Cucurbituril‐Confined Tetracation Supramolecular 2D Organic Framework for Dual‐Emission TS‐FRET

Abstract

AbstractHerein, cucurbituril‐regulated supramolecular multi‐dimensional organic framework constructed is reported by tetraphenylvinyl grafted bromophenylpyridine salt derivatives (TPE‐BrN) and cucurbit[n]uril (n = 6, 7, 8) via non‐covalent cross‐linked, giving supramolecular macrocycle‐confined fluorescence‐phosphorescence dual emission at 560 and 510 nm in solid state. Different from the formation of TPE‐BrN⊂CB[6] complexes and TPE‐BrN⊂CB[7] nanoparticle, TPE‐BrN⊂CB[8] manifested high‐efficient 2D network assembly. TPE‐BrN⊂CB[8] assembly can effectively activate triplet‐state to singlet‐state Förster resonance energy transfer (TS‐FRET) with long‐lived near‐infrared emission at 675 nm via doping organic dye Nile red (NiR) and the energy transfer efficiency reached up to 99%. Although CB[7] can also induce the typical phosphorescence emission at 510 nm, there is no TS‐FRET occurring after doping NiR into TPE‐BrN⊂CB[7] assembly due to the formation of different assembly modes. The multicolor long‐lived emission has been demonstrated very well based on the TS‐FRET process activated by CB[8] macrocyclic confined 2D organic framework, which can be successfully applied to fingerprint imaging and the construction of logic gate systems. It provides a novel method for supramolecular macrocycle confined phosphorescence regulation and the development of luminescent materials.