Photophysical and Photochemical Properties of the Pyropheophorbide-Perylene-Pyropheophorbide Triad

A covalently-bonded structure (triad PP-PDI-PP) based on pyropheophorbide dye (PP, chlorin e6 derivative) and an organic non-fullerene acceptor, perylenediimide derivative (PDI), has been obtained. The triad has a pronounced absorption in the red region of the spectrum. Compared to the native dye, the obtained triad shows partial fluorescence quenching, and its singlet oxygen generation efficiency upon red light irradiation decreases by five times. At the same time, this triad, solubilized in water by polyvinylpyrrolidone, generates superoxide anion-radical three times more efficiently than the native dye. The demonstrated results show the promising potential of such perylene-dye structures as type I photosensitizers for photodynamic therapy.