σ‐Conjugation and H‐Bond‐Directed Supramolecular Self‐Assembly: Key Features for Efficient Long‐Lived Room Temperature Phosphorescent Organic Molecular Crystals

Catherine Demangeat (1) , Yixuan B Dou (2) , Bin Hu (2) , Yann Bretonnière (3) , Chantal Andraud (3) , Anthony d'Aléo (1) , Jeong Weon Wu (4) , Eunkyoung Kim (5) , Tangui Le Bahers (3) , André‐jean Attias (1)

1 2B-FUEL - Building Blocks for Future Electronics Laboratory
2 The University of Tennessee [Knoxville]
3 ENS de Lyon - École normale supérieure de Lyon
4 EWHA - EWHA Womans University
5 Yonsei University

Long-lived room temperature phosphorescence from organic molecular crystals attracts great attention. Persistent luminescence depends on the electronic properties of the molecular components, mainly p-conjugated donoracceptor (D-A) chromophores, and their molecular packing. Here, a strategy is developed by designing two isomeric molecular phosphors incorporating and combining a bridge for s-conjugation between the D and A units and a structuredirecting unit for H-bond-directed supramolecular self-assembly. Calculations highlight the critical role played by the two degrees of freedom of the s-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.

Domaines: Chimie

Catherine Demangeat, Yixuan B Dou, Bin Hu, Yann Bretonnière, Chantal Andraud, et al.. σ‐Conjugation and H‐Bond‐Directed Supramolecular Self‐Assembly: Key Features for Efficient Long‐Lived Room Temperature Phosphorescent Organic Molecular Crystals. Angewandte Chemie International Edition, 2021, 60 (5), pp.2446-2454. ⟨10.1002/anie.202011770⟩. ⟨hal-03434235⟩