Synthesis of polyimides containing tetraphenylporphyrin moieties

Abstract

5, 15-Bis(4-aminophenyl)-10,20-diphenylporphyrin (trans-DATPP) was synthesized via the condensation of meso-(4-introphenyl)dipyrromethane and benzaldehyde. The further reaction with zinc acetylacetonate hydrate afforded zinc 5,15-bis(4-aminophenyl)-10,20-diphenylporphyrin (trans-ZnDATPP). The identification of both synthesized compounds and their intermediates was performed by spectroscopic technique. Four series of solube polyimides based on trans-DATPP or trans-ZnDATPP, 2,2' bis(trifluoromethyl)-4,4'-diaminobiphenly (PFMB), 4,4'-hexafluoroisopropylidene-diphthalic anhydride (6FDA) and 3,6-bis(3-trifluoromethylphenyl)pyrromellitic dianhydride (3FPMDA) at various ratios were then prepared. The structures of these polyimides were confirmed by FTIR and 1H-NMR, and porphyrin content in polyimides was determined by UV-vis spectroscopy. It was found that most polyimides containing either trans-DATPP or trans-ZnDATPP had higher viscosity than the polyimidewithout porphyrin moiety. In addition, the polyimides containing trans-ZnDATPP showed lower viscosity and higher glass transition temperature (Tg) than the ones containing trans-DATPP at approximately the same porphyrin content and both had higher Tg than polyimide without porphyrin. These polyimides displayed good thermal stabilities when subjected to thermogravimetric analysis. All polyimides were solube in polar aprotic solvents, THF, CH2CL2 AND acetone. Steady state fluorescence spectroscopy of these polyimides were investigated, electrochemical and time-correlated single photon counting experiments of the representative polymides indicated that these polyimides could be used in photomic applications.