Gas phase kinetics for the ozonolysis of n-butyl methacrylate, ethyl crotonate and vinyl propionate under atmospheric conditions

Rate coefficients for the reactions of ozone with n-butyl methacrylate, ethyl crotonate and vinyl propionate have been determined at 298 ± 1 K and atmospheric pressure. The following room temperature rate coefficients (in cm3 molecule−1 s−1 units) were obtained: k1(O3 + CH2C(CH3)C(O)OC4H9) = (1.0 ± 0.3) × 10−17, k2(O3 + CH3CHCHC(O)OCH2CH3) = (8.0 ± 1.8) × 10−18 and k3(O3 + CH3CH2C(O)OCHCH2) = (5.3 ± 1.3) × 10−18. This is the first kinetic study for these reactions at atmospheric pressure. The effect of substituent groups on the overall rate coefficients is analyzed. Free energy relationships are presented and atmospheric lifetimes are discussed.