Synthesis and Study of Properties for Asymmetric Triphenylamine-Zinc Phthalocyanine

Abstract

Triphenylamine-zinc phthalocyanine (TQPc) that contains a bulky triphenylamine group and three 8-oxy-quinoline groups has been found to exhibit preferable performance. The first example of TQPc has been synthesized. Its zinc complexes of the well-known electron transport material displays enhanced electron-accepting ability relative to freemetallophthalocyanines, and can also be used as chemical sensors, liquid crystals, photodynamic therapy, data storage and non-linear optics. The triphenylamine-zinc phthalocyanine is synthesized by statistical condensation. The main chemicals are aminophenol, p-chloronitrobenzene, 8-hydroxyquinoline, 4-nitrophthalonitrile and zinc acetate. The fragment 4,4'-dinitro-4"-hydroxytriphenylamine is synthesized by the reacting from aminophenol with p-chloronitrobenzene at the catalysis of anhydrous potassium carbonate. The gross yield is 27.5%, and its purity is 96.6%. In comparison with other methods, there are some advantages in this method: the materials are cheap and easily available, and the product can be used as a substituent for phthalocyanine. All compounds are characterized by H NMR, IR spectra and elemental analysis. The electronic spectra of TQPc exhibits an intense π-π* transition of triphenylamine unit identity together with characteristic B bands of the phthalocyanine core. Energy transfer through oxy bridges has been confirmed by ultraviolet irradiation of triphenylamine. The aggregative behavior is studied in DMF and CH2Cl2. The results indicate that it is not aggregative in DMF, whereas forms dimer in CH2Cl2 at 0.223× 10~2.587×10 mol/L. The equilibrium constant for the dimer is calculated at the same time, indicating that the less polar solvent is unfavorable for the presence of the monomer. The redox behavior is studied by cyclic voltammetry. Its level structure of energy band is calculated by cyclic voltammetry combined with differential voltammograms, this molecule has been found to have a low LUMO (-1.04 V vs SCE) and a deep HOMO (0.78 V vs SCE) energy level. The results indicate that it matches with the energy level of the nanocrystalline of TiO2, and is thus very promising as an electron transport material for dye-sensitized solar cells.