Highly soluble HOPEMP-functionalized phthalocyanines for photodynamic activity: Photophysical, photochemical and aggregation properties

Abstract

This study presents the synthesis, characterization, photochemical, photophysical and aggregation properties of novel 4-((1,2,2,6,6-pentamethylpiperidin-4-yl)oxy)phthalonitrile (HOPEMP-Pht) and its highly soluble peripherally tetra-substituted Mg(II) (HOPEMP-MgPc), Zn(II) (HOPEMP-ZnPc), and In(III)CI (HOPEMP-InPc) phthalocyanine derivatives as a photosensitizer for photodynamic therapy (PDT) application. The novel compounds were characterized using various techniques. These phthalocyanines exhibit good solubility in many common organic solvents such as dimethyl-formamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, acetone, chloroform, diethyl ether, dichloromethane, ethyl acetate, ethanol, methanol, hexane, and toluene. Aggregation behaviors of the HOPEMP-functionalized phthalocyanines were researched in different concentrations of dimethyl sulfoxide. To evaluate the photodynamic therapy potential of these phthalocyanines, photochemical and photophysical properties were examined in dimethyl sulfoxide for the first time. Besides, the effects of the nature of central metal atom on photochemical and photophysical properties of these phthalocyanines are also stated. As a result; singlet oxygen, photodegradation, fluorescence and aggregation properties show that these phthalocyanines can be promising photosensitizers for PDT studies.