Shi Ji-Long, Chen Rufan, Hao Huimin, Wang Cheng, Lang Xianjun
Sauvage Center for Molecular Sciences, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China.
Angew Chem Int Ed Engl. 2020 Jun 2;59(23):9088-9093. doi: 10.1002/anie.202000723. Epub 2020 Mar 26.
2D covalent organic frameworks (COFs) are receiving ongoing attention in semiconductor photocatalysis. Herein, we present a photocatalytic selective chemical transformation by combining sp carbon-conjugated porphyrin-based covalent organic framework (Por-sp c-COF) photocatalysis with TEMPO catalysis illuminated by 623 nm red light-emitting diodes (LEDs). Highly selective conversion of amines into imines was swiftly afforded in minutes. Specifically, the π-conjugation of porphyrin linker leads to extensive absorption of red light; the sp -C=C- double bonds linkage ensures the stability of Por-sp c-COF under high concentrations of amine. Most importantly, we found that crystalline framework of Por-sp c-COF is pivotal for cooperative photocatalysis with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO). This work foreshadows that the outstanding hallmarks of COFs, particularly crystallinity, could be exploited to address energy and environmental challenges by cooperative photocatalysis.
二维共价有机框架材料（COFs）在半导体光催化领域正受到持续关注。在此，我们展示了一种光催化选择性化学转化方法，即将基于sp碳共轭卟啉的共价有机框架材料（Por-sp c-COF）光催化与由623纳米红色发光二极管（LED）照射的TEMPO催化相结合。数分钟内即可迅速实现胺向亚胺的高选择性转化。具体而言，卟啉连接体的π共轭导致对红光的广泛吸收；sp -C=C-双键连接确保了Por-sp c-COF在高浓度胺下的稳定性。最重要的是，我们发现Por-sp c-COF的晶体框架对于与（2,2,6,6-四甲基哌啶-1-基）氧基（TEMPO）的协同光催化至关重要。这项工作预示着COFs的突出特性，特别是结晶度，可通过协同光催化来应对能源和环境挑战。
