Zn(II) phthalocyanine-cyclotriphosphazene dyad: synthesis, characterization, photophysical, and photochemical properties

A novel asymmetric Zn (II) phthalocyanine (Pcs) (5) peripherally substituted with one cyclotriphosphazene ring and six tert-butylphenoxy groups was synthesized and fully characterized by elemental analysis, mass, H-1, C-13, P-31 NMR, and FT-IR spectroscopies. Photophysical and photochemical properties of 5 (ground state absorption, fluorescence emission, fluorescence lifetime, fluorescence quantum yield, and singlet oxygen generation) were investigated in DMSO and THF. The determined singlet oxygen quantum yields of compound 5 in DMSO and THF were 0.62 and 0.52, respectively. These singlet oxygen quantum yields are very near the singlet oxygen quantum yield of unsubstituted Zn(II) Pcs used as the reference compound. This new Zn(II) Pcs may be a promising candidate for photodynamic therapy (PDT) with its photophysical and photochemical properties.