Bromine pentafluoride


Bromine pentafluoride, BrF5, is an interhalogen compound and a fluoride of bromine. It is a strong fluorination reagent.
BrF5 finds use in oxygen isotope analysis. Laser ablation of solid silicates in the presence of bromine pentafluoride releases O2 for subsequent analysis. It has also been tested as an oxidizer in liquid rocket propellants and is used as a fluorinating agent in the processing of uranium.

Preparation

Bromine pentafluoride was first prepared in 1931 by the direct reaction of bromine with fluorine. This reaction is suitable for the preparation of large quantities, and is carried out at temperatures over with an excess of fluorine:
For the preparation of smaller amounts, potassium bromide is used:
This route yields bromine pentafluoride almost completely free of trifluorides and other impurities.

Reactions

Bromine pentafluoride reacts violently with water, but it will form bromic acid and hydrofluoric acid, simple hydrolysis products:
It is an extremely effective fluorinating agent, being able to convert most uranium compounds to uranium hexafluoride at room temperature.

Hazards

Bromine pentafluoride is severely corrosive to the skin, and its vapors are irritating to the eyes, skin, and mucous membranes. In moist air, it will in fact release "smoke" containing hydrofluoric acid vapors coming from its reaction with the water in the air. Additionally, 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.
It may spontaneously ignite or explode upon contact with organic materials or metal dust.