Axially Chiral TADF‐Active Enantiomers Designed for Efficient Blue Circularly Polarized Electroluminescence. (24th January 2020)

• Record Type: Journal Article
• Authors: Li, Meng; Wang, Yin‐Feng; Zhang, Dongdong; Duan, Lian; Chen, Chuan‐Feng
• Is Part Of: Angewandte Chemie. Volume 132:Number 9(2020)
• Page Start: 3528
• Page End: 3532
• Publication Date: 2020-01-24
• Subjects: Axial-chirale Enantiomere -- Elektrolumineszenz -- Organische LEDs -- Thermisch aktivierte verzögerte Fluoreszenz -- Zirkular polarisiertes Licht; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201914249
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The use of a chiral, emitting skeleton for axially chiral enantiomers showing activity in thermally activated delayed fluorescence (TADF) with circularly polarized electroluminescence (CPEL) is proposed. A pair of chiral stable enantiomers, (−)‐( S )‐Cz‐Ax‐CN and (+)‐( R )‐Cz‐Ax‐CN, was designed and synthesized. The enantiomers, both exhibiting intramolecular π‐conjugated charge transfer (CT) and spatial CT, show TADF activities with a small singlet–triplet energy difference (Δ E ST ) of 0.029 eV and mirror‐image circularly polarized luminescence (CPL) activities with large g lum values. Notably, CP‐OLEDs based on the enantiomers feature blue electroluminescence centered at 468 nm with external quantum efficiencies (EQEs) of 12.5 and 12.7 %, and also show intense CPEL with g EL values of −1.2×10 −2 and +1.4×10 −2, respectively. These are the first CP‐OLEDs based on TADF‐active enantiomers with efficient blue CPEL. Abstract : Dreh‐Leuchte : Axial‐chirale Moleküle mit thermisch aktivierter verzögerter Fluoreszenz und zirkular polarisierter Elektrolumineszenz (CPEL) werden vorgestellt. Aus diesen Molekülen gefertigte CP‐OLEDs zeigen hohe Lichtausbeuten und blaue CPEL mit hohen g EL ‐Werten.