Effect of different imidazole derived moieties on the photo- and electro-luminescence properties of 2,7,12-trisubstituted triazatruxene derivatives

Abstract

Three 2,7,12-trisubstituted triazatruxene derivatives containing different imidazole derived moieties, 5,10,15-tributyl-2,7,12-tris(4-(1-(4-(tert-butyl)phenyl)-1H-phenanthro[9,10-d] imidazol-2-yl)phenyl)-10,15-dihydro-5H-diindolo[3,2-a:3′,2′-c]carbazole (2,7,12-TPI-TAT), 5,10,15-tributyl-2,7,12-tris(4-(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl)-10,15-dihydro-5H-diindolo[3,2-a:3′,2′-c]carbazole (2,7,12-TBI-TAT) and 5,10,15-tributyl-2,7,12-tris(4-(1-(4-(tert-butyl)phenyl)-4,5-diphenyl-1H-imidazol-2-yl)phenyl)-10,15-dihydro-5H-diindolo[3,2-a:3′,2′-c]carbazole (2,7,12-TIM-TAT), were synthesized by grafting different imidazole derived moieties with different electron-withdrawing abilities onto the 2-, 7- and 12-positions of a triazatruxene (TAT) core. A combination of thermal, photophysical and electrochemical characterization studies of these compounds was conducted to investigate the influence of different imidazole derived moieties on the optoelectronic properties of the compounds. Furthermore, solution-processed doped and nondoped devices based on the compounds were fabricated, in which the doped device of 2,7,12-TPI-TAT exhibited the best device performances, while the nondoped device of 2,7,12-TBI-TAT showed the best device performances.