Zhao Tingting, A Suru, Ma Yurong, Wang Nan, Liu Fangbin, Su Zhongmin
School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun, Jilin, 130022, China.
School of Chemistry and Environmental Engineering, Jilin Provincial Science and Technology Innovation Center of Optical Materials and Chemistry, Jilin Provincial International Joint Research Center of Photo-functional Materials and Chemistry, Changchun University of Science and Technology, Changchun, Jilin, 130022, China.
Chemistry. 2024 Oct 23;30(59):e202402290. doi: 10.1002/chem.202402290. Epub 2024 Oct 7.
Organoboron compounds offer a new strategy to design optoelectronic materials with high fluorescence efficiency. In this paper, the organoboron compound B-BNBP with double B←N bridged bipyridine bearing four fluorine atoms as core unit is facilely synthesized and exhibits a narrowband emission spectrum and a high photoluminescence quantum yield (PLQY) of 86.53 % in solution. Its polymorphic crystals were controllable prepared by different solution self-assembly methods. Two microcrystals possess different molecular packing modes, one-dimensional microstrips (1D-MSs) for H-aggregation and two-dimensional microdisks (2D-MDs) for J-aggregation, owing to abundant intermolecular interactions of four fluorine atoms sticking out conjugated plane. Their structure-property relationships were investigated by crystallographic analysis and theoretical calculation. Strong emission spectra with the full width at half maximum (FWHM) of less than 30 nm can also be observed in thin film and 2D-MDs. 1D-MSs possess thermally activated delayed fluorescence (TADF) property and exhibit superior optical waveguide performance with an optical loss of 0.061 dB/μm. This work enriches the diversity of polymorphic microcrystals and further reveals the structure-property relationship in organoboron micro/nano-crystals.
有机硼化合物为设计具有高荧光效率的光电子材料提供了一种新策略。本文中，以带有四个氟原子的双B←N桥连联吡啶为核心单元的有机硼化合物B-BNBP被 facilely 合成出来，并且在溶液中呈现出窄带发射光谱以及86.53%的高光致发光量子产率（PLQY）。通过不同的溶液自组装方法可控地制备了其多晶型晶体。由于四个氟原子伸出共轭平面形成丰富的分子间相互作用，两种微晶具有不同的分子堆积模式，一维微带（1D-MSs）用于H聚集，二维微盘（2D-MDs）用于J聚集。通过晶体学分析和理论计算研究了它们结构与性能的关系。在薄膜和2D-MDs中也能观察到半高宽（FWHM）小于30 nm的强发射光谱。1D-MSs具有热激活延迟荧光（TADF）特性，并且展现出优异的光波导性能，光损耗为0.061 dB/μm。这项工作丰富了多晶型微晶的多样性，并进一步揭示了有机硼微/纳米晶体中的结构-性能关系。
