Binding energy differences carbocations

Table 3.6. Binding Energy Differences of Carbocation Centers from Neighboring Carbon Atoms AEb+c c...

Table 6. Binding energy differences of carbocation centers from neighboring carbon atoms...

If the number of electron pairs for two chemical species (e.g.. reactant and product) is equal, it will matter whether the space (MO) occupied by each electron pair is different in the two systems, e.g., expanded in one case, contracted in the other, delocalized or localized, more or less spherical, more or less crowded due to the vicinity of other electron pairs, etc. Significant differences in the distribution of electron pairs occur if one compares a TS of a pericyclic reaction with reactants or products (reaction barrier), a molecule with classical bonding with an isomer possessing nonclassical (delocalized) bonding (molecular stability), a donor-acceptor complex with its separated parts (complex binding energy), isoelectronic species such as carbocations and boranes, etc. In all these cases, dynamic electron correlation should play an important role. 

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