Carbonyl fluoride, from decomposition

The decomposition products, up to a temperature of 500°C, are principally the monomer, tetrafluoroethylene, but also include perfluoropropene, other perfluro compounds containing four or five carbon atoms, and an unidentified particulate waxy fume. From 500°C to 800°C, the pyrolysis product is carbonyl fluoride, which can hydrolyze to form HE and CO2. 

Many of the carbon compounds containing both fluorine and oxygen decompose by complex mechanisms. However, the thermal decomposition of tetrafluoro-ethylene oxide is claimed to be unimolecular over the temperature range 115-140 °C, with = 5 X 10 sec and E = 31.6 kcal.mole". The products are carbonyl fluoride and perfluoroethylene plus perfluorocyclopropane (probably formed from CF2). In a pyrex glass vessel at 40-45 °C trifluoroacetylfluoride is produced by a heterogeneous process. 

This cyclization is a reaction developed by Mori, who carried out a series of investigations with tin reagent 33. Fluoride is a much more reactive anion for initiation than any of the other halides, although it often leads to decomposition of the starting materials. In the case of vinylic or aryl halogen compounds the iodides are easier to transform than the bromides, and chlorides are unrcactive. The carbonyl group can be derived from either an aldehyde or a ketone, and even esters are sufficiently electrophilic.22... 

The first method suffers from the disadvantage that fluoroiodomethane is not readily available furthermore, satisfactory yields of vinyl fluorides are not obtained on reaction with carbonyl compounds unless potassium r-butoxide is used to promote decomposition of intermediate betaines. 

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