Difluorodithieno[3,2-a:2′ ,3′ -c]phenazine as a strong acceptor for materials displaying thermally activated delayed fluorescence or room temperature phosphorescence

Abstract

Thermally activated delayed fluorescence Room temperature phosphorescence Charge-transfer emission Quantum-chemical calculations Time-resolved spectroscopy A B S T R A C T A novel strong electron-acceptor unit, 9,10-difluorodithieno[3,2-a:2 ′ ,3 ′-c]phenazine (DTPz), is synthesized and applied in the design of two donor-acceptor type emitters displaying long-lived delayed emission. Using either 9,9-dimethyl-9,10-dihydroacridine (DMAC) or triisopropyl-substituted benzo[1,2-b:4,5-b']dithiophene (BDT-TIPS) as the donor component, push-pull type chromophores exhibiting charge-transfer emission are obtained and found to afford either thermally activated delayed fluorescence (TADF) for DMAC or room temperature phosphorescence (RTP) for BDT-TIPS.