:Bromine trifluoride
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 446241217
| ImageFile = BrF3Structure.png
| ImageClass = skin-invert
| ImageSize = 120px
| ImageName = Structural formula, showing bond lengths and angles
| ImageFile1 = Bromine-trifluoride-3D-vdW.png
| ImageClass1 = bg-transparent
| ImageSize1 = 150px
| ImageName1 = Bromine Trifluoride
| Section1 = {{Chembox Identifiers
| CASNo_Ref = {{cascite|changed|??}}
| CASNo = 7787-71-5
| PubChem = 24594
| ChemSpiderID = 22996
| EC_number = 232-132-1
| UNNumber = 1746
| UNII = BD697HEL7X
| StdInChI=1S/BrF3/c2-1(3)4
| StdInChIKey = FQFKTKUFHWNTBN-UHFFFAOYSA-N
| SMILES = FBr(F)F
}}
|Section2={{Chembox Properties
| Formula = BrF3
| MolarMass = 136.90 g/mol
| Appearance = straw-coloured liquid
hygroscopic
| Density = 2.803 g/cm3 {{RubberBible87th}}
| Solubility = Reacts with water{{cite web|url=http://www.mathesongas.com/pdfs/msds/MAT03380.pdf |title=Archived copy |access-date=2012-11-25 |url-status=dead |archive-url=https://web.archive.org/web/20120513164103/http://www.mathesongas.com/pdfs/msds/MAT03380.pdf |archive-date=2012-05-13 }}
| MeltingPtC = 8.77
| MeltingPt_notes =
| BoilingPtC = 125.72
| BoilingPt_notes =
| Viscosity =
}}
|Section3={{Chembox Structure
| MolShape = T-shaped (C2v)
| Dipole = 1.19 D
}}
|Section7={{Chembox Hazards
| MainHazards = Reacts violently with water to release HF, highly toxic, corrosive, powerful oxidizer
| ExternalSDS = http://www.chammascutters.com/en/downloads/Bromine-Trifluoride-MSDS.pdf
| GHSPictograms = {{GHS03}}{{GHS05}}{{GHS06}}{{GHS08}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|271|300+310+330|314|373}}
| PPhrases = {{P-phrases|102|103|210|220|221|260|264|271|280|283|284|301+310|301+330+331|303+361+353|304+312|306+360|308+313|370+380|340|363|305+351+338+310}}
| NFPA-H = 4
| NFPA-F = 0
| NFPA-R = 4
| NFPA-S = W+OX
}}
|Section8={{Chembox Related
| OtherAnions = Bromine monochloride
| OtherCations = Chlorine trifluoride
Iodine trifluoride
| OtherCompounds = Bromine monofluoride
Bromine pentafluoride
}}
}}
Bromine trifluoride is an interhalogen compound with the formula BrF3. At room temperature, it is a straw-coloured liquid with a pungent odor 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.{{Greenwood&Earnshaw}}
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:{{cite journal | author= Lebeau P. | title= The effect of fluorine on chloride and on bromine | journal=Annales de Chimie et de Physique| year=1906 | volume=9 | pages=241–263}}
:{{chem2|Br2 + 3 F2 -> 2 BrF3}}
The disproportionation of bromine monofluoride also gives bromine trifluoride:{{cite book | author= Simons JH| title= Bromine (III) Fluoride - Bromine Trifluoride | chapter= Bromine(III) Fluoride (Bromine Trifluoride) | year=1950 | volume=3 | pages=184–186| doi= 10.1002/9780470132340.ch48 | series= Inorganic Syntheses | isbn= 978-0-470-13234-0}}
:{{chem2|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.{{cite journal | author= Gutmann V| title= Die Chemie in Bromitrifluorid | journal=Angewandte Chemie| year=1950 | volume=62 | pages=312–315| doi= 10.1002/ange.19500621305 | issue= 13–14| bibcode= 1950AngCh..62..312G }}{{cite journal | author= Meinert H| title= Interhalogenverbindungen | journal=Zeitschrift für Chemie| year=1967 | volume=7 | issue= 2 | pages=41–57| doi= 10.1002/zfch.19670070202 }}
Chemical properties
In a highly exothermic reaction, BrF3 reacts with water to form hydrobromic acid and hydrofluoric acid:
:{{chem2|BrF3 + 2 H2O -> 3 HF + HBr + O2}}
BrF3 is a fluorinating agent, but less reactive than ClF3.{{cite book|last1=Rozen|first1=Shlomo|title=Encyclopedia of Reagents for Organic Synthesis|last2=Sasson|first2=Revital|publisher=|year=2007|isbn=978-0471936237|location=|pages=|chapter=Bromine Trifluoride|doi=10.1002/9780470842898.rb266.pub2}} Already at -196 °C, it reacts with acetonitrile to give 1,1,1-trifluoroethane.{{cite journal |doi=10.1002/adsc.201000482|title=Selective Reactions of Bromine Trifluoride in Organic Chemistry|year=2010|last1=Rozen|first1=Shlomo|journal=Advanced Synthesis & Catalysis|volume=352|issue=16|pages=2691–2707}}
:{{chem2|BrF3 + CH3CN -> CH3CF3}} + {{frac|1|2}} Br2 + {{frac|1|2}} N2
The liquid is conducting, owing to autoionisation:
:{{chem2|2 BrF3 <-> BrF2(+) + BrF4(-)}}
Fluoride salts dissolve readily in BrF3 forming tetrafluorobromate:
:{{chem2|KF + BrF3 -> KBrF4}}
It reacts as a fluoride donor:A. J. Edwards and G. R. Jones. J. Chem. Soc. A, 1467
(1969)
:{{chem2|BrF3 + SbF5 -> [BrF2(+)][SbF6(-)]}}
References
{{reflist}}
External links
- [http://webbook.nist.gov/cgi/cbook.cgi?ID=C7787715 WebBook page for BrF3]
{{bromine compounds}}
{{fluorides}}
Category:Bromine(III) compounds