Photooxygenation of Tetrabenzo[a,cd,j,lm]Perylene and Tribenzo[a,h,rst]Phenanthra[10,1,2-cde]Pentaphene

The photooxygenation of tetrabenzo[a,cd,j,lm]perylene (TBP) and tribenzo[a,h,rst]phenanthra[10,1,2-cde]pentaphene (TBPP) due to exposure to visible-light was investigated by measuring the absorption spectra and applying semi-empirical molecular orbital methods. Regardless of similarity in molecular structure, TBPP undergoes photooxygenation, but TBP does not. The energy correlation diagrams were obtained by calculations of the heats of formation for TBP, TBPP and their endo-peroxides. The experimental results were explained in terms of difference in stabilization energy.