Investigation of the 3CH2 + O2 reaction in shock waves

The reaction of 3CH2 with O2 was investigated in incident shock waves for pressures near 1 bar and temperatures from 1000 to about 1800 K. 3CH2 source was diazomethane. The concentration time curves of CO and CO2 were obtained from infrared emission, the OH profiles by laser absorption measurements. Data for O and H atom formation in this reaction were reported recently. – The measurements show that about a quarter of the reaction proceeds by forming radicals directly. Three quarters of the reaction form stable products only. Main reaction product is CO with a CO to CO2 ratio near 4:1. Direct formation of OH does not exceed a few percent. A reaction channel distribution is given. – Rate constants for the total reaction 3CH2 + O2 obtained by computer simulation of the product profiles in the temperature range mentioned are below the data extrapolated from measurements performed by Vinckier et al. and Bley et al. in the temperature range around room temperature. A rate expression fitting the measured date over the whole temperature range is reported.