Browsing by Author "Whytock, David A."

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    Electron Spin Resonance Study of the Reaction of Hydrogen Atoms with Hydrogen Sulphide
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1973, 69 (2), 1973) Bradley, John N.; Trueman, Susan P.; Whytock, David A.; Zaleski, Thomas A.
    The reaction between H atoms and hydrogen sulphide, with and without added nitric oxide, has been studied by following the H atom, S atom and SH radical concentrations with time using electron spin resonance detection. The results are fully explained by the mechanism (1)–(4) H + H2S→H2+ SH, k1= 5.0 × 108 l. mol–1 s–1(1), H + SH → H2+ S, k2= 2.5 × 1010 l. mol–1 s–1(2), SH + NO → stable species, k3= 6.3 × 108 l. mol–1 s–1(3), SH + SH → H2S + S, k4= 7.8 × 109 l. mol–1 s–1. (4) with no evidence for significant surface effects (the walls were coated with boric acid). The results demonstrate conclusively that reaction (2) is very important in this system and that previous measurements of k1 which neglect this reaction may require correction.
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    Reaction of Perfluoroethyl Radicals with Cycloalkanes
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) Whytock, David A.; Clarke, John D.; Gray, Peter
    The reactions of C2F5 radicals with C4 to C7 cycloalkanes have been studied using perfluoroethyl iodide as the source of free radicals. The Arrhenius parameters obtained for the reaction C2F5+ c-RH→C2F5H + c-R were (c-R = cycloalkyl): [graphic omitted] The Arrhenius parameters are compared with those for corresponding CF3 radical reactions. From the activation energies, values for the c-R—H bond dissociation energies are derived using the Evans–Polanyi method. Bond strengths for methylene groups in C5, C6 and C7 cycloalkanes are all close to that for the Pri—H bond dissociation energy in propane.