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

In this study, peripheral and non-peripherally substituted Zn(II) phthalocyanine complexes were synthe-sized from 7-hydroxy-3-(p-tolyl)coumarin and 7-hydroxy-3-(p-tosyl)coumarin compounds. The synthe-sized new compounds were characterized using elemental analysis, FT-IR, UV-Vis, Fluorescence 1 HNMR 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 io-dide 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 prop-erties, coumarin-phthalocyanine complexes containing tolyl-/tosyl-groups can be used as photosensitiz-ing candidates in photodynamic therapy and can be developed with targeted modifications.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Peripheral and non-peripheral substituted Zn(II) phthalocyanine complexes were synthesized from 7-hydroxy-3-(p-tolyl)coumarin and 7-hydroxy-3-(p-tosyl)coumarin compounds. The newly synthesized compounds were characterized and their solubility and fluorescence quenching behavior were investigated. The photophysical and photochemical properties of the phthalocyanines were examined, and the coumarin-phthalocyanine complexes containing tolyl-/tosyl-groups showed potential for use in photodynamic therapy.