Bromine trifluoride

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Bromine trifluoride
Structural formula, showing bond lengths and angles
Bromine Trifluoride
Properties
Molecular 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 decomposes violently[3]
Solubility in sulfuric acid very soluble
Structure
Molecular shape T-shaped (C2v)
Dipole moment 1.19 D
Hazards
MSDS External MSDS
EU classification Oxidizing Agent O Very Toxic T+ Corrosive C [1]
Main hazards dangerously sensitive to water, source of HF
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 4: Very short exposure could cause death or major residual injury. E.g., VX gas Reactivity code 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g., fluorine Special hazard W+OX: Reacts with water in an unusual or dangerous manner AND is oxidizer.NFPA 704 four-colored diamond
Related compounds
Other anions Bromine monochloride
Other cations Chlorine trifluoride
Iodine trifluoride
Related compounds Bromine monofluoride
Bromine pentafluoride
Supplementary data page
Structure and
properties
n, εr, etc.
Thermodynamic
data
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Bromine trifluoride is an interhalogen compound with the formula BrF3. It is a straw-coloured liquid with a pungent odor.[4] It is soluble in sulfuric acid but explodes 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.[5]

Synthesis[edit]

Bromine trifluoride was first described by Paul Lebeau in 1906, who obtained the material by the reaction of bromine with fluorine at 20 °C:[6]

Br2 + 3 F2 → 2 BrF3

The disproportionation of bromine monofluoride also gives bromine trifluoride:[4]

3 BrF → BrF3 + Br2

Structure[edit]

Like ClF3 and IF3, the BrF3 molecule is T-shaped. 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.[7][8]

Chemical properties[edit]

BrF3 is a fluorinating agent, but less reactive than ClF3. The liquid is conducting, owing to autoionisation:[5]

2 BrF3 BrF2+ + BrF4-

Many ionic fluorides dissolve readily in BrF3 forming fluoroanions:[5]

KF + BrF3 → KBrF4

References[edit]

  1. ^ a b http://www.chammascutters.com/en/downloads/Bromine-Trifluoride-MSDS.pdf
  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. ^ http://www.mathesongas.com/pdfs/msds/MAT03380.pdf
  4. ^ a b Simons JH (1950). "Bromine (III) Fluoride - Bromine Trifluoride". Inorganic Synthesis. Inorganic Syntheses 3: 184–186. doi:10.1002/9780470132340.ch48. ISBN 978-0-470-13234-0. 
  5. ^ a b c Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419. 
  6. ^ Lebeau P. (1906). "The effect of fluorine on chloride and on bromine". Annales de Chimie et de Physique 9: 241–263. 
  7. ^ Gutmann V (1950). "Die Chemie in Bromtrifuoride". Angewante Chemie 62 (13–14): 312–315. doi:10.1002/ange.19500621305. 
  8. ^ Meinert H (1967). "Interhalogenverbindungen". Zeitschrift für Chemie 7: 41. 

External links[edit]