In this work, a π-extended acceptor strategy for designing chiral thermally activated delayed fluorescence (TADF)-active materials with highly efficient circularly polarized electroluminescence (CPEL) properties has been proposed. Consequently, three pairs of TADF-active enantiomers based on axially chiral biphenyl skeleton, namely /-, /-, /-, were designed and constructed. Various -substituted push–pull electron groups were introduced into the axially chiral skeleton to comprehend the structure–property relationship. Compared with /- and /-, /- exhibited a higher PLQY of 88.6% and a smaller Δ of 0.13 eV, ascribing to the pull electron effect of CN group to make a more delocalized distribution of LUMO orbital and a lesser overlapping of frontier molecular orbitals. Consequently, the CP-OLEDs of /- showed a remarkable external quantum efficiency up to 21.0% and 19.7% and intense CPEL signals with the electroluminescent dissymmetry factors () up to +4.2 × 10/−4.4 × 10, respectively. This work can provide an efficient and facile way to construct highly efficient CP-OLEDs based on chiral TADF-active emitters by simple molecular engineering of introducing π-extended acceptor.

中文翻译：

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具有 π 扩展受体的轴向手性 TADF 活性材料可实现高效圆偏振电致发光


在这项工作中，提出了一种π扩展受体策略，用于设计具有高效圆偏振电致发光（CPEL）特性的手性热激活延迟荧光（TADF）活性材料。因此，设计并构建了三对基于轴向手性联苯骨架的TADF活性对映体，即/-、/-、/-。将各种取代的推拉电子基团引入轴向手性骨架中以理解结构-性质关系。与/-和/-相比，/-表现出更高的PLQY（88.6%）和更小的Δ（0.13 eV），这归因于CN基团的拉电子效应使LUMO轨道分布更离域，前沿分子重叠更少轨道。因此，i-的CP-OLED表现出高达21.0%和19.7%的显着外量子效率和强烈的CPEL信号，电致发光不对称因子()分别高达+4.2×10/−4.4×10。这项工作可以提供一种有效且简便的方法，通过引入π扩展受体的简单分子工程来构建基于手性TADF活性发射体的高效CP-OLED。