Kinetics of the reactions of O 3 and OH radicals with a series of dialkenes and trialkenes at 294 ± 2 K

Rate constants for the gas phase reactions of O 3 and OH radicals with 1,3‐cycloheptadiene, 1,3,5‐cycloheptatriene, and cis ‐ and trans ‐1,3,5‐hexatriene and also of O 3 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 O 3 were (in cm 3 molecule ‐1 s −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 cm 3 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 O 3 and OH radical rate constants for alkenes and cycloalkenes.