Synthesis,Properties And Application Of Triphenylamine Derivatives

Triphenylamine（TPA）and its derivatives have good hole transporting ability with great application prospects.In this paper,a series of novel triphenylamine derivatives were designed and synthesized to expand their application prospects.They are N,N,N-tris[4-（5-formyl-3,4-ethylenedioxy-2-thienyl）]phenylamine（TPA3E-3CHO）,N,N,N-tris[4-（5-dicyanovinyl-3,4-ethylenedioxy-2-thienyl）]phenylamine（TPA3E-6CN）and N,N,N-tris[5’-（2"-cyano-N-octadecylacetamide）-3’,4’-ethylenedioxy-2’-thienyl]phenylamine（TPA3E-3NC₈）.The structures were characterized and confirmed by MS,NMR and FTIR.Molecular structures of target compounds are aRsS fOoOllows:By means of TG,TPA3E-3CHO,TPA3E-6CN and TPA3E-3NC₈ show good thermal stability and their thermal decomposition temperatures are 338°C,348°C and 362°C.The photoelectric properties of triphenylamine derivatives were also investigated by UV-vis,CV and FL.Their edge wavelength,optical bandgap,initial redox potential,electrochemical bandgap,HOMO and LUMO energy levels and fluorescence quantum efficiency were calculated.The electrochemical bandgap were 1.44 eV、1.41 eV and 1.31 eV,respectively.The target compounds were used as donor materials to prepare organic photovoltaic devices（device structure:ITO/triphenylamine derivatives/PTCDA/Al）.The power conversion efficiency（PCE）of the devices were 0.16%,0.05%,and 0.27%,respectively.It was found that the intermolecular hydrogen bond formed between donor and acceptor facilitated the transport and migration of carriers.The open circuit voltage was greatly increased with the introduction of the amide group,which can improve the PCE of the devices.The target compounds were also used as active materials to assemble electrochromic devices（ECD）and their structure was ITO/liquid or gel electrolyte containing triphenylamine derivatives/ITO.ECD based on TPA3E-3CHO,TPA3E-6CN and TPA3E-3NC₈ showed bright yellow to brownish yellow,rose red to light yellow and orange to yellow under the applied electric field.The highest optical contrast is 44.9%,20.0%and 31.0%,the coloring time is 0.3s,1.9 s and 3.7 s,the fading time is 0.3 s,1.2 s and 0.4 s,respectively.