Carbon reaction with, carbonyl difluoride

Carbonyl difluoride reacts vigorously with water, to produce carbon dioxide and hydrogen fluoride [1756]. A similar reaction is observed with concentrated sulfuric acid, and it is completely absorbed by sodium hydroxide solution [1756]. Indeed, the reaction between COFj and D O at 0 C has been used to prepare DF in purities >99.5% and yields of 90% [1554], A recent ab initio study [677aa] of the mechanism and energetics of the gas-phase reaction of carbonyl difluoride with water indicates that the reaction proceeds through two transient intermediates - CFj(OH)j and FC(0)0H. The former dissociates to the latter and HF, and the FC(0)0H then dissociates into COj and HF, consistent with the overall stoicheiometry ... 

Urea, melamine, cyanamide, dicyandiamide, and guanidine react at elevated temperatures with sulfur tetrafluoride to give (trifluoromethyl)iminosulfur difluoride (7) in 6-25% yield.172 In the presence of sodium fluoride at 25"C, urea is converted into fluorocarbonyliminosulfur difluoride (8), but at 50°C thiazyl fluoride (9) is the main product, both formed in ca. 60% yield. At higher temperatures, carbonyl difluoride (carbonic difluoride) and sulfur hexafluoride are the sole products of the reaction of urea with sulfur tetrafluoride.173... 

Oxygen difluoride reacts rapidly with selected alkenes at low temperatures however, per-fliioroalkenes are less reactive than the corresponding alkylalkenes and require either thermal or ultraviolet activation." The oxidation, which is a homogeneous chain reaction," of hexa-fluoropropene, tetrafluorocyclopropene, and pcrfluorobut-2-ene all give a variety of products such as carbon tetrafluoridc, carbonyl difluoride, hexafluoroethane, oxiranes, and other oxidation products." This reaction is not useful for preparative organic work. 

The reaction of arc-generated carbon atoms with CF in the presence of dioxygen resulted in the formation of carbonyl difluoride [1670]. COFj is also formed when a 4 1 molar ratio of CO and CF, (at a pressure of 0.7 kPa) is passed through an electric arc produced between graphite electrodes at 7500 V [1884]. 

The apparent activation energy for the y-ray induced formation of carbonyl difluoride is calculated to be 18.0 kj moP . The kinetics results indicate a chain mechanism in which primary radicals formed from the irradiation of CjF, induce its copolymerization with Oj-The resulting long-chain peroxide radicals decompose by splitting off COFj or CjF O, depending upon whether a carbon-carbon, or oxygen-oxygen bond is broken. The perfluorinated cyclopropane is considered to be formed independently, in a minor side-reaction [420]. 

Carbonyl difluoride reacts with N,Af-dimethylmethanamide (dmf) at room temperature to give a gem-difluoride accompanied by the elimination of carbon dioxide [571,632]. Although no fluoroformate intermediate could be isolated from this reaction (see Section 13.14.6), labelling of the dmf with carbon-14 at the carbonyl group showed that this carbon was retained in the difluorotrimethylamine product. The following mechanism was indicated [632] ... 

In the reaction of ethanol with COFj, the reaction is catalysed by pyridine [589]. Ethane-1,2-diol, however, is reported to react with an excess of COF at -80 C to give a 79% yield of the bis(fluoroformate) in the presence of sodium fluoride (which acts as a base to absorb the HF by-product) [24a]. No reaction occurs when carbonyl difluoride is passed into a solution of phenol in diethyl ether, and passage of COFj into a mixture of phenol, pyridine and benzene results in the production of a quantitative yield of diphenyl carbonate. Phenyl fluoroformate was prepared by heating a mixture of COF, PhOH and benzene at 100 "C, however, in an autoclave [589]. 

The reaction takes place in a rotating autoclave over eight hours, and under a partial pressure of carbon monoxide of 12 MPa. After bleeding off the carbonyl difluoride co-product and the excess of carbon monoxide, the COFI was removed by distillation at about 26.7 kPa, foliowed by a further distillation in vacuo over antimony powder to give a yield of 12% for COFI (based on IF ). The material is suitably stored in quartz vessels cooled with dry ice [1196,1751]. 

CARBONYL DIFLUORIDE or CARBONYL FLUORIDE (353-50-4) CFjO Noncombustible gas. Reacts with water or steam, producing hydrogen fluoride gas and carbon dioxide. Violent reaction with strong oxidizers bases including amines, amides, and inorganic hydroxides alcohols and glycols dinitrogen tetraoxie, hexafluoroisopropylideneaminolithium ethers in the presence of metal salts. If flow... 

CARBONYL DIFLUORIDE (353-50-4) Reacts with water or steam, producing hydrogen fluoride gas and carbon dioxide. Violent reaction with strong oxidizers, dinitrogen tetraoxide. 

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