Comparing Singlet Oxygen Generation of Schiff Base Substituted Novel Silicon Phthalocyanines by Sonophotochemical and Photochemical Applications

Effect of Direct Alkyne Substitution on the Photophysical Properties of Two Novel Octasubstituted Zinc Phthalocyanines

The synthesis of two novel phthalonitrile derivatives (3-4) bearing ethynylcyclohex-1-ene and ethynylcyclohexane groups and two peripherally octa substituted zinc (II) phthalocyanines (5-6) were prepared. The synthesis of phthalonitrile derivatives was performed with Sonagashira coupling reaction by using palladium-catalyzed. The newly synthesized compounds were characterized by using FT-IR, NMR, mass, and UV-Vis absorption spectroscopy techniques. Aggregation studies of 5 and 6 were performed in various organic solvents and different concentrations in tetrahydrofuran (THF). The photophysical studies of the Pcs were performed in THF to determine the effect of the alkyne groups on the fluorescence of the Pc ring. Substances showing fluorescence properties can be used in practical applications such as to create an image in microscopy. Fluorescence quantum yield (ΦF) and fluorescence lifetime (τF) of 5-6 were calculated. The fluorescence quenching studies of 5-6 were performed by adding the different concentrations of 1,4-benzoquinone (BQ) to a constant concentration of the Pcs in THF and it was found that benzoquinone was an effective quencher. The values of the Stern-Volmer constant (Ksv) and quenching constant (kq) of zinc phthalocyanines (5-6) were examined. All obtained results were compared with each other and with unsubstituted zinc Pc compound used as a reference.

Design consideration of phthalocyanines as sensitizers for enhanced sono-photodynamic combinatorial therapy of cancer

Cancer remains one of the diseases with the highest incidence and mortality globally. Conventional treatment modalities have demonstrated threatening drawbacks including invasiveness, non-controllability, and development of resistance for some, including chemotherapy, radiation, and surgery. Sono-photodynamic combinatorial therapy (SPDT) has been developed as an alternative treatment modality which offers a non-invasive and controllable therapeutic approach. SPDT combines the mechanism of action of sonodynamic therapy (SDT), which uses ultrasound, and photodynamic therapy (PDT), which uses light, to activate a sensitizer and initiate cancer eradication. The use of phthalocyanines (Pcs) as sensitizers for SPDT is gaining interest owing to their ability to induce intracellular oxidative stress and initiate toxicity under SDT and PDT. This review discusses some of the structural prerequisites of Pcs which may influence their overall SPDT activities in cancer therapy.