Cobalt(III) fluoride
| Cobalt(III) fluoride | |
|---|---|
-fluoride-3D-balls.png) | |
| Other names Cobalt trifluoride | |
| Identifiers | |
| CAS number | 10026-18-3  |
| PubChem | 66208 |
| ChemSpider | 59593 |
| EC number | 233-062-4 |
| Jmol-3D images | {{#if:F[Co](F)F|Image 1 |
| |
| |
| Properties | |
| Molecular formula | CoF3 |
| Molar mass | 115.928 g/mol |
| Appearance | brown powder |
| Density | 3.88 g/cm3 |
| Melting point | 927 °C; 1,701 °F; 1,200 K |
| Solubility in water | reacts |
| Structure | |
| Crystal structure | hexagonal |
| 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 (77 °F), 100 kPa) | |
| 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.[1] CoF3 is a powerful fluorinating agent that leaves CoF2 as the byproduct.
Preparation
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+ and Cl- are oxidized to Co3+ and Cl2, respectively, while F2 is reduced to F-. Cobalt(II) oxide (CoO) and cobalt(II) fluoride (CoF2) can also be converted to cobalt(III) fluoride using fluorine.
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.
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.[1] The related reagent KCoF4 is more selective.[3]
References
- ↑ 1.0 1.1 Coe, P. L. "Cobalt(III) Fluoride" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289X.rc185.
- ↑ Priest, H. F. "Anhydrous Metal Fluorides" Inorganic Syntheses McGraw-Hill: New York, 1950; Vol. 3, pages 171-183. doi:10.1002/9780470132340.ch47
- ↑ Coe, P. L. "Potassium Tetrafluorocobaltate(III)" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289X.rp251.
External links
 |
Wikimedia Commons has media related to Cobalt(III) fluoride. |
- National Pollutant Inventory - Cobalt fact sheet
- National Pollutant Inventory - Fluoride and compounds fact sheet
| |||||