The merger of a metal-organic framework and an electron-proton transfer mediator for photocatalytic selective aerobic oxidation of amines  

金属有机框架与电子-质子转移中介协同光催化胺的选择性需氧氧化

作　　者：Wenlong Sheng Xiaoxiao Wang Yuexin Wang Bing Zeng Xiang-Kui Gu Xianjun Lang 盛文龙;王晓晓;王月欣;曾冰;顾向奎;郎贤军

机构地区：[1]Hubei Key Lab on Organic and Polymeric Optoelectronic Materials,College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,China [2]School of Power and Mechanical Engineering,Wuhan University,Wuhan 430072,China

出　　处：《Science China Materials》2025年第3期795-803,共9页中国科学(材料科学)(英文版)

基　　金：supported by the National Natural Science Foundation of China(22072108 and 22372124).

摘　　要：Metal-organic frameworks(MOFs)present a multifaceted avenue for visible light photocatalysis and are candidates for environmental applications,in which electron and proton transfers are crucial.To date,the photocatalytic activity of MOFs has been attempted,but with inherent limitations against formidable redox conditions.This can be addressed by adopting an electron-proton transfer mediator to mediate the redox processes over a MOF photocatalyst.To achieve this goal,an electron-proton transfer mediator,HOOC-TEMPO(4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl),is envisioned to steer the selective oxidation of amines over a pyrene-based MOF NU-1000.There are abundant terminal hydroxyl groups of Zr-oxo cluster within the mesoporous channels of NU-1000.Supported by density functional theory calculations,the bidentate chelation of HOOC-TEMPO onto NU-1000 by reacting with the hydroxyl groups is the most feasible mode of adsorption.The optoelectronic properties of NU-1000 can be notably improved by the facile and dynamic adsorption of HOOC-TEMPO.Distinctly,1 mol%HOOCTEMPO promotes NU-1000 photocatalysis,allowing for three times of conversions in the aerobic oxidation of amines to imines.Compellingly,the hole transfer between the pyrene ligand of NU-1000 and HOOC-TEMPO is more efficient than other ligands.The merger of an electron-proton transfer mediator and MOFs creates a unique materials avenue for emerging photocatalysis.金属有机框架(MOF)被广泛用于光催化领域,是可见光驱动电子和质子转移的重要功能材料.迄今为止,MOF的光催化活性被不断提高,但在苛刻的氧化还原条件下仍然存在固有的局限性,这可以通过采用电子-质子转移中介来促进MOF光催化材料上的氧化还原过程来解决.基于此,一种电子-质子转移中介HOOC-TEMPO(4-羧基-2,2,6,6-四甲基哌啶-1-氧自由基)与芘基MOF材料NU-1000结合,可用于胺的选择性氧化.在NU-1000的介孔通道中存在大量的Zr氧团簇末端羟基.密度泛函理论(DFT)计算证明HOOC-TEMPO更倾向于与NU-1000的羟基反应双齿螯合吸附.HOOC-TEMPO的快速吸附可以显著改善NU-1000的光电性能.值得注意的是,在反应体系中加入1 mol%HOOCTEMPO可使得NU-1000光催化氧化胺为亚胺的活性提高3倍多.总之,电子-质子转移中介和MOF材料的结合为实现协同光催化体系创造了一条新途径.

关 键 词：visible light photocatalyst NU-1000 HOOC-TEMPO electron-proton transfer 

分 类 号：O62[理学—有机化学]