Bromine trifluoride
From Wikipedia, the free encyclopedia
| Bromine trifluoride | |
|---|---|
 |
|
| Properties | |
| Molecular formula | BrF3 |
| Molar mass | 136.90 g/mol |
| Appearance | straw-coloured liquid |
| Density | 2.8 g/ml, liquid |
| Melting point |
8.8 °C |
| Boiling point |
125.8 °C |
| Solubility in water | decomposes |
| Structure | |
| Molecular shape | T-shaped |
| Dipole moment | 1.19 D |
| Hazards | |
| MSDS | External MSDS |
| EU classification | not listed |
| NFPA 704 |
 0
3
3
OX
|
| 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, 100 kPa) Infobox disclaimer and references |
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Bromine trifluoride is a highly toxic and corrosive fluoride of bromine with chemical formula BrF3. It was discovered by Paul Lebeau in 1906.[1] It occurs as a colorless, yellow, or gray fuming liquid with an irritating odor. It is soluble in sulfuric acid but may explode on contact with water. While it is a potent fluorinating agent it is less reactive than ClF3. It is used to produce uranium hexafluoride, UF6 in the processing and reprocessing of nuclear fuel.[2]
Contents |
[edit] Synthesis
Bromine trifluoride can be obtained by the reaction of bromine with fluorine at 20 °C.
- Br2 + 3F2 → 2BrF3
The disproportionation of bromine monofluoride is also a source for bromine trifluoride.
- 3BrF → BrF3 + Br2[3]
[edit] Structure
Like ClF3 and IF3 the BrF3 molecule is T-shaped. With the two electron pairs the coordination number is 5. 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.[4][5]
[edit] Chemistry and Properties
Liquid BrF3 is conducting and this is attributed to dissociation:[2]
- BrF3 ⇌ BrF2+ + BrF4−
Many ionic fluorides dissolve readily in BrF3 forming solvobases[2] e.g.
- KF + BrF3 → KBrF4
[edit] References
- ^ Lebeau P. (1906). "The effect of fluorine on chloride and on bromine". Annales de Chimie et de Physique 9: 241–263.
- ^ a b c Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements, 2nd Edition, Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4.
- ^ Simons JH (1950). "Bromine (III) Fluoride - Bromine Trifluoride". Inorganic Synthesis 3: 184–186. doi:.
- ^ Gutmann V (1950). "Die Chemie in Bromtrifuoride". Angewante Chemie 62: 312–315. doi:.
- ^ Meinert H (1967). "Interhalogenverbindungen". Zeitschrift für Chemie 7: 41.
