Heavy-Atom Effect on the Thermally Activated Delayed Fluorescence Property of Naphthalimide-Phenoselenazine Electron Donor-Acceptor Dyads: Electron Transfer and Intersystem Crossing

Key Points

• The aim is to investigate the impact of heavy atoms on the delayed fluorescence properties of naphthalimide-based electron donor-acceptor dyads.
• Synthesis of naphthalimide-based dyads with 10H-phenoxazine and 10H-phenoselenazine as donors.
• Characterization of delayed fluorescence properties under thermal activation conditions.
• Analysis of electron transfer and intersystem crossing processes.
• Both NI-PXZ and NI-PSeZ exhibited significant thermally activated delayed fluorescence.
• The introduction of heavy atoms influenced electron transfer rates.
• Intersystem crossing was enhanced due to the heavy-atom effect, affecting the fluorescence lifetime.