Chemistry:Phosphorus pentabromide
| |
| |
| Names | |
|---|---|
| IUPAC name
Tetrabromophosphanium bromide
| |
| Other names | |
| Identifiers | |
3D model (JSmol)
|
|
| ChemSpider | |
| EC Number |
|
PubChem CID
|
|
| UNII | |
| UN number | 2691 |
| |
| |
| Properties | |
| PBr 5 | |
| Molar mass | 430.494 g·mol−1 |
| Appearance | Yellow crystalline solid[1] |
| Density | 3.61 g/cm3 |
| Melting point | ca. 100 °C (decomposes) |
| Boiling point | 106 °C (223 °F; 379 K) (decomposes) |
| Reacts with water | |
| Solubility | Decomposes in ethanol Soluble in CCl 4 and CS 2 |
| Hazards[1] | |
| Main hazards | Causes severe skin burns and eye damage |
| GHS pictograms | 
|
| GHS Signal word | Danger |
| HH314Script error: No such module "Preview warning".Category:GHS errors | |
| PP260Script error: No such module "Preview warning".Category:GHS errors, PP264Script error: No such module "Preview warning".Category:GHS errors, PP280Script error: No such module "Preview warning".Category:GHS errors, PP301+P330+P331Script error: No such module "Preview warning".Category:GHS errors, PP302+P361+P354Script error: No such module "Preview warning".Category:GHS errors, PP304+P340Script error: No such module "Preview warning".Category:GHS errors, PP305+P354+P338Script error: No such module "Preview warning".Category:GHS errors, PP316Script error: No such module "Preview warning".Category:GHS errors, PP321Script error: No such module "Preview warning".Category:GHS errors, PP363Script error: No such module "Preview warning".Category:GHS errors, PP405Script error: No such module "Preview warning".Category:GHS errors, PP501Script error: No such module "Preview warning".Category:GHS errors | |
| Related compounds | |
Related compounds
|
|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
 verify (what is   ?)
| |
| Infobox references | |
Phosphorus pentabromide is a reactive, yellow solid of formula PBr
5, which has the structure [PBr
4]+
Br−
(tetrabromophosphonium bromide) in the solid state but in the vapor phase is completely dissociated to PBr
3 and Br
2. Rapid cooling of this phase to 15 K leads to formation of the ionic species phosphorus heptabromide (tetrabromophosphonium tribromide [PBr
4]+
[Br
3]−
).[2]
It can be used in organic chemistry to convert carboxylic acids to acyl bromides. It is highly corrosive. It strongly irritates skin and eyes.[1] It decomposes above 100 °C to give phosphorus tribromide and bromine:[3]
Reversing this equilibrium to generate PBr
5 by addition of Br
2 to PBr
3 is difficult in practice because the product is susceptible to further addition to yield phosphorus heptabromide [PBr
4]+
[Br
3]−
.[4]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 "Phosphorus pentabromide". https://pubchem.ncbi.nlm.nih.gov/compound/Phosphorus-pentabromide.
- ↑ Corbridge, D. E. C. (2013) (in en). Phosphorus: Chemistry, Biochemistry and Technology, Sixth Edition. CRC Press. pp. 154. ISBN 978-1-4398-4088-7. https://books.google.com/books?id=5ufh9rM5ko0C&q=rapid+cooling+of+pbr5&pg=PA154.
- ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
- ↑ Popov, A. I.; Skelly, N. E. (1954). "Spectrophotometric Study of Phosphorus Pentabromide in Various Solvents". J. Am. Chem. Soc. 76 (15): 3916–3919. doi:10.1021/ja01644a014.
 |  |
