Identity Scrambling and Isomerization Networks in Systems of Excited Alkyl Radicals.

The gas phase isomerization by H-atom transfer of vibrationally excited alkyl radicals of general structure G-C-C-C-C.-C has been studied G G was an H, methyl, ethyl, iso-propyl or tert-butyl group. The radicals were produced by chemical activation by the addition of an H-atom to an appropriate alpha-olefin. The study expands on earlier findings and shows that alkyl radicals, vibrationally excited above 40 kcalmole, are involved in a characteristic process of rapid competitive, consecutive isomerization. Details of Rice-Ramsperger-Kassel-Marcus RRKM rate calculations for the more important isomerization processes are described. Author