Kinetics and mechanism of the Cl + CO reaction in air

Long-path FTIR spectroscopy was used to study the kinetics and mechanism of the reaction of Cl atoms with CO in air. The relative rate constants at 298 K and 760 torr for the forward direction of the reaction of Cl with ¹³CO and the reaction of Cl¹³CO with O₂ were k₁ = (3.4 ± 0.8) × 10^?14 cm³ molecule^?1 s^?1 and k₂ = (4.3 ± 3.2) × 10^?13 cm³ molecule^?1 s^?1, respectively (all uncertainty limits are 2σ). The rate constant for the net loss of ¹³CO due to reaction with Cl in 1 atm of air at 298 K was k_Cl+COobs = (3.0 ± 0.6) × 10^?14 cm³ molecule^?1 s^?1. The only observed carbon-containing product of the Cl + ¹²CO reaction was ¹²CO₂, with a yield of 109 ± 18%. Our results are in good agreement with extrapolations from previous studies. The reaction mechanism and the implications for laboratory studies and tropospheric chemistry are discussed. © 1996 John Wiley & Sons, Inc.