Kinetic Study of the ClOO + NO Reaction Using Cavity Ring-Down Spectroscopy

Cavity ring-down spectroscopy was used to study the reaction of ClOO with NO in 50−150 Torr total pressure of O2/N2 diluent at 205−243 K. A value of k(ClOO+NO) = (4.5 ± 0.9) × 10-11 cm3 molecule-1 s-1 at 213 K was determined (quoted uncertainties are two standard deviations). The yield of NO2 in the ClOO + NO reaction was 0.18 ± 0.02 at 213 K and 0.15 ± 0.02 at 223 K. An upper limit of k(ClOO+Cl2) < 3.5 × 10-14 cm3 molecule-1 s-1 was established at 213 K. Results are discussed with respect to the atmospheric chemistry of ClOO and other peroxy radicals.