Copolymerization And Properties Of Benzodipyrrolidones And Benzothiophene Derivatives

D-A copolymer has wide application prospects because of its excellent intramolecular charge transfer(ICT)and controllable performance.Owing to the highly conjugated structure,strong electronic transmission capacity and easy modification,benzodipyrrolidone and benzothiophene unit are widely used in the preparation of D-A copolymers.Based on these reasons,a series of D-A copolymers were synthesized based on benzodipyrrolidone and benzodithiophene.While the influences of different electron-donating and electron-withdrawing ability and conjugated degree on photophysical and electronchemical properties were mainly studied.1.The copolymerization of benzodipyrrolidone derivatives and benzotrithiophene.Two different benzodipyrrolidone monomers——BDPP substituted by benzene and BDPT substituted by thiophene were designed and synthesized.Two different benzodipyrrolidone derivatives were Stille copolymerized with benzotrithiophene to obtain D-A copolymers PBDPP-BTT,PBDPT-BTT.The structure,molecular weight,absorption spectrum,electrochemical performance and thermal stability were discussed.In the film state,the absorption range of PBDPP-BTT is about 300-900 nm,the absorption peaks are 376 nm and 586 nm respectively.And the absorption range of PBDPT-BTT is 300-1200 nm,absorption peaks are 369 nm,755 nm.The electrochemical energy gap are 1.59 eV,1.34 eV respectively.Two polymers show good thermal stability and the thermal decomposition temperature is 314 ℃ and 360 ℃.2.The copolymerization of thiophene substituted benzodipyrrolidone derivative and alkoxy substituted benzodithiophene.BDPT which was used as acceptor,was copolymerized with benzodithiophene derivatives which has different conjugated degree BDT(OR)and BDTT(OR)to get PBDPT-BDT(OR)and PBDPT-BDTT(OR).The structure,molecular weight,absorption spectrum,electrochemical performance and thermal stability were discussed.And the study showed that the absortion spectrum of them were both range from 300 nm to 1000 nm in film.The absorption peaks of PBDPT-BDT(OR)are at 365 nm and 700 nm.While PBDPT-BDTT(OR)’s are 439 nm and 745 nm.The electrochemical energy gaps are 1.58 eV and 1.23 eV respectively.Two polymers show good thermal stability and the thermal decomposition temperature is 275℃ and 337 ℃.3.The copolymerization of benzodipyrrolidione derivative BDPT and thiophene(selenophene)substituted benzodithiophene.BDPT which was used as acceptor,was copolymerized with BDT(T),BDTT(T)and BDT(Se)to acquire PBDPT-BDT(T),PBDPT-BDTT(T),PBDPT-BDT(Se).The structure,molecular weight,absorption spectrum,electrochemical performance were studied.And the discussion showed that the absorption of these three polymers ranged from 300 nm to 1200 nm.The long wavelength absorption of PBDPT-BDT(T),PBDPT-BDT(Se)and PBDPT-BDTT(T)are 693 nm,692 nm,734 nm in film.The electrochemical energy gaps are 1.72 eV,1.38 eV,1.49 eV respectively.PBDPT-BDT(T),PBDPT-BDT(Se)and PBDPT-BDTT(T)show good thermal stability and the thermal decomposition temperature is 366 ℃,252 ℃,375 ℃.