Synthesis of phthalocyanines having thio-alkyl substituents at non-peripheral positions and their photochemical and photophysical properties

Phthalocyanines possess similar structure of natural chromophore porphyrins. The phthalocyanines are known to utilize in important functional colorants for many fields. The phthalocyanines are especially expected to use photosensitizers for both dye-sensitized solar cells and photodynamic therapy of cancer. In the present study, novel non-peripheral substituted thio-alkyl zinc phthalocyanines were synthesized in order to develop second-generation photosensitizer for photodynamic therapy of cancer. In order to evaluate the influence of heteroatom existence and chain length, synthesized non-peripheral substituted thio-alkyl phthalocyanines were reported photoexcited triplet lifetime using laser-flash photolysisand singlet oxygen quantum yields by 1,3-diphenylbenzofuranemethod. Of synthesized non-peripheral substituted phthalocyanines, ultraviolet-visible spectra showed around 780 nm, photoexcited triplet lifetimes were estimated around 1 as and singlet oxygen quantum yields. It is thought that synthesized non-peripheral hetero-alkyl substituted phthalocyaines had enough ability for photodynamic therapy of cancer.