苯并硒二唑单元调控的D-π-A型低能带隙手性共轭高分子荧光传感器的设计、合成与性质研究

A series of D-π-A chiral conjugated polymer fluorescent sensors with regular structure and low band gap are constructed by alternating benzoselenadiazole acceptors and various chiral recognition units, such as binaphthol, etc, via vinylenyl bridge. These chiral polymer fluorescent sensors are excepted to exhibit high selectivity and sensitivity for various chiral molecules, such as hydroxy acid, amino alcohols and concanavalin A, etc, by the synergistic effect of the spatial structures and electronic effects of the chiral recognition units and the interaction between the chiral recognition sites with the conjugated skeletons of the polymers. We try to regulate the band gaps of these polymers by introducing the benzoselenadiazole unit to their conjugated skeletons and expect to achieve a breakthrough that their emission wavelengths red shift to the red region, which is beneficial for their fluorescence imaging for chiral molecules in cells. We try to clarify the regulatory mechanisms of fluorescence enhancement or quenching. These results can provide the theoretical basis for the design of novel chiral conjugated polymer fluorescent sensors. The implementation of the project is an important development in the field of chiral conjugated polymer fluorescent sensors and expected to provide new ideas for the design and synthesis of novel chiral conjugated polymer fluorescent sensors with excellent performance.

本项目通过引入苯并硒二唑结构单元为电子受体、以炔键为共轭桥、以联萘酚等为手性识别单元，设计并合成一系列结构规整、高级有序的D-π-A型低能带隙手性共轭高分子荧光传感器。通过改变手性识别单元的空间结构和电子效应以及调控识别位点与高分子共轭骨架间的相互作用产生协同效应，实现其对各种羟基酸、氨基醇、伴刀豆球蛋白A 等手性分子高选择性和高灵敏度的识别；通过苯并硒二唑单元调控高分子的能带隙，实现了该类手性共轭高分子发射波长红移至红光区域的突破，并将其应用范围扩大至细胞内手性分子的荧光成像；阐明荧光增强或猝灭的控制机制，为进一步探索、设计新型手性共轭高分子荧光传感器提供理论基础。项目的实施，将是对手性共轭高分子荧光传感器研究领域的重要发展和补充，同时也为结构新颖、性能优异的手性共轭高分子荧光传感器的进一步开发提供可借鉴的新思路。

本研究以4H-吡喃/1,4-二氢吡啶为基本的结构单元，以茚-1,3-二酮、米氏酸、巴比妥酸、丙二腈和氰基乙酸乙酯等吸电子单元为电子受体，以各种取代苯、萘和吲哚等芳杂环为电子给体合成了多个系列的D-π-A型4H-吡喃/1,4-二氢吡啶类共轭有机荧光分子。研究了所得共轭荧光分子的光物理性质，发现多个系列的目标化合物展现出聚集诱导发光性质，其固态样品发射涵盖从蓝色到红色的荧光，阐明了这些化合物结构与光物理性质之间的关系。研究了这些化合物在荧光传感领域方面的应用，阐明了荧光刺激响应性质的作用机制，实现了对目标分子响应能力的有效调控，筛选出了一系列对压力、温度、有机溶剂、酸性气体和金属离子等外在刺激表现出高对比度、高灵敏度和可逆性的新型荧光传感材料，并可应用于可重写光学介质的设计、分子逻辑门的构建以及荧光细胞成像等领域。本项目的研究结果是有机荧光传感材料研究领域的重要发展和补充，同时也为结构新颖、性能优异的有机荧光传感材料的进一步开发提供了可借鉴的新思路。