Carbonyl fluoride

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 C_2v 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]

Carbonyl fluoride

Structure of carbonyl fluoride 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	353-50-4 Y
3D model (JSmol)	Interactive image
ChemSpider	9246 Y
ECHA InfoCard	100.005.941
EC Number	206-534-2
PubChem CID	9623
RTECS number	FG6125000
UNII	2NU89R5398 Y
UN number	2417
CompTox Dashboard (EPA)	DTXSID7059858
InChI InChI=1S/CF2O/c2-1(3)4 Y Key: IYRWEQXVUNLMAY-UHFFFAOYSA-N Y 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
Signal word	Danger
Hazard statements	H290, H314, H330, H370
Precautionary statements	P234, P260, P261, 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)	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	Phosgene Carbonyl bromide Formyl fluoride Thiocarbonyl chloride Acetone Urea Carbonic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

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:

CF₄ + H₂O → COF₂ + 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 AgF₂ → COF₂ + 2 AgF

Carbonyl fluoride is unstable in the presence of water, hydrolyzing to carbon dioxide and hydrogen fluoride:^[4]

COF₂ + H₂O → CO₂ + 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. "Carbonyl Fluoride". NIOSH Pocket Guide to Chemical Hazards. CDC Centers for Disease Control and Prevention. Retrieved 2013-09-10.
2. 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. ISBN 978-0-08-037941-8.
4. M. W. Farlow; E. H. Man; C. W. Tullock (1960). "Carbonyl Fluoride". Inorganic Syntheses. Inorganic Syntheses. Vol. 6. pp. 155–158. doi:10.1002/9780470132371.ch48. ISBN 9780470132371.