Robust and emissive covalent organic frameworks formed via intramolecular hydrogen bond interaction

Covalent organic frameworks (COFs) are a new class of crystalline porous polymers with a periodic structure in the skeleton and pre-designable pore structure. COFs merge excellent crystallinity, porosity, stability, and emission, which is very rare. In this research, two robust and emissive COFs were formed via intramolecular hydrogen bond interaction from the nitrogen atom and hydroxyl units in the skeleton, suggesting their good porosity and excellent stability. This interaction also suppressed the nitrogen-related fluorescence quenching pathway, which afforded excellent emissive activity. Both COFs exhibited high sensitivity, selectivity, and sensibility towards 2,4,6-trinitrophenol.