Cobalt(III) fluoride
| Cobalt(III) fluoride | |
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Other names
Cobalt trifluoride |
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| Identifiers | |
| CAS number | 10026-18-3  |
| PubChem | 66208 |
| ChemSpider | 59593 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | CoF3 |
| Molar mass | 115.9284 g/mol |
| Appearance | brown solid |
| Density | 3.88 g/cm3 |
| Melting point |
927 °C[1] |
| Solubility in water | reacts |
| Hazards | |
| NFPA 704 |
 0
3
2
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| Related compounds | |
| Other anions | cobalt(III) oxide, cobalt(III) chloride |
| Other cations | iron(III) fluoride, rhodium(III) fluoride |
| Related compounds | cobalt(II) fluoride |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Cobalt(III) fluoride is the inorganic compound with the formula CoF3. This highly reactive, hygroscopic brown solid is used to synthesize organofluorine compounds.[2] CoF3 is a powerful fluorinating agent, the product being CoF2.
Contents |
[edit] Preparation
CoF3 is prepared in the laboratory by treating CoCl2 with fluorine at 250 °C:[3]
- CoCl2 + 3/2 F2 → CoF3 + Cl2
This conversion is a redox reaction: Co2+ is converted to Co3+ and chloride to chlorine at the expense of fluorine, which is converted to fluoride. Cobalt(II) oxide (CoO) and cobalt(II) fluoride (CoF2) can also be converted to cobalt(III) fluoride using fluorine.
[edit] Reactions
CoF3 decomposes upon contact with water to give oxygen:
- 4 CoF3 + 2 H2O → 4 HF + 4 CoF2 + O2
CoF3 is hygroscopic, forming a dihydrate (CAS#54496-71-8). It reacts with fluoride sources to give the anion [CoF6]3-, which is a rare example of a high-spin, octahedral cobalt(III) complex.
[edit] Applications
Used as slurry, CoF3 converts hydrocarbons to the perfluorocarbons:
- 2CoF3 + R-H → 2CoF2 + R-F + HF
Such reactions are sometimes accompanied by rearrangements or other reactions.[2] The related reagent KCoF4 is more selective.[4]
[edit] References
- ^ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3.
- ^ 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.
- ^ Priest, H. F. “Anhydrous Metal Fluorides” Inorganic Syntheses McGraw-Hill: New York, 1950; Vol. 3, pages 171-183.
- ^ 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.
[edit] External links
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Wikimedia Commons has media related to: Cobalt(III) fluoride |
- National Pollutant Inventory - Cobalt fact sheet
- National Pollutant Inventory - Fluoride and compounds fact sheet
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