Bromine pentafluoride,
Br F5, is an
interhalogen compound and a
fluoride
Fluoride (). According to this source, is a possible pronunciation in British English. is an inorganic, monatomic anion of fluorine, with the chemical formula (also written ), whose salts are typically white or colorless. Fluoride salts ...
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 simil ...
. It is a strong
fluorinating agent.
BrF
5 finds use in
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...
isotope analysis
Isotope analysis is the identification of isotopic signature, abundance of certain stable isotopes of chemical elements within organic and inorganic compounds. Isotopic analysis can be used to understand the flow of energy through a food web ...
.
Laser ablation
Laser ablation or photoablation (also called laser blasting) is the process of removing material from a solid (or occasionally liquid) surface by irradiating it with a laser beam. At low laser flux, the material is heated by the absorbed laser ...
of solid
silicates in the presence of BrF
5 releases
O2 for subsequent analysis. It has also been tested as an
oxidizer
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxid ...
in liquid
rocket propellant
Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical ...
s and is used as a fluorinating agent in the processing of
uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weakly ...
.
Preparation
BrF
5 was first prepared in 1931 by the direct reaction of bromine and fluorine.
This reaction is suitable for the preparation of large quantities, and is carried out at temperatures over with an excess of fluorine:
:Br
2 + 5 F
2 → 2 BrF
5
For the preparation of smaller amounts,
potassium bromide
Potassium bromide ( K Br) is a salt, widely used as an anticonvulsant and a sedative in the late 19th and early 20th centuries, with over-the-counter use extending to 1975 in the US. Its action is due to the bromide ion ( sodium bromide is equ ...
is used:
:KBr + 3 F
2 → KF + BrF
5
This route yields BrF
5 almost completely free of trifluorides and other impurities.
Reactions
BrF
5 reacts with water to form
bromic acid
Bromic acid, also known as hydrogen bromate, is an oxoacid with the molecular formula HBrO3. It only exists in aqueous solution.''The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals''. 14th Edition. 2006.''Van Nostrand's Scientif ...
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 antidepr ...
:
:BrF
5 + 3 H
2O → HBrO
3 + 5 HF
It is an extremely effective fluorinating agent, being able to convert most metals to their highest fluorides even at room temperature. With uranium and uranium compounds, it can be used to produce
uranium hexafluoride
Uranium hexafluoride (), (sometimes called "hex") is an inorganic compound with the formula UF6. Uranium hexafluoride is a volatile white solid that reacts with water, releasing corrosive hydrofluoric acid. The compound reacts mildly with alumin ...
:
:5 U + 6 BrF
5 → 5 UF
6 + 3 Br
2
Hazards
BrF
5 reacts violently with water, and is severely corrosive and toxic. Its vapors are also extremely irritating to all parts of the human body, especially the skin, eyes and other
mucous membrane
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It i ...
s. Like many other interhalogen compounds, it will release "smoke" containing acidic vapors if exposed to moist air, which comes from its reaction with the water in the air. Exposure to 100 ppm or more for more than one minute is lethal to most experimental animals. Chronic exposure may cause kidney damage and
liver failure.
Additionally, BrF
5 is a strong oxidizing agent and may spontaneously ignite or explode upon contact with flammable substances such as organic materials and metal dust.
References
External links
WebBook page for BrF5*
*
{{fluorine compounds
Fluorides
Bromine(V) compounds
Interhalogen compounds
Fluorinating agents
Oxidizing agents
Substances discovered in the 1930s