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Reactivity in radical abstraction reactions: Application of the curve crossing model
Author(s) -
Pross Addy,
Yamataka Hiroshi,
Nagase Shigeru
Publication year - 1991
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.610040303
Subject(s) - chemistry , hydrogen atom abstraction , isopropyl , hydrogen atom , radical , alkyl , reactivity (psychology) , computational chemistry , ab initio , transition state , photochemistry , medicinal chemistry , organic chemistry , catalysis , medicine , alternative medicine , pathology
Abstract The curve crossing model was applied to a series of hydrogen abstraction reactions from a family of alkanes, RH (R = methyl, ethyl, isopropyl, tert‐butyl) by alkyl, hydrogen and chlorine radicals. The analysis was based on quantitative data obtained from an ab initio MO study. Schematic reaction profiles for the reaction of RH with alkyl and hydrogen radicals are built up from just two configurations: reactant, DA, and product D 3* A. For the Cl atom reaction, however, a significant contribution of D + A − , a charge‐transfer configuration, is also shown to be present. A simple explanation for differences in the intrinsic barrier for the identity radical abstraction reaction based on the initial gap size between DA and D 3* A configurations is provided. The influence of the D + A − configuration on the nature of the transition state of the Cl atom reaction and its intrinsic barrier is described. It is the D + A − configuration that is responsible for the polar character often observed in radical abstraction and addition reactions.