Summary: | A study of the reaction of hydrogen atoms with cyclopropane is reported over the temperature range 628 to 779 K for pressures of 5.3 to 13.2 torr. The primary reaction is shown to be abstraction of a hydrogen atom from the ring and the following Arrhenius parameters are derived for the process k1 = 10 13.6 exp - (48.5 kJ mol-1/RT) cm 3 mol- 1 s- 1. Subsequent reaction of the cyclo-C', ilr radical with a hydrogen atom leads, via excited cyclopropane, to propene as the initial product. All other hydrocarbon products are formed following reaction between propene and atomic hydrogen. A direct study of the reaction of hydrogen atoms with propene is detailed over the same ranges of conditions as above. The data show clearly that previously accepted Arrhenius parameters for the two possible orientations of addition of Ii atoms to propene infer incorrect relative rates for the conditions of this work. In addition, evidence is presented for a consistent underestimation of II atom concentration by the ethylene titration technique for the conditions of this study.
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