A thioether-linked iodinated BODIPY-benzimidazole photosensitizer: Efficient light-induced production of singlet oxygen and superoxide radicals and photobiological activity.

A new iodinated BODIPY dye incorporating a thioether- has been synthesized and characterized. The benzimidazole unit was introduced at the meso-pentafluorophenyl position of the BODIPY scaffold via high-yield click chemistry. This substitution does not alter the strong absorption and emission properties of the BODIPY chromophore and provides a versatile platform for the attachment of pharmacologically important molecules. Further functionalization of the BODIPY core with iodine at the 3- and 5-positions yields a derivative capable of generating reactive oxygen species when irradiated with low energy light. Experimental evidence confirms the production of both singlet oxygen and superoxide radicals, indicating this complex is capable of operating by both Type I and Type II photosensitization pathways. This dual capacity could be responsible for its effectiveness as a photosensitizer and contribute to its photobiological activity against human melanoma cells.