Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, P. R. China.
Chem Asian J. 2020 Nov 2;15(21):3469-3474. doi: 10.1002/asia.202000965. Epub 2020 Sep 29.
Manipulation of supramolecular behaviors and aggregation states represents an important topic in devising intriguing photofunctional systems. Here we report a two-component macromolecular self-assembly strategy for achieving aqueous room-temperature phosphorescence (RTP) in purely organic systems. Amphiphilic triblock copolymers are used to modulate the self-assembly of planar RTP molecules in aqueous solution, leading to the formation of sheet-like RTP objects with well-defined morphology, uniform crystalline nanostructures and excellent aqueous dispersity. In contrast, the addition of the planar RTP molecules into aqueous medium only leads to precipitation and quenching of RTP properties. Powder X-ray diffraction and single-crystal X-ray diffraction studies reveal that the amphiphilic triblock copolymers can assist supramolecular columnar packing of the planar RTP molecules where multiple non-covalent interactions stabilize the triplet excited states. Interestingly, it is found that luminescent signals of the sheet-like RTP objects can be extracted from strong fluorescent environments by phosphorescence mode and emission lifetime measurement.
超分子行为和聚集态的调控是设计有趣的光功能体系的一个重要课题。在这里，我们报道了一种两亲性嵌段共聚物的自组装策略，用于在纯有机体系中实现室温磷光（RTP）。两亲性嵌段共聚物用于调节平面 RTP 分子在水溶液中的自组装，导致形成具有良好形貌、均匀结晶纳米结构和优异水分散性的片状 RTP 物体。相比之下，将平面 RTP 分子加入水相只会导致 RTP 性质的沉淀和猝灭。粉末 X 射线衍射和单晶 X 射线衍射研究表明，两亲性嵌段共聚物可以辅助平面 RTP 分子的超分子柱状堆积，其中多种非共价相互作用稳定三重态激发态。有趣的是，发现片状 RTP 物体的发光信号可以通过磷光模式和发射寿命测量从强荧光环境中提取出来。
