507-58-4Relevant academic research and scientific papers
Kinetics and mechanism of the thermal gas-phase reaction between NO 2 and perfluoropropene
Romano, Rosana M.,Czarnowski, Joanna
, p. 575 - 597 (2004)
The reaction of NO2 with perfluoropropene (C3F 6) has been studied at 413.1, 421.0 and 432.8 K, using a conventional static system. The initial pressure of NO2 was varied between 43.6 and 204.0 Torr and that of C3F6 between 10.2 and 108.5 Torr. Several experiments were made adding CF4, varying its pressure from 338.8 to 433.6 Torr. Four products were observed: NO and perfluoropropene oxide (PFPO), formed in equivalent amounts, CF3CF(NO 2)CF2NO2 and CF3C(O)CF 2NO2. The relation R = [PFPO]/([CF3CF(NO 2)CF2NO2] + [CF3C(O)CF 2NO2]) increases with temperature and decreases as the concentration of NO2 and the total pressure M increase. The yields of PFPO, based on the amount of C3F6 consumed, varied between 63 and 89% and those of CF3CF(NO2)CF 2NO2 between 0.33 and 0.08%. Increasing the temperature, the yields of CF3C(O)CF2NO2 decreased from 0.04 to 0.01%. The reaction is homogenous and the consumption rate of perfluoropropene, -d[C3F6]/dt = k1 [C 3F6][NO2], is independent of the total pressure. The following mechanism is postulated to explain the experimental results: 1) C3F6 + NO2 → CF 3C?FCF2NO2, 2) CF 3C?FCF2NO2 → PFPO + NO, 3) CF3C?FCF2NO2 +NO2 + M → CF3CF(NO2)CF2NO2 + M, 4) CF3C?FCF2NO2 + NO2 → CF3C(O)CF2NO2 + FNO. k1 = (4.57 ± 1.4) × 106 exp(-(15.44 ± 1.2) kcal mol-1/RT) dm3 mol-1 s-1. The value of k2, the rate constant for the unimolecular dissociation of the radical CF3C?FCF2NO2, was found to be of order of 1014 s-1.
