Self-reaction kinetics of the (CH3)2CHC(O)O2 and (CH3)3CC(O)O2 acylperoxy radicals between 275 and 363 K

The self-reaction rate constants of the (CH3)2CHC(O)O2 and (CH3)3CC(O)O2 acylperoxy radicals were determined by flash photolysis from 275 to 363 K yielding: k((CH3)2CHC(O)O2)=(9.15±1.1)×10−13 exp[(821±39)K/T] and k((CH3)3CC(O)O2)=(2.0±0.5)×10−12 exp[(586±70)K/T] cm3 molecule−1 s−1, corresponding to (1.44±0.11)×10−11 and (1.43±0.11)×10−11 cm3 molecule−1 s−1 at 298 K, respectively (global uncertainty of ≈30%). These values are very close to that recommended for CH3C(O)O2. In addition, the room temperature rate constants of the cross-reactions (CH3)2CHC(O)O2+(CH3)2CHO2 and (CH3)3CC(O)O2+(CH3)3CO2 were estimated at (1.0±0.5)×10−11 and (1.25±0.5)×10−11 cm3 molecule−1 s−1, respectively, also similar to those of the CH3C(O)O2 radical cross-reactions.