50717-46-9Relevant articles and documents
Thermal Reaction of the Isopropyl Radical with 2,3-Dimethylbut-2-ene
Koertvelyesi, Tamas,Seres, Laszlo
, p. 2445 - 2450 (2007/10/02)
The CH3CH(*)CH3 radical (iP*) initiated homogeneous gas-phase thermal reaction of 2,3-dimethylbut-2-ene has been studied at 490-540 K by means of the thermal decomposition of azoisopropane (AIP).The products were identified using gas-chromatography (GC) and gas chromatography-mass spectrometry (GC-MS).The rate constant for the decomposition of AIP: AIP -> 2 CH3CH(*)CH3 + N2 (1) is log(k1/s-1) = (16.36 +/- 0.49) - (201.5 +/- 5.4) kJ mol-1/θ, where θ = RTln 10.The rate constant of the H-abstraction yielding the 1,1,2-trimethylallyl radical (TMA*) relative to the corresponding self-combination was determined for the first time.CH3CH(*)CH3 + (CH3)2C=C(CH3)2 -> C3H8 + (CH3)2C=C(CH3)CH2(*) (2), CH3CH(*)CH3 + CH3CH(*)CH3 -> (CH3)2CHCH(CH3)2 (9) log2/k91/2)/dm3/2 mol-1/2> = (4.99 +/- 0.49) - (57.0 +/- 5.4) kJ mol-1/θ.The TMA* formed in the reaction (2) combines with iP* terminally and non-terminally.The ratio of the rate constants was found to be independent of temperature: k10/k11 = 2.8 +/- 0.1. iP* disproportionates with both iP* and TMA*.The disproportionation-combination ratios determined are Δ (iP*, iP*) = 0.58 +/- 0.06 and Δ (iP*, TMA*) = 0.03 +/- 0.01.
