Structurally Nontraditional Benzo[c]cinnoline-Based Electron-Transporting Materials with 3D Molecular Interaction Architecture

Angew Chem Int Ed Engl. 2022 Jun 13;61(24):e202202898. doi: 10.1002/anie.202202898. Epub 2022 Apr 12.

Abstract

The academically widely used electron-transporting materials (ETMs) typically suffer from low glass transition temperatures (Tg ) that could lead to poor device stability. Considering practical applications, we herein put forward a "3D molecular interaction architecture" strategy to design high-performance ETMs. As a proof-of-concept, a type of structurally nontraditional ETMs with the benzo[c]cinnoline (BZC) skeleton have been proposed and synthesized by the C-H/C-H homo-coupling of N-acylaniline as the key step. 2,9-diphenylbenzo[c]cinnoline (DPBZC) exhibits strong intermolecular interactions that feature a 3D architecture, which boosts Tg to exceedingly high 218 °C with a fast electron mobility (μe ) of 6.4×10-4 cm2 V-1 s-1 . DPBZC-based fluorescent organic light-emitting diodes show outstanding electroluminescent performances with an external quantum efficiency of 20.1 % and a power efficiency as high as 70.6 lm W-1 , which are superior to those of the devices with the commonly used ETMs.

Keywords: Benzo[c]Cinnoline; Electron-Transporting Material; Glass Transition Temperature; Organic Light-Emitting Diodes; Oxidative C−H/C−H Coupling Reaction.