Synthesis and photophysical properties of polyfluoroalkylyate silicon (IV) phthalocyanine

Phthalocyanine complexes are promising second-generation photosensitizers. It has many advantages in photodynamic therapy: good photothermal stability, absorption wavelength in the near-infrared region, and low cytotoxicity. However, they also have some disadvantages：easy to aggregate, poor in solubility, and lack tissue-target.Therefore, how to modify the structure of phthalocyanine is becoming a research hotspot. In this paper, a novel polyfluoroalkylyate silicon (IV) phthalocyanine (SiPc-F) was synthesized. The photophysical properties of this novel polyfluoroalkylyate silicon (IV) phthalocyanine complex (SiPc-F) were studied by UV-visible spectroscopy, steady state and time-resolved spectroscopic methods. The effect of the fluorine substituent on the photophysical properties of phthalocyanine complexes and the quantum yield of singlet oxygen was compared. The results show that the maximum absorption wavelength of polyfluoroalkylyate silicon (IV) phthalocyanine is red-shifted and the intensity is enhanced, the fluorescence intensity becomes stronger, fluorescence quantum yields and fluorescence lifetime is higher but singlet oxygen quantum yields was lower than that of non-fluorinated silicon (IV) phthalocyanine at the same concentration. Polyfluoroalkylyate silicon (IV) phthalocyanine complexes are excellent candidate photosensitizers for photodynamic therapy.