Kinetics of the reactions of O3 and OH radicals with a series of dialkenes and trialkenes at 294 ± 2 K

Rate constants for the gas phase reactions of O₃ and OH radicals with 1,3-cycloheptadiene, 1,3,5-cycloheptatriene, and cis- and trans-1,3,5-hexatriene and also of O₃ with cis-2,trans-4-hexadiene and trans -2,trans -4-hexadiene have been determined at 294 ± 2 K. The rate constants determined for reaction with O₃ were (in cm³ molecule^-1s^?1 units): 1,3-cycloheptadiene, (1.56 ± 0.21) × 10^-16; 1,3,5-cycloheptatriene, (5.39 ± 0.78) × 10^?17; 1,3,5-hexatriene, (2.62 ± 0.34) × 10^?17; cis?2,trans-4-hexadiene, (3.14 ± 0.34) × 10^?16; and trans ?2, trans -4-hexadiene, (3.74 ± 0.61) × 10^?16; with the cis- and trans-1,3,5-hexatriene isomers reacting with essentially identical rate constants. The rate constants determined for reaction with OH radicals were (in cm³ molecule^?1 s^?1 units): 1,3-cycloheptadiene, (1.31 ± 0.04) × 10^?10; 1,3,5-cycloheptatriene, (9.12 × 0.23) × 10^?11; cis-1,3,5-hexatriene, (1.04 ± 0.07) × 10^?10; and trans 1,3,5-hexatriene, (1.04 ± 0.17) × 10^?10. These data, which are the first reported values for these di- and tri-alkenes, are discussed in the context of previously determined O₃ and OH radical rate constants for alkenes and cycloalkenes.