Laser Induced Fluorescence Studies of Iodine Oxide Chemistry, Part 2. The Reaction of IO with CH3O2, CF3O2 and O3.

DILLON, T. J.; MARIA EUGENIA TUCCERI; CROWLEY, J. N.

Physical Chemistry Chemical Physics

Año: 2006 vol. 8 p. 5185 - 5198

1463-9076

The technique of pulsed laser photolysis was coupled to laser induced fluorescence detection of iodine oxide (IO) to measure rate coefficients, k for the reactions IO + CH3O2 --> products (R1, 30–318 Torr N2), IO + CF3O2 --> products (R2, 70–80 Torr N2), and IO + O3 à OIO + O2 (R3a). Values of k1 = (2 ± 1) x10-12 cm3 molecule-1 s-1, k2 = (3.6± 0.8) x10-11 cm3 molecule-1 s-1 , and k3a < 5 x10-16 cm3 molecule-1 s-1 were obtained at T = 298 K. In the course of this work, the product yield of IO from the reaction of CH3O2 with I was determined to be close to zero, whereas CH3OOI was formed efficiently at 70 Torr N2. Similarly, no evidence was found for IO formation in the CF3O2 + I reaction. An estimate of the rate coefficients k(CH3O2 + I) = 2 x 10-11 cm3 molecule-1 s-1 and k(CH3OOI + I) = 1. 5 x 10-10 cm3 molecule-1 s-1  was also obtained. The results on k1–k3 are compared to the limited number of previous investigations and the implications for the chemistry of the marine boundary layer are briefly discussed.