Chemistry:Carbonyl fluoride
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| Names | |||
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| Preferred IUPAC name
Carbonyl difluoride | |||
Other names
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| Identifiers | |||
3D model (JSmol)
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| ChemSpider | |||
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PubChem CID
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| RTECS number |
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| UNII | |||
| UN number | 2417 | ||
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| Properties | |||
| COF 2 | |||
| Molar mass | 66.007 g·mol−1 | ||
| Appearance | Colorless gas | ||
| Odor | Pungent and very irritating[1] | ||
| Density | 2.698 g/L (gas), 1.139 g/cm3 (liquid at melting point) | ||
| Melting point | −111.26 °C (−168.27 °F; 161.89 K) | ||
| Boiling point | −84.57 °C (−120.23 °F; 188.58 K) | ||
| Reacts[2] | |||
| Vapor pressure | 55.4 atm (20°C)[2] | ||
| Structure | |||
| C2v | |||
| 0.95 D | |||
| Hazards | |||
| Main hazards | Very toxic, reacts with water to release HF | ||
| GHS pictograms |    
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| GHS Signal word | Danger | ||
| H280, H290, H314, H330, H331, H370 | |||
| P234, P260, P261, P264, P270, P271, P280, P284, P301+330+331, P303+361+353, P304+340, P305+351+338, P307+311, P310, P311, P320, P321, P363, P390, P403+233, P404, P405, P410+403, P501 | |||
| NFPA 704 (fire diamond) | |||
| Flash point | Non-flammable | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible)
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none[2] | ||
REL (Recommended)
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TWA 2 ppm (5 mg/m3) ST 5 ppm (15 mg/m3)[2] | ||
IDLH (Immediate danger)
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N.D.[2] | ||
| Related compounds | |||
Related compounds
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |||
 verify (what is   ?)
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| Infobox references | |||
Carbonyl fluoride is a chemical compound with the formula COF
2. It is a carbon oxohalide. This gas, like its analog phosgene, is colourless and highly toxic. The molecule is planar with C2v symmetry, bond lengths of 1.174 Å (C=O) and 1.312 Å (C–F), and an F–C–F bond angle of 108.0°.[3]
Preparation and properties
Carbonyl fluoride is usually produced as a decomposition product of fluorinated hydrocarbons in the thermal decomposition thereof, for example from trifluoromethanol or tetrafluoromethane in the presence of water:
- CF
4 + H
2O → COF
2 + 2 HF
Carbonyl fluoride can also be prepared by reaction of phosgene with hydrogen fluoride and the fluorination of carbon monoxide, although the latter tends to result in over-fluorination to carbon tetrafluoride. The fluorination of carbon monoxide with silver difluoride is convenient:
- CO + 2 AgF
2 → COF
2 + 2 AgF
Carbonyl fluoride is unstable in the presence of water, hydrolyzing to carbon dioxide and hydrogen fluoride:[4]
- COF
2 + H
2O → CO
2 + 2 HF
Safety
Carbonyl fluoride is very toxic with a recommended exposure limit of 2 ppm as an 8-hour time weighted average and a 5 ppm as a short-term (15-minute average) exposure, where 1 ppm = 2.70 mg of carbonyl fluoride per 1 m3 of air.[1]
References
- ↑ 1.0 1.1 "Carbonyl Fluoride". NIOSH Pocket Guide to Chemical Hazards. CDC Centers for Disease Control and Prevention. https://www.cdc.gov/niosh/npg/npgd0108.html.
- ↑ 2.0 2.1 2.2 2.3 2.4 NIOSH Pocket Guide to Chemical Hazards. "#0108". National Institute for Occupational Safety and Health (NIOSH). https://www.cdc.gov/niosh/npg/npgd0108.html.
- ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 304–305. ISBN 978-0-08-037941-8.
- ↑ M. W. Farlow; E. H. Man; C. W. Tullock (1960). "Carbonyl Fluoride". Inorganic Syntheses. Inorganic Syntheses. 6. pp. 155–158. doi:10.1002/9780470132371.ch48. ISBN 9780470132371.
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