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Kinetics of CH radical reactions with N 2 O, SO 2 , OCS, CS 2 , and SF 6

1989; Wiley; Volume: 21; Issue: 9 Linguagem: Inglês

10.1002/kin.550210905

1097-4601

Steven Zabarnick, J. W. Fleming, M. C. Lin,

Advanced Chemical Physics Studies

Abstract Pulsed laser photolysis/laser‐induced fluorescence (LIF) is utilized to measure absolute rate constants of CH radical reactions as a function of temperature and pressure. Multiphoton dissociation of CHBr 3 at 266 nm is employed for the generation of CH (X 2 Π) radicals. The CH radical relative concentration is monitored by exciting fluorescence on the R 1 (2) line of the (A 2 Δ – X 2 Π) transition at 429.8 nm. A resistively heated cell allows temperature studies to be performed from room temperature to ≈︂670 K. The following Arrhenius equations are derived: With the exception of SF 6 , the reactions of sulfur containing species proceed at rates that are near the theoretical gas kinetic collision frequency. Additionally, these reactions all have activation energies that are near zero or slightly negative. These observations are consistent with an insertion‐decomposition mechanism being dominant under these conditions.