Boron phosphate
Boron phosphate is an inorganic compound with the chemical formula BPO4. The simplest way of producing it is the reaction of phosphoric acid and boric acid. It is a white infusible solid that evaporates above 1450 °C.[1]
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| IUPAC name
Boron phosphate | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.033.020  |
PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |
| BPO4 | |
| Molar mass | 105.78 g/mol |
| Density | 2.52 g/cm3 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Synthesis
Boron phosphate is synthesized from phosphoric acid and boric acid at a temperature range from 80 °C to 1200 °C. The relatively cold treatment produces a white amorphous powder, which is converted to a microcrystalline product when heated at about 1000 °C for 2 hours.[2]
The main reaction of the process is:
- H3BO3 + H3PO4 → BPO4 + 3 H2O
New ways of synthesizing the compound have also been reported, such as hydrothermal and microwave synthesis.[3]
Due to the particular industrial interest of boron phosphate, other methods are used as well:[3]
- Phosphoric acid and triethyl borate
- Triethyl phosphate and boron trichloride
- Diammonium phosphate acid and borax heated to 1000 °C
- Boric acid and phosphorus pentoxide (hydrothermal)
Structure
If obtained at pressure, the ordinary structure is isomorphous with the β-cristobalite, while subjecting it to high pressure is obtained a compound isomorphic with α-quartz.[4] The structure of AlPO4, berlinite, is isomorphous with α-quartz.[1]
Applications
It is used as a catalyst for dehydration and other reactions in organic synthesis. Also, it serves as a source of phosphates for exchange reactions in the solid state to obtain metal phosphates.[5]
References
- Corbridge DEC 2013, Phosphorus: Chemistry, Biochemistry and Technology, 6th ed., CRC Press, Boca Raton, Florida, ISBN 978-1-4398-4088-7
- Mylius, F.; Meusser, A. (1904). "Ueber die Bestimmung der Borsäure als Phosphat". Berichte der Deutschen Chemischen Gesellschaft. 37: 397–401. doi:10.1002/cber.19040370171.
- Baykal, A; Kizilyalli, M; Toprak, Muhammet S. & Kniep, R (2001). "Hydrothermal and microwave synthesis of boron phosphate, BPO4". Turkish Journal of Chemistry. 25 (4): 425–432.
- MacKenzie, J. D.; Roth, W. L.; Wentorf, R. H. (1959). "New high pressure modifications of BPO4 and BAsO4". Acta Crystallographica. 12: 79. doi:10.1107/S0365110X5900024X.
- Moffat, J. B.; Goltz, H. L. (1965). "Surface Chemistry and Catalytic Properties of Boron Phosphate: 1. Surface Area and Acidity". Canadian Journal of Chemistry. 43 (6): 1680. doi:10.1139/v65-222.