KINETICS OF THE REACTIONS OF O(3P) AND CL(2P) WITH HBR AND BR-2

A laser flash photolysis‐resonance fluorescence technique has been employed to study the kinetics of reactions (1)–(4) as a function of temperature. (Formula Presented.) In all cases, the concentration of the excess reagent, i.e., HBr or Br2, was measured in situ in the slow flow system by UV‐visible photometry. Heterogeneous dark reactions between XBr (X = H or Br) and the photolytic precursors for Cl(2P) and O(3P) (Cl2 and O3, respectively) were avoided by injecting minimal amounts of precursor into the reaction mixture immediately upstream from the reaction zone. The following Arrhenius expressions summarize our results (errors are 2σ and represent precision only, units are cm3 molecule−1 s−1): 𝓀1 = (1.76 ± 0.80) × 10−11 exp[(40 ± 100)/T]; 𝓀2 = (2.40 ± 1.25) × 10−10 exp[−(144 ± 176)/T]; 𝓀3 = (5.11 ± 2.82) × 10−12 exp[−(1450 ± 160)/T]; 𝓀4 = (2.25 ± 0.56) × 10−11 exp[−(400 ± 80)/T]. The consistency (or lack thereof) of our results with those reported in previous kinetics and dynamics studies of reactions (1)–(4) is discussed. Copyright © 1990 John Wiley & Sons, Inc.