Constructing Organic Electroluminescent Material with Very High Color Purity and Efficiency Based on Polycyclization of the Multiple Resonance Parent Core

Yincai Xu; Qingyang Wang; Jinbei Wei; Xiaomei Peng; Jianan Xue; Zhiheng Wang; Shi-Jian Su; Yue Wang

doi:10.1002/anie.202204652

Constructing Organic Electroluminescent Material with Very High Color Purity and Efficiency Based on Polycyclization of the Multiple Resonance Parent Core

Angew Chem Int Ed Engl. 2022 Jul 25;61(30):e202204652. doi: 10.1002/anie.202204652. Epub 2022 Jun 7.

Authors

Yincai Xu¹, Qingyang Wang¹, Jinbei Wei¹, Xiaomei Peng², Jianan Xue¹, Zhiheng Wang³, Shi-Jian Su², Yue Wang^{1

3}

Affiliations

¹ State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
² State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China.
³ Jihua Laboratory, 28 Huandao South Road, Foshan, 528200, Guangdong Province, P. R. China.

PMID: 35521824
DOI: 10.1002/anie.202204652

Abstract

Multiple resonance thermally activated delayed fluorescence (MR-TADF) compounds have set off an upsurge of research because of their tremendous application prospects in the field of wide color gamut display. Herein, we propose a novel MR-TADF molecular construction paradigm based on polycyclization of the multiple resonance parent core, and construct a representative multiple resonance polycyclic aromatic hydrocarbon (MR-PAH) based on the para-alignment of boron and nitrogen atoms into a six-membered ring (p-BNR). Through the retrosynthesis analysis, a concise synthesis strategy with wide applicability has been proposed, encompassing programmed sequential boron esterification, Suzuki coupling and Scholl oxidative coupling. The target model molecule BN-TP shows green fluorescence with an emission peak at 523 nm and a narrow full-width at half-maximum (FWHM) of 34 nm. The organic light-emitting diode (OLED) employing BN-TP as an emitter exhibits ultrapure green emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.26, 0.70), and achieves a maximum external quantum efficiency (EQE) of 35.1 %.

Keywords: Green Emission; Multiple Resonance; Organic Light-Emitting Diodes; Polycyclic Aromatic Hydrocarbons; Thermally Activated Delayed Fluorescence.

Grants and funding

21935005/National Natural Science Foundation of China