Carbonyl fluoride
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 477163184
| Name = Carbonyl fluoride
| ImageFileL1 = Carbonyl-fluoride-2D.png
| ImageNameL1 = Structure of carbonyl fluoride
| ImageFileR1 = Carbonyl-fluoride-3D-vdW.png
| ImageNameR1 = Space-filling model of the carbonyl fluoride molecule
| PIN = Carbonyl difluoride
| OtherNames = {{ubl|Carbon difluoride oxide|Fluoromethanoyl fluoride|Fluorophosgene}}
|Section1={{Chembox Identifiers
| SMILES = FC(F)=O
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 9246
| InChI = 1/CF2O/c2-1(3)4
| InChIKey = IYRWEQXVUNLMAY-UHFFFAOYAE
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/CF2O/c2-1(3)4
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = IYRWEQXVUNLMAY-UHFFFAOYSA-N
| CASNo = 353-50-4
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 2NU89R5398
| RTECS = FG6125000
| UNNumber = 2417
| PubChem = 9623
| EC_number = 206-534-2
}}
|Section2={{Chembox Properties
| Formula = {{chem2|COF2}}
| C=1|O=1|F=2
| Appearance = Colorless gas
| Density = 2.698 g/L (gas), 1.139 g/cm3 (liquid at melting point)
| MeltingPtC = -111.26
| BoilingPtC = -84.57
| Odor = Pungent and very irritating
| VaporPressure = 55.4 atm (20°C)
}}
|Section3={{Chembox Structure
| MolShape = C2v
| Dipole = 0.95 D
}}
|Section7={{Chembox Hazards
| ExternalSDS =
| MainHazards = Very toxic, reacts with water to release HF
| FlashPt = Non-flammable
| NFPA-H = 4
| NFPA-F = 0
| NFPA-R = 2
| NFPA-S = W
| GHSPictograms = {{GHS05}}{{GHS06}}{{GHS08}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|290|314|330|370}}
| PPhrases = {{P-phrases|234|260|261|264|270|271|280|284|301+330+331|303+361+353|304+340|305+351+338|307+311|310|311|320|321|363|390|403+233|404|405|410+403|501}}
| PEL = none{{PGCH|0108}}
| REL = TWA 2 ppm (5 mg/m3) ST 5 ppm (15 mg/m3)
}}
|Section8={{Chembox Related
| OtherFunction_label =
| OtherFunction =
| OtherCompounds = {{ubl|Phosgene|Carbonyl bromide|Formyl fluoride|Thiocarbonyl chloride|Acetone|Urea|Carbonic acid}}
}}
}}
Carbonyl fluoride is a chemical compound with the formula {{chem2|COF2|auto=1}}. 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°.{{Greenwood&Earnshaw2nd|pages=304–305}}
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:
:{{chem2|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:
:{{chem2|CO + 2 AgF2 → COF2 + 2 AgF}}
Carbonyl fluoride is unstable in the presence of water, hydrolyzing to carbon dioxide and hydrogen fluoride:{{ Cite book |author1=M. W. Farlow |author2=E. H. Man |author3=C. W. Tullock |title=Inorganic Syntheses | chapter = Carbonyl Fluoride | series = Inorganic Syntheses | year = 1960 | volume = 6 | pages = 155–158 | doi = 10.1002/9780470132371.ch48 |isbn=9780470132371 }}
:{{chem2|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.{{ cite web | url = https://www.cdc.gov/niosh/npg/npgd0108.html | publisher = CDC Centers for Disease Control and Prevention | work = NIOSH Pocket Guide to Chemical Hazards | title = Carbonyl Fluoride | access-date = 2013-09-10 }}