Gas-phase oxidation of methyl crotonate and ethyl crotonate. Kinetic study of their reactions towards OH radicals and Cl atoms

AMER CHEMICAL SOC

Año: 2012 vol. 116 p. 6127 - 6127

ate coefficients for the reactions of hydroxyl radicals and chlorine atoms with methyl crotonate and ethyl crotonate have been determined at 298 K and atmospheric pressure. The decay of the organics was monitored using gas chromatography with flame ionization detection (GC-FID) and the rate constants were determined using the relative rate method with different reference compounds. Room temperature rate coeficcients were found to be (in cm3 molecule-1 s-1): k1(OH + CH3CH=CHC(O)OCH3) = (4.65  0.65)  10-11, k2(Cl + CH3CH=CHC(O)OCH3) = (2.20  0.55)  10-10 , k3(OH + CH3CH=CHC(O)OCH2CH3) = (4.96  0.61)  10-11 and k4(Cl + CH3CH=CHC(O)OCH2CH3) = (2.52  0.62)  10-10 with uncertainties representing ± 2σ. This is the first determination of k1, k3 and k4 under atmospheric 2 pressure. The rate coefficients are compared with previous determinations for other unsaturated and oxygenated VOCs and reactivity trends are pre