Significant spectroscopic difference was found between the 3(π,π*) state of coumarins and the 3L(a) state of benzpyrene. No analogy of the partially localized triplet state associated with the coumarin chromophore was revealed in the case of the potent carcinogen, benzo[a]pyrene. Instead, the 3L(a)state of benzo[a]pyrene is characterized by more delocalization than that of the non carcinogenic benzo[e]pyrene. Therefore, the predominant photoreaction between benzo[a]pyrene and DNA bases does not seem to involve cycloaddition in contrast to the coumarin pyrimidine system. Reactivity indices have been calculated, and results are consistent with recent experimental findings. In addition, spectroscopic properties of benzo[a]pyrene and benzo[e]pyrene have been comparatively described in terms of relatively high resolution spectra, polarization measurements, and molecular orbital calculations.
|Number of pages||10|
|Journal||Photochemistry and Photobiology|
|Publication status||Published - 1973|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)