Enhanced Solution and Solid‐State Emission and Tunable White‐Light Emission Harvested by Supramolecular Approaches

Abstract

Organic luminescent materials with high quantum yields and/or white‐light‐emitting properties in particular play a crucial role in labeling and optoelectronic devices. In this work we have synthesized a new 2,3,6,7‐tetramethoxy‐9,10‐di‐p‐tolylanthracene‐bridged pillar[5]arene dimer with persistent mazarine blue fluorescent emission and much higher quantum yields in both solution and the solid state in comparison with its corresponding emissive linker without pillarene units, which exhibits typical aggregation‐caused quenching. According to the fluorescence data and single‐crystal analyses, their contrasting fluorescent performances can be rationally ascribed to their different stacking structures and intermolecular interactions. Three fluorescent guests containing different chromophores and/or terminal binding sites have also been synthesized to interact with the pillar[5]arene dimer to construct supramolecular ensembles with highly controllable luminescence, taking advantage of the stimuli‐responsive properties of the supramolecular host–guest interactions. Intriguingly, multicolor fluorescence, including white‐light emission (0.31, 0.35), which is in high demand, has been achieved by tuning the molar ratio of the host and guest and/or by changing the solvent system. This strategy holds great potential for the design and development of fluorescent materials with high quantum yields, controllable emission wavelength, and good stimuli‐responsiveness.

A stimuli-responsive pillar[5]arene-based hybrid material with enhanced tunable multicolor luminescence and ion-sensing ability

“…However, most relative research has been focused on the tuning of luminescence by taking advantage of the dynamic and reversible host-guest interactions of pillarenes, but the strategy of adjusting fluorescent properties directly by equipping chromophores with pillarene rings remains barely touched. For example, in 2019 we demonstrated a supramolecular approach of yielding intense fluorescence both in solution and solid states by covalently linking pillar[5]arene to the terminals of an anthracene derivative, and realized effective color tuning via host-guest interaction of pillar[5]arene and fluorescent guest molecules [ 25 ]. Apart from covalent modification, another powerful method for the integration of pillarenes and luminescent molecules is through coordination.…”

Pillar[n]arene‐Based Supramolecular Switches in Solution and on Surfaces

“…For example, stimuliresponsive supramolecular polymers have been fabricated in both aqueous and organic media, func tioning as drug delivery systems, [19] fluorescent gels or inks, [20] and light harvesting materials. [21] The polymerization driven by host−guest binding showed excellent reversible switching activities and responses to triggers, which can be demonstrated by macroscopic processes, including morphology changes, cargo release induced by breakage of the assemblies, visible solgel transition, fluorescence peak shifts, and changes in fluorescent intensity. This represents an important trend of the switching systems from simple host−guest complexes to larger assemblies or bulkier materials that can function and generate responsive motions at macroscopic scale.…”

Color‐Tunable Supramolecular Luminescent Materials

“…Blending multiple components with mutual compatibility into highly organized supramolecular arrays is a simple and effective approach toward the fabrication of multifunctional materials. The integration [39,107] of multiple fluorophores with complementary emission colors into supramolecular polymers can, not only retain the dynamic and reversible features associated with noncovalent bonding interactions, but also provide materials with tunable luminescent properties.…”