Reactions of alkoxy radicals with O 2 . III. i ‐C 4 H 9 O radicals

i ‐C 4 H 9 ONO was photolyzed with 366‐nm radiation at −8, 23, 55, 88, and 120°C in a static system in the presence of NO, O 2 , and N 2 . The quantum yield of i ‐C 3 H 7 CHO, Φ{ i ‐C 3 H 7 CHO}, was measured as a function of reaction of reaction conditions. The primary photochemical act isand it proceeds with a quantum yield ϕ 1 = 0.24 ± 0.02 independent of temperature. The i ‐C 4 H 9 O radicals can react with NO by two routesThe i ‐C 4 H 9 O radical can decompose viaor react with O 2 viaValues of k 4 / k 2 ≃ k 4b / k 2 were determined to be (2.8 ± 0.6) × 10 14 , (1.7 ± 0.2) × 10 15 , and (3.5 ± 1.3) × 10 15 molec/cm 3 at 23 55, and 88°C, respectively, at 150‐torr total pressure of N 2 . Values of k 6 / k 2 were determined from −8 to 120°C. They fit the Arrhenius expression:\documentclass{article}\pagestyle{empty}\begin{document}$$ \log (k_6 /k_2) = - 2.15 \pm 0.22 - (836 \pm 159)/2.303{\rm T} $$\end{document}For k 2 ≃ 4.4 × 10 11 cm 3 /s, k 6 becomes (3.2 ± 2.0) × 10 −13 exp{−(836 ± 159)/T} cm 3 /s. The reaction scheme also provides k 4b / k 6 = 3.59 × 10 18 and 5.17 × 10 18 molec/cm 3 at 55 and 88°C, respectively, and k 8b / k 8 = 0.66 ± 0.12 independent of temperature, where