Synthesis, characterization and investigation of physicochemical properties of some novel phthalocyanines

Phthalocyanines (Pcs) have long been used as industrial organic pigments, since their accidental discovery in the late 1920s. In addition to their traditional applications, in recent years Pcs have been extensively studied for use in a wide range of high technology fields such as photodynamic therapy and photocatalytic activities. The focus of this study is the synthesis of novel Pcs for use as photosensitizers in photodynamic therapy and photocatalytic activities. The syntheses of tetra-substituted phthalocyanine complexes and their spectral characterization are presented in this work. The structures and purity of these complexes are confirmed by nuclear magnetic resonance, infrared and mass spectrometry and elemental analysis. They show high solubility in most common organic solvents such as chloroform, toluene, dimethylformamide and dimethysulfoxide. The photophysical and photochemical properties of the synthesised Pcs were investigated. The Pcs are stable, well within the stability range for phthalocyanines. High kuantum yields of triplet state (ranging from 0.45 to 0.82) and singlet oxygen generation (ranging from 0.38 to 0.78) were obtained. Key Words: Phthalocyanine, fluorescence, triplet state, singlet oxygen, photobleaching