Solvent and central metal effects on the photophysical and photochemical properties of 4-benzyloxybenzoxy substituted phthalocyanines

The synthesis and characterization of new peripherally tetra-4-benzyloxybenzoxy substituted metal-free, zinc and lead phthalocyanines are described for the first time in this study. The influence of various organic solvents and the nature of the central metal ion on the spectroscopic, photophysical and photochemical properties has been investigated. General trends are described for photodegradation, singlet oxygen and fluorescence quantum yields, and fluorescence lifetimes of these compounds in different solvents. Photophysical and photochemical properties of phthalocyanine compounds are very useful for photodynamic therapy applications. Especially high singlet oxygen quantum yields are very important for Type II mechanism. The studied phthalocyanine compounds showed good singlet oxygen generation and these compounds show potential as Type II photosensitizers. The fluorescences of the studied compounds are effectively quenched by 1,4-benzoquinone in different solvents.

In this work were shown that syntheses and characterization of 4-benzyloxybenzoxy substituted metal-free, zinc and lead phthalocyanines. The photophysical (fluorescence quantum yield and lifetime), photochemical (singlet oxygen generation and photodegradation quantum yield) and fluorescence quenching properties of these novel compounds have been investigated in different solvents.Figure optionsDownload as PowerPoint slideResearch highlights
► Synthesis and characterization of metal-free, zinc and lead phthalocyanine compounds.
► Photophysical and photochemical properties in DMSO, DMF, toluene, THF.
► Ground state electronic absorption and fluorescence spectra.
► Photodynamic therapy.