手性螺旋聚（间亚苯基亚乙炔基）的合成及离子识别性能

Helical poly(meta-phenyleneethynylene)s(meta-PPEs) have attacted much attention due to application in areas such as the development of circularly polarized photo- and electroluminescent materials and enantioselective sensors and/or catalysts. The main chain of helical meta-PPEs can interact with molecular and exhibit molecular recognition and sensing properties. However, lacking ion recognition groups and only using π-conjuagted main chain as reporting groups lead to low ion recognition and sensing properties. .From the combination of ion recognition groups into the side chain of chiral meta-PPEs, we can expect the ion recognition groups arrange regularly around the helix and interact with ion and improve the ion recognition properties of optical active meta-PPEs. At same time, incorporation of photoelectric functional groups such as azobenzene, TEMPO and ferrocene into the side chain of helical meta-PPEs, we can combine the CD singal, fluorescence and photoelectric signal together to increase the ion sensing properties. The objective of this work is to prepare novel helical meta-PPEs featuring ion recognition and/or functional groups and study the chiroptical, optical, photoelectric and ion recognition properties of obtained polymers..In this work, we attemp to deseign and synthesize 3',5'-diiodo-L-tyrosine derivatives carrying ion recognition groups (such as urea,thiourea, sulfonylurea,sulfonylthiourea and sulfonamide) and/or photoelectric functional groups (such as azobenzene, TEMPO and ferrocene), polymerize tyrosine derivatives with diethynylbenzene to obtain chiral meta-PPEs. The CD and UV-vis spectroscopic will be measured to confirm whether meta-PPEs containing ion recognition and/or functional groups fold into a helical conformation. The change of fluorescence and UV-vis spectroscopic of polymers addition with ion will be meausred. The responsiveness of chiroptical and photoelectric properties to the external stimuli and ion will be researched. The influence of helical conformation, ion recognition groups and functional groups on the ion recognition and sensing properties will be examined. This study will provide the guide for the synthesis of novel helical meta-PPEs and pave the way for potential applications of these materials in chemical sensors.

螺旋聚（间亚苯基亚乙炔基）衍生物(meta-PPEs)是著名的螺旋聚合物，其螺旋共轭主链可以和客体分子相互作用，实现分子识别和传感，引起广泛的研究兴趣；存在其对客体分子的识别能力不强，信号报告基团单一，传感能力不高等缺点。本课题以3'，5'-二碘-L-酪氨酸为原料，设计合成新型手性螺旋meta-PPEs；将（硫）脲、磺酰（硫）脲等离子识别基团引入其侧链，使识别基团沿螺旋主链在立体空间规则排列，增强其离子识别性能；在其侧链上引入偶氮苯、二茂铁等功能基团，将园二色光谱、荧光和光电信号结合，提高其离子传感能力。探明螺旋结构、识别基团与功能基团等对离子识别和传感的作用机制及演化规律，揭示其离子识别机理。研究结果不仅在新型手性螺旋PPEs设计合成的理论上有所突破，丰富高分子、材料和超分子化学等相互交叉学科领域的学术内容，而且为离子传感器的设计合成提供必要的理论指导，促进我国化学传感器的应用与发展。

离子在生命科学和化学过程中扮演着重要角色，在生物学、病理学和环境监测等领域都起着重要作用。因此设计合成选择性好、灵敏度高的离子探针近年来受到了极大的关注。聚（间亚苯基亚乙炔基）衍生物(meta-PPEs)是著名的共轭聚合物，具有良好的吸光性能和荧光特性；硫脲和2-硫代海因是良好的氢键供体，可作为离子的识别基团，两者结合可制备出离子探针。设计合成新型含有硫脲聚（间亚苯基亚乙炔基）探针poly(1)、2-硫代海因探针2和3，萘基2-氰基丙烯酸酯探针4，利用红外光谱（IR）和核磁共振光谱（NMR）表征了单体和聚合物结构。这些探针均能特异性识别阴离子，当加入氟离子后，探针溶液颜色发生明显变化，紫外-可见吸收光谱吸收峰产生明显红移或生成新吸收峰。核磁滴定结果表明，探针上的硫脲和2硫代海因基团识别基团与阴离子形成氢键和/或产生去质子化作用，导致探针的颜色和荧光变化。poly(1) 对F-有比色和荧光响应，对Ag+也有荧光识别能力。poly(1)/ Ag+体系还可以进一步用于ADP的荧光检测。2-硫代海因探针2和3对F-有较高的灵敏度和较强的识别能力。由于酚羟基OH和NH的酸性和形成氢键能力的差异，2-硫代海因探针3 对F-的识别分为两个过程。探针3还可以在固态条件下作为检测F-的化学传感器，这种易于制备的氟离子检测试纸检测极限低至1.9ppm(1.9μg•L-1)。探针4在水溶液中对氟离子具有荧光识别效果，还可以应用为活体细胞荧光成像和检测细胞内的氟离子。研究结果已发表SCI论文3篇，申请中国发明专利1项，为含硫脲或2-硫代海因聚（间亚苯基亚乙炔基）子识别探针的制备提供理论基础。