Light-up covalent organic frameworks via the flexible walls design for chemical sensing

Abstract

Covalent organic frameworks (COFs) are a novel type of nanoporous and crystalline polymers with a precise and highly conjugated skeleton, making them promising candidates for constructing emissive materials. However, the strong high conjugation structures between adjacent layers easily lead to aggregation-caused quenching (ACQ) emission properties. In this study, we have designed COFs with flexible skeleton to suppressing ACQ effects, enhancing their luminescent activity. In addition, the high density of nitrogen and oxygen atoms on these flexible walls serves as binding sites for hydrogen bonding interactions, indicating sensitivity and selectivity towards nitro-explosives. This strategy establishes a new approach to creating luminescent materials for chemical sensors.