cobalt(II) phosphate
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| ImageFile1 = EntryWithCollCode38260.png
| ImageSize1 =
| ImageFile2 = Cobalt(II) phosphate.JPG
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| IUPACName =
| OtherNames = cobalt violet, cobalt(II) phosphate, cobalt orthophosphate, Pigment Violet 14
|Section1={{Chembox Identifiers
| CASNo = 13455-36-2 (tetrahydrate: 10294-50-5)
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 0B5M38T47H
| PubChem = 61615
| EINECS = 236-655-6
| SMILES = [O-]P(=O)([O-])[O-].[O-]P(=O)([O-])[O-].[Co+2].[Co+2].[Co+2]
| ChemSpiderID = 55523
| InChI = 1/3Co.2H3O4P/c;;;2*1-5(2,3)4/h;;;2*(H3,1,2,3,4)/q3*+2;;/p-6
| InChIKey = ZBDSFTZNNQNSQM-CYFPFDDLAU
| StdInChI = 1S/3Co.2H3O4P/c;;;2*1-5(2,3)4/h;;;2*(H3,1,2,3,4)/q3*+2;;/p-6
| StdInChIKey = ZBDSFTZNNQNSQM-UHFFFAOYSA-H
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|Section2={{Chembox Properties
| Formula = Co3(PO4)2
| MolarMass = 366.74231 g/mol
| Appearance = violet solid
| Density = 3.81 g/cm3
| MeltingPtC = 1160
| BoilingPtC =
| Solubility = insoluble
| SolubilityProduct = 2.05{{e|−35}}{{cite book |author1=John Rumble |title=CRC Handbook of Chemistry and Physics |date=June 18, 2018 |publisher=CRC Press |isbn=978-1138561632 |pages=5–188 |edition=99th}}
| RefractIndex = 1.7
| MagSus = 28,110.0·10−6 cm3/mol
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|Section3={{Chembox Hazards
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Cobalt phosphate is the inorganic compound with the formula Co3(PO4)2. It is a commercial inorganic pigment known as cobalt violet.Hugo Müller, Wolfgang Müller, Manfred Wehner, Heike Liewald "Artists' Colors" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a03_143.pub2}} Thin films of this material are water oxidation catalysts.{{cite journal|author1=Matthew W. Kanan |author2=Yogesh Surendranatha |author3=Daniel G. Nocera |title=Cobalt–phosphate oxygen-evolving Compound |journal=Chem. Soc. Rev. |year=2009 |volume=38 |issue=1 |pages=109–114 |doi=10.1039/B802885K |pmid=19088970}}
Preparation and structure
The tetrahydrate Co3(PO4)2•4H2O precipitates as a solid upon mixing aqueous solutions of cobalt(II) and phosphate salts.{{cite book |doi=10.1002/14356007.a07_281.pub2 |chapter=Cobalt and Cobalt Compounds |title=Ullmann's Encyclopedia of Industrial Chemistry |year=2005 |last1=Donaldson |first1=John Dallas |last2=Beyersmann |first2=Detmar |isbn=9783527303854 }}{{Cite journal |last1=Sankar |first1=Selvasundarasekar Sam |last2=Rathishkumar |first2=Arumugam |last3=Geetha |first3=Kathiresan |last4=Kundu |first4=Subrata |date=2020-10-15 |title=A Simple Route for the Synthesis of Cobalt Phosphate Nanoparticles for Electrocatalytic Water Oxidation in Alkaline Medium |journal=Energy & Fuels |volume=34 |issue=10 |pages=12891–12899 |doi=10.1021/acs.energyfuels.0c02809 |s2cid=224960926 |issn=0887-0624}} Upon heating, the tetrahydrate converts to the anhydrous material. According to X-ray crystallography, the anhydrous Co3(PO4)2 consists of discrete phosphate ({{chem|PO|4|3-}}) anions that link {{chem|Co|2+}} centres. The cobalt ions occupy both octahedral (six-coordinate) and pentacoordinate sites in a 1:2 ratio.{{cite journal |author1=Anderson, J. B. |author2=Kostiner, E. |author3=Miller, M. C. |author4=Rea, J. R. |title=Crystal structure of cobalt orthophosphate Co3(PO4)2 |journal=Journal of Solid State Chemistry |year=1975 |volume=14 |issue=4 |pages=372–377 |doi=10.1016/0022-4596(75)90058-4 |bibcode=1975JSSCh..14..372A}}{{cite journal |title=Structure refinements of Co3(PO4)2. A Note on the Reliability of Powder Diffraction Studies |author1=Nord, A. G. |author2=Stefanidis, T. |journal=Acta Chemica Scandinavica A |year=1983 |volume=37 |pages=715–721 |doi=10.3891/acta.chem.scand.37a-0715|doi-access=free}}
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See also
References
{{reflist}}
{{Cobalt compounds}}
{{Phosphates}}