Asymmetric Acridine Enables Efficient Chiral Narrow Emission

Comprehensive Summary Chiral organic emitters with narrowband emission are highly desirable for next‐generation circularly polarized organic light‐emitting diodes (CP‐OLEDs), yet their simultaneous realization of high efficiency, excellent color purity, and pronounced chirality remains a significant challenge. Here, we report a pair of green multiple‐resonance boron–nitrogen (MR‐BN) emitters in which chirality is introduced by a simple asymmetric spiro‐acridine (SA) motif. This design preserves the rigid MR framework, affording intense green emission ( λ em = 516 nm) with a narrow full width at half maximum (FWHM) of 25–26 nm and high photoluminescence quantum yields, while the bulky SA unit effectively suppresses aggregation in the solid state. The chemically fixed geometry further imparts intrinsic chirality, leading to mirror‐image circular dichroism and distinct CPL signals with | g PL | values on the order of 10 –4 . When incorporated into OLEDs, both enantiomers exhibit complete host–guest energy transfer, outstanding color purity with CIE coordinates of (0.143, 0.706) and (0.147, 0.687), and external quantum efficiencies of up to 24.1% and 23.2%, among the highest reported for green chiral emitters. This work presents a simple yet powerful molecular design strategy to integrate narrowband emission and chirality in MR systems, providing a promising pathway toward efficient, high‐color‐purity CP‐OLEDs.