The oxidation of methyl radicals at room temperature

Abstract

Using the technique of molecular modulation spectrometry, we have measured directly the rate constants of several reactions involved in the oxidation of methyl radicals at room temperature:(1)kl is in the fall-off pressure regime at our experimental pressures (20-760 torr) where the order lies between second and third and we obtain an estimate for the second-order limit of (1.2 f 0.6) X cm3/molec . sec, together with third-order rate constants of CH3 + CH302 --t 2CHaO k3 = (6.0 f 1.0) X 10-11 cm3/molec -sec.

The reaction of CH3O2 radicals with NO2

“…The correction required for the mutual reaction (9) was calculated for each experiment using the experimental values for k g and ~(CH302) [30,31]. The corrections were small, amounting to <lo% even at the lowest NO2 concentrations.…”

The kinetics of the interaction of peroxy radicals. II. Primary and secondary alkyl peroxy

“…Confirmation of the similar rate constant values for Me02 comes from the studies on photooxidation of azomethane by Parkes [6], using the technique of molecular modulation spectrophotometry and by others [7]. The overall rate constant for the second order decay of CH302 radicals, has been reported as 3.3 X los (literlM sec) which includes both the termination and nontermination steps; the ratio of these two steps was reported as 2.…”

Absolute rate constants for hydrocarbon autoxidation. 33. A product study of the self-reaction of α-tetralylperoxyls in solution

“…C?H,O,', (CH,)?CHO,', and (CH3),CO2') in the gas phase (20)(21)(22)(23)(24)(25)(26) and absolute termination rate constants are very similar in the gas and liquid phases. It has been concluded that CH30y, for example, interact by terminating and non-terminating mechanisms with the ratio of rate constants k12,,/k12,,, falling in the range 1.3 to 2 at ambient temperatures.…”