Newly synthesized peripherally octa-substituted zinc phthalocyanines carrying halogen terminated phenoxy-phenoxy moiety: comparative photochemical and photophysical features

Authors: ERKAN KIRBAÇ, ALİ ERDOĞMUŞ

Abstract: This study reports the 3 new phthalonitrile derivatives, namely 4, 5 Bis-[4-(4-bromophenoxy) phenoxy] phthalonitrile (1), 4,5 Bis-[4-(4-chlorophenoxy) phenoxy]phthalonitrile (2), and 4, 5 Bis[4-(4-fluorophenoxy) phenoxy] phthalonitrile (3). Their octasubstituted zinc phthalocyanines (4, 5, 6) are reported for the first time in this study. The resulting compounds were characterized by utilizing some spectroscopic methods, such as UV-Vis, ¹HNMR, FT-IR spectroscopy, as well as mass spectraand elemental analysis. To show photosynthesizer's potential, emission (F_F), singlet oxygen (¹O₂), and photodegradation quantum yields (Φ_Δ, Φ_d) of octaperipherally phthalocyanines (Pcs) were performed in the solutions, such as biocompatible solvent DMSO (dimethyl sulfoxide) as well as DMF (dimethylformamide) and THF (tetrahydrofuran). Solvent and octa-peripherally binding effect of the halogen (Br, Cl, F) terminated phenoxy-phenoxy groups on phthalocyanine rings for photophysicochemical properties (4, 5, and 6) were compared with the tetra-peripherally and tetra nonperipherally substituted derivatives. The new dyes (4 to 6) may be evaluated in photodynamic therapy (PDT) of cancer as photosensitizers due to efficient ¹O₂ from 0.55 to 0.75.

Keywords: Photochemistry, photophysics, zinc phthalocyanine, octa-substituted, halogen substitution

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