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...

Tetrakis(4-carboxyphenyl)porphyrin (TCPP) has been loaded on aminopropyl-silica gel by physical adsorption and by direct immobilization through formation of an amide bond to obtain chelating sorbents. These sorbents have been studied for preconcentration and separation of vanadium prior to its determination by atomic absorption spectrometry. Several parameters, such as sorption capacity of the ...

Arya Stark Instructor: Dr. Scott Oliver TA: Yashar Abdollahian Chem 151L, Section 01C Abstract. In this experiment, oxobis(2,4-pentanediono)vanadium(IV) is synthesized from a mixture of vanadium(V) oxide, sulfuric acid, acetylacetone, and ethanol. The reaction took place over heat, and came to completion when the original mixture turned blue. The solution was then filtered, neutralized, and rec...

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...

Vanadium is special in at least two respects: on the one hand, the tetrahedral anion vanadate(v) is similar to the phosphate anion; vanadate can thus interact with various physiological substrates that are otherwise functionalized by phosphate. On the other hand, the transition metal vanadium can easily expand its sphere beyond tetrahedral coordination, and switch between the oxidation states +...

Molecular structures of the isolated tetrahedral oxovanadium(IV) and bridged μ-oxo-divanadium(IV) complexes hosted by the clusters mimicking surfaces of amorphous silica-based materials were investigated using density functional theory (DFT) calculations. Principal values of the g and A tensors for the monomer vanadyl species were obtained using the coupled-perturbed DFT level of theory and the...

A new lithium vanadium fluoride Li2VF6 was prepared by reacting lithium fluoride LiF with vanadium tetrafluoride VF4 in a monel capsule at 500 ◦C. The crystal structure has been determined by means of powder X-ray diffraction. Trirutile-type dilithium hexafluorovanadate(IV) crystallizes in the tetragonal space group P42/mnm with lattice parameters a = 459.99(1), b = 459.99(1), c = 896.64(2) pm....

Vanadium-binding proteins, or Vanabins, have recently been isolated from the vanadium-rich ascidian, Ascidia sydneiensis samea. Recent reports indicate that Vanabin2 binds twenty V(IV) ions at pH 7.5, and that it has a novel bow-shaped conformation. However, the role of Vanabin2 in vanadium accumulation by the ascidian has not yet been determined. In the present study, the effects of acidic pH ...

Five oxovanadium(IV) complexes, which were divided into two groups, [V(IV)O(bhbb, nhbb)(H(2)O)(2)] (tridentate ligands: H(2)bhbb = 2-(5-bromo-2-hydroxylbenzylideneamino)benzoic acid, 1; H(2)nhbb = 2-(5-nitro-2-hydroxylbenzylideneamino)benzoic acid, 2) and [V(IV)O(cpmp, bpmp, npmp)(2)] (bidentate ligands: Hcpmp = 4-chloro-2-((phenylimino)methyl)phenol, 3; Hbpmp = 4-bromo-2-((phenylimino)methyl)p...

LO81 MODELS FOR THE ACTIVE SITES IN THE MANGANESE CATALASE, OXYGEN EVOLVING COMPLEX AND VANADIUM BROMOPEROXIDASE. V.L. Pecoraro, X. Li, J.A. Bonadies, MS. Lab, E. Larson and S. Saadeh, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-I 055, USA. Schiff Base and a-hydroxy acid complexes of manganese will be presented as models for the spectroscopic and reactivity behavior of ...