Synthesis Spectroscopic And Electrochemical Studies Of Zinc Tripyrazinoporphyrazines

The sensitizers are a key material in the component of dye-sensitized solar cells?DSSCs?and the molecular design of sensitizers also important.Donor-accpector-?bridge-acceptor?D-A-?-A?has a series of advantage when appied for DSSCs,such as adjusting orbital of energy level,avoiding the waste of energy and improving the light stability.Tetrapyrazinoporphyrazines is similar to phthalocyanine and has good absorption in the UV-Vis spectral and near infrared region.In the paper,four asymmetric tripyrazinoporphyrazine were successfully synthesized,which is aimed at expanding the moleculat structure of phthalocyanine and optimizing its photoelectric properties.2,2'-Furil,2,2'-thenil,2,2'-benzil,4,4'-DiMethylbenzilwerereactedwith diaminomaleonitrle to get 5,6-Difuryl-pyrazin-2,3–dicarbonitril?Pyz-1?,5,6-di?2-thiophen?-pyrazine-2,3-dicarbonitrile?Pyz-2?,5,6-diphenylpyrazine-2,3-dicarbonitrile?Pyz-3?,5,6-bis-?4-methylphenyl?-pyrazine-2,3-dicarbontrile?Pyz-4?.2-Amino-9,10,16,17,23,24-hexafuryl-hexanitrogen zinc tripyrazinoporphyrazine?Ami-1?,2-Amino-9,10,16,17,23,24-hexa?2-thiophen?-hexanitrogen zinc tripyrazinoporphyrazine?Ami-2?,2-Amino-9,10,16,17,23,24-hexaphenyl-hexanitrogen zinc tripyrazinoporphyrazine?Ami-3?,2-Amino-9,10,16,17,23,24-hexa?4-methylphenyl?-hexanitrogenzinctripyrazinoporphyrazine?Ami-4?were synthesizedbyPyz-1,Pyz-2,Pyz-3,Pyz-4with4-aminophthalonitrile self-syclotetramerization,respectively.At last,2-?4-carboxyphenyl?amino-9,10,16,17,23,24-hexafuryl-hexanitrogen zinc tripyrazinoporphyrazine?TPP-1?,2-?4-carboxyphenyl?amino-9,10,16,17,23,24-hexa?2-thiophen?-hexanitrogen zinc tripyrazinoporphyrazine?TPP-2?,2-?4-carboxphenyl?amino-9,10,16,17,23,24-hexaphenyl-hexanitrogenzinc tripyrazinoporphyrazine?TPP-3?,2-?4-carboxyphenyl?amino-9,10,16,17,23,24-hexa?4-methyl-phenyl?-hexanitrogen zinc tripyrazinoporphyrazine?TPP-4?were prepared by benzyl acid was introduced into Ami-1,Ami-2,Ami-3,Ami-4 with amine bond.The target compounds were characterized by FTIR,¹H NMR and elemental analyses.The characterization data of the compounds was consistent with the assigned formula.The absorption of properties of four kind zinc tripyrazinoporphyrazines were investigated according to the Uv-Vis spectroscopy recorded in DMF solution.The Q bands of TPP-1^TPP-4 have red-shift 12nm,10nm,9nm,12nm compared with Ami-1^Ami-4 and molar extinction coefficient were reduced.The study of different substituents found that TPP-1 and TPP-2 are more obvious red-shift than those of TPP-3 and TPP-4 due to the heteroatom ring has more lone pair.Compared to the unsubstituted phthalocyanine,the four tripyrazinoporphyrazines exhibited medium-intensity spectral absorption at 400-500 nm.The aggregation of the four target molecules at different concentrations was determined by UV-visible light spectroscopy,indicating that in this range of solubility,TPP-1,TPP-2,TPP-3,and TPP-4 all mainly exist in monomeric form.Cyclic voltammetry was used to study the electrochemical performance of tripyrazinoporphyrazines zinc.Four kinds of tripyrazinoporphyrazines zinc have similar cyclic voltammograms and the LUMO and HOMO energy levels were calculated.The results show that the LUMO energy level of zinc hexaazaphthalocyanine is about 0.5⁰.6V higher than that of nano-TiO₂,which can be helpful for excited electrons and provide power.Another,it can avoid level waste.The tripyrazinoporphyrazines zinc has a lower HOMO level than the electrolyte I^-/I₃^-,which suppresses the recombination of electrons and acceletate dye regeneration.