Acta Chimica Sinica ›› 2021, Vol. 79 ›› Issue (11): 1401-1408.DOI: 10.6023/A21070355 Previous Articles     Next Articles

Article

基于八氢联萘酚的大位阻手性发光材料构建及光电性质研究

梁志鹏, 唐瑞, 邱雨晨, 王阳*(), 陆洪彬*(), 吴正光*()   

  1. 南通大学化学化工学院 南通 226019
  • 投稿日期:2021-07-31 发布日期:2021-09-13
  • 通讯作者: 王阳, 陆洪彬, 吴正光
  • 基金资助:
    项目受国家自然科学基金(22005158); 项目受国家自然科学基金(22072068)

Construction and Properties of Octahydrobinaphthol-based Chiral Luminescent Materials with Large Steric Hindrance

Zhi-Peng Liang, Rui Tang, Yu-Chen Qiu, Yang Wang(), Hongbin Lu(), Zheng-Guang Wu()   

  1. School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China
  • Received:2021-07-31 Published:2021-09-13
  • Contact: Yang Wang, Hongbin Lu, Zheng-Guang Wu
  • Supported by:
    National Natural Science Foundation of China(22005158); National Natural Science Foundation of China(22072068)

Using chiral luminescent material as the emitting core in organic light-emitting diodes (OLEDs) would make these devices possess circularly polarized electroluminescence (CPEL) performance, namely CP-OLEDs, which are of great value for facilitating the development of the next generation of display technologies, especially for implementing real 3D display. In this study, a pair of octahydrobinaphthol (OBN)-based thermally activated delayed fluorescence (TADF) materials, (S/R)-OBN-tBuCz, are developed by ingeniously merging a chiral source (OBN) and a luminophore skeleton (tert-butylcarbazole cyanobenzene). The peripheral sixteen hydrogen atoms in cyclohexane part of OBN unit and the larger tertiary butyl group could effectively increase the steric hindrance of chiral luminescence molecules, reduce the intermolecular stacking effect and inhibit concentration quenching, for effectively improving the luminescence efficiency of the devices. The synthesized chiral luminescent materials exhibit bright green light emission (523 nm), high photoluminescence quantum yield (85.2%), a small ΔEST of 0.05 eV with TADF property as well as excellent thermal stability. The chiroptical properties of (S/R)-OBN-tBuCz enantiomers in the ground and excited states are investigated by circular dichroism (CD) and circularly polarized luminescence (CPL) spectra, and the strong symmetrically circularly polarized luminescent signals with gPL of +8.6×10-4 and –6.5×10-4 in toluene solution are observed for (S)-OBN-tBuCz and (R)-OBN-tBuCz, respectively, indicating that the chirality is successfully induced into the TADF skeleton through chirality transmitting of OBN unit. Considering the efficient TADF and CPL properties, the enantiomers are employed as chiral emitters for fabricating CP-OLEDs. The electroluminescent devices based on (S/R)-OBN-tBuCz exhibit decent performances with the turn-on voltage of 3.9 V, the maximum brightness of 27709 cd•m-2, the maximum current efficiency of 43.8 cd•A-1, the maximum power efficiency of 33.5 lm•W-1, the maximum external quantum efficiency of 12.4% and low efficiency roll-off as well as obvious circularly polarized electroluminescence signals with gEL of +1.57×10-3 and –0.90×10-3, respectively. The design strategy of rationally merging chiral source and TADF skeleton can promote the development of chiral luminescent materials and circularly polarized electroluminescent devices.

Key words: chiral luminescent material, circularly polarized luminescence, octahydrobinaphthol, large steric hindrance, circularly polarized organic light-emitting diodes