Noncovalent Bridged Bis(Coumarin‐24‐Crown‐8) Phosphorescent Supramolecular Switch

• Published in: Advanced optical materials Vol. 10; no. 24
• Main Authors: Wang, Hui‐Juan, Xing, Wen‐Wen, Yu, Zhen‐Hai, Zhang, Heng‐Yi, Xu, Wen‐Wen, Liu, Yu
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 19.12.2022
• Subjects: Afterglows; Coumarin; crown ether; Energy transfer; Materials science; Optics; Phosphorescence; Photoluminescence; photo‐switch; Polyvinyl alcohol; Rhodamine; Room temperature; supramolecular assembly; triplet‐to‐singlet Förster‐resonance energy transfer (TS‐FRET)
• ISSN: 2195-1071; 2195-1071
• DOI: 10.1002/adom.202201903

A multicolor room temperature phosphorescence (RTP) supramolecular photo‐switch encryption film is constructed by the coassembly of coumarin‐24‐crown‐8 (C24C8), diarylethene dicationic alkylammonium derivative (1), rhodamine B (RhB) and poly(vinyl alcohol) (PVA). Benefiting from the tightly binding of C24C8 and secondary alkylammonium ion, 1 formed noncovalent bridged bis(coumarin‐24‐crown‐8), which displayed photo‐switchable RTP with green afterglow (more than 5 s) after coassembly with PVA. Especially doping with RhB gave a photo‐switchable highly efficient phosphorescence‐harvesting system with multicolor through triplet‐to‐singlet Förster‐resonance energy transfer (TS‐FRET). The energy transfer efficiency and antenna effect of C24C8+RhB@PVA film reached 88.3% and 62.6 when the donor/acceptor ratio is 50:1, respectively. Therefore, diarylethene noncovalent bridged bis(coumarin‐24‐crown‐8) supramolecular assembly not only displays a multicolor photoluminescence‐switch, but also presents a phosphorescent photo‐switch with afterglow, which provides a simple and feasible way to construct smart RTP materials through host‐guest strategy. A photo‐switchable phosphorescence energy transfer system is constructed through the coassembly of host phosphor coumarin‐24‐crown‐8 (C24C8), molecular switch diarylethene dicationic alkylammonium derivative (1), rhodamine B (RhB) and poly(vinyl alcohol) (PVA). Both 1⊂C24C8@PVA and 1⊂C24C8+RhB@PVA showed reversibly photoswitchable luminescence with a long lifetime. Finally, the phosphorescent photo‐switch films were used for information encryption with afterglow.