Synthesis, photophysical and photochemical properties of unsymmetrical zinc(II) phthalocyanines bearing 8-hydroxyquinoline unit

Abstract

8-Hydroxyquinolines (8-HQs) are very important molecules in the field of biochemistry. They may play different roles due to their chelating ability. Especially, its interaction with different metals such as iron and copper, which have important functions in the growth of cancer cells, helps inhibit proliferation. Moreover, the metal com-plexes of 8-HQ derivatives contribute to the generation of singlet oxygen species. On the other hand, phthalo-cyanines are macrocyclic compounds that have the capacity to generate singlet oxygen species and anticancer activity by photodynamic therapy. In this study, unsymmetrical zinc(II) phthalocyanine derivatives bearing one 8-HQ group and three tert-butyl groups (8-MeQ-ZnPc and 8-HQ-ZnPc) were prepared. For the synthesis of target molecules, unsymmetrical zinc(II) phthalocyanine containing methoxyquinoline unit (8-MeQ-ZnPc) was pre-pared first, and then the demethylation reaction was successfully carried out with BBr3 for obtaining hydrox-yquinoline counterpart (8-HQ-ZnPc). The fluorescence, singlet oxygen, and photodegradation quantum yields of 8-MeQ-ZnPc and 8-HQ-ZnPc were measured in DMSO, and the results show that the photosensitizers can be a promising anticancer agent candidates.