Tunable covalent organic framework electrochemiluminescence from non-electroluminescent monomers
Wei‐Rong Cui, Yajie Li, Qiao‐Qiao Jiang, Qiong Wu, Ru‐Ping Liang, Qiu‐Xia Luo, Li Zhang, Juewen Liu, Jian‐Ding Qiu
Abstract
It is hard to find new electrochemiluminescence (ECL) luminophores using existing research strategies, especially from ECL non-active monomers. Here, fully conjugated covalent organic frameworks with trithiophene (BTT-COFs) are found to have ultra-high ECL efficiencies (up to 62.2%), even in water and without exogenous co-reactants. Quantum chemistry calculations confirm that the periodic BTT-COFs arrays promote intramolecular electron transfer generating ECL from non-ECL monomers. Modulation of ECL performance is possible by substituting the monomers for those with different electron-withdrawing properties. In addition, the cyano group weaved in the skeleton provides the dense sites for post-functionalization. As a typical use case, a highly selective ECL probe for uranyl ions is reported. The tunable ECL luminophore family possesses a broader development space than the traditional emitters, demonstrates the prospects of ECL-COFs, and affords an idea for detecting various contaminants through the rational design of target ligands.