Ascidians, especially those belonging to the suborder Phlebobranchia, can accumulate high levels of vanadium. Vanadium-binding proteins (vanabins) were first isolated from a vanadium-accumulating ascidian, Ascidia sydneiensis samea, and then the vanabins were cloned, their expression was studied, and metal-binding assays were conducted. In order to unravel the mechanism of vanadium accumulation...

A series of mononuclear V((V)), V((IV)) and V((III)) complexes were investigated by V L-edge near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The spectra show significant sensitivity to the vanadium oxidation state and the coordination environment surrounding the vanadium center. The L-edge spectra are interpreted with the aid of the recently developed Density Functional Theory/...

Vanadium pentoxide coatings were grown by atmospheric pressure chemical vapor deposition varying the gas precursor ratio (vanadium (IV) chloride:water) and the substrate temperature. All samples were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, cyclic voltammetry, and transmittance measurements. The water flow rate was found to affect the crystallinity a...

In our effort to study vanadium chalcogenide chemistry, we have synthesized and characterized a class of non-oxido divanadium(IV) and divanadium(V) complexes with chalcogenide and dichalcogenide as bridges. All structures consist of a similar divanadium motif, in which two metal centers are bridged by one μ-chalcogenide and one μ-η(2):η(2)-dichalcogenide, forming a V2(μ-E)(μ-η(2):η(2)-E2) (E = ...

1-(2-Hydroxy-4-methoxybenzophenone)-4-phenylthiosemicarbazone (HMBPT) was investigated as a new reagent for the flotation of vanadium(IV). At pH approximately 1.5, vanadium(IV) forms a 1:1 pale-violet complex with HMBPT in aqueous solution. An intense clear violet layer was formed after flotation, by adding an oleic acid (HOL) surfactant. The composition of the float was 1:1 [V(IV)]:[HMBPT]. A ...

The oxovanadium(IV) complexes LVO and L'VO (L = dianion of 5,14-dihydro-6,8,15.17tetramethyldibenzo[b.i][l,4.8,ll]tetraazacyclotetradecine. H2L. and L' = dianion of 5.14-dihydro-6,15-dimethyl-8,17-diphenyldibenzo[b,i][l,4,8,1 l]tetraazacyclotetradecine, H2L') are redox active as indicated by cyclovoltammetric measurements and confirmed by preparative methods: Reversible oxidation to the corresp...

Conducting polymers of a Schiff-base ligand and the corresponding oxo-vanadium(IV) complex have been synthesized, characterized, and studied. The metal-free ligand polymer allows for direct comparison between the properties of the ligand polymer and corresponding conducting metallopolymer. The role of the metal centers in the conducting metallopolymer is elucidated unambiguously.