Rational design and excited-state properties study of efficient hot exciton luminescent materials

Conventional TADF materials face a fundamental trade-off between small S 1 -T 1 energy gap and fast S 1 radiative decay due to S 1 's dual role in RISC and emission. To address this conflict, we theoretically designed a series of novel ‘donor-anthracene-acceptor’ molecules via excited-state kinetics regulation and multi-parameter optimization. All molecules exhibit distinct T 2 excitation channels, decoupling T 2 → S 1 RISC from S 1 → S 0 emission. This strategy holds the potential for independent control of exciton utilization and luminescence intensity. DFT calculations reveal how the anthracene-donor/acceptor dihedral angle critically influences S 1 -T 2 SOC, revealing a structure-property relationship for SOC tuning. Our calculations predict that the optimized candidate C4 would significantly suppress T 2 → T 1 internal conversion, with a predicted T 2 lifetime of 183 ns that could facilitate efficient spin-flip. This work proposes promising theoretical candidates for efficient hot exciton emitters and provides a computational framework for guiding the precise control of exciton kinetics via systematic excited-state analysis. • The designed D-AN-A molecule decouples the orbital paths of exciton conversion and radiative transitions. • This study demonstrates how the D/A–AN dihedral angle regulates the spin-orbit coupling (SOC). • The designed molecule C4 exhibits an ultra-small ΔE(S 1 -T 2 ), enhanced SOC, and a low internal conversion rate.