Oxides carbonyl difluoride

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. 

SYNS CARBON DIFLUORIDE OXIDE CARBON FLUORIDE OXIDE CARBONIC DIFLUORIDE CARBON OXYFLUORIDE CARBONYL DIFLUORIDE DIFLUOROFORMALDEHYDE FLUOPHOSGENE FLUOROFORMYL FLUORIDE FLUOROPHOSGENE RCRA WASTE NUMBER U033... 

Carbonyl difluoride is usually the major product of the oxidation of tetrafluoroethene, CFj=CF3, whether the oxidation is induced thermally, photochemically or by ionising radiation. 

Carbonyl difluoride is the principal product of the oxidation of tetrafluoroethene by molecular oxygen, whether induced thermally, photolytically, or by ionizing (X-ray or y-ray) radiation. A comparison of the methods has been carried out for the gas phase in a static system, and the results are summarized in Table 13.2 [320]. Tetrafluoroethene oxide, CjF O (13.2), and hexafluorocyclopropane, (CF2)3 (13.3), are formed as additional gaseous products... 

Carbonyl difluoride is formed frequently during the oxidation of many fluorine-containing halocarbons. The "simplest" fluorocarbon, CFj (prepared from the decomposition of trifluoromethyl fluorophosphoranes), when generated at 100 C in the presence of Oj, gives COFj [1299]. 

The oxidation of haiogenated methanes by SO 3 is particuiariy worthy of mention. By choice of the halogen substituents, each of the more common carbonyl dihalides, both symmetrical and asymmetrical, can be prepared by a convenient laboratory method. For the synthesis of carbonyl difluoride, the reagents CF Clj or CF Br may be used. The addition of CFjBtj (0.5 mol) to SO 3 (2.5 mol) at 35-44 C over 2 h resulted in a yield (based on CFjBrj) of COFj of 63 %, according to [1875] ... 

Fluorination of high molecular weight polyethers with elemental fluorine (diluted with helium) at room temperature gave fluorinated polyethers, which were depolymerized by further treatment with flowing F -He at 55-210 "C to produce carbonyl difluoride, amongst the decomposition products [1197c]. COFj is also formed in the oxidative thermal degradation of polyethers derived from hexafluoropropene oxide [1582]. Polymeric C F Oj decomposes, at an unspecified temperature, into carbonyl difluoride [760], The presence of... 

Carbonyl difluoride will react with partially oxidized charcoals to produce graphite fluorides, containing up to 10% fluoride [ICI29]. Treatment of carbonyl difluoride with carbon monoxide at temperatures in excess of 350 C and elevated pressures, and in the presence of a catalyst e.g. Fe or CuFj), is reported to generate tetrafluoroethene [842] ... 

Carbonyl difluoride has been used as a plasma etchant for silicon, and was found to etch the surface rapidly [397]. A CF -Oj plasma etchant has also been used COFj is formed as a primary oxidation product [153]. An excess of O, in the plasma causes loss of COF 2 by reaction with singlet oxygen (vide infra), with a concomitant drop in the formation of SiF [153]. COF2 will also thermally (625 C) etch Si(lll) surfaces, and photochemically... 

Bis(trifluoromethyl)carbene, from bis(trifluoromethyl)(liazirine, reacts with carbonyl difluoride at 180 C over 4 h in a sealed tube, to give a yield (40%) of the adduct, perfluoroisobutene oxide, along with hexafluoropropanone (10%) [1300] ... 

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