Bromine trifluoride is an

interhalogen compound In chemistry, an interhalogen compound is a molecule which contains two or more different halogen atoms (fluorine, chlorine, bromine, iodine, or astatine) and no atoms of elements from any other group. Most interhalogen compounds known are binar ...

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 In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers ...

and an ionizing inorganic solvent. It is used to produce uranium hexafluoride (UF₆) in the processing and reprocessing of nuclear fuel.

Synthesis

Bromine trifluoride was first described by Paul Lebeau in 1906, who obtained the material by the reaction of

bromine Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table (halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a simila ...

with

fluorine Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactiv ...

at 20 °C: : The disproportionation of bromine monofluoride also gives bromine trifluoride: :

Structure

Like ClF₃ and IF₃, the BrF₃ molecule is T-shaped and planar. In the

VSEPR Valence shell electron pair repulsion (VSEPR) theory ( , ), is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gillespie-Nyholm the ...

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 pair In chemistry, an electron pair or Lewis pair consists of two electrons that occupy the same molecular orbital but have opposite spins. Gilbert N. Lewis introduced the concepts of both the electron pair and the covalent bond in a landmark paper he ...

s being greater than that of the Br-F bonds.

Chemical properties

In a highly exothermic reaction, BrF₃ reacts with water to form

hydrobromic acid Hydrobromic acid is a strong acid formed by dissolving the diatomic molecule hydrogen bromide (HBr) in water. "Constant boiling" hydrobromic acid is an aqueous solution that distills at and contains 47.6% HBr by mass, which is 8.77 mol/L. H ...

and

hydrofluoric acid Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepress ...

: : BrF₃ is a fluorinating agent, but less reactive than ClF₃. Already at -196 °C, it reacts with acetonitrile to give 1,1,1-trifluoroethane. : + Br₂ + N₂ The liquid is

conducting Conducting is the art of directing a musical performance, such as an orchestral or choral concert. It has been defined as "the art of directing the simultaneous performance of several players or singers by the use of gesture." The primary duti ...

, owing to autoionisation: : Fluoride salts dissolve readily in BrF₃ forming tetrafluorobromate: : It reacts as a fluoride donor:A. J. Edwards and G. R. Jones. J. Chem. Soc. A, 1467 (1969) :

References

External links

WebBook page for BrF3
{{fluorine compounds Bromine(III) compounds Fluorides Interhalogen compounds Fluorinating agents Oxidizing agents Substances discovered in the 1900s