INVESTIGADORES
TUCCERI Maria Eugenia
artículos
Título:
A Laser Photolysis - Resonance fluorescence study of the reactions: I + O3 --> IO + O2; O + I2 --> IO + I and I + NO2 + M --> INO2 + M at 298 K.
Autor/es:
MARIA EUGENIA TUCCERI; DILLON, T. J.; CROWLEY, J. N.
Revista:
Physical Chemistry Chemical Physics
Referencias:
Año: 2005 vol. 7 p. 1657 - 1663
ISSN:
1463-9076
Resumen:
Laser flash photolysis coupled to resonance fluorescence detection of I atoms was used to measure the rate
coefficients for the reactions: I + O3 à IO + O2 (R1), O + I2 à IO + I (R6) and I + NO2 + M à INO2 + M
(R7). All experiments were conducted under pseudo first-order conditions, and the accuracy of the results was
enhanced by online determination of reagent concentrations by optical absorption. Bimolecular rate coefficients
for reactions (R1) and (R6) were determined to be k1 = (1.28 ± 0.06) x 10-12 and k6 = (1.2 ± 0.1)x 10-10 cm3
molecule-1 s-1 at 298 ± 2 K, independent of pressure. Rate coefficients for the termolecular reaction (R7), also
at 298 ± 2 K, were found to be in the falloff region between 3rd and 2nd order behaviour and, when combined
with other datasets obtained at higher and lower pressures, were adequately described by a simplified Troe
function with the parameters: k7,0(He, 330 K) = 1.48 x 10-31 cm6 molecule-2 s-1, FC(He) = 0.43, and
k7,¥ = 1.1 x 10-10 cm3 molecule-1 s-1 for He as bath gas. In N2 (or air) the following parameters were obtained
k7,0(N2, 300 K) = 3.2 ± 10-31 cm6 molecule-2 s-1, FC(N2) = 0.48, with k7,,¥ set to 1.1x 10-10 cm3 molecule-1 s-1 as obtained from analysis of the falloff curve obtained in He.