The Cl-initiated oxidation of CH2=CHOC(O)CH3 and CH2=CHCH2 OC(O)CH3 in the troposphere: kinetics and product distribution

M. B. BLANCO, I. BEJAN, I. BARNES, P. WIESEN AND M. TERUEL

Los Cocos, Córdoba, Argentina

Conferencia; 9th Latin American Conference on Physical Organic Chemistry (CLAFQO); 2007

Acetates are emitted to the atmosphere from vegetation and through their use in industry¹. Another potential source is emission from automobiles; a number of acetates, including allyl (CH₂=CHCH₂OC(O)CH₃) and vinyl acetate (CH₂=CHOC(O)CH₃), have been detected as products in the combustion of rape methyl esters used as fuel alternatives or additives.

The rate coefficients were determined using the relative method. The experiments were performed at room temperature and atmospheric pressure in a large volume photoreactor using in situ FTIR analysis to monitor the decay of the organics and the reference compounds. The following room temperature rate coefficients (in cm³ molecule^-1 s^-1 units) were measured: k₁ = (1.30±0.45) × 10^-10, k₂= (2.68±0.91) × 10^-10 where the uncertainties are a combination of the 2s statistical errors from the linear regression analysis and a contribution to cover errors in the rate constants of the references hydrocarbons.  This is the first kinetic study of these reactions under atmospheric conditions. The effect of substituent atoms or groups on the overall rate coefficients is analyzed in comparison with literature rate coefficients for other unsaturated compounds.