Yu Changjiang, Cheng Chao, Liu Zhangzhan, Ni Zhigang, Zhao Zujin, Lu Hua, Hao Erhong, Jiao Lijuan
Key Laboratory of Functional Molecular Solids, Ministry of Education, School of Chemistry and Materials Science, Anhui Normal University Wuhu 241002 China
State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology Guangzhou 510640 China
Chem Sci. 2025 Mar 27;16(18):7971-7980. doi: 10.1039/d5sc01025j. eCollection 2025 May 7.
Molecular engineering is a reliable approach for the development of circularly polarized luminescence (CPL) materials for various applications. However, creating dual-state CPL platforms that possess chirality while achieving a delicate balance between molecular rigidity and flexibility remains a formidable challenge. In this study, a novel bisarylboron-anchored pyrrolylsalicylhydrazone (BOPSH) platform was synthesized a facile "one-pot" condensation. These key aryl-boron substituents not only provide structural rigidity to the fluorophore, enhancing the bright emission and suppressing emission quenching from π-π stacking in solid states due to their twisting and bulky steric effects, but also generate a boron-stereogenic center and enable strong CPL by promoting intramolecular charge-transfer transitions. As a result, these BOPSHs show intense absorption and strong dual-state emissions in both solution and solid states (with value approaching unity), emitting across the visible region with excellent chemical, photostability, and thermal stability. Meanwhile, their enantiomers display dual-state CPL performance, with luminescence dissymmetry factors ( ) up to 9.40 × 10, and CP electroluminescence (EL) with a dissymmetry factor ( ) of 3.07 × 10, along with excellent maximum external quantum efficiencies ( ) of 5.0%, approaching the theoretical limit for fluorescent molecules. We expect our study to break new ground in the construction of chiral dual-state materials with diverse structures.
分子工程是开发用于各种应用的圆偏振发光(CPL)材料的可靠方法。然而,创建具有手性同时在分子刚性和柔韧性之间实现微妙平衡的双态CPL平台仍然是一项艰巨的挑战。在本研究中,通过简便的“一锅法”缩合合成了一种新型的双芳基硼锚定的吡咯基水杨腙(BOPSH)平台。这些关键的芳基硼取代基不仅为荧光团提供结构刚性,由于其扭曲和庞大的空间效应增强了固态下的明亮发射并抑制了π-π堆积导致的发射猝灭,而且还产生了一个硼立体中心并通过促进分子内电荷转移跃迁实现强CPL。结果,这些BOPSHs在溶液和固态中均表现出强烈的吸收和强双态发射(g值接近1),在可见光区域发射,具有出色的化学、光稳定性和热稳定性。同时,它们的对映体表现出双态CPL性能,发光不对称因子(glum)高达9.40×10-3,CP电致发光(EL)的不对称因子(gEL)为3.07×l0-3,以及出色的最大外量子效率(EQE)为5.0%,接近荧光分子的理论极限。我们期望我们的研究在构建具有多样结构的手性双态材料方面开辟新天地。