Reactions of ozone with olefins: Ethylene, allene, 1,3-butadiene, and trans- 1,3-pentadiene

The reactions of O3 with ethylene, allene, 1,3‐butadiene, and trans‐1,3‐pentadiene have been studied in the presence of excess O2 over the temperature range 232 to 298 K. The initial O3 pressure was varied from 4–18 mtorr, and the olefin pressure was varied from 0.1 to 4.5 torr (ethylene), 2.8 to 39.6 torr (allene), 52.7 to 600 mtorr (1,3‐butadiene) or 26.2 to 106 mtorr (trans‐1,3‐pentadiene). The O3 decay was monitored by ultraviolet absorption. The reactions are first order in both O3 and olefin, and the rate coefficients are independent of the O2 pressure. For the O3‐ethylene system, various diluent gases (O2, N2, air) were used and the rate coefficients were found to be independent of the nature of the diluent gas. The various rate coefficients fit the Arrhenius expressions (k in cm3 s−1): \documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{l}{\rm For C}_{\rm 2} {\rm H}_4 :k\{ 232 - 298{\rm K}\} {\rm } = {\rm }(7.72 \pm 0.89){\rm } \times {\rm 10}^{ - 15} \exp [- 5080{\rm } \pm {\rm }60)/RT] \\ {\rm For C}_{\rm 3} {\rm H}_4 :k\{ 252 - 298{\rm K}\} {\rm } = {\rm }(1.54 \pm 0.25){\rm } \times {\rm 10}^{ - 15} \exp [- 5343{\rm } \pm {\rm }87)/RT] \\ {\rm For 1,3 - C}_{\rm 4} {\rm H}_{\rm 6} :k\{ 254 - 299{\rm K}\} {\rm } = {\rm }(2.20 \pm 0.44){\rm } \times {\rm 10}^{ - 14} \exp [- 4828{\rm } \pm {\rm }109)/RT] \\ {\rm For trans - 1,3 - C}_{\rm 5} {\rm H}_{\rm 8} :k\{ 238 - 298{\rm K}\} {\rm } = {\rm }(1.07 \pm 0.25){\rm } \times {\rm 10}^{ - 13} \exp [- 4608{\rm } \pm {\rm }122)/RT] \\ \end{array}$$\end{document} where the reported uncertainties are one standard deviation and R is in cal/mol K.