基于正交自组装的多金属氧簇杂化超分子聚合物及其功能研究

Polyoxometalates (POMs) are nano-sized inorganic clusters with diverse topologies and multiple functions. However, due to their inorganic characteristic, POMs show poor miscibility to organic substrate and poor processability, which greatly limit their applications. Supramolecular polymers are polymeric aggregates in which building blocks are held together by non-covalent bonds or dynamic covalent bonds. These polymeric materials combine the processing property of polymers and the stimuli-responsiveness of soft matter. The integration of polyoxometalates and supramolecular polymers can combine the functions of polyoxometalates and the excellent soft matter characteristics and supramolecular self-assembly behavior of supramolecular polymers, and even generate synergistic functions. This research project aims to use the concept of orthogonal self-assembly to build organically modified polyoxometalate-based supramolecular polymers through the combination of organic modification of polyoxometalate and surfactant-based ionic self-assembly strategies. We will systematically study the influence factors on the self-assembly of these novel supramolecular polymers, such as polyoxometalate structure, organically modified functional groups and their interactions. Furthermore, we will focus on the study of relationship among building block, driving force, self-assembled structure and its modulation. Based on this, we will further study the relationship between the self-assembled structure of supramolecular polymers and the performance of polyoxometalates to achieve tunable properties of POM by their self-assembled structures, and pave a way to the functionalization and device application of polyoxometalates.

多金属氧簇是一类结构多样、功能丰富的纳米尺寸的无机簇合物。然而，其有机相容性较差、不易加工，严重限制了其应用。超分子聚合物是构筑基元通过非共价作用或动态共价键连接而成的聚集体，兼具高分子的可加工性和软物质的刺激响应特性。如何将多金属氧簇丰富的结构和功能与超分子聚合物优异的软物质特性和超分子组装行为相结合来构筑杂化超分子聚合物，甚至产生新的协同性能具有重要意义。本项目拟运用正交自组装的策略，将多金属氧簇有机修饰与表面活性剂离子自组装方法相结合来构筑有机修饰多金属氧簇基超分子聚合物。我们将系统地研究多金属氧簇结构、有机修饰基团、分子间相互作用等对超分子聚合物组装结构的影响，探讨构筑基元、驱动力和组装结构及其调控之间的相互规律。在此基础上，探索超分子聚合物组装结构与多金属氧簇功能性之间的关系，实现超分子聚合物组装结构对其功能的调控，为多金属氧簇的功能化和器件化开辟一条新的思路。

有机-无机杂化高分子是高分子和超分子化学研究的一个热点。其中的一个重要领域就是功能性无机构筑基元的引入和拓展。在本项目中，我们选择了结构多样、功能丰富的多金属氧簇为无机构筑基元，通过对其进行有机共价修饰改善其有机相容性和稳定性，进而通过正交自组装策略构筑多金属氧簇基有机-无机杂化高分子材料。首先：针对多金属氧簇有机共价修饰方法，在直接修饰的基础上，重点开发了席夫碱法、CDI法和异氰酸酯法等高效的多金属氧簇后修饰方法，并制备了一系列配位基团、多重氢键体系修饰的多金属氧簇；其次，在多金属氧簇基高分子构筑方面，开发了普适性较广的沉淀聚合策略，通过反应性基团修饰多金属氧簇与六氯环三磷腈之间的沉淀聚合制备得到了一类具有电荷选择性吸附能力的多孔材料。这种方法简单高效，可操作性强，适用于其他可有机修饰的簇合物和功能单体；最后，结合功能基团有机共价修饰的多金属氧簇与表面活性剂之间的静电相互作用，利用正交自组装策略，实现了多金属氧簇基超分子聚合物的制备。通过配位、氢键、光交联等策略可以将不同类型的多金属氧簇引入到超分子高分子体系，并发挥其功能特性。这个方法也适用于其他簇合物体系。本研究极大丰富了多金属氧簇基杂化高分子体系的构筑方法，更重要的是实现了其本征属性和功能特性的有机结合。