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°.

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

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.