RATES OF REACTION OF ATOMIC OXYGEN .2. SOME C2 TO C8 ALKANES

Rate constants have been measured for the reactions of atomic oxygen (O3P) with eight straight and branched chain alkanes from 250 to 600°K, and for six other branched chain alkanes at 307°K. The reactions are interpreted on the basis of a hydrogen atom abstraction mechanism, and Arrhenius parameters are derived for abstraction of primary, secondary, and tertiary hydrogen atoms. The activation energies are found to be in the order primary > secondary > tertiary. For abstraction at secondary C-H bonds, the activation energy is observed to decrease with increasing molecular complexity of the alkane. A method for estimating the rate constants of other atomic oxygen-alkane reactions is given.