Synthesis And Properties Of Thiophene Polymer And Thiophene Derivatives

In this paper,the polymerization methods of thiophene polymers and their applications are reviewed firstly.In chapter 2 and chapter 3,five thiophene homopolymers and six new thiophene copolymers were prepared by Fe Cl₃ one-step method.In chapter 4,two new benzodithiophene derivatives were prepared by SUZUKI coupling reaction.The contents as follows:（1）Polythiophene（PTh）,Poly（3-hexylthiophene）（P3HT）,Poly（3-hexoythiophene）（P3HOT）,Poly（3-hepoxythiophene）（PHPOT）,Poly（3-（2-（2-（2-methoxyethoxy）ethoxy）ethoxy）thiophene）（PMET,side chain abbreviated to MPEG-3O）were prepared by Fe Cl₃ chemical oxidation.The properties of homopolymers were investigated in their photophysical property,thermal stability,electrical property,energy band gap,energy level and solubility.It was found that the solubility of PHPOT in chlorobenzene（7.0 mg/m L）was better than that of P3HT（0.1mg/m L）and PTh（insoluble）,and PMET had the best solubility because of its flexible side group MPEG-3O（73 mg/m L）.The comparison of HOMO energy levels showed that only PHPOT（-5.19 e V）was equivalent to P3HT（-5.20 e V）.At present,P3HT has been reported as a hole transport material for perovskite solar cells,so PHPOT is expected to be used in the hole transport layer of perovskite solar cells.Based on the above,we combined the advantages of three thiophene monomers,HPOT,MET and 3HT,respectively and three kinds of copolymers were synthesized,namely P（HPOT-3HT）,P（HPOT-MET）and P（HPOT-3HT-MET）.By comparing their properties（energy level and solubility）,it was found that the terpolymer P（HPOT-3HT-MET）containing alkyl,alkoxy and polyether groups（-5.19 e V,1.0mg/m L）may be used in hole transport materials for perovskite solar cells.（2）A new thiophene derivative monomer 2-（2-（2-methoxyethoxy）ethoxy）ethyl thiophene-3-carboxylate（MECT）was also synthesized.The results showed that the homopolymer of MECT could not be synthesized by Fe Cl₃ chemical oxidation or electrochemistry method respectively,which was attributed to the strong electron-absorbing group of the ester bond directly connected with thiophene ring.Three copolymers P（MECT-3HT）,P（MECT-HPOT）and P（MECT-HPOT-3HT）were obtained by copolymerization of MECT with active thiophene monomer 3HT or HPOT.The solubility（9.0 mg/m L）and energy level（-5.19 e V）of P（MECT-HPOT）were suitable.The electron-absorbing group ester bond has little effect on the energy level of the copolymer.（3）Two new benzodithiophene derivatives named 2,6-bistriphenylamine-4,8-bis（phenylethyl-oxy）benzo[1,2-B:4,5-B’]dithiophene（BDT-1-TPA）and 2,6-bistriphenylamine-4,8-bis（p-methoxy-phenylethyl-oxy）benzo[1,2-B:4,5-B’]dithiophene（BDT-2-TPA）were synthesized by SUZUKI coupling reaction and the purity of the products has yet to be improved.The structures and properties of these polymers and benzodithiophene derivatives were characterized by NMR,IR,thermogravimetric method,UV-Vis,electrochemical cyclic voltammetry（CV） respectively.