One Molecular Platform, Three Distinct Narrowband Organoboron TADF Emitters: A Divergent One‐Pot Strategy From Green to Red

ABSTRACT Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters enable narrowband electroluminescence with exceptional color purity in organic light‐emitting diodes (OLEDs). However, extending emission to longer wavelengths, particularly into the red region, while preserving spectral sharpness remains challenging. Here, we report a divergent one‐pot borylation strategy that transforms a single 5,11‐dihydroindolo[3,2‐ b ]carbazole platform into three structurally distinct organoboron MR‐TADF emitters spanning green to red. This approach harnesses competing mono‐ and double‐borylation pathways that coexist under the reaction conditions to generate multiple emitters in a single operation. The resulting MR‐TADF emitters ( BN‐G , BN‐Y , and BN‐R ) exhibit ultranarrow green, yellow, and red photoluminescence with full widths at half maximum below 25 nm and near‐unity quantum yields (96%–100%) in doped films. OLEDs based on these emitters achieve maximum external quantum efficiencies of up to 35.3%, with emission maxima spanning 516–601 nm. This study establishes a unified design strategy for generating multiple high‐performance MR‐TADF emitters from a single precursor, providing a versatile platform for the development of color‐tunable narrowband optoelectronic materials.