Azatriangulene‐Based Conductive C═C Linked Covalent Organic Frameworks with Near‐Infrared Emission

Abstract Two near‐infrared (NIR) emissive π ‐conjugated covalent organic frameworks (COFs) pTANG1 and pTANG2 are synthesized using Knoevenagel condensation of trioxaazatriangulenetricarbaldehyde (TATANG) with benzene‐ and biphenyldiacetonitriles, respectively. The morphology of the COFs is affected by the size of TATANG precursor crystals. Donor–acceptor interactions in these COFs result in small bandgaps (≈1.6 eV) and NIR emission (λ max = 789 nm for pTANG1). pTANG1 can absorb up to 9 molecules of water per unit cell, which is accompanied by a marked quenching of the NIR emission, suggesting applications as humidity sensors. p ‐Doping with magic blue significantly increases the electrical conductivities of the COFs by up to 8 orders of magnitude, with the room temperature conductivity of pTANG1 reaching 0.65 S cm −1 , the highest among reported C═C linked COFs. 1 H NMR relaxometry, temperature‐dependent fluorescence spectroscopy, and DFT calculations reveal that the higher rigidity of the shorter phenylene linker is responsible for the more extended conjugation (red‐shifted emission, higher electrical conductivity) of pTANG1 compared to pTANG2.