Topic 11.2. Structure-Reactivity Relationships in Hydrogen Abstraction Reactions

Topic 11.2. Structure-Reactivity Relationships in Hydrogen Abstraction Reactions 

Roberts and Steel investigated the applicability of an extended Bell-Evans-Polyani relationship to a series of hydrogen abstraction reactions. They developed a correlation equation that incorporated additional terms for electronegativity differences and for radical stabilization effects  

Another kind of approach is based on estimates from first principles. The fundamental concept of these approaches is that the E of a hydrogen abstraction reaction will be determined mainly by the strength of the C-H and H-X bonds and by repulsions between R3C and X in the transition state. 

Structure-Reactivity Relationships in Hydrogen Abstraction Reactions 

The problem is to formulate these relationships quantitatively. One approach, called the interacting state model (ISM) uses the Morse curves for the C-H and H-X bonds as the starting point and describes the TSs in terms of the length of the C-H and C-X bonds at the The total bond order is taken to be 1.0 unless one of the 

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