Long-lived room temperature phosphorescence from organic molecular crystals attracts great attention. Persistent luminescence depends on the electronic properties of the molecular components, mainly π-conjugated donor–acceptor (D-A) chromophores, and their molecular packing. Here, a strategy is developed by designing two isomeric molecular phosphors incorporating and combining a bridge for σ-conjugation between the D and A units and a structure-directing unit for H-bond-directed supramolecular self-assembly. Calculations highlight the critical role played by the two degrees of freedom of the σ-conjugated bridge on the chromophore optical properties. The molecular crystals exhibit RTP quantum yields up to 20 % and lifetimes up to 520 ms. The crystal structures of the efficient phosphorescent materials establish the existence of an unprecedented well-organization of the emitters into 2D rectangular columnar-like supramolecular structure stabilized by intermolecular H-bonding.
Bibliographical noteFunding Information:
This research was supported by the Asian Office of Aerospace Research and Development (AOARD, FA 2386‐17‐1‐4060). We are very grateful to Prof. Ha‐Jin Lee from the Korea Basic Science Institute (KBSI, Western Seoul Center) for the single crystal measurements. The authors thank the SYSPROD project and AXELERA Pôle de Compétitivité for financial support (PSMN Data Center). J.W.W. acknowledges NRF grant (2017R1E1A1A01075394, 2014M3A6B3063708). A.J.A. and C.D. thank Dr. Jean‐Louis Fave (INSP, Université Sorbonne Université, Paris) for the very fruitful and friendly discussions.
All Science Journal Classification (ASJC) codes