The formation of O and H atoms in the reaction of CH2 with O2 was investigated behind incident shock waves at temperatures between 1000 K and 1700 K and at total densities between 5 · 10−6 and 1 · 10−5 mol/cm3 by means of Atomic Resonance Absorption Spectroscopy (ARAS) at 130.5 nm and 121.6 nm, respectively. The contribution of O and H forming channels was found to be about 20%. The rates of formation of O and H atoms in this reaction were determined to be k1a = (4 ± 2) · 1010 cm3/mol · s k1e = (5 ± 2) · 1010 cm3/mol · s In the temperature range investigated an over all rate constant can be represented by k1 = (5 ± 3) · 1011 cm3/mol · s. A comparison with low temperature data leads to a change of the apparent energy of activation of the overall reaction in the temperature range between 300 and 1000 K.

The pyrolysis of methanol was investigated behind incident shock waves at temperatures and densities between 1400 and 2200 K and 1 · 10−6 and 5 · 10−6 mol/cm3, respectively. Narrow band‐width laser absorption for OH radicals and ARAS technique for H atoms was used to determine the decomposition channels. For the experimental conditions described above the direct OH‐formation is found to be the main channel of about 80% of the decomposition rate. The channel leading to H and CH2OH is found to be less than 5%. There remains the possibility of channels leading from methanol to 1CH2 + H2O or to CH2O + H2.

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.

Chemical Kinetics J Elementary Reactions J Radicals J Shock WavesThe reaction of methyl radicals with methanol was investigated behind incident shock waves at temperatures between 1200 and 1400 K.The kinetic data were obtained from time resolved absorption measurements of CH3 at the wavelength A = 216.5 nm. The results suggest a curved Arrhenius plot, which can be extrapolated to real flame conditions. A comparison with other methyl radical reactions shows coherence in the temperature dependence of the rate coefficients.