Search

Macrocyclic receptors have emerged as versatile and efficient molecular tools for the recognition and sensing of anions, playing a pivotal role in molecular recognition and supramolecular chemistry. The following review provides an overview of the recent advances in the design, synthesis, and applications of macrocyclic receptors specifically tailored for anion recognition. The unique structural features of macrocycles, such as their well-defined structures and pre-organised binding sites, contribute to their exceptional anion-binding capabilities that have led to their application across a broad range of the chemical and biological sciences. [ABSTRACT FROM AUTHOR]

Efficient utilization of light energy is crucial for various technological applications ranging from solar energy conversion to optoelectronic devices. Supramolecular light-harvesting systems (LHS) have emerged as promising platforms for enhancing light absorption and energy transfer process. In this Feature Article, we highlight the utilization of tetraphenylethylene (TPE) chromophores as antennas in supramolecular assemblies for light harvesting applications. TPE, as an archetypal aggregation-induced emission (AIE) chromophore, offers unique advantages such as high photostability and efficient light-harvesting capabilities upon self-assembly. We discuss the design principles and synthetic strategies employed to construct supramolecular assemblies incorporating TPE chromophores, elucidating their roles as efficient light-harvesting antennas. Furthermore, we delve into the mechanisms governing energy transfer processes within these assemblies, such as Förster resonance energy transfer (FRET). The potential applications of these TPE-based supramolecular systems in various fields, including photocatalysis, reactive oxygen species generation, optoelectronic devices and sensing, are explored. Finally, we provide insights into future directions and challenges in the development of next-generation supramolecular LHSs utilizing TPE chromophores. [ABSTRACT FROM AUTHOR]

The fabrication of supramolecular light‐harvesting systems (LHS) with sequential energy transfer is of significance in utilizing light energy. In this study, we report the non‐covalent self‐assembly of a sequential LHS by pillar[5]arene‐based host‐guest interaction in water and its applications in white light‐emitting diode (LED) device and latent fingerprint imaging. The host‐guest complex WP5⊃ ${ \supset }$ G self‐assembles into nanoparticles in water and shows enhanced aggregation‐induced emission (AIE) effect. The nanoparticles can be further used to construct sequential LHS with fluorescent dyes 4,7‐di(2‐thienyl)‐benzo[2,1,3]thiadiazole (DBT) and sulforhodamine 101 (SR101). Impressively, the system shows white‐light emission when the molar ratio of WP5⊃ ${ \supset }$ G/DBT/SR101 is 1100/2/16. The material can be coated on a LED bulb to achieve white‐light emission. In addition, the sequential LHS exhibit multicolor fluorescence including red emission, which have been successfully applied to high‐resolution imaging of latent fingerprints. Therefore, we demonstrated a general strategy for the construction of sequential LHS in water based on macrocyclic host‐guest interaction and explored its multi‐functional applications in white‐light LED device and imaging of latent fingerprints, which will promote future development and application of supramolecular LHSs. [ABSTRACT FROM AUTHOR]

Organic luminescent materials with time‐dependent emission colors show promising applications in the fields of chemical sensing, high‐resolution bioimaging, and high‐security information encryption. Herein a time‐dependent fluorescence system based on a spirocyclic scaffold‐bridged cyanostilbene dimer (SDCS) as the single component in a mixed CH3CN/H2O solvent is presented. Specifically, the original orange‐emitting nanoparticles prepared from SDCS by reprecipitation can transform into green‐emitting nanosheets over time driven by supramolecular self‐assembly. It is worth noting that such a transformation rate can be controlled by tuning the water fraction. Based on these unique properties, fluorescent binary codes are developed, enabling time‐dependent information encryption with a higher level of security. Moreover, the dual color can be individually fixed by solid matrices such as hydrogel or powder. The obtained luminescent powders are successfully used in two‐color fluorescence imaging of latent fingerprints. This work demonstrates the use of a supramolecular strategy to control multiple emissions in a single‐component system for multifunctional applications. [ABSTRACT FROM AUTHOR]

Two novel fluorescent probes L1 and L2 for recognizing Al3+ have been prepared by cooperating salicylaldehyde‐derived Schiff base groups onto the upper rim of the calix[4]arene. Of these probes, L2 is the most effective at recognizing Al3+, displaying a highly selective fluorescence "on" response with an emission wavelength at 478 nm and a Stokes shift of 88 nm. Additionally, probe L2 can form a 1 : 1 coordination complex with Al3+ with a binding constant of 2.6×1010 M−1. Furthermore, its fluorescence intensity exhibits a good linear relationship with Al3+ concentration within the range of 2.0×10−5 M to 1.4×10−4 M, and the probe has a low detection limit of 4.36×10−7 M. [ABSTRACT FROM AUTHOR]

Tunable photoluminescent materials have attracted great attention in the past decade. In the meantime, the light harvesting phenomenon in natural photosynthesis has greatly inspired the creation of luminescent materials. However, the environmental response properties of natural systems are less well modeled in this research field. In this study, we designed and synthesized a tadpole-type amphiphilic monomer (M), which contains a cyanostilbene group as the hydrophobic segment and oligo(ethylene glycol) (OEG) chains as the hydrophilic segment. M can self-assemble into nanoparticles in pure water due to its amphiphilicity. These nanoassemblies not only show tunable lower critical solution temperature (LCST) behavior but also exhibit temperature-responsive fluorescence. By co-assembling the hydrophobic dye DBT (energy acceptor) into M (antenna/energy donor) nanoparticles, an efficient artificial light-harvesting system with tunable fluorescence and temperature-responsive properties was constructed. Interestingly, white light emission can be achieved by incorporation of 1.67% acceptor at room temperature, which turns light purple at high temperature. This process can be repeated in heating/cooling cycles, reminiscent of the high-temperature inhibiting properties of natural photosynthesis. This work not only demonstrates a biomimetic stimuli-responsive light-harvesting system, but also provides a new idea for creating tunable luminescent materials in the pure aqueous phase. [ABSTRACT FROM AUTHOR]

Integration of both excellent mechanical performance and remarkable durability into composite hydrogel materials is highly demanded yet challenging. Herein, a synergistic strategy of combining covalent crosslinks with nanosheet‐reinforced dynamic interactions is developed for the design and fabrication of deformable and recoverable nanocomposite hydrogels. Layered double hydroxide nanosheets and a trace amount of covalent crosslinks are simultaneously incorporated into the network, providing profound synergy in mechanical enhancement and durability extension. The resultant materials displayed high deformability (stretchability >1100%, compressibility >90%), considerable springiness and resilience, rapid and excellent recovery over 2000 cycles of compression and retraction as well as a 100% hysteresis ratio after only 1 min during large stretching. Notably, these networks are also transparent and ionically conductive. To demonstrate the utility, a wearable strain sensor is constructed for sensing and detecting human motions (e.g., subtle movement of mouth‐opening and large motion of joint‐bending), exhibiting a linear response with high sensitivity (gauge factor as high as 7.66) over 100–300% strain. This line of research will inspire renewed interest and work into synergic exploitation of nanospecies‐reinforced interactions and covalent crosslinks into the design of high‐performance composite materials. [ABSTRACT FROM AUTHOR]