Photophysical and photochemical properties and comparison of tolyl and tosyl coumarin-bearing phthalocyanines

• Published in: Journal of molecular structure Vol. 1274; p. 134565
• Main Authors: Kazancıçok, Zehra, Güler, Hatice Esra, Özdemir, Mücahit, Pişkin, Mehmet, Bulut, Mustafa, Yalçın, Bahattin, Salan, Ümit
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.02.2023
• Subjects: Coumarin; Photodynamic therapy; Phthalocyanine; Singlet oxygen; Synthesis; Phthalocyanine; Photodynamic therapy; Synthesis; Singlet oxygen; Coumarin
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2022.134565

•Design and synthesis of peripheral and non-peripherally substituted Zn(II) phthalocyanine complexes.•Phthalocyanines have been characterized by spectroscopic methods.•Effects of the substituent positions on the photophysical and photochemical properties.•Singlet oxygen and fluorescence quantum yields of the novel phthalocyanines.•Tosyl group effects in UV–Vis and fluorescence spectra. In this study, peripheral and non-peripherally substituted Zn(II) phthalocyanine complexes were synthesized from 7‑hydroxy-3-(p-tolyl)coumarin and 7‑hydroxy-3-(p-tosyl)coumarin compounds. The synthesized new compounds were characterized using elemental analysis, FT-IR, UV–Vis, Fluorescence 1HNMR spectroscopy and MALDI-TOF mass spectrometry. All the synthesized phthalocyanine complexes showed good solubility in organic solvents such as acetone, dichloromethane, chloroform, pyridine, and ethyl acetate. Fluorescent quenching behavior was investigated using 1,4-benzoquinone and potassium iodide as a quencher. The photophysical (fluorescent quantum yields and lifetimes) and photochemical (single oxygen and photodegradation quantum yields) properties of these new phthalocyanines were examined in dimethyl sulfoxide. Phthalocyanine complexes containing 7‑hydroxy-3-(p-tolyl)coumarin had higher singlet oxygen quantum yields than phthalocyanine complexes containing 7‑hydroxy-3-(p-tosyl)coumarin. Phthalocyanines to which coumarins are peripherally bound were more advantageous than their non-peripherally bound derivatives. As a result of their photophysical and photochemical properties, coumarin-phthalocyanine complexes containing tolyl-/tosyl- groups can be used as photosensitizing candidates in photodynamic therapy and can be developed with targeted modifications.