Low‐pressure rate coefficients of the reaction of O(3P) with CF3I and CH3I

Abstract

AbstractAbsolute rate coefficients for the gas‐phase reactions of CF3I and CH3I with O(3P) atoms were measured at 298 K by the discharge flow technique coupled to resonance fluorescence to monitor O(3P) atoms. This is the first kinetic study for these reactions under low‐pressure conditions (1.56–3.26 Torr). The overall rate coefficients were (5.2 ± 0.7) × 10−12 and (2.3 ± 0.3) × 10−11 cm3 molecule−1 s−1, respectively. The experiments were carried out under pseudo‐first‐order conditions with [O(3P)]0 ≪ [RI]0.The results are compared with previous measurements using different experimental techniques at higher pressures. Free energy relationships and atmospheric implications are discussed. Copyright © 2008 John Wiley & Sons, Ltd.