Kinetic studies of the reaction of the SO radical with NO2 and ClO from 210 to 363 K

The rates of the reactions of the SO radical with NO2 and ClO have been determined in a discharge flow system near 1 Torr pressure with detection of radical and molecular species using collision-free sampling mass spectrometry. The rate constants were determined from the decay of SO radicals in the presence of an excess of NO2 and ClO. The NO2 reaction was studied between 210 and 363 K and found to be temperature invariant: SO+NO2→SO2+NO; k1=(1.37±0.10)×10−11 cm3 s−1. Similarly, the ClO reaction was observed to be independent of temperature in the interval from 248 to 363 K: SO+ClO→SO2+Cl; k2=(3.22±0.48)×10−11 cm3 s−1. Comparison is made with previous studies of these reactions at room temperature and with other radical–radical reactions involving SO or ClO.