Temperature Dependence Kinetic Studies of the Reaction of O(3P) with CHI3and C2H5I and the 298 K Reaction of OH(X2Π) with CHI3
Autor: | Shaoliang Zhang, Cornelius Zetzsch, L. Bosland, Anne Monod, Rafal Strekowski |
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Rok vydání: | 2014 |
Předmět: |
Arrhenius equation
Radical Organic Chemistry Photodissociation Analytical chemistry chemistry.chemical_element 02 engineering and technology Atmospheric temperature range 010402 general chemistry 021001 nanoscience & nanotechnology 7. Clean energy 01 natural sciences Biochemistry 0104 chemical sciences Inorganic Chemistry symbols.namesake Xenon Resonance fluorescence chemistry 13. Climate action symbols Flash photolysis Physical and Theoretical Chemistry 0210 nano-technology Helium |
Zdroj: | International Journal of Chemical Kinetics. 46:554-566 |
ISSN: | 0538-8066 |
Popis: | A flash photolysis-resonance fluorescence technique was used to investigate the kinetics of the OH(X-2 Pi) radical and O(P-3) atom-initiated reactions with CHI3 and the kinetics of the O(P-3) atom-initiated reaction with C2H5I. The reactions of the O(P-3) atom with CHI3 and C2H5I were studied over the temperature range of 296 to 373 K in 14 Torr of helium, and the reaction of the OH (X-2 Pi) radical with CHI3 was studied at T = 298 K in 186 Torr of helium. The experiments involved time-resolved resonance fluorescence detection of OH (A(2)Sigma(+) -> X-2 Pi transition at lambda = 308 nm) and of O(P-3) (lambda = 130.2, 130.5, and 130.6 nm) following flash photolysis of the H2O/He, H2O/CHI3/He, O-3/He, and O-3/C2H5I/He mixtures. A xenon vacuum UV (VUV) flash lamp (lambda > 120 nm) served as a photolysis light source. The OH radicals were produced by the VUV flash photolysis of water, and the O(P-3) atoms were produced by the VUV flash photolysis of ozone. Decays of OH radicals and O(P-3) atoms in the presence of CHI3 and C2H5I were observed to be exponential, and the decay rates were found to be linearly dependent on the CHI3 and C2H5I concentrations. Measured rate coefficients for the reaction of O(P-3) atoms with CHI3 and C2H5I are described by the following Arrhenius expressions (units are cm(3) s(-1)): k(O+C2H5I)(T) = (17.2 +/- 7.4) x 10(-12) exp[-(190 +/- 140)K/T] and k(O+CHI3)(T) = (1.80 +/- 2.70) x 10(-12) exp[-(440 +/- 500)K/T]; the 298 K rate coefficient for the reaction of the OH radical with CHI3 is k(OH+CHI3)(298 K) = (1.65 +/- 0.06) x 10(-11) cm(3) s(-1). The listed uncertainty values of the Arrhenius parameters are 2 sigma-standard errors of the calculated slopes by linear regression. (C) 2014 Wiley Periodicals, Inc. |
Databáze: | OpenAIRE |
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