Converting Azine Linkage into Highly Stable(Thio)Urea-Based Bicyclic-Fused-Ring Connections in Covalent Organic Frameworks via Criss-Cross[3+2]Cycloaddition  

作　　者：Zhi-Bei Zhou Hui-Hui Sun Qiao-Yan Qi Xin Zhao 

机构地区：[1]Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules,Shanghai Institute of Organic Chemistry,University of Chinese Academy of Sciences,Chinese Academy of Sciences,Shanghai 200032

出　　处：《CCS Chemistry》2024年第9期2230-2240,共11页中国化学会会刊（英文）

基　　金：supported by the National Science Fund for Distinguished Young Scholars of China(grant no.21725404);the Science and Technology Committee of Shanghai Municipality,China(grant no.20JC1415400).

摘　　要：Exploring new linkage chemistry is of fundamental significance for covalent organic frameworks(COFs)to expand their structure and functional diversity.Herein,we report a strategy for converting azine linkage into urea-and thiourea-based fused-ring connections in COFs by criss-cross[3+2]dipolar cycloaddition of azine with HNCO or KSCN.The as-prepared COFs with cyclized linkages exhibited enhanced chemical and thermal stability by locking the dynamic C=N linkages in the progenitor.Moreover,functions could be introduced into the skeleton of COFs by this postsynthetic cyclization method,which enabled significant improvements in functionality,demonstrated by the studies on CO_(2)/N_(2) selective sorption,proton conduction,and Hg^(2+)adsorption.The use of this[3+2]cycloaddition strategy not only enriched the chemistry of linkage conversion for COFs but also offered a new way to fabricate fused-ring-linked COFs,thereby representing a high level of controllability on connectivity and functionality of COFs.

关 键 词：covalent organic frameworks linkage chemistry structural transformation [3+2]cycloaddition AZINE 

分 类 号：O62[理学—有机化学]