Reinvestigation of Some Absolute Rate Measurements of O-Atom Reactions with Olefins

Abstract

The rate constants, activation energies, and pre-exponential factors for the primary reactions of atomic oxygen with ethylene, butene-1, iso-butene, and cis-butene-2 have been determined. The measurements were carried out in a fast-flow system in which O atoms were produced by electrical discharge. Possible sources of error such as the presence of O2 and the effect of surface reactions are shown to be unimportant. The results show a systematic deviation from those of previous studies in which a photolysis technique was used to obtain relative rate data. The possibility of secondary attack on the olefins is discussed and considered an unlikely cause for the observed discrepancies.