Engineering Ru(N^N)_(3)-modified covalent organic framework for photocatalytic olefin epoxidation

作     者：Yan-Lin Li Sheng-Li Huang Guo-Yu Yang 

作者机构：Key Laboratory of Cluster Science(Ministry of Education)Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China 

出 版 物：《Science China Chemistry》 (中国科学（化学英文版）)

年 卷 期：2024年第67卷第11期

页      面：3719-3728页

核心收录：

学科分类：081704[工学-应用化学] 081705[工学-工业催化] 07[理学] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学] 

基　　金：supported by the National Natural Science Foundation of China (21971011  21831001) 

主　　题：polypyridyl Ru covalent organic framework olefin epoxidation photocatalysis 

摘      要：Photocatalytic olefin oxidation using air as an oxidant is an environmentally friendly method for producing epoxides. Covalent organic frameworks(COFs) have emerged as promising photocatalysts in various organic synthesis reactions. The combination of tri-(2-pyridinal aldehyde)-containing precursor with 4,4’,4’’-(1,3,5-triazine-2,4,6-triyl)trianiline generated(N^N)-I-COF. Via imine-to-quinoline transformation and coordination anchorage of Ru(N^N)_(3)unit, Ru(N^N)_(3)@Q-COF was obtained with improved chemical stability, skeleton conjugation, and novel photochemical characteristics, and demonstrated excellent photocatalytic activity in olefin epoxidation with a wide range of substrates. The presence of H_(2)O played a crucial role in the formation of reactive oxygen species(ROSs), which in turn influenced the olefin oxidation process. The hydrophilicity of Ru(N^N)_(3) facilitated the approach of H_(2)O and O_(2) to the photogenerated charges, thereby promoting ROSs generation. The lipophilicity of Q-COF allowed for the absorption of olefin substrates, and its nano-channels increased encountering possibility between olefins and ROSs. Consequently, Ru(N^N)_(3)@Q-COF provided an intriguing platform for olefin photooxidation and could be recycled multiple times without any degradation in performance. This report revealed that the conversion of classical ROSs into less potent oxidants with rapid kinetic rates played a crucial role in achieving highly efficient and selective epoxidation of terminal olefins.