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Significations et usages de Vanadium

Définition

vanadium (n.)

1.a soft silvery white toxic metallic element used in steel alloys; it occurs in several complex minerals including carnotite and vanadinite

Vanadium (n.)

1.(MeSH)A metallic element with the atomic symbol V, atomic number 23, and atomic weight 50.94. It is used in the manufacture of vanadium steel. Prolonged exposure can lead to chronic intoxication caused by absorption usually via the lungs.

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Merriam Webster

VanadiumVa*na"di*um (?), n. [NL., fr. Icel. Vanadīs, a surname of the Scandinavian goddess Freya.] (Chem.) A rare element of the nitrogen-phosphorus group, found combined, in vanadates, in certain minerals, and reduced as an infusible, grayish-white metallic powder. It is intermediate between the metals and the non-metals, having both basic and acid properties. Symbol V (or Vd, rarely). Atomic weight 50.94 (C12=12.000).

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Définition (complément)

⇨ voir la définition de Wikipedia

Synonymes

vanadium (n.)

atomic number 23, V

Locutions

Isotopes of vanadium • Lac Doré Vanadium Deposit • Panzhihua New Steel and Vanadium • Vanadium bromoperoxidase • Vanadium carbide • Vanadium carbonyl • Vanadium chloride • Vanadium nitride • Vanadium oxide • Vanadium oxytrichloride • Vanadium redox battery • Vanadium steel • Vanadium tetrachloride • Vanadium(II) chloride • Vanadium(II) oxide • Vanadium(III) bromide • Vanadium(III) chloride • Vanadium(III) fluoride • Vanadium(III) iodide • Vanadium(III) oxide • Vanadium(III) sulfate • Vanadium(IV) fluoride • Vanadium(IV) oxide • Vanadium(V) oxide • Vanadium(V) oxytrifluoride • Vanadium-40 • Vanadium-41 • Vanadium-42 • Vanadium-43 • Vanadium-44 • Vanadium-44m • Vanadium-45 • Vanadium-46 • Vanadium-46m • Vanadium-47 • Vanadium-48 • Vanadium-49 • Vanadium-50 • Vanadium-51 • Vanadium-52 • Vanadium-53 • Vanadium-54 • Vanadium-54m • Vanadium-55 • Vanadium-56 • Vanadium-57 • Vanadium-58 • Vanadium-59 • Vanadium-60 • Vanadium-60m1 • Vanadium-60m2 • Vanadium-61 • Vanadium-62 • Vanadium-63 • Vanadium-64 • Vanadium-65

Dictionnaire analogique

Wikipedia

Vanadium

                   
titaniumvanadiumchromium
-

V

Nb
Appearance
blue-silver-grey metal
General properties
Name, symbol, number vanadium, V, 23
Pronunciation /vəˈndiəm/
və-NAY-dee-əm
Element category transition metal
Group, period, block 54, d
Standard atomic weight 50.9415(1)
Electron configuration [Ar] 3d3 4s2
Electrons per shell 2, 8, 11, 2 (Image)
Physical properties
Phase solid
Density (near r.t.) 6.0 g·cm−3
Liquid density at m.p. 5.5 g·cm−3
Melting point 2183 K, 1910 °C, 3470 °F
Boiling point 3680 K, 3407 °C, 6165 °F
Heat of fusion 21.5 kJ·mol−1
Heat of vaporization 459 kJ·mol−1
Molar heat capacity 24.89 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 2101 2289 2523 2814 3187 3679
Atomic properties
Oxidation states 5, 4, 3, 2, 1, -1
(amphoteric oxide)
Electronegativity 1.63 (Pauling scale)
Ionization energies
(more)
1st: 650.9 kJ·mol−1
2nd: 1414 kJ·mol−1
3rd: 2830 kJ·mol−1
Atomic radius 134 pm
Covalent radius 153±8 pm
Miscellanea
Crystal structure body-centered cubic
Magnetic ordering paramagnetic
Electrical resistivity (20 °C) 197 nΩ·m
Thermal conductivity 30.7 W·m−1·K−1
Thermal expansion (25 °C) 8.4 µm·m−1·K−1
Speed of sound (thin rod) (20 °C) 4560 m·s−1
Young's modulus 128 GPa
Shear modulus 47 GPa
Bulk modulus 160 GPa
Poisson ratio 0.37
Mohs hardness 6.7
CAS registry number 7440-62-2
Most stable isotopes
Main article: Isotopes of vanadium
iso NA half-life DM DE (MeV) DP
48V syn 15.9735 d ε+β+ 4.0123 48Ti
49V syn 330 d ε 0.6019 49Ti
50V 0.25% 1.5×1017y ε 2.2083 50Ti
β 1.0369 50Cr
51V 99.75% 51V is stable with 28 neutrons
· r

Vanadium (play /vəˈndiəm/ və-NAY-dee-əm) is a chemical element with the symbol V and atomic number 23. It is a hard, silvery gray, ductile and malleable transition metal. The element is found only in chemically combined form in nature, but once isolated artificially, the formation of an oxide layer stabilizes the free metal somewhat against further oxidation. Andrés Manuel del Río discovered vanadium in 1801 by analyzing a new lead-bearing mineral he called "brown lead," and named the new element erythronium (Greek for "red") since, upon heating, most of its salts turned from their initial color to red. Four years later, however, he was convinced by other scientists that erythronium was identical to chromium. The element was rediscovered in 1831 by Nils Gabriel Sefström, who named it vanadium after the Germanic goddess of beauty and fertility, Vanadís (Freyja). Both names were attributed to the wide range of colors found in vanadium compounds. Del Rio's lead mineral was later renamed vanadinite for its vanadium content.

The element occurs naturally in about 65 different minerals and in fossil fuel deposits. It is produced in China and Russia from steel smelter slag; other countries produce it either from the flue dust of heavy oil, or as a byproduct of uranium mining. It is mainly used to produce specialty steel alloys such as high speed tool steels. The most important industrial vanadium compound, vanadium pentoxide, is used as a catalyst for the production of sulfuric acid.

Large amounts of vanadium ions are found in a few organisms, possibly as a toxin. The oxide and some other salts of vanadium have moderate toxicity. Particularly in the ocean, vanadium is used by some life forms as an active center of enzymes, such as the vanadium bromoperoxidase of some ocean algae. Vanadium is probably a micronutrient in mammals, including humans, but its precise role in this regard is unknown.

Contents

  History

Vanadium was originally discovered by Andrés Manuel del Río, a Spanish-born Mexican mineralogist, in 1801. Del Río extracted the element from a sample of Mexican "brown lead" ore, later named vanadinite. He found that its salts exhibit a wide variety of colors, and as a result he named the element panchromium (Greek: παγχρώμιο "all colors"). Later, Del Río renamed the element erythronium (Greek: ερυθρός "red") as most of its salts turned red upon heating. In 1805, the French chemist Hippolyte Victor Collet-Descotils, backed by del Río's friend Baron Alexander von Humboldt, incorrectly declared that del Río's new element was only an impure sample of chromium. Del Río accepted the Collet-Descotils' statement and retracted his claim.[1]

In 1831, the Swedish chemist Nils Gabriel Sefström rediscovered the element in a new oxide he found while working with iron ores. Later that same year, Friedrich Wöhler confirmed del Río's earlier work.[2] Sefström chose a name beginning with V, which had not been assigned to any element yet. He called the element vanadium after Old Norse Vanadís (another name for the Norse Vanr goddess Freyja, whose facets include connections to beauty and fertility), because of the many beautifully colored chemical compounds it produces.[2] In 1831, the geologist George William Featherstonhaugh suggested that vanadium should be renamed "rionium" after del Río, but this suggestion was not followed.[3]

  The Model T made use of vanadium steel in its chassis.

The isolation of vanadium metal proved difficult. In 1831, Berzelius reported the production of the metal, but Henry Enfield Roscoe showed that Berzelius had in fact produced the nitride, vanadium nitride (VN). Roscoe eventually produced the metal in 1867 by reduction of vanadium(II) chloride, VCl2, with hydrogen.[4] In 1927, pure vanadium was produced by reducing vanadium pentoxide with calcium.[5] The first large-scale industrial use of vanadium in steels was found in the chassis of the Ford Model T, inspired by French race cars. Vanadium steel allowed for reduced weight while simultaneously increasing tensile strength.[6]

  Creation

The stable form of vanadium is created in supernovas via the r-process.[7]

  Characteristics

  Highpure (99.95%) vanadium cuboids, ebeam remelted and macro etched

Vanadium is a hard, ductile, silver-gray metal. Some sources describe vanadium as "soft", perhaps because it is ductile, malleable and not brittle.[8][9] Vanadium is harder than most metals and steels (see Hardnesses of the elements (data page) and iron). It has good resistance to corrosion and it is stable against alkalis, sulfuric and hydrochloric acids.[10] It is oxidized in air at about 933 K (660 °C, 1220 °F), although an oxide layer forms even at room temperature.

  Isotopes

Naturally occurring vanadium is composed of one stable isotope 51V and one radioactive isotope 50V. The latter has a half-life of 1.5×1017 years and a natural abundance 0.25%. 51V has a nuclear spin of 7/2 which is useful for NMR spectroscopy.[11] 24 artificial radioisotopes have been characterized, ranging in mass number from 40 to 65. The most stable of these isotopes are 49V with a half-life of 330 days, and 48V with a half-life of 16.0 days. All of the remaining radioactive isotopes have half-lives shorter than an hour, most of which are below 10 seconds. At least 4 isotopes have metastable excited states.[11] Electron capture is the main decay mode for isotopes lighter than the 51V. For the heavier ones, the most common mode is beta decay. The electron capture reactions lead to the formation of element 22 (titanium) isotopes, while for beta decay, it leads to element 24 (chromium) isotopes.

  Chemistry and compounds

  Oxidation states of vanadium, from left +2 (lilac), +3 (green), +4 (blue) and +5 (yellow).

The chemistry of vanadium is noteworthy for the accessibility of the four adjacent oxidation states 2-5. In aqueous solution the colours are lilac V2+(aq), green V3+(aq), blue VO2+(aq) and, at high pH, yellow VO42-. Vanadium(II) compounds are reducing agents, and vanadium(V) compounds are oxidizing agents. Vanadium(IV) compounds often exist as vanadyl derivatives which contain the VO2+ center.[10]

Ammonium vanadate(V) (NH4VO3) can be successively reduced with elemental zinc to obtain the different colors of vanadium in these four oxidation states. Lower oxidation states occur in compounds such as V(CO)6, [V(CO)6] and substituted derivatives.[10]

The vanadium redox battery utilizes all four oxidation states; one electrode uses the +5/+4 couple and the other uses the +3/+2 couple. Conversion of these oxidation states is illustrated by the reduction of a strongly acidic solution of a vanadium(V) compound with zinc dust. The initial red color characteristic of the polyvanadates such as [H2V10O28]4-, are replaced by the blue color of [VO(H2O)5]2+, followed by the green color of [V(H2O)6]3+ and then violet, due to [V(H2O)6]2+.[10]

The most commercially important compound is vanadium pentoxide, which is used as a catalyst for the production of sulfuric acid.[10] This compound oxidizes sulfur dioxide (SO2) to the trioxide (SO3). In this redox reaction, sulfur is oxidized from +4 to +6, and vanadium is reduced from +5 to +3:

V2O5 + 2 SO2 → V2O3 + 2 SO3

The catalyst is regenerated by oxidation with air:

V2O3 + O2 → V2O5

  Oxy-anions and cations

  the decavanadate structure

The oxyanion chemistry of vanadium(V) is complex: the predominance diagram for vanadates in aqueous solution shows at least 11 species to be predominant under specified conditions of pH and concentration.[12] The tetrahedral vanadate ion, VO3−
4
, is the principal species present at pH 12-14. On acidification, the monomer [HVO4]2- and dimer [V2O7]- are formed, with the monomer predominant at vanadium concentration of less than ca. 10−2M (pV > 2; pV is equal to minus the logarithm of the total vanadium concentration/M). The formation of the divanadate ion is analogous to the formation of the dichromate ion. As the pH is reduced, further protonation and polymerization to polyvanadates occur: at pH 4-6 [H2VO4]- is predominant at pV greater than ca. 4, while at higher concentrations trimers and tetramers are formed. Between pH 2-4 decavanadates predominate. In decavanadates there is a distorted octahedron of oxygen atoms around each vanadium atom.[10] Vanadic acid, H3VO4 has a very low concentration because protonation of the tetrahedral species [H2VO4]- results in the preferential formation of the octahedral [VO2(H2O)4]+ species. In strongly acidic solutions, pH<2. [VO2(H2O)4]+ is the predominant species, while the oxide V2O5 precipitates from solution at high concentrations. The oxide is formally the inorganic anhydride of vanadic acid. The structures of many of these and other vanadate ions have been determined by X-ray crystallography of crystalline compounds.

The acid dissociation constants for the vanadium and phosphorus series are remarkably similar. Chains, rings and clusters involving tetrahedral vanadium, analogous to the polyphosphates, are known. The correspondence between vanadate and phosphate chemistry can be attributed to the similarity in size and charge of phosphorus(V) and vanadium(V). Orthovanadate VO3−
4
is used in protein crystallography[13] to study the biochemistry of phosphate.[14]

  The Pourbaix diagram for vanadium in water

The Pourbaix diagram for vanadium in water, which shows the redox potentials between various vanadium species in different oxidation states is also complex.[15]

Vanadium(V) also forms various peroxo-complexes. The species VO(O)2(H2O)4+ is present in acidic solutions. In alkaline solutions species with 2, 3 and 4 peroxide groups are present; the last forms violet crystals M3V(O2)4 nH2O (M=Li, Na, K, NH4+), in which the vanadium has an 8-coordinate dodecahedral structure.[16][17]

  Chalcogenide and halide compounds

Vanadium forms a very large variety of binary compounds with sulfur, selenium and tellurium, often with complicated structures. The tetrahedral sulfa-anion [VS4]3-, analogous to the orthovanadate ion, is well-known, but there are no thio-analogues of the polymeric oxo-vanadates.[18]

All four halides are known for oxidation states +2 and +3, but the iodide is not known for V(IV) and VF5 is the only halide known for oxidation state 5. VCl4 may be used as a catalyst for polymerization of dienes.

Examples of oxyhalides include.[19]

  • vanadium(V): VOF3, VOX3 and VO2X (X=F, Cl)
  • vanadium(IV): VOX2 (X=F, Cl, Br)
  • vanadium(III): VOX, (X=Cl,Br)

  Coordination compounds

  A ball-and-stick model of VO(acac)2

Vanadium's early position in the transition metal series lead to three rather unusual features of the coordination chemistry of vanadium. Firstly, metallic vanadium has the electronic configuration [Ar]3d34s2, so compounds of vanadium are relatively electron-poor. Consequently, most binary compounds are Lewis acids (electron pair acceptors); examples are all the halides forming octahedral adducts with the formula VXnL6−n (X = halide; L = other ligand). Secondly, the vanadium ion is rather large and can achieve coordination numbers higher than 6, as is the case in [V(CN)7]4−. Thirdly, the vanadyl ion, VO2+, is featured in many complexes of vanadium(IV) such as vanadyl acetylacetonate (V(=O)(acac)2). In this complex, the vanadium is 5-coordinate, square pyramidal, meaning that a sixth ligand, such as pyridine, may be attached, though the association constant of this process is small. Many 5-coordinate vanadyl complexes have a trigonal bypyramidal geometry, such as VOCl2(NMe3)2.[20]

  Organometallic compounds

Organometallic chemistry of vanadium is well developed, but organometallic compounds are of minor commercial significance. Vanadocene dichloride is a versatile starting reagent and even finds minor applications in organic chemistry.[21] Vanadium carbonyl, V(CO)6, is a rare example of a metal carbonyl containing an unpaired electron, but which exists without dimerization. The addition of an electron yields V(CO)
6
(isoelectronic with Cr(CO)6), which may be further reduced with sodium in liquid ammonia to yield V(CO)3−
6
(isoelectronic with Fe(CO)5).[22][23]

  Occurrence

  Vanadinite

Metallic vanadium is not found in nature, but is known to exist in about 65 different minerals. Economically significant examples include patronite (VS4),[24] vanadinite (Pb5(VO4)3Cl), and carnotite (K2(UO2)2(VO4)2·3H2O). Much of the world's vanadium production is sourced from vanadium-bearing magnetite found in ultramafic gabbro bodies. Vanadium is mined mostly in South Africa, north-western China, and eastern Russia. In 2010 these three countries mined more than 98% of the 56,000 tonnes of produced vanadium.[25]

Vanadium is also present in bauxite and in fossil fuel deposits such as crude oil, coal, oil shale and tar sands. In crude oil, concentrations up to 1200 ppm have been reported. When such oil products are burned, the traces of vanadium may initiate corrosion in motors and boilers.[26] An estimated 110,000 tonnes of vanadium per year are released into the atmosphere by burning fossil fuels.[27] Vanadium has also been detected spectroscopically in light from the Sun and some other stars.[28]

  Production

  Ferrovanadium chunks
  Electrolytically refined vanadium dendritic crystals (99,9%)
  Iodide refined vanadium

Most vanadium is used as an alloy called ferrovanadium as an additive to improve steels. Ferrovanadium is produced directly by reducing a mixture of vanadium oxide, iron oxides and iron in an electric furnace. Vanadium-bearing magnetite iron ore is the main source for the production of vanadium.[29] The vanadium ends up in pig iron produced from vanadium bearing magnetite. During steel production, oxygen is blown into the pig iron, oxidizing the carbon and most of the other impurities, forming slag. Depending on the used ore, the slag contains up to 25% of vanadium.[29]

Vanadium metal is obtained via a multistep process that begins with the roasting of crushed ore with NaCl or Na2CO3 at about 850 °C to give sodium metavanadate (NaVO3). An aqueous extract of this solid is acidified to give "red cake", a polyvanadate salt, which is reduced with calcium metal. As an alternative for small-scale production, vanadium pentoxide is reduced with hydrogen or magnesium. Many other methods are also in use, in all of which vanadium is produced as a byproduct of other processes.[29] Purification of vanadium is possible by the crystal bar process developed by Anton Eduard van Arkel and Jan Hendrik de Boer in 1925. It involves the formation of the metal iodide, in this example vanadium(III) iodide, and the subsequent decomposition to yield pure metal.[30]

2 V + 3 I2 is in equilibrium with 2 VI3

  Applications

  Tool made from vanadium steel

  Alloys

Approximately 85% of vanadium produced is used as ferrovanadium or as a steel additive.[29] The considerable increase of strength in steel containing small amounts of vanadium was discovered in the beginning of the 20th century. Vanadium forms stable nitrides and carbides, resulting in a significant increase in the strength of the steel.[31] From that time on vanadium steel was used for applications in axles, bicycle frames, crankshafts, gears, and other critical components. There are two groups of vanadium containing steel alloy groups. Vanadium high-carbon steel alloys contain 0.15% to 0.25% vanadium and high speed tool steels (HSS) have a vanadium content of 1% to 5%. For high speed tool steels, a hardness above HRC 60 can be achieved. HSS steel is used in surgical instruments and tools.[32]

Vanadium stabilizes the beta form of titanium and increases the strength and temperature stability of titanium. Mixed with aluminium in titanium alloys it is used in jet engines and high-speed airframes. One of the common alloys is Titanium 6AL-4V, a titanium alloy with 6% aluminium and 4% vanadium.[33]

  Other uses

  Vanadium(V) oxide is a catalyst in the contact process for producing sulfuric acid

Vanadium is compatible with iron and titanium, therefore vanadium foil is used in cladding titanium to steel.[34] The moderate thermal neutron-capture cross-section and the short half-life of the isotopes produced by neutron capture makes vanadium a suitable material for the inner structure of a fusion reactor.[35][36] Several vanadium alloys show superconducting behavior. The first A15 phase superconductor was a vanadium compound, V3Si, which was discovered in 1952.[37] Vanadium-gallium tape is used in superconducting magnets (17.5 teslas or 175,000 gauss). The structure of the superconducting A15 phase of V3Ga is similar to that of the more common Nb3Sn and Nb3Ti.[38]

The most common oxide of vanadium, vanadium pentoxide V2O5, is used as a catalyst in manufacturing sulfuric acid by the contact process[39] and as an oxidizer in maleic anhydride production.[40] Vanadium pentoxide is also used in making ceramics.[41] Another oxide of vanadium, vanadium dioxide VO2, is used in the production of glass coatings, which blocks infrared radiation (and not visible light) at a specific temperature.[42] Vanadium oxide can be used to induce color centers in corundum to create simulated alexandrite jewelry, although alexandrite in nature is a chrysoberyl.[43] The possibility to use vanadium redox couples in both half-cells, thereby eliminating the problem of cross contamination by diffusion of ions across the membrane is the advantage of vanadium redox rechargeable batteries.[44] Vanadate can be used for protecting steel against rust and corrosion by electrochemical conversion coating.[45] Lithium vanadium oxide has been proposed for use as a high energy density anode for lithium ion batteries, at 745 Wh/L when paired with a lithium cobalt oxide cathode.[46] It has been proposed by some researchers that a small amount, 40 to 270 ppm, of vanadium in Wootz steel and Damascus steel, significantly improves the strength of the material, although it is unclear what the source of the vanadium was.[47]

  Biological role

Vanadium plays a very limited role in biology, and is more important in ocean environments than on land.[48]

  Ascidiacea (sea squirts) contain vanadium as vanabin.
  Tunicates such as this bluebell tunicate contain vanadium as vanabin.

  Bromoperoxidases in algae

Organobromine compounds in a number of species of marine algae are generated by the action of a vanadium dependent bromoperoxidase. This is a haloperoxidase in algae which requires bromide and is an absolutely vanadium-dependent enzyme. Most organobromine compounds in the sea ultimately arise via the action of this vanadium bromoperoxidase.[49]

  Vanadium accumulation in tunicates and ascidians

German chemist Martin Henze discovered vanadium in the blood cells (or coelomic cells) of Ascidiacea (sea squirts) in 1911.[50][51] It is essential to ascidians and tunicates, where it is stored in the highly acidified vacuoles of certain blood cell types, designated vanadocytes. Vanabins (vanadium binding proteins) have been identified in the cytoplasm of such cells. The concentration of vanadium in their blood is up to 10 million times higher than the concentration of vanadium in the seawater around them. The function of this vanadium concentration system, and these vanadium-containing proteins, is still unknown.

  Nitrogen fixation

A vanadium nitrogenase is used by some nitrogen-fixing micro-organisms, such as Azotobacter. In this role vanadium replaces more common molybdenum or iron, and gives the nitrogenase slightly different properties.[52]

  Fungi

Several species of macrofungi, namely Amanita muscaria and related species, accumulate vanadium (up to 500 mg/kg in dry weight). Vanadium is present in the coordination complex, amavadin,[53] in fungal fruit-bodies. However, the biological importance of the accumulation process is unknown.[54][55] Toxin functions or peroxidase enzyme functions have been suggested.

  Mammals and birds

Rats and chickens are also known to require vanadium in very small amounts and deficiencies result in reduced growth and impaired reproduction.[56] Vanadium is a relatively controversial dietary supplement, primarily for increasing insulin sensitivity[57] and body-building. Whether it works for the latter purpose has not been proven, and there is some evidence that athletes who take it are merely experiencing a placebo effect.[58] Vanadyl sulfate may improve glucose control in people with type 2 diabetes.[59][60][61][62][63] In addition, decavanadate and oxovanadates are species that potentially have many biological activities and that have been successfully used as tools in the comprehension of several biochemical processes.[64]

  Safety

All vanadium compounds should be considered toxic. Tetravalent VOSO4 has been reported to be over 5 times more toxic than trivalent V2O3.[65] The Occupational Safety and Health Administration (OSHA) has set an exposure limit of 0.05 mg/m3 for vanadium pentoxide dust and 0.1 mg/m3 for vanadium pentoxide fumes in workplace air for an 8-hour workday, 40-hour work week.[66] The National Institute for Occupational Safety and Health (NIOSH) has recommended that 35 mg/m3 of vanadium be considered immediately dangerous to life and health. This is the exposure level of a chemical that is likely to cause permanent health problems or death.[66]

Vanadium compounds are poorly absorbed through the gastrointestinal system. Inhalation exposures to vanadium and vanadium compounds result primarily in adverse effects on the respiratory system.[67][68][69] Quantitative data are, however, insufficient to derive a subchronic or chronic inhalation reference dose. Other effects have been reported after oral or inhalation exposures on blood parameters,[70][71] on liver,[72] on neurological development in rats,[73] and other organs.[74]

There is little evidence that vanadium or vanadium compounds are reproductive toxins or teratogens. Vanadium pentoxide was reported to be carcinogenic in male rats and male and female mice by inhalation in an NTP study,[68] although the interpretation of the results has recently been disputed.[75] Vanadium has not been classified as to carcinogenicity by the United States Environmental Protection Agency.[76]

Vanadium traces in diesel fuels present a corrosion hazard; it is the main fuel component influencing high temperature corrosion. During combustion, it oxidizes and reacts with sodium and sulfur, yielding vanadate compounds with melting points down to 530 °C, which attack the passivation layer on steel, rendering it susceptible to corrosion. The solid vanadium compounds also cause abrasion of engine components.[citation needed]

  See also

  References

  1. ^ Cintas, Pedro (2004). "The Road to Chemical Names and Eponyms: Discovery, Priority, and Credit". Angewandte Chemie International Edition 43 (44): 5888–94. DOI:10.1002/anie.200330074. PMID 15376297. 
  2. ^ a b Sefström, N. G. (1831). "Ueber das Vanadin, ein neues Metall, gefunden im Stangeneisen von Eckersholm, einer Eisenhütte, die ihr Erz von Taberg in Småland bezieht". Annalen der Physik und Chemie 97: 43. Bibcode 1831AnP....97...43S. DOI:10.1002/andp.18310970103. 
  3. ^ Featherstonhaugh, George William (1831). The Monthly American Journal of Geology and Natural Science: 69. 
  4. ^ Roscoe, Henry E. (1869–1870). "Researches on Vanadium. Part II". Proceedings of the Royal Society of London 18 (114–122): 37. DOI:10.1098/rspl.1869.0012. 
  5. ^ Marden, J. W.; Rich, M. N. (1927). "Vanadium". Industrial and Engineering Chemistry 19 (7): 786. DOI:10.1021/ie50211a012. 
  6. ^ Betz, Frederick (2003). Managing Technological Innovation: Competitive Advantage from Change. Wiley-IEEE. pp. 158–159. ISBN 0-471-22563-0. http://books.google.com/?id=KnpGtu-R77UC&pg=PA158. 
  7. ^ A.G.W. Cameron (June 1957). "Stellar Evolution, Nuclear Astrophysics, and Nucleogenesis". CRL-41. http://www.fas.org/sgp/eprint/CRL-41.pdf. 
  8. ^ George F. Vander Voort (1984). Metallography, principles and practice. ASM International. pp. 137–. ISBN 978-0-87170-672-0. http://books.google.com/books?id=GRQC8zYqtBIC&pg=PA137. Retrieved 17 September 2011. 
  9. ^ François Cardarelli (2008). Materials handbook: a concise desktop reference. Springer. pp. 338–. ISBN 978-1-84628-668-1. http://books.google.com/books?id=PvU-qbQJq7IC&pg=PA338. Retrieved 17 September 2011. 
  10. ^ a b c d e f Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils; (1985). "Vanadium" (in German). Lehrbuch der Anorganischen Chemie (91–100 ed.). Walter de Gruyter. pp. 1071–1075. ISBN 3-11-007511-3. 
  11. ^ a b Georges, Audi (2003). "The NUBASE Evaluation of Nuclear and Decay Properties". Nuclear Physics A (Atomic Mass Data Center) 729: 3–128. Bibcode 2003NuPhA.729....3A. DOI:10.1016/j.nuclphysa.2003.11.001. 
  12. ^ Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. ISBN 0080379419.  p. 984
  13. ^ Sinning, Irmgard; Hol, Wim G.J. (2004). "The power of vanadate in crystallographic investigations of phosphoryl transfer enzymes". FEBS Letters 577 (3): 315–21. DOI:10.1016/j.febslet.2004.10.022. PMID 15556602. 
  14. ^ Seargeant, Lorne E.; Stinson, Robert A. (1979). "Inhibition of human alkaline phosphatases by vanadate". Biochemical Journal 181 (1): 247–50. PMC 1161148. PMID 486156. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1161148. 
  15. ^ Al-Kharafi, F. M.; Badawy, W. A. (1997). "Electrochemical behavior of vanadium in aqueous solutions of different pH". Electrochimica Acta 42 (4): 579. DOI:10.1016/S0013-4686(96)00202-2. 
  16. ^ Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. ISBN 0080379419. , p994.
  17. ^ Strukul, Giorgio (1992). Catalytic oxidations with hydrogen peroxide as oxidant. Springer. p. 128. ISBN 0-7923-1771-8. http://books.google.com/?id=Lmt3x9CyfLgC&pg=PA128. 
  18. ^ Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. ISBN 0080379419.  p.988
  19. ^ Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. ISBN 0080379419.  p.993
  20. ^ Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. ISBN 0080379419.  p. 996
  21. ^ Wilkinson, G. and Birmingham, J.G. (1954). "Bis-cyclopentadienyl Compounds of Ti, Zr, V, Nb and Ta". Journal of the American Chemical Society 76 (17): 4281. DOI:10.1021/ja01646a008. 
  22. ^ Bellard, S.; Rubinson, K. A.; Sheldrick, G. M. (1979). "Crystal and molecular structure of vanadium hexacarbonyl". Acta Crystallographica B35 (2): 271. DOI:10.1107/S0567740879003332. 
  23. ^ Elschenbroich, C.; Salzer A. (1992). Organometallics : A Concise Introduction. Wiley-VCH. ISBN 3-527-28165-7. 
  24. ^ "mineralogical data about Patrónite". mindata.org. http://www.mindat.org/min-3131.html. Retrieved 2009-01-19. 
  25. ^ Magyar, Michael J.. "Mineral Commodity Summaries 2011: Vanadium". United States Geological Survey. http://minerals.usgs.gov/minerals/pubs/commodity/vanadium/mcs-2011-vanad.pdf. Retrieved 2011-01-15. 
  26. ^ Pearson, C. D.; Green J. B. (1993). "Vanadium and nickel complexes in petroleum resid acid, base, and neutral fractions". Energy Fuels 7 (3): 338. DOI:10.1021/ef00039a001. 
  27. ^ Anke, Manfred (2004). "Vanadium – An element both essential and toxic to plants, animals and humans?". Anal. Real Acad. Nac. Farm. 70: 961. 
  28. ^ Cowley, C. R.; Elste, G. H.; Urbanski, J. L. (1978). "Vanadium abundances in early A stars". Astronomical Society of the Pacific 90: 536. Bibcode 1978PASP...90..536C. DOI:10.1086/130379. 
  29. ^ a b c d Moskalyk, R. R.; Alfantazi, A. M. (2003). "Processing of vanadium: a review". Minerals Engineering 16 (9): 793. DOI:10.1016/S0892-6875(03)00213-9. 
  30. ^ Carlson, O. N.; Owen, C. V. (1961). "Preparation of High-Purity Vanadium Metals by the Iodide Refining Process". Journal of the Electrochemical Society 108: 88. DOI:10.1149/1.2428019. 
  31. ^ Chandler, Harry (1998). Metallurgy for the Non-metallurgist. ASM International. pp. 6–7. ISBN 978-0-87170-652-2. http://books.google.com/?id=arupok8PTBEC. 
  32. ^ Davis, Joseph R. (1995). Tool Materials: Tool Materials. ASM International. ISBN 978-0-87170-545-7. http://books.google.com/?id=Kws7x68r_aUC&pg=PA11. 
  33. ^ Peters, Manfred; Leyens, C. (2002). "Metastabile β-Legierungen". Titan und Titanlegierungen. Wiley-VCH. pp. 23–24. ISBN 978-3-527-30539-1. http://books.google.com/?id=sxdR882jQpYC&pg=PA23. 
  34. ^ Lositskii, N. T.; Grigor'ev A. A.; Khitrova, G. V. (1966). "Welding of chemical equipment made from two-layer sheet with titanium protective layer (review of foreign literature)". Chemical and Petroleum Engineering 2 (12): 854–856. DOI:10.1007/BF01146317. 
  35. ^ Matsui, H.; Fukumoto, K.; Smith, D. L.; Chung, Hee M.; Witzenburg, W. van; Votinov, S. N. (1996). "Status of vanadium alloys for fusion reactors". Journal of Nuclear Materials 233–237 (1): 92–99. Bibcode 1996JNuM..233...92M. DOI:10.1016/S0022-3115(96)00331-5. 
  36. ^ "Vanadium Data Sheet". Allegheny Technologies – Wah Chang. http://www.wahchang.com/pages/products/data/pdf/Vanadium.pdf. Retrieved 2009-01-16. 
  37. ^ Hardy, George F.; Hulm, John K. (1953). "Superconducting Silicides and Germanides". Physical Reviews 89 (4): 884–884. Bibcode 1953PhRv...89Q.884H. DOI:10.1103/PhysRev.89.884. 
  38. ^ Markiewicz, W.; Mains, E.; Vankeuren, R.; Wilcox, R.; Rosner, C.; Inoue, H.; Hayashi, C.; Tachikawa, K. (1977). "A 17.5 Tesla superconducting concentric Nb3Sn and V3Ga magnet system". IEEE Transactions on Magnetics 13 (1): 35–37. Bibcode 1977ITM....13...35M. DOI:10.1109/TMAG.1977.1059431. 
  39. ^ Eriksen, K. M.; Karydis, D. A.; Boghosian, S.; Fehrmann, R. (1995). "Deactivation and Compound Formation in Sulfuric-Acid Catalysts and Model Systems". Journal of Catalysis 155 (1): 32–42. DOI:10.1006/jcat.1995.1185. 
  40. ^ Abon, Michel; Volta, Jean-Claude (1997). "Vanadium phosphorus oxides for n-butane oxidation to maleic anhydride". Applied Catalysis A: General 157 (1–2): 173–193. DOI:10.1016/S0926-860X(97)00016-1. 
  41. ^ Lide, David R. (2004). "vanadium". CRC Handbook of Chemistry and Physics. Boca Raton: CRC Press. pp. 4–34. ISBN 978-0-8493-0485-9. 
  42. ^ Manning, Troy D.; Parkin, Ivan P.; Clark, Robin J. H.; Sheel, David; Pemble, Martyn E.; Vernadou, Dimitra (2002). "Intelligent window coatings: atmospheric pressure chemical vapour deposition of vanadium oxides". Journal of Materials Chemistry 12 (10): 2936–2939. DOI:10.1039/b205427m. 
  43. ^ White, Willam B.; Roy, Rustum; McKay, Chrichton (1962). "The Alexandrite Effect: And Optical Study". American Mineralogist 52: 867–871. http://www.minsocam.org/ammin/AM52/AM52_867.pdf. 
  44. ^ Joerissen, Ludwig; Garche, Juergen; Fabjan, Ch.; Tomazic G. (2004). "Possible use of vanadium redox-flow batteries for energy storage in small grids and stand-alone photovoltaic systems". Journal of Power Sources 127 (1–2): 98–104. DOI:10.1016/j.jpowsour.2003.09.066. 
  45. ^ Guan, H.; Buchheit R. G. (2004). "Corrosion Protection of Aluminum Alloy 2024-T3 by Vanadate Conversion Coatings". Corrosion 60 (3): 284–296. DOI:10.5006/1.3287733. 
  46. ^ Kariatsumari, Koji (February 2008). "Li-Ion Rechargeable Batteries Made Safer". Nikkei Business Publications, Inc.. http://techon.nikkeibp.co.jp/article/HONSHI/20080129/146549/. Retrieved 10-12-2008. 
  47. ^ Verhoeven, J. D.; Pendray, A. H.; Dauksch, W. E. (1998). "The key role of impurities in ancient damascus steel blades". Journal of the Minerals, Metals and Materials Society 50 (9): 58–64. Bibcode 1998JOM....50i..58V. DOI:10.1007/s11837-998-0419-y. 
  48. ^ Helmut, Sigel; Astrid, Sigel, eds. (1995). Vanadium and Its Role in Life. Metal Ions in Biological Systems. 31. CRC. ISBN 0-8247-9383-8. 
  49. ^ Butler, Alison; Carter-Franklin, Jayme N. (2004). "The role of vanadium bromoperoxidase in the biosynthesis of halogenated marine natural products". Natural Product Reports 21 (1): 180–8. DOI:10.1039/b302337k. PMID 15039842. 
  50. ^ Henze, M (1911). "Untersuchungen fiber das Blut der Ascidien. I. Mitteilung". Z. Physiol. Chem. 72 (5–6): 494–50. http://books.google.co.uk/books?id=x5g8AAAAIAAJ. 
  51. ^ Michibata, H; Uyama, T; Ueki, T; Kanamori, K (2002). "Vanadocytes, cells hold the key to resolving the highly selective accumulation and reduction of vanadium in ascidians". Microscopy Research and Technique 56 (6): 421–434. DOI:10.1002/jemt.10042. PMID 11921344. 
  52. ^ Robson, R. L.; Eady, R. R.; Richardson, T. H.; Miller, R. W.; Hawkins, M.; Postgate, J. R. (1986). "The alternative nitrogenase of Azotobacter chroococcum is a vanadium enzyme". Nature (London) 322 (6077): 388–390. Bibcode 1986Natur.322..388R. DOI:10.1038/322388a0. 
  53. ^ Kneifel, Helmut; Bayer, Ernst (1997). "Determination of the Structure of the Vanadium Compound, Amavadine, from Fly Agaric". Angewandte Chemie International Edition in English 12 (6): 508. DOI:10.1002/anie.197305081. ISSN 10.1002/anie.197305081. 
  54. ^ Falandysz, J.; Kunito, T., Kubota, R.; Lipka, K.; Mazur, A.; Falandysz, Justyna J.; Tanabe, S. (2007). "Selected elements in fly agaric Amanita muscaria". Journal of Environmental Science and Health, Part A 42 (11): 1615–1623. DOI:10.1080/10934520701517853. PMID 17849303. 
  55. ^ Berry, Robert E.; Armstrong, Elaine M.; Beddoes, Roy L.; Collison, David; Ertok, Nigar; Helliwell, Madeleine; Garner, David (1999). "The Structural Characterization of Amavadin". Angew. Chem. Int. Ed. 38 (6): 795–797. DOI:10.1002/(SICI)1521-3773(19990315)38:6<795::AID-ANIE795>3.0.CO;2-7. 
  56. ^ Schwarz, Klaus; Milne, David B. (1971). "Growth Effects of Vanadium in the Rat". Science 174 (4007): 426–428. Bibcode 1971Sci...174..426S. DOI:10.1126/science.174.4007.426. JSTOR 1731776. PMID 5112000. 
  57. ^ Yeh, Gloria Y.; Eisenberg, David M.; Kaptchuk, Ted J.; Phillips, Russell S. (2003). "Systematic Review of Herbs and Dietary Supplements for Glycemic Control in Diabetes". Diabetes Care 26 (4): 1277–1294. DOI:10.2337/diacare.26.4.1277. PMID 12663610. http://care.diabetesjournals.org/cgi/content/full/26/4/1277. 
  58. ^ Talbott, Shawn M.; Hughes, Kerry (2007). "Vanadium". The Health Professional's Guide to Dietary Supplements. Lippincott Williams & Wilkins. pp. 419–422. ISBN 978-0-7817-4672-4. http://books.google.com/?id=hV2_TdmoDo8C&pg=PA419. 
  59. ^ Halberstam, M et al.; Cohen, N; Shlimovich, P; Rossetti, L; Shamoon, H (1996). "Oral vanadyl sulfate improves insulin sensitivity in NIDDM but not in obese nondiabetic subjects". Diabetes 45 (5): 659–66. DOI:10.2337/diabetes.45.5.659. PMID 8621019. 
  60. ^ Boden, G et al.; Chen, X; Ruiz, J; Van Rossum, GD; Turco, S (1996;). "Effects of vanadyl sulfate on carbohydrate and lipid metabolism in patients with non-insulin dependent diabetes mellitus". Metabolism 45 (9): 1130–5. DOI:10.1016/S0026-0495(96)90013-X. PMID 8781301. 
  61. ^ Goldfine, AB et al.; Patti, ME; Zuberi, L; Goldstein, BJ; Leblanc, R; Landaker, EJ; Jiang, ZY; Willsky, GR et al. (2000). "Metabolic effects of vanadyl sulfate in humans with non-insulin-dependent diabetes mellitus: in vivo and in vitro studies". Metabolism 49 (3): 400–10. DOI:10.1016/S0026-0495(00)90418-9. PMID 10726921. 
  62. ^ Badmaev, V et al.; Prakash, Subbalakshmi; Majeed, Muhammed (1999). "Vanadium: a review of its potential role in the fight against diabetes". Altern Complement Med. 5 (3): 273–291. DOI:10.1089/acm.1999.5.273. PMID 10381252. 
  63. ^ Goldwaser, I et al.; Li, J; Gershonov, E; Armoni, M; Karnieli, E; Fridkin, M; Shechter, Y (1999). "L-Glutamic Acid gamma -Monohydroxamate. A Potentiator of Vanadium-Evoked Glucose Metabolism in vitro and in vivo". J Biol Chem 274 (37): 26617–26624. DOI:10.1074/jbc.274.37.26617. PMID 10473627. 
  64. ^ Aureliano, Manuel; Crans, Debbie C. (2009). "Decavanadate and oxovanadates: Oxometalates with many biological activities". Journal Inorganic Biochemistry 103: 536–546. DOI:10.1016/j.jinorgbio.2008.11010. 
  65. ^ Roschin, A. V. (1967). "Toxicology of vanadium compounds used in modern industry". Gig Sanit. (Water Res.) 32 (6): 26–32. PMID 5605589. 
  66. ^ a b "Occupational Safety and Health Guidelines for Vanadium Pentoxide". Occupational Safety and Health Administration. http://www.osha.gov/SLTC/healthguidelines/vanadiumpentoxidedust/recognition.html. Retrieved 2009-01-29. 
  67. ^ Sax, N. I. (1984). Dangerous Properties of Industrial Materials, 6th ed.. Van Nostrand Reinhold Company. pp. 2717–2720. 
  68. ^ a b Ress, N. B.; et al. (2003). "Carcinogenicity of inhaled vanadium pentoxide in F344/N rats and B6C3F1 mice". Toxicological Sciences 74 (2): 287–296. DOI:10.1093/toxsci/kfg136. PMID 12773761. 
  69. ^ Jörg M. Wörle-Knirsch, Katrin Kern, Carsten Schleh, Christel Adelhelm, Claus Feldmann, and Harald F. Krug (2007). "Nanoparticulate Vanadium Oxide Potentiated Vanadium Toxicity in Human Lung Cells". Environ. Sci. Technol. 41 (1): 331–336. DOI:10.1021/es061140x. PMID 17265967. 
  70. ^ Ścibior, A.; Zaporowska, H.; Ostrowski, J. (2006). "Selected haematological and biochemical parameters of blood in rats after subchronic administration of vanadium and/or magnesium in drinking water". Archives of Environmental Contamination and Toxicology 51 (2): 287–295. DOI:10.1007/s00244-005-0126-4. PMID 16783625. 
  71. ^ Gonzalez-Villalva, A.; et al. (2006). "Thrombocytosis induced in mice after subacute and subchronic V2O5 inhalation". Toxicology and Industrial Health 22 (3): 113–116. DOI:10.1191/0748233706th250oa. PMID 16716040. 
  72. ^ Kobayashi, Kazuo et al. (2006,). "Pentavalent vanadium induces hepatic metallothionein through interleukin-6-dependent and -independent mechanisms". Toxicology 228 (2–3): 162–170. DOI:10.1016/j.tox.2006.08.022. PMID 16987576. 
  73. ^ Soazo, Marina; Garcia, Graciela Beatriz (2007). "Vanadium exposure through lactation produces behavioral alterations and CNS myelin deficit in neonatal rats". Neurotoxicology and Teratology 29 (4): 503–510. DOI:10.1016/j.ntt.2007.03.001. PMID 17493788. 
  74. ^ Barceloux, Donald G.; Barceloux, Donald (1999). "Vanadium". Clinical Toxicology 37 (2): 265–278. DOI:10.1081/CLT-100102425. PMID 10382561. 
  75. ^ Duffus, J. H. (2007). "Carcinogenicity classification of vanadium pentoxide and inorganic vanadium compounds, the NTP study of carcinogenicity of inhaled vanadium pentoxide, and vanadium chemistry". Regulatory Toxicology and Pharmacology 47 (1): 110–114. DOI:10.1016/j.yrtph.2006.08.006. PMID 17030368. 
  76. ^ Opreskos, Dennis M. (1991). "Toxicity Summary for Vanadium". Oak Ridge National Laboratory. http://rais.ornl.gov/tox/profiles/vanadium_f_V1.html. Retrieved 2008-11-08. 

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