Synthesis And Properties Of Photosensitizing Dyes Derivatives Of Porphyrins

Porphyrin compounds have unique light absorption properties,excellent stability and structural modulability,and play an important role in the study of dye-sensitized solar cells.However,its narrow spectral absorption has limited its application in dye-sensitized solar cells.Schiff base compounds have a-RC?N-structure,and azo compounds have an ?N?N? structure;their absorption spectra are complementary to those of porphyrins.Therefore,two kinds of carbazole Schiff base porphyrins and two kinds of azo porphyrins were successfully synthesized in this paper,aiming to broaden the spectral absorption range of porphyrins.The meso-tetrakis(4-carbazole)phenylporphyrin(TCPP)was prepared with carbazole,p-fluorobenzaldehyde and pyrrole as the main raw materials.Synthesis of meso-tetra(4-nitro)phenylporphyrin from p-nitrobenzaldehyde and pyrrole and reduction of meso-tetrakis(4-aminophenyl)porphyrin from carbazole-aldehyde [p-(PN-carbazolylbenzylideneimino)]phenylporphyrin(TCIPP).Meso-tetrakis(4-aminophenyl)porphyrin was diazotized and then reacted with 2-naphthol and 8-hydroxyquinoline to give meso-tetra[4-(2-hydroxyazonaphthyl)benzene Based on porphyrin(TNNPP)and meso-tetrakis[4-(8-hydroxyazoquinoline)phenyl]porphyrin(TNQPP).Using infrared spectroscopy,ultraviolet-visible spectroscopy,cyclic voltammetry,etc.,the structure,spectral characteristics and electrochemical properties of the target compounds were determined.The UV-Vis spectra of two kinds of carbazole Schiff base porphyrins and two kinds of azo porphyrin dyes in DMF solution were tested at different concentrations,which showed that they were soluble in 0.2×10-5 to 1×10-5 mol/L.Degrees range within the monomeric form.Cyclic voltammetry was used to study the redox properties of two carbazolyl Schiff base porphyrins and two azo porphyrin dyes.The LUMO and HOMO levels of the four porphyrins were calculated from the cyclic voltammograms.The ELUMOs were-3.18 e V,-3.49 e V,-3.55 e V,and-3.38 e V,EHOMO were-5.71 e V,-5.08 e V,-4.82 e V,and-4.74 e V,respectively.The energy level structure diagram is drawn.The results show that the LUMO level of the four porphyrins is higher than that of the Ti O2 conduction band,and the excited electrons are injected into the nano-Ti O2 conduction band;its HOMO energy level is higher than that of the electrolyte I-/I-3.The low level allows the oxidation dye to obtain electrons from the I-/I-3 electrolyte and achieve dye regeneration...