Thermolabile hydrocarbons, 34.. Kinetics of the generation of 1,3-di-tert-butylallyl radicals by thermal CC bond cleavage reactions
✍ Scribed by Herberg, Clemens ;Verevkin, Sergej P. ;Nölke, Margot ;Beckhaus, Hans-Dieter ;Rüchardt, Christoph
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 796 KB
- Volume
- 1995
- Category
- Article
- ISSN
- 0947-3440
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The title radicals were generated by thermal decomposition of (E,E)‐meso‐ and (E,E)‐(±)‐5,6‐di‐tert‐butyl‐2,2,9,9‐tetramethyl‐3,7‐decadiene (4a, b), (E)‐5‐(1,1‐dimethylethyl)‐2,2,6‐trimethyl‐6‐phenyl‐3‐heptene (6), and (E)‐5‐(diphenyl‐methyl)‐2,2,6,6‐tetramethyl‐3‐heptene (7). The activation parameters of these reactions were calculated from the rate constants which were followed over a 40°C temperature range. The enthalpies of formation of 4a, b were determined from the enthalpies of combustion and enthalpies of vaporization, those of 6 and 7 by MM2 calculation. From these data and their comparison with those of comparable saturated hydrocarbons of similar strain the radical stabilization enthalpy of the title radical RSE = 11.4 ± 1.5 kcal/mol was determined, which is in good agreement with results obtained from other model compounds (12.6 kcal/mol) previously.