Chromium(IV) fluoride

Chromium fluoride is an inorganic compound with the chemical formula CrF₄. It has a dark greenish-black color when solid. It rapidly hydrolyzes in presence of moisture in air or directly in water.

Synthesis

Powdered chromium or CrCl₃ is exposed to fluorine gas at a temperature of 350-500 °C, which creates a mix of CrF₄ and CrF₅. The CrF₄ settles out as varnish-like brown beads upon cooling.

Reactions

Chromium fluoride is easily reduced.
It will react with water: