Design, synthesis and photophysical properties of a (quinolin-3-yl)methanone-based thermally activated delayed fluorescence emitter

A new (quinolin-3-yl)methanone-based emitter, PQLM-DMAC, is designed with a highly twisted donor-acceptor conformation. A simple synthetic approach is used to prepare PQLM-DMAC, and its thermal, theoretical, photophysical, and electroluminescence are systematically studied to highlight the applicability in organic light-emitting diodes (OLEDs). PQLM-DMAC exhibits separated frontier molecular orbital distribution and thus can emit prominent thermally activated delayed fluorescence (TADF) suitable for triplet harvesting in OLEDs. Furthermore, PQLM-DMAC exhibits short excited-state lifetimes and decent photoluminescence quantum yield, enabling high efficiencies and low efficiency roll-offs in OLEDs.