偶氮苯骨架的多孔高分子:结构创新及应用研究进展

Progress in Azobenzene Porous Organic Polymers:Innovative Structure Evolutions and Applications

偶氮苯骨架的多孔高分子(Azo-POPs)具有化学稳定性好、比表面积高以及易功能化修饰等特点,在多个领域表现出了巨大的应用前景,引起了人们的广泛关注.本综述首先梳理了近些年来将偶氮苯结构单元引入到多孔高分子骨架中的方式,包括多氨基芳烃与多(亚)硝基芳烃的缩合聚合、多氨基芳烃的氧化偶联聚合、多硝基芳烃的还原偶联聚合,以及富电子芳烃与多重氮盐的偶联聚合等途径,指出了富电子芳烃与多重氮盐的偶联聚合条件温和、聚合效率高且官能团耐受性好.简述了功能性Azo-POPs的例子与特点,分析并论证了其中三(β-羟基-偶氮)苯结构向三(β-酮-腙)环己烷结构的不可逆异构化;并对Azo-POPs在气体及蒸气的吸附与存储、多相催化、水中污染物的去除、气体膜分离与电化学等领域的应用进行了分析与总结.最后分析并指出了发展Azo-POPs所面临的挑战,并结合已有的研究报道探讨了Azo-POPs的未来发展方向及前景.

Porous polymers with azobenzene skeleton(Azo-POPs),which possess good chemical stability,high specific surface area,and easy functionalization and modification,have shown great application prospects in a number of fields and attracted much attention.In this review,we firstly sorted out the ways of introducing azobenzene structural elements into porous polymer skeletons in recent years,including the condensation polymerization of polyaminoaromatics and poly(nitroso)aromatics,the oxidative coupling polymerization of polyaminoaromatics,the reductive coupling polymerization of poly(nitroso)aromatics and the coupling polymerization of electron-rich aromatics with polydiazonium salts,etc.It is pointed out that the coupling polymerization of electron-rich aromatic hydrocarbons with polydiazonium salts has mild conditions,high polymerization efficiency and good functional group tolerance.The examples and characteristics of functional Azo-POPs is briefly described.The electron cloud,polar dipole interactions and alkalinity provided by amino or hydroxyl groups in Azo-POPs,can significantly improve the adsorption capacity of porous polymers for metal ions,polar compounds and CO_(2).Then the paper analyzes and demonstrates the irreversible isomerization of tris(β-hydroxyazo)benzene structure to tris(β-keto-hydrazone)cyclohexane structure,and analyzes and summarizes the applications of Azo-POPs in the fields of gas and vapor adsorption and storage,multiphase catalysis,removal of pollutants in water,gas membrane separation and electrochemistry.Finally,the challenges to the development of Azo-POPs are analyzed and pointed out,and the future development direction and prospect of Azo-POPs are discussed in the light of the existing research reports.