2,3:6,7‒Naphthalene bis(dicarboximide) Cyclophane: A Photo‒functional Host for Ambient Delayed Fluorescence in Solution

Abstract Harvesting triplet excitons of heavy atom‐free purely organic chromophores under aerated conditions is challenging due to the quenching of long‐lived triplet states by molecular oxygen and vibrational dissipation. Herein, we show a supramolecular approach of triplet harvesting via mitigating quenching pathways of a triplet harvester. Specifically, we used a host–guest system based on 2,3 : 6,7‐naphthalene bis(dicarboximide)‐derived cyclophane ( NBICy ) and carbazole derivative ( EtCz ). Complexation studies and single‐crystal X‐ray analysis showed the formation of a rigid host–guest complex ( K ≈10 4 M −1 in CCl 4 ), resulting in triplet‐exciton stabilization under aerated conditions via mitigating vibrational interference and oxygen quenching. Photophysical studies elucidate the delayed fluorescence emission from the charge‐transfer state ( 1 CT) with a quantum yield (QY) of 6–8 % under ambient conditions which increased up to 36 % in an inert atmosphere.