Photophysical and Photochemical Properties of New Coumarin-Substituted Zinc and Indium Phthalocyanines for Photodynamic Therapy

In this study, we synthesized and characterized zinc (II) and indium (III) acetate phthalocyanine derivatives, modified with 7-hydroxy-8-methyl-4-(2,3,4,5-tetrafluorophenyl)coumarin, as potential photosensitizers for photodynamic therapy (PDT). The synthesized phthalocyanines were characterized using various analytical techniques, including elemental analysis, UV-Vis, FT-IR spectroscopy, and MALDI-TOF mass spectrometry. The study focused on the photophysical and photochemical properties of these compounds, particularly their singlet oxygen and photodegradation quantum yields. Zinc phthalocyanine exhibited lower fluorescence quantum yield and higher stability, whereas indium phthalocyanine showed superior singlet oxygen generation. These findings suggest that coumarin-substituted phthalocyanines hold promise as effective photosensitizers in PDT, with indium derivatives demonstrating enhanced photodynamic efficacy.