Cobalt(II) phosphate
Chemical compound
From Wikipedia, the free encyclopedia
Cobalt phosphate is the inorganic compound with the formula Co3(PO4)2. It is a violet solid that is insoluble in water.
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Other names
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| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.033.309 |
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CompTox Dashboard (EPA) |
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| Properties | |
| Co3(PO4)2 | |
| Molar mass | 366.74231 g/mol |
| Appearance | violet solid |
| Density | 3.81 g/cm3 |
| Melting point | 1,160 °C (2,120 °F; 1,430 K) |
| insoluble | |
Solubility product (Ksp) |
2.05×10−35[1] |
| 28,110.0·10−6 cm3/mol | |
Refractive index (nD) |
1.7 |
| Hazards | |
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| Warning | |
| H302, H315, H317, H319, H335 | |
| P261, P264, P264+P265, P270, P271, P272, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P333+P317, P337+P317, P362+P364, P403+P233, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Structure
According to X-ray crystallography, the anhydrous Co3(PO4)2 consists of discrete phosphate (PO3−
4) anions that link Co2+
centres. The cobalt ions occupy both octahedral (six-coordinate) and pentacoordinate sites in a 1:2 ratio.[3][4]
Preparation
The tetrahydrate Co3(PO4)2•4H2O precipitates as a solid upon mixing aqueous solutions of cobalt(II) and phosphate salts.[5][6] Upon heating, the tetrahydrate converts to the anhydrous material.
Uses
Thin films of this material are water oxidation catalysts.[7]
It is also a commercial inorganic pigment known as cobalt violet (PV14).[8]
The color of Cobalt Phosphate differentiates depending on its hydration state. Three different compounds are usually reported including, violet anhydrous cobalt phosphate, a tetrahydrate described as violet-pink or deep violet, and the pink octahydrate.[9]
