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

Abstract

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.

Hydration‐Facilitated Fine‐Tuning of the AIE Amphiphile Color and Application as Erasable Materials with Hot/Cold Dual Writing Modes

“…Fine‐tuning of luminescent colors of an organic material is important to achieve multi‐color displays and to meet the need of next generation light‐emitting materials . However, obtaining light emission of an appropriate wavelength remains a challenge .…”

Fluorescent Supramolecular Polymers Formed by Crown Ether-Based Host-Guest Interaction

“…However, control of the fluorescence properties of supramolecular assemblies in a simple way and over a large range is one of the greatest challenges associated with the construction of fluorescent supramolecular assemblies. As an example, Xu et al ( 2018b ) first synthesized a series of P21C7-functionalized rhomboidal metallacycles 48a−48h by variation of the substituents present on dipyridyl donor 46 and on P21C7-based 60° diplatinum(II) acceptor 47 ( Figure 14A ). As a result, the structures of metallacycles 48 differed in the number and position of amino groups on the pyridine ligands or in the electronic effect and the conjugated structure of the aniline moiety at the para- position.…”

“…(B) Optical photographs of the unpainted (a,b) and painted (c,d) UV-LED recorded under UV light (λ ex = 365 nm): (a,c) LED off, (b,d) LED on. Adapted with permission from Xu et al ( 2018b ); copyright 2018, American Chemical Society. (C) Cartoon representation of the construction of supramolecular metallacycles, linear supramolecular polymers, and cross-linked supramolecular polymeric networks.…”

Polymeric Systems Containing Supramolecular Coordination Complexes for Drug Delivery

“…In recent decades, supramolecular coordination complexes (SCCs) have rapidly developed and attracted considerable attention because of their well-defined sizes and shapes and wide applications [ 10 , 11 , 12 , 13 , 14 ]. For example, numerous two-dimensional (2D) metallacycles and three-dimensional (3D) metallacages with various functions have been synthesized through coordination-driven assemblies, and they have wide applications in catalysis, sensors, amphiphilic self-assembly, supramolecular polymers, host−guest chemistry, and drug delivery [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Moreover, SCC-based materials are potential candidates for drug delivery for to the following reasons: first, the unique cavities of SCCs facilitate drug transport owing to the SCC’s hydrophobic property and adjustable size [ 28 , 29 ].…”