碳碳键链接的二维共价有机框架研究进展

Research Progress of Carbon-carbon Bond Linked Two-dimensional Covalent-Organic Frameworks

二维共价有机框架(Two-dimensional Covalent-Organic Frameworks,2D COFs)是指一类由π-共轭构筑单元通过共价键连接形成的具有二维拓扑结构的晶态多孔材料.由于其独特的周期性多孔结构、高比表面积、优异的稳定性等特点在离子传输、光电材料、催化等领域展现出了巨大的应用潜力.其中,碳碳键链接的共价有机框架因兼具优异的稳定性和良好的结晶性,被认为是最具有前景的二维聚合物材料之一.近年来,基于不同的设计原则和合成策略涌现出了许多具有不同结构和优异性能的碳碳键链接共价有机框架.在这篇综述中,按照构筑单元的拓扑结构对碳碳键链接共价有机框架进行分类,并归纳总结了迄今为止C=C和C—C键链接的二维共价有机框架在合成方法、结构创新、性能提升以及实际应用领域的研究进展.该综述旨在为相关领域的研究人员更好地设计和合成具有多种功能的多孔结晶材料提供参考,从而促进碳碳键链接共价有机框架材料在光电领域的进一步发展和应用.

Two-dimensional polymers(2DPs)are a type of planar polymer materials that possess regular porous structures.They fulfill the demand for thin,high-performing,and stable materials in flexible devices,making them highly potential candidates for applications in the field of flexible electronics.As a special class of covalent two-dimensional polymer materials,two-dimensional covalent organic frameworks(COFs)refer to crystalline porous materials with a two-dimensional topology formed by connectingπ-conjugated building units through covalent bonds.The unique electronic structure of COFs gives them better electrical properties compared to other two-dimensional polymers.Furthermore,their unique periodic porous structure,high specific surface area,and excellent stability make them highly suitable for various applications such as ion transport,optoelectronic materials,and catalysis.Among these,carbon-carbon bond-linked COFs are regarded as one of the most promising types of two-dimensional polymers due to their excellent stability and good crystallinity.In recent years,many carbon-carbon bonded COFs with different structures and excellent properties have emerged based on different design principles and synthesis strategies.In this review,we summarize and introduce four common synthesis methods for preparing C=C bonded COFs,namely solvent-thermal method,melt-polymerization method,interface polymerization method,and copper template method.Furthermore,we categorize C=C bonded COFs into four classes:[C2+C3],[C2+C2],[C3+C3],and[C4+C2],according to the topological structure of the building units.We focus on analyzing the relationship between the composite structure of these COFs and their stability,electrical properties,catalytic performance,and other properties.Additionally,we compile and summarize the research progress of C=C bonded COFs in terms of synthesis methods,structural innovation,performance improvement,and practical applications.This compilation will be beneficial for researchers in the subsequent studies of C=C bonded COFs to select building units based on target structure and performance application and conduct pre-design.Furthermore,this review also includes previously overlooked C—C bonded COFs,providing a more comprehensive reference.In summary,this review aims to provide guidance for researchers in related fields to better design and synthesize multifunctional crystalline porous materials,thereby promoting the further development and application of carbon-carbon bond-linked COFs in various fields.