The development of organic materials with white-light emission and thermally activated delayed fluorescence (TADF) properties in the solid state remain a challenge. Herein, a series of white-light-emitting organic luminogens have been developed and are found to show aggregation-induced delayed fluorescence (AIDF) characteristics. The AIDF emitters present dual-emission consisted of prompt fluorescence and TADF in the crystalline state. Their white-light emissions can be easily tuned by altering the chemical structure and connecting position of the heterocyclic aromatic substituent. Under the stimuli of mechanical force and solvent vapor, the compounds exhibit remarkable and reversible mechanochromism, in which their emission colors are switchable between white and yellow. Upon grinding, they also display linearly tunable luminescence colors, as well as force-induced TADF enhancement, which may be associated with the more compact molecular packing and the restriction of intramolecular motions. The results from time-resolved emission scanning and theoretical calculation suggest that the dual-emission of the AIDF luminogens likely results from the twisted intramolecular charge transfer transitions of the molecules, and the reversible mechanochromism properties probably stem from the interconversion of the quasi-axial and the quasi-equatorial conformations.

开发具有白光发射和固态热激活延迟荧光（TADF）特性的有机材料仍然是一个挑战。在此，已经开发了一系列发白光的有机发光体，并发现它们具有聚集诱导延迟荧光（AIDF）特性。AIDF发射器呈现双发射，由瞬发荧光和结晶态TADF组成。通过改变杂环芳族取​​代基的化学结构和连接位置，可以很容易地调节它们的白光发射。在机械力和溶剂蒸气的刺激下，这些化合物表现出显着的可逆机械致变色性，其发光颜色可在白色和黄色之间切换。研磨后，它们还显示出线性可调的发光颜色，以及力诱导的 TADF 增强，这可能与更紧凑的分子堆积和分子内运动的限制有关。时间分辨发射扫描和理论计算的结果表明，AIDF发光体的双重发射可能是由于分子的扭曲分子内电荷转移跃迁，而可逆的机械致变色性质可能源于分子间的相互转换。准轴构象和准赤道构象。