Bromine trifluoride
Bromine trifluoride is an interhalogen compound with the formula BrF3. It is a straw-coloured liquid with a pungent odor.[5] It is soluble in sulfuric acid but reacts violently with water and organic compounds. It is a powerful fluorinating agent and an ionizing inorganic solvent. It is used to produce uranium hexafluoride (UF6) in the processing and reprocessing of nuclear fuel.[6]
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Identifiers | |
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3D model (JSmol) |
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ChemSpider | |
ECHA InfoCard | 100.029.211 ![]() |
EC Number |
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PubChem CID |
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UNII | |
UN number | 1746 |
CompTox Dashboard (EPA) |
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Properties | |
BrF3 | |
Molar mass | 136.90 g/mol |
Appearance | straw-coloured liquid hygroscopic |
Odor | Choking, pungent[1] |
Density | 2.803 g/cm3 [2] |
Melting point | 8.77 °C (47.79 °F; 281.92 K) |
Boiling point | 125.72 °C (258.30 °F; 398.87 K) |
Reacts with water[3] | |
Solubility in sulfuric acid | very soluble |
Structure | |
T-shaped (C2v) | |
1.19 D | |
Hazards[4] | |
Main hazards | dangerously sensitive to water, source of HF |
Safety data sheet | See: data page http://www.chammascutters.com/en/downloads/Bromine-Trifluoride-MSDS.pdf |
GHS pictograms | ![]() ![]() ![]() ![]() |
GHS Signal word | Danger |
H271, H330, H314, H373 | |
P102, P103, P210, P220, P221, P260, P264, P271, P280, P283, P284, P301+310, P301+330+331, P303+361+353, P304+312, P306+360, P308+313, P370+380, P340, P363, P305+351+338+310 | |
NFPA 704 (fire diamond) | |
Related compounds | |
Other anions |
Bromine monochloride |
Other cations |
Chlorine trifluoride Iodine trifluoride |
Related compounds |
Bromine monofluoride Bromine pentafluoride |
Supplementary data page | |
Refractive index (n), Dielectric constant (εr), etc. | |
Thermodynamic data |
Phase behaviour solid–liquid–gas |
UV, IR, NMR, MS | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
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Infobox references | |
Synthesis
Bromine trifluoride was first described by Paul Lebeau in 1906, who obtained the material by the reaction of bromine with fluorine at 20 °C:[7]
- Br2 + 3 F2 → 2 BrF3
The disproportionation of bromine monofluoride also gives bromine trifluoride:[5]
- 3 BrF → BrF3 + Br2
Structure
Like ClF3 and IF3, the BrF3 molecule is T-shaped and planar. In the VSEPR formalism, the bromine center is assigned two electron pairs. The distance from the bromine each axial fluorine is 1.81 Å and to the equatorial fluorine is 1.72 Å. The angle between an axial fluorine and the equatorial fluorine is slightly smaller than 90° — the 86.2° angle observed is due to the repulsion generated by the electron pairs being greater than that of the Br-F bonds.[8][9]
Chemical properties
BrF3 rapidly and exothermically reacts with water to release hydrobromic acid and hydrofluoric acid:
- BrF3 + 2H2O → 3HF + HBr + O2
BrF3 is a fluorinating agent, but less reactive than ClF3[10] Already at -196 °C, it reacts with acetonitrile to give 1,1,1-trifluoroethane.[11]
- BrF3 + CH3CN → CH3CF3 + 1/2 Br2 + 1/2 N2
The liquid is conducting, owing to autoionisation:[6]
- 2 BrF3 ⇌ BrF2+ + BrF4−
Fluoride salts dissolve readily in BrF3 forming tetrafluorobromate:[6]
- KF + BrF3 → KBrF4
It react as a fluoride donor:[12]
- BrF3 + SbF5 → [BrF2+][SbF6−]
References
- http://www.chammascutters.com/en/downloads/Bromine-Trifluoride-MSDS.pdf
- Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3.
- "Archived copy" (PDF). Archived from the original (PDF) on 2012-05-13. Retrieved 2012-11-25.CS1 maint: archived copy as title (link)
- "Safety Data Sheet Bromine Trifluoride" (PDF). Airgas. Retrieved 16 January 2020.
- Simons JH (1950). "Bromine(III) Fluoride (Bromine Trifluoride)". Bromine (III) Fluoride - Bromine Trifluoride. Inorganic Syntheses. 3. pp. 184–186. doi:10.1002/9780470132340.ch48. ISBN 978-0-470-13234-0.
- Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
- Lebeau P. (1906). "The effect of fluorine on chloride and on bromine". Annales de Chimie et de Physique. 9: 241–263.
- Gutmann V (1950). "Die Chemie in Bromitrifluorid". Angewandte Chemie. 62 (13–14): 312–315. doi:10.1002/ange.19500621305.
- Meinert H (1967). "Interhalogenverbindungen". Zeitschrift für Chemie. 7 (2): 41–57. doi:10.1002/zfch.19670070202.
- Rozen, Shlomo; Sasson, Revital (2007). "Bromine Trifluoride". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/9780470842898.rb266.pub2. ISBN 978-0471936237.
- Rozen, Shlomo (2010). "Selective Reactions of Bromine Trifluoride in Organic Chemistry". Advanced Synthesis & Catalysis. 352 (16): 2691–2707. doi:10.1002/adsc.201000482.
- A. J. Edwards and G. R. Jones. J. Chem. Soc. A, 1467 (1969)