Cobalt(III) fluoride is the inorganic compound with the formula CoF3.
[1] The related cobalt(III) chloride is also known but is extremely unstable.
[3] Cobalt trifluoride can be prepared in the laboratory by treating CoCl2 with fluorine at 250 °C:[4][3] In this redox reaction, Co2+ and Cl− are oxidized to Co3+ and Cl2, respectively, while F2 is reduced to F−.
[3] CoF3 decomposes upon contact with water to give oxygen: It reacts with fluoride salts to give the anion [CoF6]3−, which is also features high-spin, octahedral cobalt(III) center.
[5] In the gas phase, CoF3 is calculated to be planar in its ground state, and has a 3-fold rotation axis (point group D3h).