Vanadium phosphate

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Vanadium phosphate
Identifiers
  • (anhydrous):12359-27-2
  • (dihydrate):12293-87-7
3D model (JSmol)
ChemSpider
  • (anhydrous):InChI=1S/H3O4P.O.V/c1-5(2,3)4;;/h(H3,1,2,3,4);;/q;;+3/p-3
    Key: MEVGAPWXIYXSPM-UHFFFAOYSA-K
  • (dihydrate):InChI=1S/H3O4P.2H2O.O.V/c1-5(2,3)4;;;;/h(H3,1,2,3,4);2*1H2;;/q;;;;+3/p-3
    Key: IZKARBHCKXOZGC-UHFFFAOYSA-K
  • (anhydrous):[O-]P(=O)([O-])[O-].O=[V+3]
  • (dihydrate):O.O.[O-]P(=O)([O-])[O-].O=[V+3]
Properties
H4O7PV (dihydrate)
Molar mass 197.94 (dihydrate)
Appearanceyellow solid (dihydrate)
insoluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Vanadium phosphates are inorganic compounds with the formula VOxPO4 as well related hydrates with the formula VOxPO4(H2O)n. Some of these compounds are used commercially as catalysts for oxidation reactions.

Contents

Vanadium(V) phosphates

A common vanadium phosphate is VOPO4•2H2O.

Seven polymorphs are known for anhydrous VOPO4, denoted αI, αII, β, γ, δ, ω, and ε. [lower-alpha 1] [1] [2] [3] These materials are composed of the vanadyl group (VO) and phosphate (PO43−). They are yellow, diamagnetic solids, although when contaminated with vanadium(IV) derivatives, samples exhibit EPR signals and have bluish cast. For these materials, vanadyl refers to both vanadium(V) oxo and vanadium(IV) oxo centers, although conventionally vanadyl is reserved for derivatives of VO2+.

Structure of the V-O-P framework of VOPO4(H2O)2 (one lattice water and all hydrogen atoms are omitted). VOPO4(H2O)2 (no hydrogen shown).tif
Structure of the V-O-P framework of VOPO4(H2O)2 (one lattice water and all hydrogen atoms are omitted).

Preparation, reactions, and applications of VOPO4•2H2O

Heating a suspension of vanadium pentoxide and phosphoric acid gives VOPO4•2H2O, isolated as a bright yellow solid. [4] According to X-ray crystallography, the V(V) centers are octahedral, with long, weak bonds to aquo ligands. [5]

Reduction of this compound with alcohols gives the vanadium(IV) phosphates.

These compounds are catalysts for the oxidation of butane to maleic anhydride. A key step in the activation of these catalysts is the conversion of VO(HPO4)•0.5H2O to the pyrophosphate (VO)2(P2O7). This material (CAS#58834-75-6) is called vanadyl pyrophosphate as well as vanadium oxide pyrophosphate. [6]

Vanadium(IV) phosphates

Several vanadium(IV) phosphates are known. These materials are typically blue. In these species, the phosphate anion is singly or doubly protonated. Examples include the hydrogenphosphates, VOHPO4.4H2O and VO(HPO4).0.5H2O, as well as the dihydrogen phosphate VO(H2PO4)2.

Portion of the crystal structure of VO(HPO4) 0.5H2O. The vanadium is octahedrally coordinated and phosphorus is tetrahedral. Water is a bridging ligand. Color code: red = O; gray = V, H; ochre = P. VO(HPO4)0.5H2O.tif
Portion of the crystal structure of VO(HPO4) 0.5H2O. The vanadium is octahedrally coordinated and phosphorus is tetrahedral. Water is a bridging ligand. Color code: red = O; gray = V, H; ochre = P.

Vanadium(III) phosphates

Vanadium(III) phosphates lacking the oxo ligand have the formula VPO4•H2O and VPO4•2H2O. The monohydrate is isostructural with MgSO4•H2O [8] It adopts the structure of the corresponding hydrated aluminium phosphate. Oxidation of VPO4•H2O yields the two-electron electroactive[ clarification needed ] material ε-VOPO4 [9]

Notes

  1. ↑ The αI and αII polymorphs are sometimes called α1 and α2 instead.

Related Research Articles

Phosphate Chemical compound

In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid H
3PO
4.

Vanadium Chemical element, symbol V and atomic number 23

Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) somewhat stabilizes the free metal against further oxidation.

Polyoxometalate

In chemistry, a polyoxometalate is a polyatomic ion, usually an anion, that consists of three or more transition metal oxyanions linked together by shared oxygen atoms to form closed 3-dimensional frameworks. The metal atoms are usually group 6 or less commonly group 5 transition metals in their high oxidation states. They are usually colorless or orange, diamagnetic anions. Two broad families are recognized, isopolymetalates, composed of only one kind of metal and oxide, and heteropolymetalates, composed of one metal, oxide, and a main group oxyanion. Many exceptions to these general statements exist.

Calcium phosphate is a family of materials and minerals containing calcium ions (Ca2+) together with inorganic phosphate anions. Some so-called calcium phosphates contain oxide and hydroxide as well. Calcium phosphates are white solids of nutritious value and are found in many living organisms, e.g., bone mineral and tooth enamel. In milk, it exists in a colloidal form in micelles bound to casein protein with magnesium, zinc, and citrate–collectively referred to as colloidal calcium phosphate (CCP). Various calcium phosphate minerals are used in the production of phosphoric acid and fertilizers. Overuse of certain forms of calcium phosphate can lead to nutrient-containing surface runoff and subsequent adverse effects upon receiving waters such as algal blooms and eutrophication.

Vanadium(V) oxide Chemical compound

Vanadium(V) oxide (vanadia) is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the industrial perspective, it is the most important compound of vanadium, being the principal precursor to alloys of vanadium and is a widely used industrial catalyst.

Tricalcium phosphate Chemical compound

Tricalcium phosphate (sometimes abbreviated TCP) is a calcium salt of phosphoric acid with the chemical formula Ca3(PO4)2. It is also known as tribasic calcium phosphate and bone phosphate of lime (BPL). It is a white solid of low solubility. Most commercial samples of "tricalcium phosphate" are in fact hydroxyapatite.

Calcium pyrophosphate Chemical compound

Calcium pyrophosphate (Ca2P2O7) is a chemical compound, an insoluble calcium salt containing the pyrophosphate anion. There are a number of forms reported: an anhydrous form, a dihydrate, Ca2P2O7·2H2O and a tetrahydrate, Ca2P2O7·4H2O. Deposition of dihydrate crystals in cartilage are responsible for the severe joint pain in cases of calcium pyrophosphate deposition disease (pseudo gout) whose symptoms are similar to those of gout. Ca2P2O7 is commonly used as a mild abrasive agent in toothpastes, because of its insolubility and nonreactivity toward fluoride.

Dicalcium phosphate Chemical compound

Dicalcium phosphate is the calcium phosphate with the formula CaHPO4 and its dihydrate. The "di" prefix in the common name arises because the formation of the HPO42– anion involves the removal of two protons from phosphoric acid, H3PO4. It is also known as dibasic calcium phosphate or calcium monohydrogen phosphate. Dicalcium phosphate is used as a food additive, it is found in some toothpastes as a polishing agent and is a biomaterial.

Sodium orthovanadate Chemical compound

Sodium orthovanadate is the inorganic compound with the chemical formula Na3VO4·2H2O (sodium orthovanadate dihydrate). It is a salt of the VO3−
4 oxyanion. It is a colorless, water-soluble solid.

Bridging ligand

In coordination chemistry, a bridging ligand is a ligand that connects two or more atoms, usually metal ions. The ligand may be atomic or polyatomic. Virtually all complex organic compounds can serve as bridging ligands, so the term is usually restricted to small ligands such as pseudohalides or to ligands that are specifically designed to link two metals.

Vanadyl sulfate Chemical compound

Vanadyl(IV) sulfate describes a collection of inorganic compounds of vanadium with the formula, VOSO4(H2O)x where 0 ≤ x ≤ 6. The pentahydrate is common. This hygroscopic blue solid is one of the most common sources of vanadium in the laboratory, reflecting its high stability. It features the vanadyl ion, VO2+, which has been called the "most stable diatomic ion".

Dipotassium phosphate Chemical compound

Dipotassium phosphate (K2HPO4) (also dipotassium hydrogen orthophosphate; potassium phosphate dibasic) is the inorganic compound with the formula K2HPO4.(H2O)x (x = 0, 3, 6). Together with monopotassium phosphate (KH2PO4.(H2O)x), it is often used as a fertilizer, food additive, and buffering agent. It is a white or colorless solid that is soluble in water.

Zinc pyrophosphate Chemical compound

Zinc pyrophosphate (Zn2P2O7) is an ionic inorganic chemical compound composed of Zn2+ cations and pyrophosphate anions.

Copper(II) phosphate Chemical compound

Copper(II) phosphate are inorganic compounds with the formula Cu3(PO4)2.n(H2O). They can be regarded as the cupric salt of phosphoric acid. Anhydrous copper(II) phosphate is a blue solid. It is produced by a high-temperature reaction between diammonium phosphate and copper(II) oxide.

Silver phosphate Chemical compound

Silver phosphate or silver orthophosphate is a light sensitive, yellow, water-insoluble chemical compound composed of silver and phosphate ions of formula Ag3PO4.

Zirconium phosphates (zirconium hydrogen phosphate) are acidic, inorganic cation exchange materials that have a layered structure with formula Zr(HPO4)2∙nH2O. These salts have high thermal and chemical stability, solid state ion conductivity, resistance to ionizing radiation, and the capacity to incorporate different types of molecules with different sizes between their layers. There are various phases of zirconium phosphate which vary in their interlaminar spaces and their crystalline structure. Among all the Zirconium phosphate phases the most widely used are the alpha (Zr(HPO4)2∙H2O) and the gamma (Zr(PO4)(H2PO4)∙2H2O) phase. The salts have been widely used in several applications such as: drug delivery, catalysis, nanocomposite, nuclear waste management, clinical dialyzer, among others.

Vanadyl acetylacetonate Chemical compound

Vanadyl acetylacetonate is the chemical compound with the formula VO(acac)2, where acac– is the conjugate base of acetylacetone. It is a blue-green solid that dissolves in polar organic solvents. The coordination complex consists of the vanadyl group, VO2+, bound to two acac– ligands via the two oxygen atoms on each. Like other charge-neutral acetylacetonate complexes, it is not soluble in water.

Cobalt(II) phosphate Chemical compound

Cobalt phosphate is the inorganic compound with the formula Co3(PO4)2. It is a commercial inorganic pigment known as cobalt violet. Thin films of this material are water oxidation catalysts.

Vanadyl nitrate Chemical compound

Vanadyl nitrate, also called vanadium oxytrinitrate or vanadium oxynitrate is an inorganic compound of vanadium in the +5 oxidation state with nitrate ligands and oxygen. The formula is VO(NO3)3. It is a pale yellow viscous liquid.

Oxalate phosphate

The oxalate phosphates are chemical compounds containing oxalate and phosphate anions. They are also called oxalatophosphates or phosphate oxalates. Some oxalate-phosphate minerals found in bat guano deposits are known. Oxalate phosphates can form metal organic framework compounds.

References

  1. ↑ Gautier, Romain; Gautier, Régis; Hernandez, Olivier; Audebrand, Nathalie; Bataille, Thierry; Roiland, Claire; Elkaïm, Erik; Pollès, Laurent Le; Furet, Eric; Fur, Eric Le (2013-05-15). "DFT-assisted structure determination of α1- and α2-VOPO4: new insights into the understanding of the catalytic performances of vanadium phosphates". Dalton Transactions. 42 (22): 8124–8131. doi:10.1039/C3DT50217A. ISSN   1477-9234. PMID   23584576.
  2. ↑ "New Contributions to the Structural Chemistry of Vanadyl Orthophosphate VOPO4". edoc.mpg.de. Retrieved 2019-09-13.
  3. ↑ Girgsdies, Frank; Schneider, Matthias; Brückner, Angelika; Ressler, Thorsten; Schlögl, Robert (2009-07-01). "The crystal structure of δ-VOPO4 and its relationship to ω-VOPO4". Solid State Sciences. 11 (7): 1258–1264. Bibcode:2009SSSci..11.1258G. doi:10.1016/j.solidstatesciences.2009.03.017. hdl: 11858/00-001M-0000-0010-FAAA-9 . ISSN   1293-2558.
  4. ↑ Brody, John F.; Johnson, Jack W.; Vaughey, Jack (2007-01-05), Murphy, Donald W.; Interrante, Leonard V. (eds.), "Vanadyl Phosphates and Organylphosphonates", Inorganic Syntheses, John Wiley & Sons, Inc., pp. 241–248, doi:10.1002/9780470132616.ch45, ISBN   9780470132616
  5. ↑ Tietze, Hr (1981). "The crystal and molecular structure of oxovanadium(V) orthophosphate dihydrate, VOPO4(H2O)2". Australian Journal of Chemistry. 34 (10): 2035. doi:10.1071/CH9812035. ISSN   0004-9425.
  6. ↑ Dummer, N.F.; Bartley, J.K.; Hutchings, G.J. (2011), "Vanadium Phosphate Materials as Selective Oxidation Catalysts", Advances in Catalysis, Elsevier, 54, pp. 189–247, doi:10.1016/b978-0-12-387772-7.00004-6, ISBN   9780123877727
  7. ↑ Koo, Hyun-Joo; Whangbo, Myung-Hwan; VerNooy, Paul D.; Torardi, Charlie C.; Marshall, William J. (2002). "Flux Growth of Vanadyl Pyrophosphate, (VO)2P2O7, and Spin Dimer Analysis of the Spin Exchange Interactions of (VO)2P2O7 and Vanadyl Hydrogen Phosphate, VO(HPO4)·0.5H2O". Inorganic Chemistry. 41 (18): 4664–4672. doi:10.1021/ic020249c. ISSN   0020-1669. PMID   12206689.
  8. ↑ Vaughey, J. T.; Harrison, William T. A.; Jacobson, Allan J.; Goshorn, David P.; Johnson, Jack W. (1994). "Synthesis, structure, and properties of two vanadium(III) phosphates: V(PO4)•H2O and V1.23(PO4)(OH)0.69(H2O)0.31•0.33H2O". Inorganic Chemistry. 33 (11): 2481–2487. doi:10.1021/ic00089a027. ISSN   0020-1669.
  9. ↑ Lim, S; Vaughey, J. T.; Harrison, W. T. A.; Dussack, L. L.; Jacobson, A. J.; Johnson, J. W. (1996). "Redox transformations of simple vanadium phosphates: the synthesis of ε-VOPO4". Solid State Ionics. 84 (3–4): 219–226. doi:10.1016/0167-2738(96)00007-0.
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