Synthesis And Optical Characteristics Of Congugated Compounds Containing Triphenylamine Unit

Organic light-emitting diodes (OLED) materials have been widely considered with both the advantages of full-color, low energy consumption, fast response, wide viewing angle etc. It arouses great concern to the people and it is considered to be the leader of the next generation of large-size high-resolution displays and solid-state lighting panels.Based on the properties of better ability to supply electron,lower oxidation potential, higher hole-transporting rate, better dissolubility and amorphous film-forming ability, stronger fluorescence, triphenylamine units conjugated compounds were not only used as hole transport materials, but also used as the electron transport materials and light emitting materials.1. Synthesis of conjugated compounds containing triphenylamine unit(1)2-nitro fluorene (1a) and2-amino fluorene (1b) were synthesized through the nitration reaction and the reduction reaction using fluorene as the raw material,4,4’-diformyltriphenylamine(2a),4-formyl-4’-[(trans)-(4-me thylstyryl)] triphenylamine (3a),4-formyl-4’-[(trans)-(a-vinyl-naphthalene)] triphenylamine (3b),4,4’-[(trans)-(α-vinyl-naphthalene)] triphenylamine (3c) were synthesized through the Vilsmeyer reaction, Wittig reaction using triphenylamine as raw material;(2)4-(p-methylstyryl)-4’-(2-aminofluorenyl) methylenetriphenylamine(5a),4-(p-methylstyryl)-4’-(4-nitrophenyl) methyle-netriphenylamine(5b),4-(p-methylstyryl)-4’-(a-naphthylamine)methylenetri-phenylamine(5c), bis-[4-(p-methylstyryl)-4’-formyl-triphenylamine]phenyl-enediamine bis-Schiff base (5d) bis-[4-(p-methylstyryl)-triphenylamine]-4’-formyl biphenyl diamine bis-Schiff base(5e)1,4-bis-[4’-(trans)-(4-met-hylstyryl)-4"-N,N-diphenylaminostyryl] benzene(6a),1,4-bis-[4’-(trans)-(a-vinyl-naphthalene)-4"-N,N-diphenylaminostyryl] benzene(6b),4-formyl-4’,4"-bis-[(trans)-(a-vinyl-naphthalene)]triphenylamine(7a),4,4’-bis-[(trans)-(a-vinyl-naphthalene)]-4"-[(trans)-(4-methylstyryl)] triphenylamine(7b),4,4’-bis-[(trans)-(a-vinyl-naphthalene)]-4-[(trans)-(styryl)] triphenylamine (7c) were synthesized by means of the Vilsmeyer reaction, Wittig reaction, amine-aldehyde condensation reaction using triphenylamine as raw material. All of the synthetic intermediates and target compounds above were characterized by1HNMR,13CNMR and IR.The synthesis reaction conditions of intermed-iate3a and target product7a were optimized to determine the better reaction conditions.2. The study of the optical performance of5a-5e,6a-6b,7a-7c(1)The UV-Visible maximum absorption wavelengths of5a-5e,6a-6b,7a-7c were between380-420nm and they were in the visible region. And as the polarity of the solvent increases, the maximum absorption wavelength of UV has occurred a significant blue shift;(2)The maximum fluorescence emissi-on wavelengths of5a-5e,6a-6b,7a-7c were between440-540nm. As the increasing polarity of the solvent,5b showed red shift and5a,5c-5e showed blue shift;(3) The Stokes shift values of5a-5e,6a-6b,7a-7c were relatively small. The result shows that excited state molecules lose smaller energy and have higher luminous efficiency.