Tailored Cis–Trans Isomeric Metal–Covalent Organic Frameworks for Coordination Configuration-Dependent Electrochemiluminescence
Tianrui Liu, Qiantu Tao, Yufei Wang, Rengan Luo, Jing Ma, Jianping Lei
Abstract
Precise manipulation of the coordination configuration within substances can modulate the band structure and catalytic properties of the target material. Metal–covalent organic frameworks (MCOFs), a crystal material amalgamating the benefits of metal–organic frameworks (MOFs) and covalent organic frameworks (COFs), can integrate a predetermined coordination environment into the frameworks for amplifying the catalytic effect. In this study, we delicately synthesize isomeric MCOFs using bis(glycinato)copper as the aminoligand via kinetically and thermodynamically favorable pathways to yield cis-MCOF and trans-MCOF products, respectively, thereby introducing a cis–trans isomeric coordination field into the framework. Moreover, the twisted skeleton derived from the flexibility of amino acid and β-ketoenamine linkages endows trans-MCOF with surprising water dispersibility. Compared to cis-MCOF, the trans isomerism displays a significant enhancement in cathodic electrochemiluminescence via the catalysis of Cu nodes toward K 2 S 2 O 8 . The density of states analysis shows that the d-band center of trans-MCOF is closer to the Fermi level, leading to more stable adsorption binding to promote the catalysis. This study is the first report on constructing predesign coordination configuration MCOFs via an easy-handling method, which gives the guidelines for the design of amino acid-based MCOF materials.