136649-69-9Relevant academic research and scientific papers
Kinetics and mechanism of the thermal gas-phase oxidation of tetrachloroethene by molecular oxygen in presence of trifluoromethylhypofluorite, CF3OF
Czarnowski, Joanna
, p. 183 - 197 (1998)
The oxidation of tetrachloroethene by molecular oxygen in presence of CF3OF has been studied at 314.0, 324.2, 334.1 and 344.3 K. The initial pressure of CF3OF was varied between 2.0 and 8.2 Torr, that of CCl2CCl2 between 8.7 and 21.7 Torr, that of O2 between 33.2 and 730.7 Torr. Several runs were made adding N2 at pressure varying between 250.4 and 525.9 Torr. The major products were CCl3C(O)Cl and COCl2. CF3OCCl2C(O)Cl, CCl2FC(O)Cl, CF3OCCl2CCl2F and CCl2FCCl2F were formed in traces. The oxidation is a chain reaction. Its rate increases with total pressure. The following mechanism, where E = CCl2CCl2, R = CCl2FCCl2, CF3OCCl2CCl2 or CCl3CCl2, R′ = CCl2F, CF3OCCl2 or CCl3 and M = effective pressure, explains the experimental results: 1) CF3OF+E → R+CF3O 3, 7) R+O2+M → RO2+M 5) RO → R′C(O)Cl+Cl 9) CCl3CCl2O → CCl3C(O)Cl+Cl 11) CCl3+O2+M → CCl3O2+M 13) CCl3O → COCl2+Cl 15) R+CF3OF → RF+CF3O 2) CF3O+E → R 4, 8) 2RO2 → 2RO+O2 6) Cl+E → CCl3CCl2 10) CCl3CCl2O → CCl3+COCl2 12) CCl3O2+RO2 → CCl3O+RO+O2 14) 2R → recombination products, k9 = (3.0±1.4) × 1013 exp(-9.66±1 kcal mol-1/RT) s-1. by R. Oldenbourg Verlag, Muenchen 1998.
Kinetics and mechanism of the thermal gas-phase reaction between trifluoromethylhypofluorite, CF3OF, and tetrachloroethene
Czarnowski
, p. 489 - 495 (2007/10/03)
The thermal gas-phase reaction of CF3OF with CCL2CCL2 has been studied between 313.8 and 343.8 K. The initial pressure of CF3OF was varied between 10.8 and 77.5 torr and that of CCl2CCl2 between 3.7 and 26.8 torr. CF3OF was always present in excess, varying the initial ratio of CF3OF to that of CCl2CCl2 from 1.3 to 10. Three products were formed: CF3OCCl2CCl2F, CCl2FCCl2F, and CF3O(CCl2CCl2)2OCF3. The yields of CF3OCCl2CCl2F were 98-99.5%, based on the sum of the products. The reaction was a homogeneous chain reaction not affected by the total pressure. In presence of O2 the oxidation of CCl2CCl2 to CCl3C(O)Cl and COCl2 occurred. The proposed basic reaction steps are: generation of the radicals CF3O· and CCl2FCCl2· (k1) in a biomolecular process between CF3OF and CCl2CCl2, formation of the radical CF3OCCl2CCl2· by addition of CF3O· to CCl2CCl2, chain generation of CF3O· by abstraction of fluorine atom from CF3OF by CF3OCCl2CCl2· (k4), and chain termination by recombination of the radicals CF3OCCl2CCl2·. The expressions obtained for the constants k1 and k4 are: k1 = 3.16 ± 0.6 × 107 exp(- 15.2 ± 1.7 Kcal mol-1/RT) dm3 mol-1 s-1; k4 = 3.7 ± 0.5 × 109 exp(- 6.0 ± 1.1 Kcal mol-1/RT) dm3mol-1s-1.
Relative Rate Constants for the Reactions of CF3OF with Olefins in Solution
Navarrini, W.,Russo, A.,Tortelli, V.
, p. 6441 - 6443 (2007/10/03)
The addition reactions of CF3OF to chloro fluoro olefins have been studied in solution at low temperature (-78, -105 deg C), and their relative rate constants have been determined using the kinetic approach of competition reactions.The reactivity and regio- and stereoselectivity are consistent with a free radical chain-propagating reaction in which the alkenes are attacked by the CF3O* radical generated by homolytic cleavage of the O-F bond in the CF3OF molecule.
