Synthesis And Photoelectric Properties Of Triarylamine Polymers

Triphenylamine（TPA）derivatives,including small molecules and polymers,are well-known candidates for hole transport materials and electrochromic materials due to their resulting stable radical cations.Polymers containing triphenylamine units are widely used in organic light-emitting diodes（OLED）,electrochromism devices（ECD）and memory devices（MD）,etc.In this paper,we therefore synthesized four kinds of novel poly（triphenylamine ether）sbyBuchwald-Hartwigcouplingreaction.Poly[N-p-phenoxy-N-[4-[2-（2-methoxyethoxy）ethoxy]ethoxy]triphenylamine（P1）and poly[N,N-bis（4-phenoxy）]triphenylamine（P2）were synthesized from the reaction of1,2-bis[β,β’-（p-bromophenoxy）ethoxy]ethane with 4-phenoxyaniline and p-Anisidine,respectively.Similarly,poly[N,N-bis（4-phenoxy）]triphenylamine（P3）and poly[N-（4-phenoxy）-N-（4-methoxy）]triphenylamine（P4）were synthesized from the reaction of bis（4-bromophenyl）ether with 4-phenoxyaniline and p-Anisidine.Besides,P1 and P2 are poly（triphenylamine alkyl ether）s;P3 and P4 are poly（triphenylamine aryl ether）s.The structures of polymers were determined by FT-IR spectrum,1H-NMR spectrum;The thermal properties of these polymers were investigated with thermal gravimetric analysis and all the polymers exhibit excellent thermodynamic stability;Cyclic voltammogram（CV）was recorded in two different electrolyte solution.0.1 M tetrabutyl ammonium perchlorate（TBAP）and p-toluenesulfonic acid（TsOH）in anhydrous acetonitrile was employed as the supporting electrolyte,respectively.In TBAP/CH₃CN electrolyte solution,P1 and P2 have two well-defined redox waves.The colour is changed from colourless to blue then to red.P3 and P4 only have one well-defined redox wave.The colour is changed from colourless to blue.In TsOH/CH₃CN electrolyte solution,all these polymers just have one well-defined redox wave and the colour is changed from colourless to blue.Furthermore,polymers were doped by TsOH for memory device applications.The resulting doped film exhibited non-volatile Flash resistive switching behavior with high ON/OFF ratio up to 10⁴ and a long retention time of 2.5×10³s.The results show that poly（triphenylamine alkyl ether）s（P1 and P2）and poly（triphenylamine aryl ether）s（P3 and P4）present huge differences in the field of electrochromism and resistive switching behavior,and have a perfect application prospect in the field of photoelectric.