Columbium pentafluoride, CbF5, is obtained when the pentoxide is dissolved in hydrofluoric acid.
The oxyfluoride, CbOF3, results when a mixture of the pentoxide and fluorspar is heated in a current of hydrochloric acid.
It burns when heated in air, forming the pentoxide and sulphur dioxide.
It is only known in solution; evaporation of the solution yields the pentoxide.
It burns readily in air, and is converted into the pentoxide when fused with acid potassium sulphate.