超分子聚合物制备新方法:超分子单体的共价聚合

Covalent Polymerization of Supramonomer: A New Way for Fabrication of Supramolecular Polymers

超分子聚合物是超分子化学与高分子化学交叉的前沿研究领域,近年来受到了国内外研究学者的广泛关注.可控制备超分子聚合物对于研究超分子聚合物的结构与性能关系、设计合成特定功能的超分子聚合物具有重要的意义.本文将总结通过超分子单体的共价聚合反应以制备超分子聚合物的方法.不同于传统的制备超分子聚合物的方法,超分子单体的共价聚合方法将不易调控的非共价聚合转化为可控的共价聚合,为实现超分子聚合物的可控制备提供了新思路.

Supramolecular polymers are polymeric arrays of monomeric units that held together by highly directional and reversible noncovalent interactions, resulting in polymeric properties in solution and bulk. Due to the dynamic nature of noncovalent interactions, supramolecular polymers display fascinating properties such as reversibility, adaptiveness, self-healing, and stimuli-responsiveness, which are different from their covalent counterparts. These attributes have endowed supramolecular polymers with great potential applications in the field of functional materials, and also have motivated chemists to construct a variety of supramolecular polymers and supramolecular polymeric materials. In conventional supramolecular polymerization, bifunctional covalent monomers should be first synthesized and then supramolecularly polymerized. In contrast, we have proposed a new method for constructing supramolecular polymers by covalent polymerization of supramonomers. Bifunctional supramonomers are first fabricated through noncovalent interactions and then subjected to covalent polymerization. The driving forces for the fabrication of supramonomers are multiple hydrogen bonds, host-guest interactions, and others. This feature article is aimed to summarize the ways for covalent polymerization of supramonomers, including click polymerization and enzyme-triggered condensation of supramonomers based on the host-guest interactions of cucurbit[8]uril and tripeptide Phe-Gly-Gly derivatives, photo-triggered cycloaddition of anthracene end-capped supramonomers driven by pillar[5]arene based host-guest interactions, and olefin metathesis polymerization of quadruple hydrogen bonded supramonomers. The advantage of the covalent polymerization of supramonomers is to transfer a not-easy tractable supramolecular polymerization to an easy tractable covalent polymerization. We envision that more noncovalent interactions with higher binding affinity could be used to drive the formation of supramonomers; and more controlled covalent reactions with higher efficiency and milder reaction conditions could be used in the covalent polymerization of supramonomers. By utilizing this method, the controllable fabrication of supramolecular polymers could be realized, which is vital to the study of structure-property relationship of supramolecular polymers, as well as to the design and the construction of functional supramolecular polymers.