Preparation And Properties Research Of Porphyrin Derivitives In Dye-sensisized Solar Cell

As a new type of organic solar cells, dye-sensitized solar cells have a bright future and great potential for development. And porphyrin received wide attention in the application as sensitive dyes for its unique photophysical and chemical properties. In this paper , 1,3-dipolar cycloaddition was applied in the modifying of porphyrins to give four porphyrin dyes with carboxyl, whose photoelectron conversion properties have also been studied.The stable porphyrin triphenylphosphine has been synthesized by formylation, reduction, chloromethylation and condensation in theβposition of tetraphenylporphyrin. And then ester group was introduced through the Wittig reaction between porphyrin triphenylphosphine with methyl 4-formylbenzoate.Then the corresponding zinc porphyrin have been obtained by metalation. 2-[3'-(2,6-dichloro)phenyl-5'-(methyl 4-formate-based)phenyl-4',5'-dihydro -isoxazole] zinc tetraphenylporphyrin 13a and 2-[3'-(2,4,6- trimethyl)phenyl-5'- (methyl4-formate-based)phenyl-4',5'-dihydro-isoxazole] zinc tetraphenylporphyrin 13b have been prepared separately via the 1,3-dipolar cycloaddition reaction between zinc porphyrin and 2,6-dichlorophenyl nitrile oxide and 2,4,6-trimethylphenyl nitrile oxide. And finally target compounds with carboxyl was received from 13a-b by ester hydrosis. Compound 13a was characterized by its crystal structure. And the result demonstrated that the reaction position of 1,3-dipolar cycloaddition was ethenyl but not pyrrole ring.5,10,15,20-(methyl 4-formate-based) tetraphenylporphyrin was prepared by Alder method, which then reacted with two dipoles 12a-b via 1,3-dipolar cycloaddition to get corresponding dihydroporphins and tetrahydro-porphines. Then corresponding metal porphins were prepared by two means in which only dihydro-metal porphins were got. One metod is to get dihydro-metal porphins from dihydroporphins by metalation and the other is to receive them by the 1,3-dipolar cycloaddition between zinc porphyrin and corresponding dipoles. And the former has a higher yield. Try to completely and partially hydrolyzed dihydro-metal porphins to get final products with carboxyls.Spectra analysis and photoelectron conversion properties have been studied on porphyrin dye moleculars with carboxyls in theβ-position 14a-b and porphyrin dye moleculars with carboxyls in the meso-position 21a-b. The UV spectra showed that compound 14a-b had the same absorption as zinc tetraphenylporphyrin for the reason that electronic transmission of conjugation was destroyed. But the UV absorption of compound 21a-b were strengthened and had a obvious red shift because that the cycloaddition of pyrrole ring reduced greatly the symmetry of parent porphyrin ring. Similar with UV spectra, the fluorescence emission strength of 14a-b were weaken and 14a-b were increased. The fluorescent lifetime of 14a,14b,21a and 21b were 1.73ns,1.74ns,1.54ns and 1.52ns, which were all much longer than 0.1-10ps that the excited state electron was injected into TiO2 conduction band. And optical performance testing demonstrated that the photoelectron conversion efficiency of 21a-b were higher than 14a-b...