Kinetic studies of OH reactions with propylal, butylal and 1,3-dioxolane

Abstract

Rate coefficients have been measured for the gas phase reactions of hydroxyl (OH) radicals with three acetals, di-n-propoxymethane (n-C3H7OCH2On-C3H7), di-n-butoxymethane (n-C4H9OCH2On-C4H9) and 1,3-dioxolane. The experiments were carried out using the pulsed laser photolysis - laser induced fluorescence technique over the temperature range 243–372 K and the kinetic data were used to derive the following Arrhenius expressions (in units of cm3 molecule−1 s−1): di-n-propoxymethane, k1=(4.39±1.06)×10−12 exp[(563±74)/T]; di-n-butoxymethane, k2=(5.15±0.66)×10−12 exp[(590±38)/T]; and 1,3-dioxolane, k3=(6.70±0.86)×10−12 exp[(154±36)/T]. At 298 K, the rate coefficients obtained (in units of 10−12 cm3 molecule−1 s−1) are: k1=(27.6±2.3), k2=(37.0±5.2) and k3=(11.1±0.9). The results are discussed in terms of structure–activity relationships and used to derive atmospheric lifetimes for these acetals.