Calculated reactivity of the mutagenic cyclopenta-polycyclic aromatic hydrocarbon, 3, 4-epoxycyclopenta[cd]pyrene

Delocalization energies of the 1- and 4-pyrenyl carbocations resulting from epoxide ring opening of 3, 4-epoxycyclopenta[cd]pyrene have been calculated with semi-empirical and ab-initio molecular orbital procedures. The delocalization energy difference between carbocations is found to be larger than previously obtained from simple pi molecular orbital calculations. Certain general features, expected for the reactivity of the cyclopenta-polycyclic aromatic hydrocarbon series are also pointed out.