17167-98-5Relevant articles and documents
Kinetic Study of the Reaction of Chlorine Atoms with CF3I and the Reactions of CF3 Radicals with O2, Cl2 and NO at 296 K
Kaiser, E. W.,Wallington, T. J.,Hurley, M. D.
, p. 205 - 218 (1995)
The kinetics of the gas-phase reaction of Cl atoms with CF3I have been studied relative to the reaction of Cl atoms with CH4 over the temperature range 271 - 363 K.Using k(Cl + CH4) = 9.6*10-12 exp(-2680/RT) cm3 molecule-1 s-1, we derive k(Cl + CF3I) = 6.25*10-11 exp(-2970/RT) in which Ea has units of cal mol-1.CF3 radicals are produced from the reaction of Cl with CF3I in a yield which was indistinguishable from 100percent.Other relative rate constant ratios measured at 296 K during these experiments were k(Cl + C2F5I)/k(Cl + CF3I) = 11.0 +/- 0.6 and k(Cl + C2F5I) /k(Cl + C2H5Cl) = 0.49 +/- 0.02.The reaction of CF3 radicals with Cl2 was studied relative to that with O2 at pressures from 4 to 700 torr of N2 diluent.By using the published absolute rate constants for k(CF3 + O2) at 1-10 torr to calibrate the pressure dependence of these relative rate constants, values of the low- and high-pressure limiting rate constants have been determined at 296 K using a Troe expression: k0(CF3 + O2) = (4.8 +/- 1.2)*10-29 cm6 molecule-2 s-1; kinfinite(CF3 + O2) = (3.95 +/- 0.25)*10-12 cm3 molecule-1 s-1; Fc = 0.46.The value of the rate constant k(CF3 + Cl2) was determined to be (3.5 +/- 0.4)*10-14 cm3 molecule-1 s-1 at 296 K.The reaction of Cl atoms with CF3I is a convenient way to prepared CF3 radicals for laboratory study.
Gas-phase reactions of oxide and superoxide anions with CF4, CF3Cl, CF3Br, CF3I, and C2F4 at 298 and 500 K
Morris, Robert A.
, p. 2372 - 2381 (2007/10/02)
Rate constants and product branching fractions have been measured for the gas-phase reactions of oxide (O-) and superoxide (O2-) anions with the halocarbons CF4, CF3Cl, CF3Br, CF3I, and C2F4 using a variable temperature-selected ion flow tube (VT-SIFT) instrument operated at 298 and 500 K.The reactions of O- with CF3X (X = Cl, Br, I) are fast and produce F-, XF-, and XO- for all X.For CF3Cl and CF3Br, X- is also formed.For CF3I, CF3- and IOF- are minor products.O- reacts rapidly with C2F4 producing F- as the major ionic product, along with contributions from reactive detachment and minor formation of FCO-, CF3-, and C2F3O-.The reaction of O2- with CF3Cl is slow, and both clustering and X- formation were observed.For CF3Br and CF3I, the reactions with O2- are fast, and nondissociative charge transfer was observed in addition to X- formation.O2- reacts rapidly with C2F4 by reactive detachment, in addition to producing F- as the major ionic product with smaller amounts of F2-, FCO-, FCO2-, CF3O-, and C2F4O-.O- and O2- were both found to be unreactive with CF4 at 298 and 500 K.The efficiencies of the reactions of both O- and O2- with CF3X are greater for the heavier halides at both 298 and 500 K.The rate constants for the reactions of O2- with CF3X appear to correlate both with the rates of thermal electron attachment to CF3X and with the electron affinities of CF3X, indicating that the O2- + CF3X reaction mechanism may involve initial electron transfer followed by dissociation.Thus the negative electron affinity of CF3Cl may explain the very slow rate for reaction with O2- despite the available exothermic pathways.