以纳米容器为基元的超分子晶态材料构筑及功能研究

Nanocontainers are the materials which have nanoscale cavities encapsulating the guests. As host materials, they are applied widely in the fields such as guest-recognition, active species-stabilization, catalysis, reaction mechanism illustration, etc.. This project plans to construct a continuous three-dimensional networked anionic supramolecular crystalline MOF materials by the secondary assembly of a discrete water-soluble polyphenols nanocontainer, realize the controlled hierarchical supramolecular assembly, and provide a new strategy for the design and preparation of novel catalytic materials. Meanwhile, the different performances in host-guest recognition and catalysis will be analyzed before and after the secondary assembly, when the materials are present in the solution phase and in the solid state, respectively. The intrinsic link between solution supramolecular chemistry and solid state supramolecular chemistry will be explored. On the other hand, with the aid of in situ snapshot technique of single-crystal diffraction, we expect to more intuitively observe the precise models of the host-guest interactions and capture the labile reaction intermediates which not under normal conditions. The visualization of chemical reactions provides a possible way to clarify the internal mechanisms of the reactions, especially, involving in cations. This also provide a guidance to improve the rate and selectivity of chemical reactions.

纳米容器是一类具有能够包覆客体物种的纳米级空腔的材料，其作为主体材料，在客体识别、稳定活泼物种、催化、反应机理研究等领域有着广泛的应用。本项目拟由离散的水溶性的多酚纳米容器通过二级组装的方法构建具有三维网络结构的阴离子型超分子晶态MOF材料，实现超分子的分级可控组装，为新型催化材料的制备提供一种新策略。同时分析其在二级组装前后，溶液和固体两种形态下对于主客体识别及催化性质等方面的差异，探讨溶液超分子化学和固态超分子化学的内在联系。另一方面，借助于单晶衍射的“原位瞬态照相”技术，更加直观的观察到纳米容器内主客体相互作用的精确模型，捕捉到常规条件下无法捕获的活性反应中间体，实现化学反应的可视化，进而为证明涉及到阳离子参与的化学反应的内在机理提供一种可能的途径，也为提高化学反应的反应速率和选择性提供指导。

纳米容器由于具有能够包覆客体物种的纳米级空腔，常被用于负载、稳定、分离、检测、催化等应用。通过纳米容器二级组装的过程，可以模拟自然界，有助于对自然界分级、有序自组装的理解，并为新型材料的制备提供一种新思路。本项目在离散的纳米容器的设计构筑与功能化应用及其二级组装方面展开了探索研究。我们设计构筑了一系列的离散的纳米容器，分别研究了配体结构的调控对稀土有机纳米容器结构的系统性演变和发光性质的影响及其在传感检测和稀土分离领域的应用、钯基金属-有机大环的阴离子诱导匹配自组装及其互相转化、吡啶鎓盐水溶性“纳米容器”超分子仿生催化，取得了若干研究成果。但在进行二级组装构筑三维晶态材料方面，由于前期走过一些弯路，相关研究有点滞后。改变策略之后的相关工作仍然在推进中。我们发展了分步组装、诱导匹配自组装等新的自组装合成手段，为发光无机有机杂化材料、新型分子探针、纳米催化等材料的开发等提供了新型超分子材料设计策略。