Carbonyl fluoride

Carbonyl fluoride
Structure of carbonyl fluoride
Structure of carbonyl fluoride
Space-filling model of the carbonyl fluoride molecule
Space-filling model of the carbonyl fluoride molecule
Names
Preferred IUPAC name
Carbonyl difluoride
Other names
  • Carbon difluoride oxide
  • Fluoromethanoyl fluoride
  • Fluorophosgene
Identifiers
CAS Number
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.005.941
EC Number
  • 206-534-2
PubChem CID
RTECS number
  • FG6125000
UNII
UN number 2417
CompTox Dashboard (EPA)
InChI
  • InChI=1S/CF2O/c2-1(3)4 checkY
    Key: IYRWEQXVUNLMAY-UHFFFAOYSA-N checkY
  • InChI=1/CF2O/c2-1(3)4
    Key: IYRWEQXVUNLMAY-UHFFFAOYAE
SMILES
  • FC(F)=O
Properties
Chemical formula
COF2
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)
Solubility in water
Reacts[2]
Vapor pressure 55.4 atm (20°C)[2]
Structure
Molecular shape
C2v
Dipole moment
0.95 D
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Very toxic, reacts with water to release HF
GHS labelling:
Pictograms
GHS05: CorrosiveGHS06: ToxicGHS08: Health hazard
Signal word
Danger
Hazard statements
H290, H314, H330, H370
Precautionary statements
P234, P260, P264, P270, P271, P280, P284, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P307+P311, P310, P311, P320, P321, P363, P390, P403+P233, P404, P405, P410+P403, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamond
4
0
2
W
Flash point Non-flammable
NIOSH (US health exposure limits):
PEL (Permissible)
none[2]
REL (Recommended)
TWA 2 ppm (5 mg/m3) ST 5 ppm (15 mg/m3)[2]
IDLH (Immediate danger)
N.D.[2]
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)
Infobox references

Carbonyl fluoride is a chemical compound with the formula COF2. 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

Carbonyl fluoride is produced from trifluoromethanol. The latter is produced in turn by protonation of in-situ generated trifluoromethoxide.[4]

Of potential relevance to atmospheric chemistry, tetrafluoromethane hydrolyses to carbonyl fluoride:

CF4 + H2O → COF2 + 2 HF

Carbonyl fluoride can also be prepared by reaction of phosgene with hydrogen fluoride as well as 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:[5]

CO + 2 AgF2 → COF2 + 2 AgF

Reactions

Carbonyl fluoride readily hydrolyzes to carbon dioxide and hydrogen fluoride:[5]

COF2 + H2O → CO2 + 2 HF

When produced in situ, carbonyl fluoride converts carboxylic acids to acyl fluorides:[4]

CF2O + RCO2H → RCOF + HF + CO2

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. ^ a b "Carbonyl Fluoride". NIOSH Pocket Guide to Chemical Hazards. CDC Centers for Disease Control and Prevention. Retrieved 2013-09-10.
  2. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0108". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 304–305. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
  4. ^ a b Bonnefoy, Clémence; Gallego, Adrien; Delobel, Clément; Raynal, Betty; Decourt, Maxime; Chefdeville, Emmanuel; Hanquet, Gilles; Panossian, Armen; Leroux, Frédéric R.; Toulgoat, Fabien; Billard, Thierry (2024). "Unlocking the Power of Acyl Fluorides: A Comprehensive Guide to Synthesis and Properties". European Journal of Organic Chemistry. 27 (18) e202400142. doi:10.1002/ejoc.202400142.
  5. ^ a b M. W. Farlow; E. H. Man; C. W. Tullock (1960). "Carbonyl Fluoride". Inorganic Syntheses. Vol. 6. pp. 155–158. doi:10.1002/9780470132371.ch48. ISBN 9780470132371. {{cite book}}: ISBN / Date incompatibility (help)