Radical decomposition P scission

To verify the preferential breakdown of the C-C bond in a radical at the P position, it is necessary to investigate the dynamics leading to the decomposition of a radical. The following reaction has been studied (Xiao et al. 1997)  

To investigate the possible molecular size effect on the calculated energetics, the P scission reactions of a primary pentyl, hexyl, and heptyl radical have also been studied (Xiao et al. 1997). The calculated activation energy Ea and heat of reaction AH at the B3LYP/6-31G level are 30.43 and 23.41 kcal/mol for butyl O ethylene + ethyl 30.52 and 23.58 kcal/mol for pentyl o ethylene + propyl 30.38 and 23.35 kcal/mol for hexyl ethylene + butyl and 30.39 and 23.37 kcd/mol for heptyl O ethylene + pentyl. The results again suggest that the kinetics is largely controlled by the type of reaction, rather than the size of the system. 

To describe the decomposition of a secondary radical, the following reaction has been studied  

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Radical decomposition (P scission to yield an olefin and a smaller radical). 

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