Channel specific rate constants for reactions of O(1D) with HCl and HBr

Abstract

Time resolved resonance fluorescence detection of O(3P) and H(2S) has been employed in conjunction with pulsed laser photolysis of O3/HX/He mixtures to determine absolute rate coefficients and product yields for reactions of O(1D) with HCl(1) and HBr(2) at 297 K. Total rate coefficients for O(1D) removal are found to be, in units of 10−10 cm3 molecule−1 s−1, k1=1.50±0.18 and k2=1.48±0.16, where the quoted errors are 2σ and represent precision only. The absolute accuracy of these rate coefficients is estimated to be ±20%. Formation of O(3P)+HX is found to account for 9%±5% of the overall rate of reaction (1) and 20%±7% of the overall rate of reaction (2). Formation of H(2S)+XO is found to account for 24%±5% of the overall rate of reaction (1) but <4.5% of the overall rate of reaction (2). By difference, the OH+X(2P) channel accounts for 67%±10% of the overall rate of reaction (1) and 80%±12% of the overall rate of reaction (2).