Vanadium is an important metal used almost exclusively in ferrous and non-ferrous alloys due to its physicochemical and mechanical properties such as grain refinement, high tensile strength, hardness and fatigue resistance; it has a wide range of uses in the metallurgical and chemical sectors [1–3]. There are mainly three kinds of raw materials, bone coal, vanadium slag and waste vanadium catal...

The oxidation of methanol to formaldehyde on silica supported vanadium oxide is studied by density functional theory. For isolated vanadium oxide species silsesquioxane-type models are adopted. The first step is dissociative adsorption of methanol yielding CH3O(O=)V(O-)2 surface complexes. This makes the O=V(OCH3)3 molecule a suited model system. The rate-limiting oxidation step involves hydrog...

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 = ...

Vanadium (CAS No. 7440-62-2) is an element that exists in a number of oxidation states ranging from -1 to +5 and can be found in various locales around the world. Absorption of vanadium from the gastrointestinal tract is poor and most ingested vanadium is typically converted to vanadyl. Excretion of absorbed vanadium is primarily via urine while unabsorbed vanadium is mainly eliminated in feces...

A spectroscopic investigation of complexes used to catalyze the oxidative carbonylation of toluene to p-toluic acid was conducted. Rhodium complexes were analyzed by (103)Rh and (13)C NMR, UV-visible spectroscopy, and infrared spectroscopy. In the presence of vanadium and oxygen, the resting state of the Rh-catalyst was found to exist as a Rh(III) complex with carbonyl and trifluoroacetate liga...

The two-coordinate metal amide complexes V{N(SiMePh2)2}2 (1) and Cr{N(SiMe2Ph)2}2 (2) were synthesized by reaction of two equivalents LiN(SiMePh2)2 with VI2(THF)4 or CrCl2(THF)2 in n-hexane. Their crystal structures showed that they have bent coordination, N-V-N = 137.0(4)°, N-Cr-N 139.19(5)°, at the metals. vanadium complex displayed no tendency to isomerize as previously observed for some V(I...

The study of DNA/BSA interaction and the catalytic potential of four mononuclear oxidoalkoxido vanadium(v) [VVO(L1-4)OEt] (1-4) and one dinuclear oxidoalkoxido mixed-ligand vanadium(v) [{VO(L2)OEt}2(Q)]{Q = 4,4'-bipyridine}(5) complexes, with tridentate binegative aroylazine ligands are reported [where H2L1 = anthranylhydrazone of 2-hydroxy-1-napthaldehyde, H2L2 = salicylhydrazone of 2-hydroxy-...

A sensitive and simultaneous spectrophotometric flow injection method for the determination of vanadium(IV) and vanadium(V) is proposed. The method is based on the effect of ligands such as 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ) and diphosphate on the conditional redox potential of iron(III)/iron(II) system. A four-channel flow system is assembled. In this flow system, diluted hydrochloric...

The discovery of high levels of vanadium-containing compounds in ascidian blood cells goes back to 1911. Ascidians, which are also known as tunicates or sea squirts, belong to a subphylum of the Chordata, between the vertebrates and invertebrates. This discovery attracted the attention of an interdisciplinary group of chemists, physiologists, and biochemists, in part because of interest in the ...

Vanadium can be an important contaminant in groundwaters impacted by mining activities. In order to determine if microorganisms of the Geobacteraceae, the predominant dissimilatory metal reducers in many subsurface environments, were capable of reducing vanadium(V), Geobacter metallireducens was inoculated into a medium in which acetate was the electron donor and vanadium(V) was the sole electr...