Synthesis, characterization, photophysical and photochemical properties of peripherally tetra-1,2,4-triazol-3-ylthio substituted metal-free phthalocyanine and its zinc(II) and lead(II) derivatives

Phthalonitrile (3) including 4-(4-fluorophenyl)-5-(4-methoxyphenyl)-4H-1,2,4-triazole-3-thio substituent and its peripherally tetra substituted metal-free (4), zinc(II) (5) and lead(II) (6) phthalocyanine derivatives were prepared and characterized by FTIR, mass, H-1-NMR and C-13-NMR spectroscopic data. All studied phthalocyanines had good solubility in common organic solvents and did not aggregate. The photophysical and photochemical behaviors of the phthalocyanine complexes (4-6) were examined in DMSO to determinate their PDT potential. Singlet oxygen, fluorescence and photodegradation quantum yields showed that zinc(II) phthalocyanine (5) has potential as Type II photosensitizer for PDT applications.