具有多重自组装功能的主体分子的设计合成及其竞争调控识别机制研究

How to improve the recognition selectivity of chemosensor for certain guest is a challenge. General research focused on the modification of binding sites of the chemosensor to improve the recognition selectivity. This project introduced the “competitive self-assembly control model” into the design of chemosensor to improve the recognition selectivity and signal reporting ability. The key point of the “competitive self-assembly control model” is as follow: by rational introducing the multi self-assembly sites into the chemosensor, the chemosensor could be in certain self-assembly state with certain fluorescent and colorimetric properties. When the chemosensor meet the guest molecules or ions, some guest will involve the self-assembly of the chemosensors’ and induce a change of the chemosensors’ self-assembly state and optical properties, which lead to the specific selective recognition of certain guest. According to this “competitive.self-assembly control model”, this project will design and synthesize a series of chemosensors which contain multi self-assemble sites. By carefully study the self-assembly property and ions recognition property in different solvents, the chemosensors with specific selectivity for certain molecule or ion could be pick out. These chemosensors could act as the specific selective chemosensor for those guest ion or molecule. The fluorescent and colorimetric recognition ability of the chemosensor will be studied systematically. This project will also carefully study the “competitive self-assembly” host-guest recognition mechanism as well as the influence of chemosensors’ structure on the self-assembly and host-guest recognition. This project has the promising application perspective and important academic value in host-guest reognition field.

提高传感器分子对特定客体的选择性是超分子主客体识别研究的难点。传统研究主要通过改进传感器分子结合位点以提高其识别选择性。本项目在传感器分子的设计中引入了“竞争自组装控制模式”来提高传感器分子对特定客体的识别选择性和信号报告能力。该模式的思路是：在传感器分子中引入多种自组装位点，使传感器分子处于一种自组装状态，并具有一定的荧光、颜色等光学性质。当遇到特定客体分子或离子时，客体通过一定的方式竞争参与传感器分子的自组装，使其自组装状态改变，导致其光学性质变化，从而实现对特定客体的选择性识别。根据这一思路，本项目将设计合成多个系列的具有多重自组装位点的传感器分子，研究其在不同溶剂中的自组装性能，并系统研究其对常见阴离子及金属离子的识别性能。筛选出能对特定客体有单一选择性荧光、比色识别性能的传感器分子，并系统研究其“竞争自组装”识别机理和构效关系，这在分子、离子识别领域具有重要的应用价值和学术意义。

在超分子化学的研究中，主客体化学是超分子化学研究的基础，而自组装是超分子化学的核心。提高主客体组装的选择性是超分子化学研究的难点。传统研究主要通过改进主体分子结合位点以提高其识别选择性。本项目在主体分子的设计中引入了多种弱相互作用协同的竞争自组装模式来提高主体分子对特定客体的识别选择性、灵敏性和信号报告能力。该模式的核心思路是在主体分子中引入多种自组装位点，使主体分子通过多种弱相互作用的协同产生自组装。这种自组装状态具有一定的荧光、颜色等光学性质。当遇到特定客体分子或离子时，客体通过一定的方式竞争参与上述的自组装体系，使其自组装状态改变，导致其光学性质变化，从而实现对特定客体的选择性识别。本项目成功设计合成了以柱芳烃、吩嗪、萘酰亚胺为主的多种超分子主体分子，系统研究了其自组装性能、聚集诱导发射性能和超分子刺激响应性能。并通过多种实验手段和密度泛函理论系统研究了其自组装机理和传感识别机制。创新性的通过利用柱芳烃、吩嗪、萘酰亚胺类主体与客体间的“阴离子-π”作用、“阳离子-π”作用、“外墙-π”作用、多重氢键作用之间的协同效应，实现了对汞、铁、氰根、铜等离子和染料分子、氨基酸分子等的高灵敏检测以及吸附分离。与此同时，制备了相应的离子检测试纸或吸附分离材料。研制的部分超分子主体可用于细胞中的离子检测或细胞荧光成像。因此，该项目不仅丰富了超分子主体的设计思路，为超分子主体化合物的设计合成和刺激响应性能调控提供了一定的经验，而且在智能荧光材料以及生物成像方面具有广阔的应用前景。