Garain Swadhin, Li Pei-Lun, Shoyama Kazutaka, Würthner Frank
Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Center for Nanosystems Chemistry (CNC), Universität Würzburg, Theodor-Boveri-Weg, 97074, Würzburg, Germany.
Angew Chem Int Ed Engl. 2024 Oct 21;63(43):e202411102. doi: 10.1002/anie.202411102. Epub 2024 Sep 6.
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 M in CCl), 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 (CT) with a quantum yield (QY) of 6-8 % under ambient conditions which increased up to 36 % in an inert atmosphere.
在曝气条件下，由于分子氧对长寿命三重态的猝灭以及振动耗散，收获无重原子的纯有机发色团的三重态激子具有挑战性。在此，我们展示了一种通过减轻三重态捕集器的猝灭途径来进行三重态捕集的超分子方法。具体而言，我们使用了基于2,3 : 6,7-萘双（二甲酰亚胺）衍生的环芳（NBICy）和咔唑衍生物（EtCz）的主客体体系。络合研究和单晶X射线分析表明形成了刚性主客体络合物（在CCl中K≈10 M），通过减轻振动干扰和氧猝灭，在曝气条件下实现了三重态激子的稳定。光物理研究表明，在环境条件下，电荷转移态（CT）的延迟荧光发射量子产率（QY）为6-8%，在惰性气氛中可提高至36%。
