The present results show that indeed the structural data allow us to decide which vanadium centers must be considered formally as + 5 and which as + 4, at least with respect to the limit of strong localization. In fact, if the V3 and V3a centers were to be considered as vanadium(Iv), or as intermediates between vanadium(rv) and vanadium(v), they would be involved in several strong p o x 0 bridg...

The biological image of the transition element vanadium ferments a great deal of contradiction-from toxicity to essentiality. Importance of this element as micro-nutrient is yet to be unequivocally accepted by biologists and biomedical scientists. In spite of toxicity, it seems interesting to analyze the different biological roles of the element. Vanadium compounds have been proven to be associ...

Two novel vanadium(III) complexes: V(dipic)(Hbdc)(H2O)2 (1) and [V2(dipic)2(H2btec)(H2O)4]·2H2O (2) (H2dipic = 2,6-pyridinedicarboxylic acid, H2bdc = 1,3-benzene-dicarboxylic acid, H4btec = 1,2,4,5-benzenetetracarboxylic acid) are synthesized by the reaction of V2(SO4)3, 2,6-pyridinedicarboxylic acid and 1,3-benzene-dicarboxylic acid (for 1) or 1,2,4,5-benzenetetracarboxylic acid (for 2) under ...

A new solvo-hydrothermal method has been developed for the synthesis of uniform vanadium oxide nanocrystals (NCs) with various sizes and shapes in aliphatic amine/toluene/water using V(V) diperoxo alkylammonium complexes. The vanadium complex precursors were prepared from an ion exchange reaction of V(V) diperoxo gels and tetraalkylammonium bromide in the water-toluene mixture using H(2)O(2) so...

By nonenzymatic model reactions, the influence o f vanadium (V 0 2+, V 0 3~) and other metal ions (A l3+, Fe2+, Fe3+, Zn2+, N i2+, Cr3+) on the transamination of 4,5-dioxovaleric acid (D O VA) with L-alanine (A la ) to 6 -aminolevulinic acid (<5-ALA) and pyruvic acid (P A ) with pyridoxal phosphate (P L P ) is investigated. The examinations o f the partial reactions show that V 0 2+, V 0 3~ and...

We investigate the effect of interfacial buffer layers—vanadium oxide V2O5 and cesium carbonate Cs2CO3 —on the performance of polymer solar cells based on regioregular poly3-hexylthiophene and 6,6 -phenyl C60 butyric acid methyl ester blend. The polarity of solar cells can be controlled by the relative positions of these two interfacial layers. Efficient inverted polymer solar cells were fabric...

This study describes a new simple, sensitive and selective catalytic kinetic spectrophotometricmethod for the determination of vanadium (V). The method is based upon the catalytic effect ofvanadium (V) on the oxidation of Carminic acid by bromate in sulfuric acid media. The reaction wasfollowed spectrophotometrically by measuring the decrease in absorbance at 490 nm and thedependence of sensiti...

Fuel oil used in power plants contain metal impurities like Vanadium. After combustion, this metal remains in boiler fuel ash in the form of oxide. In this research, extraction of Vanadium oxide from fuel ash has been investigated. Two processes were used for this purpose. A pyro- hydrometallurgy and a hydrometallurgy process. In the pyro-hydrometallurgy process, using sodium carbonate, salt ro...

The nomenclature of selected vanadium compounds is given in Table 1. Chem. Abstr. Serv. Reg. No.: 1314-62-1 Deleted CAS Reg. No.: 12503-98-9; 56870-07-6; 87854-55-5; 87854-56-6; 16616537-3; 172928-47-1; 184892-22-6; 200577-85-1; 203812-34-4; 251927-12-5; 41054690-6 Chem. Abstr. Serv. Name: Vanadium oxide (V2O5) IUPAC Systematic Name: Vanadium oxide Synonyms: CI 77938; divanadium pentaoxide; pen...

A di-vanadium-substituted Lindqvist-type polyoxometalate [Cu(C12H8N2)2]2[V2W4O19]·4H2O (1) was hydrothermally synthesized and characterized structurally by single crystal X-ray diffraction analysis. X-ray photoelectron spectroscopy and energy disperse spectroscopy tests further prove the existence of vanadium. Ultraviolet photoelectron spectroscopy and density functional theoretical studies ind...