Reactions of alkoxy radicals with O2. I. C2H5O radicals

Abstract
C2H5ONO was photolyzed with 366 nm radiation at −48, −22, −2.5, 23, 55, 88, and 120°C in a static system in the presence of NO, O2, and N2. The quantum yield of CH3CHO, Φ{CH3CHO}, was measured as a function of reaction conditions. The primary photochemical act is equation image and it proceeds with a quantum yield ϕ1a = 0.29 ± 0.03 independent of temperature. The C2H5O radicals can react with NO by two routes equation image The C2H5O radical can also react with O2 via equation image Values of k6/k2 were determined at each temperature. They fit the Arrhenius expression: Log(k6/k2) = −2.17 ± 0.14 − (924 ± 94)/2.303 T. For k2 ≃ 4.4 × 10−11 cm3/s, k6 becomes (3.0 ± 1.0) × 10−13 exp{−(924 ± 94)/T} cm3/s. The reaction scheme also provides k8a/k8 = 0.43 ± 0.13, where equation image