FLOW-TUBE KINETICS STUDY OF THE REACTION BETWEEN GROUND-STATE HYDROGEN-ATOMS AND NITROMETHANE

The kinetics of the H + CH3NO2 reaction have been studied by using a discharge-flow resonance-fluorescence technique. H atoms are produced from microwave discharges through NH3/Ar mixtures. The data in the 360-570 K range are well fitted by the empirical expression k(T) = 7.8 x 10(-12) exp(-1878K/T) cm3 molecule-1 s-1. Precision of the data varies from +/- 6 to +/- 11%, and the resulting accuracy is estimated to be better than +/- 20%, where both figures represent 2-sigma statistical confidence intervals. Results of some experiments where H-2 was discharged indicate that the channel leading to OH and CH3NO is significant for the reaction. A comparison of the kinetics of several reactions where a methyl-group hydrogen is abstracted by H atoms indicates that such a channel is not important in the present work but could become significant at elevated temperatures. To confirm the accuracy achieved with the present apparatus, measurements on the H + C6H6 reaction have been made in the 410-530 K range and are compared to results from other studies.