A series of novel dendritic carbazole-functionalized subporphyrins, T(Cz-Gn)SubPs (n = 1–3), have been synthesized from pyridine–tri(pyrrol-1-yl)borane and the corresponding aldehydes. This study has demonstrated that intramolecular energy transfer from the carbazole dendron to the subporphyrin core occurs with a high efficiency which decreases with increasing dendron generation, in accord with the
3,6-Disubstituted carbazole building blocks are coupled via copper-catalyzed Ullmann reactions to afford trimeric and heptameric carbazoles with excellent solubilites in organic solvents. Alternatively, oligomeric carbazoles with phenylene spacers, that are more stable towards oxidation, can be obtained via palladium-catalyzed Suzuki coupling reactions. (C) 2003 Elsevier Science Ltd. All rights reserved.
Deep-blue thermally activated delayed fluorescence dendrimers with reduced singlet-triplet energy gap for low roll-off non-doped solution-processed organic light-emitting diodes
Compared with the reported small molecular TADF emitter bis[4-(3,6-di-tert-butylcarbazole)phenyl]sulfone (G1), dendrimers G2 and G3 inherited the blue light emission but exhibited a reduced singlet-triplet energy gap (ΔEST) with increasing the dendron generation. The efficient triplet-to-singlet (T1-to-S1) transition processes, excellent thermal and amorphous stabilities, good solution processability
开发了两种由二苯砜核和寡咔唑树枝状分子组成的TADF树枝状聚合物。与报道的小分子TADF发射体双[4-(3,6-二叔丁基咔唑)苯基]砜(G1)相比,树枝状聚合物G2和G3继承了蓝色发光,但单线态-三重态的能隙减小(Δ E ST),并增加树突的产生。高效的三重态到单重态(T 1到S 1)过渡过程,出色的热稳定性和非晶态稳定性,良好的溶液可加工性以及适当的HOMO / LUMO能级,这些树枝状聚合物可以用作溶液的非掺杂发射层。 OLED。的G2器件实现了深蓝光,其发射峰在428 nm处,CIE坐标在(0.15,0.12),并且在高电流密度下效率较低。
Carbazole dendronised triphenylamines as solution processed high Tg amorphous hole-transporting materials for organic electroluminescent devices
Carbazole dendrimers up to 4th generation were synthesized. They showed significantly high Tg, amorphous and stable electrochemical properties, and great potential as solution processed hole-transporting materials for OLEDs. Alq3-based green devices exhibited high luminance efficiency and CIE coordinates of 4.45 cd A−1 and (0.29, 0.53), respectively.