A Pulsed Laser Photolysis-Resonance Fluorescence Kinetic Study of the Atmospheric Cl Atom-Initiated Oxidation of Propene and a Series of 3-Halopropenes at Room Temperature

Abstract

Absolute rate coefficient measurements have been carried out for the reactions of Cl atoms with propene and a series of 3-halopropenes, at room temperature (298 ± 2) K using a newly constructed laser photolysis-resonance fluorescence (PLP-RF) system. The rate coefficients obtained (in units of cm3 molecule−1 s−1) are: propene (1.40± 0.24) ×10−10, 3-fluoropropene (4.92 ± 0.42) ×10−11, 3-chloropropene (7.47 ± 1.50) × 10−11, 3-bromopropene (1.23± 0.14) ×10−10 and 3-iodopropene (1.29± 0.15) ×10−10. In order to test this new system, the reactions of Cl atoms with acetone and isoprene have also been studied and compared with data previously reported. The rate coefficients determined at room temperature for these last two reactions are (2.93 ± 0.20) ×10−12 cm3 molecule−1 s− 1 and (3.64± 0.20)×10−10 cm3 molecule−1 s−1, respectively. The measured values were independent of pressure over the range 20–200 Torr. The influence of the different halogen atoms substituents on the reactivity of these alkenes with Cl atoms as well as the atmospheric implications of these measurements are studied and discussed for the first time in this work and compared with the reactivity with NO3 and OH radicals.