First-Principles Prediction of the Mechanisms for the Isomerization and Decomposition of 2- Hydroxypropyl, 2-Hydroxyprop-2-yl and 2-propoxy Radicals

摘要

The mechanisms for the isomerization and decomposition of 2-Hydroxypropyl, 2-Hydroxyprop-2-yl and 2-propoxyrnradicals have been studied by the G2M//B3LYP/6-311G (d, p) method. All possible free radical formation channels werernidentified and their corresponding rate constants were evaluated by using the transition-state-theory (TST) and the Rice-rnRamsperger-Kassel-Marcus (RRKM) theory. Among the 9 low-lying product channels identified, the decomposition ofrn2-propoxy radical to form CH3 + CH3C(H)O, and H + (CH_3)_2CO through process (6) and (7), respectively, are dominantrnat high-pressure limit over the temperature range 285 – 2500 K. At low pressure, process (6) is only dominant over 285-rn500 K. The predicted low- and high-pressure limit rate constants for these two major product channels can be given byrnk_6~0 = 6.5 × 10~(43) T~(-16.15) exp (-13352/T), k_7~0 = 1.6 × 10~(39) T~(-14.94) exp (-15278/T) cm~3 molecule~(-1) s~(-1), k_6~∞ = 1.4 × 10~(13) T~(0.47) exp (-7464/T) and k_7~∞ = 1.5 × 10~(11) T~(0.88) exp (-8922/T) s~(-1), respectively.