Journal Articles (before-1995)

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    Reactions of CF3 radicals with benzotrifluoride and the C—H bond strength in C6H5CF3 and C6H6
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (5), 1972) Bérces, T.; Márta, F.; Szilágyi, I.
    The reactions of CF3 with benzotrifluoride (BTF) were studied at 1029, 1070 and 1132 K. The RCF3H/R½C2F6[BTF] ratio was found to decrease with increasing benzotrifluoride pressure, which was interpreted as simultaneous formation of C2F6 by CF3 recombination and an inversion reaction between CF3 and C6H5CF3. From experiments in the absence and presence of hydrogen, we obtained log(k2/l. mol–1 s–1)=(9.1 ± 0.3)–(9.4 ± 1.2)/θ and log(k7/l. mol–1 s–1)=(8.7 ± 0.1)–(9.3 ± 0.1)/θ, (θ= 2.303 RT/kcal mol–1) for the rate coefficients of H-abstraction by CF3 from C6H5CF3 and H2, respectively. Hence we obtained, with an assumed value for the activation energy of step (–2), D°(CF3C6H4—H)= 109.0 ± 2.5 kcal mol–1. CF3H + C6H4CF3→ CF3+ C6H5CF3(–2).
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    Photochemistry of Anhydrides: Part 1.—Photolysis of Perfluoroacetic Anhydride Vapour: A New Source of CF3 Radicals
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (1), 1972) Chamberlain, G. A.; Whittle, E.
    The photolysis of perfluoroacetic anhydride was studied in the temperature range 19–177°C using wavelengths in the range 254–265 nm. The photolysis is exceptionally simple and is quantitatively described by the reactions (CF3CO)2O +hν→ 2CF3+ CO + CO2, CF3+ CF3 [graphic omitted] C2F6, The anhydride was tested as a source of CF3 radicals by photolyzing it in the presence of CH4 and of cyclohexane. For the reactions CF3+ CH4→ CF3H + CH3(7), CF3+ c-C6H12→ CF3H + c-C6H11, (12), we obtain log(k7/k1c)/(cm3/2 mol–1/2 s–1/2)=(5.93 ± 0.32)–(12500 ± 700)/θ, (logk12/k1/2c)/(cm3/2 mol–1/2 s–1/2)=(5.18 ± 0.15)–(5560 ± 220)/θ, where θ= 2.303 RT/cal mol–1. These results agree with previous ones obtained using conventional sources of CF3 radicals. We conclude that perfluoroacetic anhydride is a convenient new source of CF3 radicals.