An inorganic interhalogen species with the formula BrF5 that was tried as a rocket oxidizer in the 1960's. It is made from the direct combination of bromine and fluorine at temperatures above 150 C. Unlike its cousins perchloryl fluoride and chlorine pentafluoride, bromine pentafluoride is a liquid at room temperature and pressure. Its density is also quite high, around 2.4 g/cc, meaning that a large mass of it can be stored in a small space. Like chlorine pentafluoride, Bromine pentafluoride is one of the most powerful (in terms of specific impulse) non-cyrogenic liquid oxidizers in existence (except when coupled with carbon-containing fuels like kerosene.
However, like chlorine pentafluoride, it corrodes tanks quite easily; even the almighty Teflon is eventually eaten away by it. However, some metals (like steel) form surface fluorides that inhibit corrosion by bromine pentafluoride. Therefore, only those metals that form a fluoride layer can be used to store it.