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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]

A guest molecule containing a short alkyl spacer between the tetraphenylethylene group and the methylpyridinium group was designed and synthesized. After complexation with a water‐soluble pillar[5]arene, the resulting host‐guest complex can further self‐assemble into fluorescence‐emitting nanoparticles in water. By loading a commercially available dye Rhodamine 6G into the nanoparticles, an efficient artificial light‐harvesting system with high donor/acceptor ratios (>400/1) was successfully constructed. The obtained systems show considerable antenna effects with values of more than 10 times. The system also exhibits tunable fluorescence emission behavior and can be used as a fluorescent ink for information encryption. [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]

Responsive fluorescent nanomaterials have been received considerable attention in recent years. In this work, a bola‐type amphiphilic molecule, CSO, was synthesized which contains a hydrophobic cyanostilbene core and hydrophilic oligo(ethylene glycol) (OEG) coils at both sides. The cyanostilbene group is aggregation‐induced emission (AIE) active, while the OEG coils are thermo‐responsive. As a result, the CSO molecules can self‐assemble into blue‐fluorescent nanoassemblies with lower critical solution temperature (LCST) behavior in aqueous media. It is noteworthy that the LCST behavior can be reversibly regulated with changes in concentration and the introduction of K+. Intriguingly, fluorescence of CSO assembly shows a blue‐shift upon heating. Finally, by employing CSO as a light capturing antenna and energy donor, an artificial light harvesting system with tunable emission and thermo‐responsive characteristics was fabricated. This study not only demonstrates an integrated approach to create responsive fluorescent nanomaterials, but also shows great potential for producing luminescent materials and mimicking photosynthesis in nature. [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]

The development of stimuli‐responsive fluorescent materials in water based on organic molecule has drawn significant interest. Herein, we designed and synthesized an amphiphilic molecule M containing a fixed tetraphenylethylene moiety (FTPE) as hydrophobic part and tri(ethylene glycol) (TEG) chains as hydrophilic part. Notably, the FTPE moiety is aggregation‐induced emission (AIE) active, while the TEG chains are thermo‐responsive. M can self‐assemble into fluorescent nanoparticles (NPs) in water, which showed lower critical solution temperature (LCST) behavior. Moreover, its clouding point can be reversibly tuned upon the concentration variation. Interestingly, the NPs can be acted as a fluorescence thermometer in aqueous media owing to their unique AIE and LCST behaviors. Our work herein not only provides an integration strategy to construct stimuli‐responsive fluorescent materials but also shows great potential in biological applications including bioimaging and biosensors. [ABSTRACT FROM AUTHOR]

Pillar[n]arenes are new generation of supramolecular macrocyclic host, which exhibit excellent host−guest recognition properties. In the last decade, functional materials constructed from pillar[n]arenes have been attracted more and more attention and displayed outstanding characteristics, such as stimuli‐responsiveness, self‐healing and adaptability. In this mini‐review, we provide a survey of the pillar[n]arene‐based literatures covering light‐harvesting systems, functional hydrogels, and solid materials. It is anticipated that more and more pillar[n]arenes‐based advanced materials with multi‐functional properties will appear in the near future. [ABSTRACT FROM AUTHOR]

Cobalt-catalyzed C−H amination of arenes with alkylamines by the assistance of 8-aminoquinoline as auxiliary through sp2 C−H bond functionalization has been achieved. Attractive features of this protocol include the low loading of the cobalt catalyst and the readily available reagents. [ABSTRACT FROM AUTHOR]

Two novel photochromic macrocycles 1 and 2 bearing dithienylethene units and urea building blocks have been synthesized, and their photochromic properties are described. Macrocycle 2 shows good photochromic properties, while the relatively smaller size of macrocycle 8b exhibits photochemically inactive properties due to the unfavourable ring conformational constraint. Moreover, the crystal structures of the urea-protected precursor macrocyles 3a, 3b, and 8b are presented. [ABSTRACT FROM AUTHOR]

The title reaction features low catalyst loading and readily available reagents, but it only applies to cyclic amines. [ABSTRACT FROM AUTHOR]

Review: 61 refs. [ABSTRACT FROM AUTHOR]