50311-48-3Relevant academic research and scientific papers
Kinetic and mechanistic studies of the reactions of CF3O radicals with NO and NO2
Fockenberg,Somnitz,Bednarek,Zellner
, p. 1411 - 1420 (2007/10/03)
The reactions of CF3O radicals with (1) NO and (2) NO2 were-studied using two different experimental techniques. A laser photolysis/LIF detection method was applied for measuring the rate constants as a function of temperature (T=222-302 K) and total pressure (ptot = 7-107 mbar). Whereas the reaction with (1) NO was found to be independent of temperature and pressure with k1 = (4.5±1.2)×10-11 cm3 s-1, the reaction with (2) NO2 was found to be dependent on both of these variables. The temperature dependence of k2 in the high pressure limit can be given by the expression k2, ∞ (T)=(8±5)×10-13 exp ((863±194) K/T) cm3 s-1. The product distributions of the two reactions were determined in separate experiments using steady-state photolysis combined with FTIR spectroscopy. For reaction (1) only CF2O was found as a reaction product with a yield of 0.93±0.10, independent of temperature. For reaction (2) several products (CF3ONO2, CF2O, FNO2) were identified, the overall yield, however, is dominated (≥90%) by the recombination product CF3ONO2. A theoretical analysis of the detailed mechanisms of both reactions was made by performing ab initio energy and geometry predictions in combination with RRKM calculations. Both reactions were found to proceed via an initial addition mechanism involving the CF3ONOx (x=1, 2) intermediate and a four-center transition state. A direct abstraction of an F atom by NO or NO2 can be excluded. WILEY-VCH Verlag GmbH, 1997.
Thermal Decomposition of CF3O2NO2
Mayer-Figge, A.,Zabel, F.,Becker, K. H.
, p. 6587 - 6593 (2007/10/03)
The unimolecular decomposition rate constant of CF3O2NO2 has been measured in detail as a function of temperature, pressure, and collision partner (M = N2, O2, NO).Temperatures were between 264 and 297 K, and total pressures ranged from 3 to 1013 mbar.The first-order decay of CF3O2NO2 in the presence of excess NO was followed in a temperature-controlled DURAN glass chamber by long-path IR absorption, using the absorption bands at 1768 and 1303 cm-1.At 1013 mbar, the first-order decomposition rate constants are best represented by the Arrhenius expression k3 = 5.7E15exp-1/RT> s-1 (2?).The temperature and pressure dependencies of k3 are well reproduced by the equation log(k3/k3,infinite) = log3,0/k3,infinite)/(1 + k3,0/k3,infinite)> + log(Fc)3,0/k3,infinite)/Nc>2>-1, Nc = 0.75-1.27 log(Fc) with the parameters k3,0/ = 2.4E-5exp(-78.4 kJ mol-1/RT) cm3 molecule-1 s-1, k3,infinite = 1.49E16exp-1/RT> s-1, Fc = 0.31, and k3,0(M=O2) ca. k3,0(M=N2).By combining the present decomposition rate constants with recombination rate constants k-3 from Caralp et al., the following thermochemical data for the equilibrium CF3O2NO2 CF3O2 + NO2 (k3,k-3) are derived from second- and third-law evaluations: ΔH0r,298 = 102.7 +/- 2.0 kJ mol-1, ΔS0r,298 = 163 +/- 7 J mol-1 K-1.The temperature dependence of the equilibrium constant between 200 and 300 K is described by the expression Kc = k3/k-3 = 3.80E27exp molecules cm-3.Consistency of the data on k3 (this work) and k-3 is shown by comparing experimental and theoretical limiting low-pressure rate constants, which lead to the reasonable value βc = 0.17 for the collision efficiency of N2.The present data confirm that CF3O2NO2 is thermally quite stable in the upper troposphere and lower stratosphere and that its lifetime is probably limited by photolysis in these regions of the atmosphere.
Some reactions of CF3OO derivatives with inorganic nitrogen compounds. Synthesis and vibrational spectrum of trifluoromethyl peroxynitrate
Hohorst, Frederick A.,DesMarteau, Darryl D.
, p. 715 - 719 (2007/10/12)
Trifluoromethyl peroxynitrate, CF3OONO2, is obtained in high yield by the reaction of trifluoromethyl hydroperoxide with dinitrogen pentoxide or fluoroperoxytrifluoromethane with dinitiogen tetioxide. Physical and chemical properties of the new compound are reported along with an assignment of the vibrational spectrum based on Cs symmetry.
