Thermal Reactions of Isobutyl Radicals

摘要

Deuterium labeled isobutane (CH3)3CD was pyrolyzed to generate (CH3)3C and CH2CD(CH3)2radicals. The competition between reactions (5) and (6) was studied by isotopic analysis of the hydrogen, methane, and isobutene fractions.CH2CDlpar;CH3rpar;2rarr;CH2equals;Clpar;CH3rpar;2plus;DCH2CDlpar;CH3rpar;2rarr;CH2equals;CDCH3plus;CH3.Reaction (5) was found to be of negligible importance relative to reaction (6) up to 540deg;C and it is concluded that previous estimates ofk5/k6(in the nondeuterated species) are too high by at least an order of magnitude. The expulsion of molecular hydrogen by isobutyl orthyphen;butyl does not occur in competition with other unimolecular reactions of these radicals.