The mechanism and kinetic studies on oxidation reaction of acetofenate initiated by HOx, NO3, O3, and Cl radicals†
Abstract
Acetofenate (AF) is a widely used pesticide. The mechanism of HOx, NO3, O3, and Cl initiated oxidation reactions of AF was investigated with density functional theory. For each of the OH, NO3, and Cl, both addition and hydrogen abstraction were investigated, for each of the HO2 radicals and O3, addition reactions were investigated. The cycloaddition reactions of O3 were considered, including the exploration of isomerization. Based on the potential energy surface, the rate constants were calculated with the transition state theory method over a temperature range of 200–400 K and fitted with the Arrhenius formulas. The rate constants of the AF reaction with OH, HO2, NO3, O3, and Cl, are 4.04 × 10−13, 7.02 × 10−33, 6.93 × 10−20, 1.45 × 10−25, and 5.07 × 10−12 cm3 per molecule per s at 298.15 K, respectively. The OH-initiated reactions are dominant according to the branching ratio of reaction constants. The atmospheric lifetime of the reaction species was estimated according to rate constants.