- Formation of bromodifluoroacetyl fluoride, CF2BrC(O)F, in the thermal gas-phase oxidation of bromotrifluoroethene, CF2CFBr, initiated by trifluoromethylhypofluorite, CF3OF
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The oxidation of CF2CFBr by molecular O2, initiated by CF3OF, has been studied at 273, 253.5, 239 and 218 K. The initial pressure of CF3OF was varied between 0.9 and 2.4 Torr, that of CF2CFBr between 11.5 and 30.7 Torr and that of O2 between 42.5 and 100.7 Torr. The main product was CF2BrC(O)F (yields 81-95% based on the CF2CFBr consumed). Minor amounts of C(O)F2 and C(O)FBr and traces of bromotrifluoroethene epoxide were also formed. The reaction is a chain reaction with bromine atoms as chain carriers. Its basic steps are: the thermal generation of CF3O{radical dot} radical by abstraction of fluorine atom from CF3OF, chain initiation by addition of CF3O{radical dot} to the double bond of alkene, leading, in presence of O2, to the formation of bromine atom and chain propagation by the reaction of bromine atom with CF2CFBr, originating CF2BrCFBrO{radical dot} radical. The predominant fate of the latter is the bromine atom extrusion with C{single bond}C bond scission playing the minor role. The full mechanism is postulated.
- Czarnowski, Joanna
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p. 736 - 739
(2008/09/16)
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- Bromodifluoroacetyl fluoride, CF2BrC(O)F: Experimental and theoretical studies
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Bromodifluoroacetyl fluoride, CF2BrC(O)F, was prepared through the gas-phase reaction of bromotrifluoroethene, CF2CFBr, with molecular oxygen initiated either by NO2 or CF3OF. The compound was experimentally studied by FTIR spectroscopy of the gas phase and also isolated in Ar and N2 matrices at low temperature. The energy differences between the possible conformers were theoretically studied, as well as the vibrational spectra of the conformers.
- Arce, Valeria B.,Czarnowski, Joanna,Romano, Rosana M.
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