Bromine pentafluoride
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| Names | |||
|---|---|---|---|
| IUPAC name
Bromine pentafloride | |||
| Identifiers | |||
7789-30-2  | |||
| ChemSpider | 23008 | ||
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| Jmol-3D images | Image | ||
| PubChem | 24606 | ||
| RTECS number | EF9350000 | ||
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| Properties | |||
| BrF5 | |||
| Molar mass | 174.894 g.mol−1 | ||
| Appearance | Pale yellow liquid | ||
| Density | 2.466 g/cm3 | ||
| Melting point | −61.30 °C (−78.34 °F; 211.85 K) | ||
| Boiling point | 40.25 °C (104.45 °F; 313.40 K) | ||
| reacts | |||
| Structure | |||
| Molecular shape | Square pyramidal | ||
| Hazards | |||
| MSDS | External MSDS | ||
| Main hazards | reacts violently with water, powerful oxidizer[1] | ||
| R/S statement | R8 R23/24/25 R34 S45 S36/37/39 | ||
| NFPA 704 | |||
| Flash point | Non-flammable | ||
| US health exposure limits (NIOSH): | |||
| PEL (Permissible) |
none[1] | ||
| REL (Recommended) |
TWA 0.1 ppm (0.7 mg/m3)[1] | ||
| IDLH (Immediate danger) |
N.D.[1] | ||
| Related compounds | |||
| Other anions |
Bromine monochloride | ||
| Other cations |
Chlorine pentafluoride Iodine pentafluoride | ||
| Related compounds |
Bromine monofluoride Bromine trifluoride | ||
| Supplementary data page | |||
| Refractive index (n), Dielectric constant (εr), etc. | |||
| Thermodynamic data |
Phase behaviour solid–liquid–gas | ||
| UV, IR, NMR, MS | |||
| Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |||
verify (what is: / ?) | |||
| Infobox references | |||
Bromine pentafluoride, BrF5, is an interhalogen compound and a fluoride of bromine. It is a strong fluorination reagent.
BrF5 finds use in oxygen isotope analysis. Laser ablation of solid silicates in the presence of bromine pentafluoride releases O2 for subsequent analysis.[2] It is also been tested as an oxidizer in liquid rocket propellants and is used as a fluorinating agent in the processing of uranium.
Preparation
Bromine pentafluoride was first prepared in 1931 by the direct reaction of bromine with fluorine.[3] This reaction is suitable for the preparation of large quantities, and is carried out at temperatures over 150 °C (302 °F) with an excess of fluorine:
- Br2 + 5 F2 → 2 BrF5
For the preparation of smaller amounts, potassium bromide is used:[3]
- KBr + 3 F2 → KF + BrF5
This route yields bromine pentafluoride almost completely free of trifluorides and other impurities.[3]
Reactions
Bromine pentafluoride reacts explosively with water, but when moderated by dilution with acetonitrile, it will form bromic acid and hydrofluoric acid, simple hydrolysis products:[4]
- BrF5 + 3 H2O → HBrO3 + 5 HF
It is an extremely effective fluorinating agent, converting most uranium compounds to the hexafluoride at room temperature.
Hazards
Bromine pentafluoride is severely corrosive to the skin, and its vapors are irritating to the eyes, skin, and mucous membranes. Exposure to 100 ppm for a few minutes is lethal to most experimental animals. Chronic exposure may cause nephrosis and hepatosis.[5]
It may spontaneously ignite or explode upon contact with organic materials or metals in powdered form.[5]
References
- ↑ 1.0 1.1 1.2 1.3 "NIOSH Pocket Guide to Chemical Hazards #0065". National Institute for Occupational Safety and Health (NIOSH).
- ↑ Clayton, R.; Mayeda, T. K. (1963). "The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analysis". Geochimica et Cosmochimica Acta 27 (1): 43–48. Bibcode:1963GeCoA..27...43C. doi:10.1016/0016-7037(63)90071-1.
- ↑ 3.0 3.1 3.2 Hyde, G. A.; Boudakian, M. M. (1968). "Synthesis routes to chlorine and bromine pentafluorides". Inorganic Chemistry 7 (12): 2648–2649. doi:10.1021/ic50070a039.
- ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 834. ISBN 0080379419.
- ↑ 5.0 5.1 Patnaik, Pradyot (2007). A comprehensive guide to the hazardous properties of chemical substances (3rd ed.). Wiley-Interscience. p. 480. ISBN 0-471-71458-5.