Laser magnetic resonance study of the gas phase reactions of OH with CO, NO, and NO2

Abstract

A laser magnetic resonance spectrometer has been used in combination with a discharge-flow system to measure the gas phase reaction rates of the OH radical with CO, NO, and NO2 at 296°K and over a pressure range 0.4-5 torr. For the bimolecular reaction OH+CO←CO2+H we measure a rate constant, k = 1.56×10-13 cm3/molecule · sec. For the termolecular reactions OH+NO+M→HNO2+M, M=He, k=4.0×10-31 cm6/molecule2 · sec; M = Ar, k=4.4×10-31 cm6/molecule2 · sec; M = N2, k = 7.8×10-30 cm6/ molecule2 · sec. For the reaction OH+NO2+N 2→HNO3+N2, k = 2.9×10-30 cm6/molecule2 · sec. Laser magnetic resonance detection of radicals is shown to be extremely sensitive, linear, and versatile. A complete description of this technique is presented with a discussion of its potential in the study of the reactions of free radicals. Copyright © 1974 American Institute of Physics.