298 K rate coefficients for the reaction of OH with i-C₃H₇I, n-C₃H₇I and C₃H₈

S. A. Carl (1) , J. N. Crowley (2)

1 Atmospheric Chemistry Department [MPIC]
2 Department of Chemistry [Leuven]

The kinetics of the title reactions were investigated using the laser photolysis - resonance fluorescence method, employing the sequential two-photon dissociation of NO₂ in the presence of H₂ as the OH source. The 298 K rate constant for OH + C₃H₈ was found to be (1.15±0.1) × 10^-12 cm³ s^-1, in excellent agreement with the literature recommendation, and with a separate determination using HNO₃ photolysis at 248 nm as the OH source. The 298 K rate constants for OH + n-C₃H₇I and i-C₃H₇I were measured for the first time and found to be (1.47±0.08) and (1.22±0.06) × 10^-12 cm³ s^-1, respectively. The errors include an assessment of systematic error due to concentration measurement, which, for the propyl-iodides was minimised by on-line UV-absorption spectroscopy. The implications of these results for the reactive iodine budget of the marine boundary layer are discussed.

Domaines: Océan, Atmosphère

S. A. Carl, J. N. Crowley. 298 K rate coefficients for the reaction of OH with i-C₃H₇I, n-C₃H₇I and C₃H₈. Atmospheric Chemistry and Physics Discussions, 2001, 1 (1), pp.23-41. ⟨hal-00300846⟩