vo2+ and its complexes with ethylenediamine (en), acetylacetonate (acac), 2, 2’-bipyridine(bpy) ligands, immobilized within nanoreactors of al-mcm-41 designated as vo2+/al-mcm-41 or vol2/al-mcm-41, were prepared and characterized by x-ray powder diffraction (xrd), ft-ir, bet nitrogen adsorption-desorption and chemical analysis techniques. vo2+/al-mcm-41 and vol2/al-mcm-41 were found to catalyze...

6.1.2. Aqueous V(III) Chemistry 877 6.1.3. Oxidation State of Vanadium in Tunicates 878 6.1.4. Uptake of Vanadate into Tunicates 879 6.1.5. Vanadium Binding Proteins: Vanabins 879 6.1.6. Model Complexes and Their Chemistry 880 6.1.7. Catechol-Based Model Chemistry 880 6.1.8. Vanadium Sulfate Complexes 881 6.2. Fan Worm Pseudopotamilla occelata 883 7. Vanadium Nitrogenase 883 7.1. Nitrogenases 8...

The reaction of the oxidovanadium(V) complexes with N,N-dimethylhydrazine was demonstrated to afford the corresponding vanadium(V) dimethylhydrazido complexes. The substituent at the 3-position of the tris(2-hydroxyphenyl)amine ligand was found to influence the electronic environment of the vanadium center. The crystal structure of the non-substituted vanadium(V) dimethylhydrazido complex exhib...

The stoichiometry and thermodynamic stability of vanadium(IV/V) complexes of Triapine and two related α(N)-heterocyclic thiosemicarbazones (TSCs) with potential antitumor activity have been determined by pH-potentiometry, EPR and (51)V NMR spectroscopy in 30% (w/w) dimethyl sulfoxide/water solvent mixtures. In all cases, mono-ligand complexes in different protonation states were identified. Dim...

Isostructural vanadium, niobium and tantalum complexes of bis(3,5-di-tert-butyl-2-phenol)amine ([ONO]H3), were prepared and characterized to evaluate the impact of the metal ion on redox-activity of the ligand platform. New vanadium and niobium complexes with the general formula, [ONO]MCl2L (M = V, L = THF, 1-V; M = Nb, L = Et2O, 1-Nb) were prepared and structurally analysed by X-ray crystallog...

A series of vanadium(V) complexes with o-dioxolene (catecholato) ligands and an ancillary ligand, (N-(salicylideneaminato)ethylenediamine) (hensal), were investigated using 51V solid-state magic angle spinning NMR spectroscopy (51V MAS NMR) to assess the local environment of the vanadium(V). The solid-state 51V NMR parameters of vanadium(V) complexes with a related potentially tetradentate anci...

Interest in vanadium chemistry has increased since the recognition of the involvement of vanadium ions in many important biological systems.1 The distinctive preference of the vanadium ion for N/O donor atom types has prompted the synthesis and characterization of many model complexes containing N/O donor ligands, the spectroscopic properties and solution behavior of which have been investigate...

Vanadium plays an important role in life and one of its most relevant properties identified is its capacity to act as insulin-enhancing agent, either in the form of its inorganic salts or complexes with organic ligands. Besides the antidiabetic action, vanadium complexes are known to possess potent anticancer activity, which deserve increasing attention for application to biomedical sciences. S...

Complexes of oxovanadium(lV) with N,N' -ethylene-bis-(2-aminobenzamide) [EBAB], N,N ' -propylene-bis-(2ami nobenzamide) [PBAB], N.N ' -(o-phenylene)-bis-(2-aminobenzamide) [PhBAB] , N,N' -ethylene-bis-(3-carboxypropenamide) [EBCP], N,N' -propylene-bis-(3-carboxypropenamide) [PBCP]and 1-(2'-hydroxyphenyl)-3-phenyl-I ,3-propanedione [HPPPD] have been prepared and characterized by chemical analyse...

During asymmetric cyanohydrin synthesis catalysed by vanadium(V)oxo(salen) complexes, the catalysts are reduced to vanadium(IV)oxo(salen) as determined by EPR spectroscopy; the reducing agent is cyanide which is oxidised to cyanogen via a non-radical mechanism.