Thermal reaction of azoisopropane in the presence of (E)-CH3CH CHCH3 : reactions of the radical 2-Ċ3H7
Abstract
The azoisopropane-initiated thermal reaction of (E)-CH3CHCHCH3 has been studied in the temperature range 489.5–542.0 K.
For the reactions (CH3)2CHNNCH(CH3)2→ 2 2-Ċ3H7+ N2(1), 2-Ċ3H7+(E)-CH3CHCHCH3→ C3H8+(E)-Ċ4H7(4), →(CH3)2CHCH(CH3)ĊH(CH3)(5), 2 2-Ċ3H7→(CH3)2 CHCH(CH3)2(2) the following Arrhenius parameters were determined: log(k1/s– 1)=(16.42 ± 0.30)–(201.9 ± 3.0) kJ mol– 1/θ, log[(k4/k1/22)/dm3/2 mol– 1/2 s– 1/2]=(3.64 ± 0.40)–(46.9 ± 2.1) kJ mol– 1/θ, log[(k5/k1/22)/dm3/2 mol– 1/2 s– 1/2](2.53 ± 0.60)–(39.5 ± 2.4) kJ mol–1/θ where θ=RT In 10.
For the cross-combination ratios of the radicals 2-Ċ3H7 and (Z)-Ċ4H7, ϕ[2-Ċ3H7, (Z)-Ċ4H7]t= 2.12 ± 0.10 was obtained, where the subscript t refers to the terminal combination.
Formation of certain characteristic products was observed in various addition/isomerization/dissociation processes. 2-Ċ3H7 addition to (E)-CH3CHCHCH3 is suggested as the rate-determining step, followed by 1, 4- and 1,5-H-atom shifts.