Metallacycle-Cored Supramolecular Polymers: Fluorescence Tuning by Variation of Substituents

摘要

Herein, we present a method for the preparation of supramolecular polymers with tunable fluorescence via the combination of metal-ligand coordination and phenanthrene-21-crown-7(P21C7)- based host-guest interaction. A suite of rhomboidal metallacycles with different substituents were prepared via the coordination-driven self-assembly of a P21C7- based 60° diplatinum (II) acceptor and 120° dipyridyl donors. By the variation of the substituents on the dipyridyl donors, the metallacycles exhibit emission wavelengths spanning the visible region (λmax = 427–593 nm). Metallacycle-cored supramolecular polymers were obtained via host-guest interactions between bisammonium salts and P21C7. The supramolecular polymers exhibit similar emission wavelengths of the individual metallacycles and higher fluorescent efficiency in solution and thin films. Utilizing a yellow-emitting supramolecular polymer thin film with high quantum yield (0.22), a white-light-emitting LED was fabricated by painting the thin film onto an ultra violet-LED. This study presents an efficient approach for tuning the properties of fluorescent supramolecular polymers and potential of metallacycle-cored supramolecular polymers as a platform for the fabrication of light-emitting materials with good processability and tunability.