Uranyl fluoride is the

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

with the formula . It is most notable as a contaminant in the production of

uranium tetrafluoride Uranium tetrafluoride is the inorganic compound with the formula UF4. It is a green solid with an insignificant vapor pressure and low solubility in water. Uranium in its tetravalent ( uranous) state is important in various technological process ...

. As shown by

X-ray crystallography X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring th ...

, the uranyl centers are surrounded by six fluoride ligands . This salt is very soluble in water as well as

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption (chemistry), absorption or adsorption from the surrounding Natural environment, environment, which is usually at normal or room temperature. If water mol ...

. It changes in color from brilliant orange to yellow after reacting with water. Uranyl fluoride is stable in air up to 300 °C, above which slow decomposition to occurs. When heated to decomposition, emits toxic

hydrofluoric acid Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colorless, acidic and highly corrosive. A common concentration is 49% (48–52%) but there are also stronger solutions (e.g. 70%) and pure HF has a boiling p ...

fumes. It is formed in the hydrolysis of uranium hexafluoride (): : It can also be formed in the hydrofluorination of uranium trioxide (): :

References

{{Inorganic-compound-stub Uranyl compounds Metal halides Oxyfluorides