UP - logo
E-viri
Celotno besedilo
Recenzirano
  • Axially Chiral TADF‐Active ...
    Li, Meng; Wang, Yin‐Feng; Zhang, Dongdong; Duan, Lian; Chen, Chuan‐Feng

    Angewandte Chemie International Edition, February 24, 2020, Letnik: 59, Številka: 9
    Journal Article

    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 (ΔEST) of 0.029 eV and mirror‐image circularly polarized luminescence (CPL) activities with large glum 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 gEL 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. Let's twist again: Axially chiral molecules with thermally activated delayed fluorescence and circularly polarized electroluminescence (CPEL) are presented. CP‐OLEDs based on these molecules display high efficiencies and blue CPEL with large gEL values.