Atmospheric chemistry of 1,3-dioxolane: Kinetic, mechanistic, and modelingstudy of OH radical initiated oxidation

An absolute rate pulse radiolysis technique was used to measure k(OH + 1,3- dioxolane) = (8.8 +/- 0.9) x 10(-12) cm(3) molecule(-1) s(-1) at 295 K in 1 000 mbar of Ar. Relative rate techniques were used to study the reactions o f OH radicals and Cl atoms with 1,3-dioxolane and Cl atoms with ethylene ca rbonate and methylene glycol diformate at 300 K in 1 bar of synthetic air. Rate coefficients were k(OH + 1,3-dioxolane) = (1.04 +/- 0.16) x 10(-11), k (Cl+ 1,3-dioxolane) = (1.6 +/- 0.3) x 10(-10), k(CI + ethylene carbonate) = (7.1 +/- 1.7) x 10(-12), and k(C1 $ methylene glycol diformate) = (5.6 +/- 0.7) x 10(-13) cm3 molecule(-1) s(-1). OH radical and chlorine atom initia ted oxidation of 1,3-dioxolane in 1 bar of N-2/O-2 mixtures at 298 K in the presence of NOx gives ethylene carbonate and methylene glycol diformate, M olar yields of ethylene carbonate and methylene glycol diformate were 0.48 +/- 0.07 and 0.50 +/- 0.14 for OH radical initiation and 0.43 +/- 0.07 and 0.53 +/- 0.07 for Cl atom initiation. Product yields were independent of O- 2 partial pressure over the range studied (60-800 mbar). A photochemical me chanism was developed to describe the OH-initiated degradation of 1,3-dioxo lane in the presence of NOx. The results are discussed with respect to the available literature data concerning the atmospheric chemistry of ethers.