Abstract
A series of axial di-substituted silicon(IV) phthalocyanines with electron-donating and electron-withdrawing properties were synthesized. The compounds were characterized by elemental analysis, 1H NMR, IR, and ESI-MS. The effect of axial ligands on the photophysical properties of silicon phthalocyanines was studied by UV/Vis, steady-state and time-resolved fluorescence spectroscopic analyses. Compared with silicon phthalocyanines with electron-donating properties, silicon phthalocyanines with electron-withdrawing properties could expand the π-conjugation in the dyes, resulting in a redshift of Q bands, lower fluorescence emission intensity and fluorescence quantum yields, but increasing fluorescence lifetimes. These results strongly suggest that the molecular design of phthalocyanines is essential for construction of photoactive materials.
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Acknowledgements
This research was supported by the National Natural Science Foundation of China (21274021, 61335011, and 81471703), and the college students’ innovative and entrepreneurial training program of Fujian Province (hxhg-21).