The regioisomeric effect on the excited-state fate leading to room-temperature phosphorescence or thermally activated delayed fluorescence in a dibenzophenazine-cored donor–acceptor–donor system

Regioisomeric and substituent effects in a twisted D–A–D molecular scaffold on the photophysical properties has been revealed. The studied compounds display distinct difference in TADF, dual TADF&RTP, and dual RTP, depending on the host used.