Studied On Synthesis, Characterization And Photodynamic Properties Of Axially Substituted Silicon Naphthalocyanine

Photosensitizers are research topic for photodynamic therapy (PDT) on field of international chemistry and medicine. Nowadays, planar structured phthalocyanine and naphthalocyanine derivatives as photosensitizers have been widely studied. But, naphthalocyanine compounds containing axial ligands has received few attention, which possess many special properties than others, such as:(1) avoid aggregation, improve the ability of ¹O₂ production and enhance photosensitized activation; (2) axially substituted silicon naphthalocyanine compounds without substituted groups on ring framework are easy synthesized due to no presence of isomer; (3) cell uptake increase with conjugate system. Therefore, Studied on synthesis and photo-physics, photo-chemistry properties of axially substituted naphthalocyanine compounds as photosensitizers seem to be important academic sense and promising application are investigated. Silicon naphthalocyanine compounds containing axial ligands bases on larger conjugate system and their main absorption peaks agreeing with optimal for light penetrating tissue were investigated in this dissertation. A series of silicon naphthalocyanine compounds containing axial ligands (NcSiCl₂, NcSi(OH)₂, NcSi(CH₃O)₂, NcSi(C₂H₅O)₂, NcSi(C₃H₇O)₂, NcSi(C₄H₉O)₂, Br₄NcSiCl₂) were synthesized, the method for preparing 2,3-naphthalonitrile and 4-bromine-2,3-naphthalonitrile as precursors were improved. And, the obtained compounds were characterized by IR, UV/Vis, Ms and elemental analysis. Moreover, the relative properties of the above obtained compounds were also studied supplying references to design of medication. 1. The UV/Vis and fluorescence spectra of axially alkoxy substituted silicon naphthalocyanine compounds (SiNc(OR)2, R= CH3, C2H5, C3H7 and C4H9) have been investigated in DMSO,DMF and CH2Cl2, respectively. The effect axially and ring substituted groups and different solvent on them was discussed. The results indicate that the maximal absorption band of the compounds increase with carbon number of axial alkoxy ligands in same solvent. 2. The thermal analysis for the compounds was measured with TGA, the thermal decomposition mechanisms were proposed. Moreover, the electrochemistry properties in non-aqueous were investigated. 3. Photodynamic efficiency of photosensitizer is dependent on itself stability for photo irradiation. Photo-stable properties of naphthalocyanine compounds containing different substituted groups were investigated in DMSO,DMF and CH2Cl2, respectively. The results indicate that the photo-stable properties of axially substituted naphthalocyanine compounds are higher than that of ring substituted naphthalocyanine. 4. The excited singlet state and excited triplet state photophysical parameters (fluorescence quantum yield, fluorescence decay rate, life of excited single-state and triplet state, rate constant of first excited single-state and triplet state, triplet-triplet state three-dimensional time resolved absorption spectra) of the series of silicon naphthalocyanines were obtained. The effect axially and ring substituted groups on the excited singlet state and excited triplet state were also discussed. 5. The abilities of singlet oxygen (1O2) production of a series naphthalocyanines were studied. The effect and rule of three-dimensional structure and axially substituted groups on the abilities of singlet oxygen(1O2) production were discussed. The results show that the abilities of singlet oxygen(1O2) production of silocon naphthalocyanine containing axial ligands are higher than that of ring substituted naphthalocyanine compounds. 6. Amino acids (L-tryptophan, L-cysteine L-Tryosine and cholesterin) ofphoto-oxidation using a series of naphthalocyanines were carried out. Photo-oxidation rate of L-Tryosine is higher than other amino acids for same naphthalocyanine compounds in our experimental conditions, which is accord with the ability of singlet oxygen(1O2) production. 7. The photodynamic activities of silicon naphthalocyanine containing axial ligands for cancer cell were tested. It is found that NcSi(OCH3)2 has strong photodynamic effect to kill cancer cells.