A molecular orbital treatment on the reactivity of some polycyclic aromatic hydrocarbon diol-epoxides

The total energies of several aromatic hydrocarbon diol-epoxides and their carbonium cations were calculated by using the semi-empirical CNDO/2 SCF MO calculations. The reactivity of the diol-epoxides toward electrophilic reagents was evaluated from the energy difference between the diol-epoxide and its carbonium cation. Next, the total energies of the diol-epoxides and their carbonium cations were divided into several components, which represent the contributions of parts of molecules to the total energy. That is, the total energy was represented as the sum of the block energies and inter-block energies, which were defined in relation to the parts of the molecules. By using this concept of the block and the inter-block energies the reactivities of the diol-epoxides were interpreted in connection with the molecular structure.