A donor–acceptor cage for circularly polarized TADF emission

Abstract

Herein, we report the first example of chiral donor–acceptor cage DA-2 displaying efficient circularly polarized thermally activated delayed fluorescence (CP-TADF) with |g_lum| values up to 2.1 × 10⁻³ and PLQY of 32%. A small ΔE_ST of 0.051 eV and quasi-parallel (θ = 6°) transition electric and magnetic dipole moments were realized from the through-space charge transfer interaction between the parallelly aligned donor and acceptor in DA-2. This D–A cage configuration has provided a novel design strategy for discovering potential efficient CP-TADF emitters.