Kinetics, mechanism and CH3C(O)CH3 formation in the Cl-initiated oxidation of 1,8-cineole at 298 K and atmospheric pressure

Abstract

Kinetics of the reaction of chlorine atoms with the biogenic monoterpene 1,8-cineole was studied by gas chromatography with flame ionization detection at 298 K and 760 Torr. The relative rate coefficient corrected by photolysis was determined to be (in cm3 molecule−1 s−1): (2.2 ± 0.2) × 10−10. Additionally, a product study was performed by solid-phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS). The following ketones were observed as products: acetone, 1,3,3-trimethyl-2-oxabiciclo[2.2.2]octan-5-one and 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-one. Reactivity trends and a general mechanism of the title reaction, including acetone formation, are discussed to assess possible atmospheric implications.