Relative roles of K region and bay region towards determining the carcinogenic potencies of polycyclic aromatic hydrocarbons.

Using the quantum mechanical MINDO/3 method a bond reactivity index based on superdelocalization of electrons in a compound has been formulated in order to estimate the relative carcinogenic properties of polycyclic aromatic hydrocarbons. The values of the index calculated for the K region as well as the bay region suggest that a knowledge of the reactivities of both regions is necessary for a reasonable estimation of the relative carcinogenic potencies of PAHs. However, no direct relationship between the two reactivity indices was observed in the calculations. It was found that the results for the bay-region reactivity index correlated well with the relative carcinogenic potencies of the molecules.