Uranyl fluoride is the inorganic compound with the formula . It is most notable as a contaminant in the production of uranium tetrafluoride.
As shown by X-ray crystallography, the uranyl centers are surrounded by six fluoride ligands .
It is formed in the hydrolysis of uranium hexafluoride ():
It can also be formed in the hydrofluorination of uranium trioxide ():
This salt is very soluble in water as well as hygroscopic. It changes in color from brilliant orange to yellow upon hydration. Starting around 300 ðC, hydrolysis by the water vapor in air becomes significant, resulting in HF fumes.