Bromine trifluoride

Bromine trifluoride is an interhalogen compound with the formula BrF₃. At room temperature, it is a straw-coloured liquid with a pungent odor^[5] which decomposes violently on contact 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]

Bromine trifluoride

Identifiers
CAS Number	7787-71-5 N
3D model (JSmol)	Interactive image
ChemSpider	22996
ECHA InfoCard	100.029.211
EC Number	232-132-1
PubChem CID	24594
UNII	BD697HEL7X
UN number	1746
CompTox Dashboard (EPA)	DTXSID70894170
InChI InChI=1S/BrF3/c2-1(3)4 Key: FQFKTKUFHWNTBN-UHFFFAOYSA-N
SMILES FBr(F)F
Properties
Chemical formula	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)
Solubility in water	Reacts with water[3]
Structure
Molecular shape	T-shaped (C2v)
Dipole moment	1.19 D
Hazards[4]
Occupational safety and health (OHS/OSH):
Main hazards	Reacts violently with water to release HF, highly toxic, corrosive, powerful oxidizer
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H271, H300+H310+H330, H314, H373
Precautionary statements	P102, P103, P210, P220, P221, P260, P264, P271, P280, P283, P284, P301+P310, P301+P330+P331, P303+P361+P353, P304+P312, P305+P351+P338+P310, P306+P360, P308+P313, P340, P363, P370+P380
NFPA 704 (fire diamond)	4 0 4 W OX
Safety data sheet (SDS)	http://www.chammascutters.com/en/downloads/Bromine-Trifluoride-MSDS.pdf
Related compounds
Other anions	Bromine monochloride
Other cations	Chlorine trifluoride Iodine trifluoride
Related compounds	Bromine monofluoride Bromine pentafluoride
Supplementary data page
Bromine trifluoride (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) 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 lone pairs. The distance from the bromine atom to each axial fluorine atom is 1.81 Å and to the equatorial fluorine atom is 1.72 Å. The angle between an axial fluorine atom and the equatorial fluorine atom 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

In a highly exothermic reaction, BrF₃ reacts with water to form hydrobromic acid and hydrofluoric acid:

BrF₃ + 2 H₂O → 3 HF + 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 ⇌ BrF+2 + BrF−4

Fluoride salts dissolve readily in BrF₃ forming tetrafluorobromate:^[6]

KF + BrF₃ → KBrF₄

It reacts as a fluoride donor:^[12]

BrF₃ + SbF₅ → [BrF+2][SbF−6]

References

1. "Safety Data Sheet : Bromine Trifluoride" (PDF). Chammascutters.com. Retrieved 2022-03-17.
2. Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3.
3. "Archived copy" (PDF). Archived from the original (PDF) on 2012-05-13. Retrieved 2012-11-25.{{cite web}}: CS1 maint: archived copy as title (link)
4. "Safety Data Sheet Bromine Trifluoride" (PDF). Airgas. Retrieved 16 January 2020.
5. Simons JH (1950). "Bromine(III) Fluoride (Bromine Trifluoride)". Bromine (III) Fluoride - Bromine Trifluoride. Inorganic Syntheses. Vol. 3. pp. 184–186. doi:10.1002/9780470132340.ch48. ISBN 978-0-470-13234-0.
6. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
7. Lebeau P. (1906). "The effect of fluorine on chloride and on bromine". Annales de Chimie et de Physique. 9: 241–263.
8. Gutmann V (1950). "Die Chemie in Bromitrifluorid". Angewandte Chemie. 62 (13–14): 312–315. Bibcode:1950AngCh..62..312G. doi:10.1002/ange.19500621305.
9. Meinert H (1967). "Interhalogenverbindungen". Zeitschrift für Chemie. 7 (2): 41–57. doi:10.1002/zfch.19670070202.
10. Rozen, Shlomo; Sasson, Revital (2007). "Bromine Trifluoride". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/9780470842898.rb266.pub2. ISBN 978-0471936237.
11. Rozen, Shlomo (2010). "Selective Reactions of Bromine Trifluoride in Organic Chemistry". Advanced Synthesis & Catalysis. 352 (16): 2691–2707. doi:10.1002/adsc.201000482.
12. A. J. Edwards and G. R. Jones. J. Chem. Soc. A, 1467 (1969)

External links

• WebBook page for BrF3