Cobalt(II) phosphate
_phosphate.JPG?lang=en) | |
| Names | |
|---|---|
| Other names
cobalt violet, cobalt(II) phosphate, cobalt orthophosphate, Pigment Violet 14
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| Identifiers | |
| ECHA InfoCard | 100.033.309 |
| EC Number |
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PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| Co3O8P2 | |
| Molar mass | 366.74231 |
| Appearance | violet solid |
| Density | 3.81 g/cm3 |
| insoluble | |
Refractive index (nD)
|
1.7 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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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.[1] Thin films of this material catalyze the oxidation of water.[2]
A swatch of cobalt violet, popular among the French impressionists.
Preparation and structure
It precipitates as a solid tetrahydrate upon mixing aquous solutions of cobalt(II) and phosphate salts. The anhydrous material consists of discrete phosphate (PO43−) anions that link Co2+ centres.
The cobalt ions occupy both octahedral (six-coordinate) and pentacoordinate sites in a 1:2 ratio.[3]
References
- ^ 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
- ^ Matthew W. Kanan, Yogesh Surendranatha, Daniel G. Nocera "Cobalt–phosphate oxygen-evolving compound" Chem. Soc. Rev., 2009, volume 38, 109-114. doi:10.1039/B802885K
- ^ Anderson, J. B.; Kostiner, E.; Miller, M. C.; Rea, J. R. "Crystal structure of cobalt orthophosphate Co3(PO4)2" Journal of Solid State Chemistry 1975, vol. 14, 372-7.
