Reaction rate coefficients of OH radicals and Cl atoms with ethyl propanoate n-propyl propanoate, methyl 2-methylpropanoate, and ethyl n-butanoate

Abstract

Kinetics of the reactions of OH radicals and Cl atoms with four saturated esters have been investigated. Rate coefficients for the gas-phase reactions of OH radicals with ethyl propanoate (k1, n-propyl propanoate (k 2), methyl 2-methylpropanoate (k3), and ethyl n-butanoate (k4) were measured using a conventional relative rate method and the pulsed laser photolysis-laser induced fluorescence technique. At (296 ± 2) K, the rate coefficients obtained by the two methods were in good agreement. Significant curvatures in the Arrhenius plots have been observed in the temperature range 243-372 K for k3, k4 and K4. The rate coefficients for the reactions of the four esters with Cl atoms were determined using the relative rate method at (296 ± 2) K and atmospheric pressure. The values obtained are presented, compared with the literature values when they exist, and discussed. Reactivity trends and atmospheric implications for these esters are also presented.