Cobalt(III) fluoride

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Cobalt(III) fluoride
Image:Cobalt(III) fluoride.jpg
Systematic name Cobalt(III) fluoride
Other names Cobalt trifluoride
Cobaltic fluoride
Cobalt fluoride
Cobaltic trifluoride
Molecular formula CoF3
Molar mass 115.93 g/mol
Density 3.88 g/cm3
Melting point 926 °C
CAS number [10026-18-3]
Disclaimer and references

Cobalt(III) fluoride is the chemical compound with the formula CoF3. This highly reactive, hygroscopic brown solid is used to synthesize organofluorine compounds.[1] CoF3 is a powerful fluorinating agent, the product being CoF2.

CoF3 is prepared in the laboratory by treating CoCl2 with fluorine at 250 °C:[2]

CoCl2 + 3/2 F2 → CoF3 + Cl2

This conversion is a redox reaction, Co2+ is converted to Co3+. Fluorine is a powerful oxidant, so strong that it oxidizes chloride to chlorine.

CoF3 is hygroscopic and can be converted to the anion [CoF6]3-, a rare example of a high-spin, octahedral cobalt(III) complex.

Used as slurry, CoF3 converts hydrocarbons to the perfluorocarbons:

2CoF3 + R-H → CoF2 + R-F + HF

Such reactions are accompanied by rearrangements.[1] The related reagent KCoF4 is more selective.[3]

[edit] References

  1. ^ a b Coe, P. L. "Cobalt(III) Fluoride" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.
  2. ^ Priest, H. F. “Anhydrous Metal Fluorides” Inorganic Syntheses McGraw-Hill: New York, 1950; Vol. 3, pages 171-183.
  3. ^ Coe, P. L. "Potassium Tetrafluorocobaltate(III)" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.

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