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[?,?'-?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.