Reactions of trifluoromethyl radicals with iodine and nitric oxide

Abstract

The reactions 2 and 3 have been studied by competitive methods. Use of previous Arrhenius[Formula: see text][Formula: see text]parameters for reaction 2 leads to k3 = 1.3 × 1010 exp −[(700 ± 100J)/RT]. Arrhenius parameters of reactions 2 and 3 are compared with those for reactions of other radicals with I2 and NO.

Time-resolved tunable diode laser detection of products of the infrared multiphoton dissociation of hexafluoroacetone: a line-strength and band-strength measurement for trifluoromethyl

“…To the best of our knowledge the only published rate constant for the reaction of CF3 and NO is a high-pressure-limited value of 1.6 X 10"11 cm3 molecule"1 s"1, measured at total pressures greater than 20 Torr. 23…”

Review of Rate Constants and Exploration of Correlations of the Halogen Transfer Reaction of Trisubstituted Carbon-Centered Radicals with Molecular Halogens

“…We are not aware of any real-time measurements of k I (R • ) that do not involve deconvolution of rate constant ratios or sums, and in comparison to chlorine and bromine transfer, these data are even still more limited in scope and often seriously scattered. Key examples of the probably less accurate data are collected in Table . ,,− For simple alkyl radicals, the E values are systematically negative to an even greater extent than for chlorine or bromine transfer and E is near zero even for the relatively unreactive trifluoromethyl.…”

“…Photolysis of hexafluoroacetone in the presence of competitive pairs of HX and X 2 ,, gave a lengthy series of rate constant ratios for trifluoromethyl that were ultimately anchored to an absolute value of k t . Thus, k I (CF 3 • ) = [ k I / k HBr ]­[ k HBr / k Br ]­[ k Br / k HCl ]­[ k HCl / k t 1/2 ]­[ k t 1/2 ] = [4.35 exp­(+2983/ RT ) (358–503 K)]­[0.264 exp­(−2171/ RT ) (328–607 K)]­[13.8 exp­(+4400/ RT ) (451–600 K)]­[(3.47 × 10 4 ) exp­(−5070/ RT cm 3/2 mol –1/2 s –1/2 ) (293–478 K)]­[6.8 × 10 12 cm 3 mol –1 s –1 ( T -independent)] 1/2 , where we have altered k t from that originally used to a more current value (see above) , and the Δ E values are in cal/mol. In the units used herein and centered on ∼450 K, this product leads to the value given as 8a″ .…”