Centrosymmetric Molecular Strategy With Quadruple Boron-Nitrogen Heteroarenes Enabling Efficient Ultra-Narrowband Emission.
Realizing ultra-narrowband multiple-resonance thermally activated delayed fluorescence (MR-TADF) with long-wavelength emission remains a formidable challenge due to the increased vibronic coupling and excited-state relaxation with the extension of π-conjugated framework. In this contribution, a proof-of-concept of cent...