Synthesis And Spectra Study Of Substituted Phthalocyaninatozinc

Photodynamic Therapy (PDT) is a developing technique for cancer therapy where photosensitizer played a key function and phthalocyaninatozinc is believed to be the most effective one. In principle, the effect of photosensitizer depends on the ability of singlet oxytgen generation under illumination and the style of substitution will affect this ability of phthalocyanines.Eleven substituted metallophthalocyanines were synthesized from eight substituted phthalonitrile obtained from 3-nitryl phthalonitrile and 4-nitryl phthalonitrile. Substituents are phthalimidobutoxy, butoxy, octanylthio, methyl, methoxy and 4-carboxylphenyloxy. Center atoms are Cu, Zn, Co, and Pd, respectively, for tetraphthalimidobutoxyphthalocyanines and Zn for other Pcs. Characterizations were carried out by IR, MS, elemental analysis, UV/VIS, and crystal structural analysis.The effects of center metal, substituteents, solvent and surfactant (CTAB) on absorption and fluorescence spectra of the phthalocyanines were investigated. Focal point of discussion was the effects of substitutents on fluorescence spectra and fluorescence quantum yields (ФF). For Pcs with electron donating substituents, substitution atβposition results in largerФF than atαposition. The presence of phthalimido in substituents has no obvious influence onФF of Pcs. Protonation of the ring skeleton of ZnPc, performed by addition of TFA, led to a large decrease ofФF.The influence of group on photostability of phthalocyaninatozinc was also investigated. Decomposition ofβ-(pbto)4PcZn is the fastest one in these Pcs. For phthalocyaninatozinc, substitution atβposition results in larger photobleaching rate than atαposition. A blue shift ofλmax was found in octanylthiophthalocyanine which was not observed in other Pcs.Although some substituents will lower the singlet oxygen generation ability of Pcs, but also likely improve the transportation and distribution of Pcs in organism. So a comprehensive survey should be offered in the structure design and choice of photosensitizer.