Intramolecular locking and coumarin insertion: a stepwise approach for TADF design

Abstract

Three novel TADF (thermally activated delayed fluorescence) emitters based on the well-studied Qx-Ph-DMAC fluorophore are designed and synthesized. The photophysical properties of these materials are studied from a theoretical and...

Isomeric modulation of thermally activated delayed fluorescence in dibenzo[a,c]phenazine-based (deep) red emitters

“…57 Instead, intersystem crossing occurs more readily between 1 CT and 3 LE states (according to the El Sayed rule 58 ), and is promoted by vibronic coupling (VC) in case of rISC for D-A TADF materials. 59–61 As no neighbouring 3 LE states are present in proximity to T 1 ( 3 CT) to enhance upconversion via vibronic coupling, T 1 is expected to act as an exciton sink, despite the relatively small Δ E ST . 59 This is further corroborated by the large SOC value for the transition from T 1 to the ground state (Fig.…”