Phosphorus pentabromide
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Phosphorus pentabromide | |
---|---|
IUPAC name | phosphorus pentabromide |
Other names | phosphorus(V) bromide |
Identifiers | |
CAS number | [7789-69-7] |
Properties | |
Molecular formula | PBr5 |
Molar mass | 430.49 g/mol |
Melting point |
ca. 100 °C (decomposes) |
Boiling point |
106 °C (decomposes) |
Solubility in water | decomposes |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
Phosphorus pentabromide is a reactive, yellow solid of formula PBr5, which has the structure PBr4+ Br− in the solid state but in the vapor phase is completely dissociated to PBr3 and Br2. Rapid cooling of this phase to 15 K leads to formation of an ionic species [PBr4]+[Br3]-.
It can be used in organic chemistry to convert carboxylic acids to acyl bromides. It is highly corrosive and should be handled with care. It decomposes above 100 °C to give phosphorus tribromide and bromine: