the coprecipitation method from vanadium (V) oxytrichloride and tin (IV) chloride. The best reactive conditions were determined, such as the concentration of the reactants, pH value, surfactants, amount of V 2O 5 doped, reaction temperature, and time. The particle size is in the range from 5.2 to 6.5 nm . It decreases with increasing amounts of doping V 2O 5. The morphology of V 2O 5-doped SnO 2 nanocrystalline powders is spherical, and the distribution of particle size is uniform as seen from transmission electron microscopy (TEM).

Enantioselective Radical Cross-Coupling Reactions of Silyl Enol Ethers Using Chiral Oxovanadium

Abstract Asymmetric induction was observed in radical cross-coupling reactions of silyl enol ethers using chiral oxovanadium generated in situ from 8-phenylmenthol and vanadium oxytrichloride in the presence of MS4A (molecular sieves-4A).

ChemInform Abstract: Synthesis of Triphenylene and Dibenzopyrene Derivatives: Vanadium Oxytrichloride, a Novel Reagent.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of Triphenylene and Dibenzopyrene Derivatives: Vanadium Oxytrichloride a Novel Reagent

Synthesis of Triphenylene and Dibenzopyrene Derivatives: Vanadium Oxytrichloride a Novel Reagent

The gas-phase on-line production of vanadium oxytrihalides, VOX 3 and their identification by infrared spectroscopy

A new route has been devised, leading to the production of VOX 3 molecules where XF, Br and I by an on-line process using vanadium oxytrichloride, VOCl 3 as a starting compound passed over the following heated salts NaF, KBr and KI at 375, 700 and 550°C, respectively. The products have been characterized by the IR spectra of their vapors. The low resolution gas phase on-line Fourier transform infrared spectra reported for the first time show strong bands with PQR type structure, centered at 1058, 1035, 1030 and 1025 cm −1 assigned to the ν 1( a 1), the OV stretching fundamental mode of VOF 3, VOCl 3, VOBr 3 and VOI 3, respectively.

Preparation and properties of vanadium-doped SnO 2 nanocrystallites

The vanadium-doped SnO 2 nanocrystalline powder was synthesized by the co-precipitation method from the vanadium (V) oxytrichloride and tin (IV) chloride. The preparation conditions were investigated, such as the concentration of the reactants, pH, the surfactant, the amount of vanadium-doped powder, the reactive temperature and time. The crystal size, morphology and properties of the nanocrystalline powders were examined by differential thermal analysis (DTA), transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques. The effect of the crystal size of the sample on the properties of vanadium-doped SnO 2 nanocrystalline powder was discussed.

Oxidation of Triphenylphosphine by Vanadium Oxytrichloride

A kinetic study on triphenylphosphine oxidation with VOCl3 was carried out in CCl4 and THF. The different mechanisms were elucidated; oxygen was activated dissociatively on solid vanadium complex in CCl4, while oxygen was coordinated molecularly on soluble vanadium complex in THF.

Vanadium oxytrichloride, a novel reagent for the oxidative trimerization of o-dialkoxybenzenes to hexaalkoxytriphenylenes

Triphenylene derivatives with six peripheral chains can make excellent discotic liquid crystals showing great promise in electronic devices. Vanadium oxytrichloride was found to be a novel reagent for the preparation of various triphenylene derivatives. Symmetrically substituted hexaalkoxytriphenylenes were obtained from o-dialkoxybenzenes by oxidative trimerization with VOCl3 in high yields. Oxidative coupling of a 3,3',4,4'-tetraalkoxybiphenyl with 1,2-dialkoxybenzenes yielded unsymmetrically substituted derivatives of triphenylene; a direct coupling of a 3,3',4,4'-tetraalkoxybiphenyl with alkoxyphenol produced monofunctionalized triphenylenes.