New non-peripherally substituted zinc phthalocyanines; synthesis, and comparative photophysicochemical properties

Abstract

In this study, the three new phthalonitriles (1, 2, 3) and their non-peripherally tetra substituted zinc phthalocyanines (3)-Tetra [bromophenoxy] phthalocyaninato zinc (II) (np4), (3)-Tetra [chlorophenoxy] phthalocyaninato zinc (II) (np5) and (3)-Tetra [fluorophenoxy] phthalocyaninato zinc(II) (np6) are reported for the first time. All phthalonitriles and their phthalocyanines have been characterized by using spectroscopic methods, FT-IR, H-1 NMR, electronic spectroscopy and mass spectra as well as elemental analysis. To investigate photosynthesizer's properties; fluorescence, singlet oxygen and photodegradation quantum yields of non-peripherally Pcs were measured in dimethylsulfoxide (DMSO), dimethylformamide (DMF) and tetrahydrofuran (THF) solutions. Non-peripherally position and solvent effect on the photophysical and photochemical parameters of the chloro, fluoro, bromo phenoxy-phenoxy substituted phthalocyanines (np4, np5 and np6) are also compared with the corresponding tetra-peripherally substituted analogues. The values of non-peripherally zinc phthalocyanines (np4 to np6) could be classified as photosensitizers in the photocatalytic applications such as photodynamic therapy (PDT) of cancer due to having good singlet oxygen yields (ranging from 0.52 to 0.85). (C) 2019 Elsevier B.V. All rights reserved.