Gas phase decomposition and isomerization reactions of 2‐pentoxy radicals

The rate of decomposition of 2‐pentoxy radical to acetaldehyde and n‐propyl radical has been studied in the presence of NO in competition with nitrite formation at and above 200 kPa pressure over the temperature range of 363‐413 K. The rate coefficient for the decomposition is given as log(kla/s−1) = (14.2 ± 0.4) ‐ (13.8 ± 0.8) kcal mol−1/RT ln 10. Isomerization of 2‐pentoxy radical by 1,5‐hydrogen shift has been investigated in the range 279–385 K in competition with the decomposition in a static system, with methyl radicals present in high concentration to ensure trapping of the isomerized free radicals. The rate coefficient for isomerization is given as log(k3/s−1) = (11.1 ± 0.7) ‐ (9.5 ± 1.1) kcal mol−1/RT ln 10. The implications of the results for atmospheric chemistry are discussed.