Synthesis dibromo substituted BOPHY dye for the singlet oxygen generation

A dibromo substituted BOPHY derivative (2) was prepared and found to exhibit photo-sensitization capability. Rapid oxidation of 80% DPBF at the first 6 min was observed suggesting that 2 is a superior photo-sensitizer than methylene blue. The HOMO–LUMO band gap for the lowest energy absorption bands of the BOPHY 1 is smaller than that of PS 2, which is in good agreement with the red shift in the absorption observed between 1 and 2.