Evaluation of HX (X = Cl, Br, O) product distributions from chemiluminescence. I. H atom reactions

Abstract

The HX product state distributions from the H+Cl2, Br2, NO2Cl, PCl3, and NO2 reactions have been studied by the infrared chemiluminescence technique in two different laboratories with two types of reactors; a fast-flow system with = 1 Torr of Ar buffer gas and a low-pressure, cold-wall system (usually called the cold-wall arrested-relaxation method). The same Einstein coefficients were used in both laboratories to convert intensities to populations and emphasis is placed upon evaluation of the reliability of the resulting vibrational-rotational HX distributions. Good agreement was found between the HX distributions from the cold-wall reactors from the two laboratories and for both types of reactors for all of the reactions, except PCl3. For the H+Cl2, Br2 and NO2 reactions, our general results are in good accord with presently accepted data; but, our experiments provide somewhat more detail than in the literature. The NO2Cl results are new and = 0.40 and = 0.01. The H+PCl3 reaction appears to proceed by two channels and the HCl chemiluminescence cannot be assigned only to HCl formation via direct Cl atom abstraction.