Peripherally, non-peripherally and axially pyrazoline-fused phthalocyanines: synthesis, aggregation behaviour, fluorescence, singlet oxygen generation, and photodegradation studies

Abstract

In this study, the synthesis of phthalocyanine compounds, which are known as second-generation photosensitizing agents in photodynamic therapy and play an important role in the treatment of cancer, is presented. Pyrazoline-fused axial silicon phthalocyanine (HY-SiPc), peripheral zinc phthalocyanine (HY-ZnPc^p), and non-peripheral zinc phthalocyanine (HY-ZnPc^np) were synthesized and characterized by common spectroscopic methods (NMR, FT-IR, UV-Vis spectroscopies, and mass spectrometry). In order to determine the photophysical and photochemical properties, the solvent effect in different organic solvents (THF, DMSO, CHCl₃, DMF, and EtOAc) was studied, and DMSO was chosen as a suitable solvent for further studies. According to the results, the pyrazoline-fused peripheral zinc phthalocyanine (HY-ZnPc^p) showed the highest singlet oxygen production, and it is thought to be a photosensitizer candidate for photodynamic therapy.