Phosphoryl bromide
Phosphoryl bromide, also known as phosphorus oxybromide, is an inorganic compound with the formula POBr3.[2]
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Names | |||
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Other names
Phosphorus oxybromide | |||
Identifiers | |||
3D model (JSmol) |
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ChemSpider | |||
ECHA InfoCard | 100.029.252 | ||
EC Number |
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PubChem CID |
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UNII | |||
UN number | 1939 2576 | ||
CompTox Dashboard (EPA) |
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Properties | |||
POBr3 | |||
Molar mass | 286.69 g/mol | ||
Density | 2.82 g cm−3 | ||
Melting point | 56 °C (133 °F; 329 K) | ||
Boiling point | 192 °C (378 °F; 465 K) | ||
Structure[1] | |||
Pnma, No. 62 | |||
a = 9.467 Å, b = 9.938 Å, c = 6.192 Å | |||
Formula units (Z) |
4 | ||
Hazards | |||
GHS labelling: | |||
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Danger | |||
H290, H314, H335 | |||
P234, P260, P261, P264, P271, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P363, P390, P403+P233, P404, P405, P501 | |||
Related compounds | |||
Related compounds |
Phosphorus tribromide Thiophosphoryl bromide Phosphoryl fluoride Phosphoryl chloride | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references |
Preparation
Phosphoryl bromide is prepared by the reaction between phosphorus pentabromide and phosphorus pentoxide:[3][4]
- 3 PBr5 + P2O5 → 5 POBr3
It can also be prepared via the slow addition of liquid bromine to phosphorus tribromide at 0 °C, followed by the slow addition of water and vacuum distillation of the resulting slurry.
Structure and properties
Phosphoryl bromide forms colorless crystals or thin plates with a faint orange tint.[5] Its crystals belong to the orthorhombic space group Pnma,[1][6] with intermolecular Br–O bridges creating infinite chains within the structure. The intermolecular bonding causes distortions from the C3v symmetry found in the free molecule.[1]
It reacts violently with water, forming phosphoric acid and hydrobromic acid. It is soluble in ether, benzene, chloroform, carbon disulfide, and concentrated sulfuric acid.[5] It is stored in sealed glass ampoules.
Uses
Phosphoryl bromide finds use as a specialist brominating agent
References
- Templeton, Lieselotte K.; Templeton, David H. (1971). "The crystal structure of POBr3: space group and refinement by least squares". Acta Crystallogr. B. 27 (8): 1678–1679. doi:10.1107/S0567740871004564. S2CID 97905269.
- Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 501–503. ISBN 978-0-08-037941-8.
- Hönigschmid, O.; Hirschbold‐Wittner, F. (1940). "Das Atomgewicht des Phosphors. Analyse des Phosphoroxybromids". Zeitschrift für anorganische und allgemeine Chemie (in German). 243 (4): 355–360. doi:10.1002/zaac.19402430406. ISSN 1521-3749.
- Booth, Harold S.; Seegmiller, C. G.; Baker, Philip S.; Wexler, Sol; Johnson, Roy D. (2007-01-05), Fernelius, W. Conard (ed.), "Phosphorus(V) Oxybromide: (Phosphoryl Tribromide)", Inorganic Syntheses, Hoboken, NJ, USA: John Wiley & Sons, Inc., pp. 151–152, doi:10.1002/9780470132333.ch44, ISBN 978-0-470-13233-3, retrieved 2020-09-30
- Perry, Dale L. (2011). Handbook of Inorganic Compounds (2nd ed.). Boca Raton: Taylor & Francis. p. 310. ISBN 978-1-4398-1461-1. OCLC 587104373.
- Okuda, Tsutomu.; Hosokawa, Kazuto.; Yamada, Koji.; Furukawa, Yoshihiro.; Negita, Hisao. (1975). "Structural study of phosphoryl bromide by means of nuclear quadrupole resonance". Inorganic Chemistry. 14 (5): 1207–1209. doi:10.1021/ic50147a048. ISSN 0020-1669.