Manipulating Single‐Molecule Exciplex TADF and Deep‐Blue RTP Through Non‐Covalent π–π Interaction in a Molecular Foldamer

Abstract

AbstractAlthough the π–π stacking has been widely applied for constructing aggregated emitters in optoelectronics fields, the role of intramolecular non‐covalent π–π interactions has not been well studied. Here, a supramolecular foldermer M‐σ‐C, with the electron donor (D) and acceptor (A) units spatially separated with a non‐covalent bond at a close distance by methylene linker is designed and synthesized. This gives a face‐to‐face D/A stacking configuration with supramolecular π–π interactions. Temperature‐dependent nuclear magnetic resonance measurements and single crystal analyses confirm its folding configuration. In solutions, M‐σ‐C exhibits a single‐molecule exciplex thermally activated delayed fluorescence (TADF) property ascribing to the efficient intramolecular through‐space charge transfer (CT) process. While single‐molecule deep‐blue room temperature phosphorescence (RTP) with a long afterglow lifetime of 236 ms is observed in a nonpolar matrix, which represents the record lifetime among current 3CT‐character featured RTP. This work indicates that intramolecular non‐covalent interactions play an important role in manipulating high‐performance single‐molecule exciplex TADF and RTP, and provide a feasible molecular design strategy for supramolecular chemistry involving the development of optoelectronic materials.