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Poly(ionic liquid) (PIL)‐based porous membranes are extensively investigated as soft polymer actuators. While PILs have shown significant advancements in membrane fabrication and stabilization of metal nanoparticles (MNPs), research on integrating MNPs into porous membranes to achieve actuation behavior under multiple stimuli is limited. Herein, this work presents a new paradigm for designing a porous PIL‐polyacrylic acid (PAA) membrane with a distinct MNP gradient via a top‐bottom diffusion approach involving a metal salt precursor solution and NaBH4 as a reducing agent. The strong binding sites provided by PILs, combined with the gradient distribution of ‐COO− groups across the membrane cross‐section, play a significant role in controlling the MNPs' gradient distribution. Interestingly, the MNPs within the membrane display excellent catalytic activity in exothermic reactions such as H2O2 decomposition, dissipating uneven heat that quickly permeates the membrane network. This induces asymmetrical swelling of polymer chains, resulting in rapid membrane bending. Furthermore, such MNP‐loaded membrane could serve as a portable test paper for visually monitoring H2O2. This advancement paves the way for the development of intricate smart actuation materials and expands their practical applications in various real‐life scenarios. [ABSTRACT FROM AUTHOR]

Biological cell membrane featuring smart mass-transport channels and sub-10 nm thickness was viewed as the benchmark inspiring the design of separation membranes; however, constructing highly connective and adaptive pore channels over large-area membranes less than 10 nm in thickness is still a huge challenge. Here, we report the design and fabrication of sub-8 nm networked cage nanofilms that comprise of tunable, responsive organic cage-based water channels via a free-interface-confined self-assembly and crosslinking strategy. These cage-bearing composite membranes display outstanding water permeability at the 10−5 cm2 s−1 scale, which is 1–2 orders of magnitude higher than that of traditional polymeric membranes. Furthermore, the channel microenvironments including hydrophilicity and steric hindrance can be manipulated by a simple anion exchange strategy. In particular, through ionically associating light-responsive anions to cage windows, such ‘smart’ membrane can even perform graded molecular sieving. The emergence of these networked cage-nanofilms provides an avenue for developing bio-inspired ultrathin membranes toward smart separation.Drawing inspiration from biological cell membranes, here, the authors create sub-8 nm membranes with adaptive nanofluidic channels, mimicking the cell membrane properties, by interconnecting 0D nanoporous molecules at the oil/water interface. [ABSTRACT FROM AUTHOR]

A cage hybrid (C-Cage–PB) was developed by electrostatic complexation of a quaternary ammonium cage (C-Cage+) and an anionic inorganic Prussian blue (PB−). Given the unique synergy of the two parts, such a cage hybrid can be used as a promising platform for the efficient removal of toxic compounds in wastewater through adsorption, delivery or catalytic degradation via a Fenton oxidation reaction. In addition, C-Cage–PB can encapsulate Pd clusters, which amplifies the function of the hybrid for enhanced catalytic performance in the sequential degradation of toxic organic compounds and heavy metal pollution in wastewater treatment. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive nanoporous materials represent a newly emerging category of functional materials, for which instant and significant response behavior is strongly demanded but still challenging. Herein, a new kind of conjugated poly(ionic liquid)s (PILs) synthesized via a simple one‐pot spontaneous nucleophilic substitution and polymerization between 4,4'‐vinylenedipyridine and propargyl bromide is reported. A nanoporous membrane actuator is further developed via ionic complexation between the current PIL and trimesic acid. The actuator carries a gradient density in the hydrophobicity content along the membrane cross‐section, which results in a fast response to moisture. [ABSTRACT FROM AUTHOR]

Multiple charge separation has been successfully realized by a proton‐coupled electron transfer reaction in an organic cocrystal. Benefiting from the adjustable electronic energy level of the electron donor and acceptor through thermal‐induced proton migration, distinct optical absorption behaviors combined with color changes to blue or green are observed in these charge‐separated states. It is of interest to note that such charge‐separated states exhibit a longer lifetime of over a month as a result of the excellent coplanarity and π‐π interaction of the electron acceptors. Moreover, the enhanced absorption toward longer wavelengths endows the charge‐separated state with near‐infrared (808 nm) photothermal conversion for imaging and bacterial inhibition, whereby the conversion performance can be controlled by the degree of proton migration. [ABSTRACT FROM AUTHOR]

Multiple charge separation has been successfully realized by a proton‐coupled electron transfer reaction in an organic cocrystal. Benefiting from the adjustable electronic energy level of the electron donor and acceptor through thermal‐induced proton migration, distinct optical absorption behaviors combined with color changes to blue or green are observed in these charge‐separated states. It is of interest to note that such charge‐separated states exhibit a longer lifetime of over a month as a result of the excellent coplanarity and π‐π interaction of the electron acceptors. Moreover, the enhanced absorption toward longer wavelengths endows the charge‐separated state with near‐infrared (808 nm) photothermal conversion for imaging and bacterial inhibition, whereby the conversion performance can be controlled by the degree of proton migration. [ABSTRACT FROM AUTHOR]

The controlled synthesis of subnanometer‐sized metal clusters (MCs) presents a fascinating prospect for the research of size‐dependent properties. In this study, a facile approach by employing porous racemic organic cage crystals as supports for immobilizing a broad range of noble MCs (e.g., Ru, Ir, Rh) is reported. Downsizing the support to the nanoscale leads to resultant MCs with precisely controlled sizes < 0.7 nm. Such enhanced stabilization ability is a result of enhanced metal–support interactions as well as the nanoconfinement of organic cages in controlling the growth of MCs. Moreover, the obtained MCs display excellent catalytic performance in a series of liquid‐phase reactions owing to a decrease in the diffusion resistance from the substrate to MCs immobilized by the nano‐sized cage support. [ABSTRACT FROM AUTHOR]

The effective capture of iodine with high volatility and poisonousness is significant for reprocessing the spent nuclear fuel. In this article, we report a hierarchically porous poly(ionic liquid)‐organic cage composite membrane (PIL@CC3) possessing a gradient content distribution of CC3 cage crystals throughout the membrane to capture iodine vapor. The introduction of microporous CC3 can significantly enhance the uptake capacity of iodine up to 980 mg g−1, which is superior to that of a pristine PIL membrane carrying large meso‐ and macropores (99 mg g−1), and CC3 crystalline powder (662 mg g−1). Such enhanced performance benefits from the micro‐meso‐macroporous structure of the PIL@CC3 membrane in which the large meso‐ and macropores facilitate the mass transfer of iodine molecules from the external environment into the surface of the CC3 crystal, followed by diffusion of iodine molecules from the CC3 surface into the interior and exterior pores of the CC3 crystal. In addition, the asymmetric distribution of CC3 crystals across the PIL@CC3 membrane also displays its advantage in intercepting trace iodine, revealing its great potential for practical application. This study provides an idea for constructing hierarchically porous membrane composites for the removal of toxic vapors. [ABSTRACT FROM AUTHOR]

Living systems integrate complex sequential chemical reactions by spatially organizing enzymes confined inside subcellular organelles. Inspired by the ingenuity from nature, we have shown that the integrated artificial Pd cluster@porous organic cage-C3N4 catalyst can boost a series of sequential reactions, from simple two-step, to complicated multistep and even convergent catalysis. Specifically, the Pd cluster encapsulated cationic cage (Pd@C-Cage+) undergoes ionic complexation with anionic carbon nitride (C3N4–), in which C-Cage+ compartmentalizes the dual catalytic centers (Pd cluster and C3N4–) to accelerate diverse reactions via a substrate channelling effect. Moreover, the current artificial catalyst system (Pd@C-Cage+/C3N4–) is able to integrate diverse logic networks to achieve intricate digital designs by combining two concatenated AND gates and various inputs, which will inspire future chemical synthesis with enhanced efficiency. [ABSTRACT FROM AUTHOR]

The construction of hierarchically nanoporous composite for high-performance catalytic application is still challenging. In this work, a series of host-in-host ionic porous materials are crafted by encapsulating ionic organic cages into a hyper-crosslinked, oppositely charged porous poly(ionic liquid) (PoPIL) through an ion pair-directed assembly strategy. Specifically, the cationic cage (C-Cage) as the inner host can spatially accommodate a functional Au cluster, forming a [Au⊂C-Cage+]⊂PoPIL− supramolecular composite. This dual-host molecular hierarchy enables a charge-selective substrate sorting effect to the Au clusters, which amplifies their catalytic activity by at least one order of magnitude as compared to Au confined only by C-Cage as the mono-host (Au⊂C-Cage+). Moreover, we demonstrate that such dual-host porous system can advantageously immobilize electrostatically repulsive Au⊂C-Cage+ and cationic ferrocene co-catalyst (Fer+) together into the same microcompartments, and synergistically speed up the enzyme-like tandem reactions by channelling the substrate to the catalytic centers via nanoconfinement. The encapsulation of catalysts within hosts is a strategy to tune their reactivity. Here, the authors encapsulate a gold cluster within a porous cage and study its reactivity. [ABSTRACT FROM AUTHOR]

The harmful effect of poisonous oxoanions on the water environment highlights the urgent demand for effective adsorption materials. Rather than utilizing open framework materials carrying continuous pores as oxoanion traps, nanoporous molecular cages with discrete pores show promise since they are supposed to have higher adsorption efficiency. However, they are rarely reported in the field of decontamination. Herein, we utilize a nanoporous cationic organic cage, I-Cage-Cl, as a type of adsorbent that can efficaciously and selectively trap hazardous oxoanions from aqueous solutions via anion exchange. Specifically, cationic I-Cage-Cl shows a superior uptake capacity of CrO42– (540 mg g–1) that surpasses the reported nanoporous cationic frameworks along with excellent selectivity for CrO42– even with a 500-fold excess of interfering ions (Br–, NO3–, ClO4–, and BF4–). Furthermore, we fabricate an I-Cage-SPSf composite membrane (SPSf = sulfonated polysulfone), which can rapidly reduce trace Cr-(VI) below the drinking water standard while also exhibiting extremely high water flux (80 L m–2 h–1 bar–1) and admirable reproducibility. These intriguing features indicate that nanoporous organic cages are promising candidates for wastewater treatment. [ABSTRACT FROM AUTHOR]

Imparting mesopores to organic cages of an intrinsic microporous nature to build up hierarchically porous cage soft materials is a grand challenge and will reshape the property and application scope of traditional organic cage molecules. Herein, we discovered how to engineer mesopores into microporous organic cages via their host–guest interactions with long chain ionic surfactants. Equally important, the ionic head of surfactants equips the supramolecularly assembled porous structures with charge‐selective uptake and release function in solution. Interestingly, such hierarchically porous organic cage can serve as a nanoreactor once trapping enzymes within the cavity, which show 5‐fold enhanced activity of enzymatic catalysis when compared with the free enzymes. [ABSTRACT FROM AUTHOR]

Imparting mesopores to organic cages of an intrinsic microporous nature to build up hierarchically porous cage soft materials is a grand challenge and will reshape the property and application scope of traditional organic cage molecules. Herein, we discovered how to engineer mesopores into microporous organic cages via their host–guest interactions with long chain ionic surfactants. Equally important, the ionic head of surfactants equips the supramolecularly assembled porous structures with charge‐selective uptake and release function in solution. Interestingly, such hierarchically porous organic cage can serve as a nanoreactor once trapping enzymes within the cavity, which show 5‐fold enhanced activity of enzymatic catalysis when compared with the free enzymes. [ABSTRACT FROM AUTHOR]

The capability to significantly shorten the synthetic period of a broad spectrum of open organic materials presents an enticing prospect for materials processing and applications. Herein we discovered 1,2,4‐triazolium poly(ionic liquid)s (PILs) could serve as a universal additive to accelerate by at least one order of magnitude the growth rate of representative imine‐linked crystalline open organics, including organic cages, covalent organic frameworks (COFs), and macrocycles. This phenomenon results from the active C5‐protons in poly(1,2,4‐triazolium)s that catalyze the formation of imine bonds, and the simultaneous salting‐out effect (induced precipitation by decreasing solubility) that PILs exert on these crystallizing species. [ABSTRACT FROM AUTHOR]

The capability to significantly shorten the synthetic period of a broad spectrum of open organic materials presents an enticing prospect for materials processing and applications. Herein we discovered 1,2,4‐triazolium poly(ionic liquid)s (PILs) could serve as a universal additive to accelerate by at least one order of magnitude the growth rate of representative imine‐linked crystalline open organics, including organic cages, covalent organic frameworks (COFs), and macrocycles. This phenomenon results from the active C5‐protons in poly(1,2,4‐triazolium)s that catalyze the formation of imine bonds, and the simultaneous salting‐out effect (induced precipitation by decreasing solubility) that PILs exert on these crystallizing species. [ABSTRACT FROM AUTHOR]

Poly(ionic liquid)s (PILs), as an innovative class of polyelectrolytes, are composed of polymeric backbones with IL species in each repeating unit. The combined merits of the polymers and ILs make them promising materials for composites in materials science. Particularly, the integration of PILs with functional substances (PIL composites) opens up a new dimension in utilizing ionic polymers by offering novel properties and improved functions, which impacts multiple subfields of our chemical society. This review summarizes recent developments of PIL composites with a special emphasis on the preparation techniques that are based on the intrinsic properties of the PILs and the synergistic effects between the PILs and substances of interest for diverse applications. [ABSTRACT FROM AUTHOR]

The ability to grow properly sized and good quality crystals is one of the cornerstones of single-crystal diffraction, is advantageous in many industrial-scale chemical processes1–3, and is important for obtaining institutional approvals of new drugs for which high-quality crystallographic data are required4–7. Typically, single crystals suitable for such processes and analyses are grown for hours to days during which any mechanical disturbances—believed to be detrimental to the process—are carefully avoided. In particular, stirring and shear flows are known to cause secondary nucleation, which decreases the final size of the crystals (though shear can also increase their quantity8–14). Here we demonstrate that in the presence of polymers (preferably, polyionic liquids), crystals of various types grow in common solvents, at constant temperature, much bigger and much faster when stirred, rather than kept still. This conclusion is based on the study of approximately 20 diverse organic molecules, inorganic salts, metal–organic complexes, and even some proteins. On typical timescales of a few to tens of minutes, these molecules grow into regularly faceted crystals that are always larger (with longest linear dimension about 16 times larger) than those obtained in control experiments of the same duration but without stirring or without polymers. We attribute this enhancement to two synergistic effects. First, under shear, the polymers and their aggregates disentangle, compete for solvent molecules and thus effectively 'salt out' (that is, induce precipitation by decreasing solubility of) the crystallizing species. Second, the local shear rate is dependent on particle size, ultimately promoting the growth of larger crystals (but not via surface-energy effects as in classical Ostwald ripening). This closed-system, constant-temperature crystallization driven by shear could be a valuable addition to the repertoire of crystal growth techniques, enabling accelerated growth of crystals required by the materials and pharmaceutical industries. A method of growing crystals that does not require undisturbed solutions involves adding polyelectrolytes to the starter solution and shearing (that is, stirring). [ABSTRACT FROM AUTHOR]

A nanoporous material bearing a high ion density and inherent organic radical character was synthesized by a facile one-pot process, which exhibits photo-, piezo- and chemochromism, driven by the diverse electron transfer processes between the acceptor framework and different electron donors. The responsive behavior is useful for its sensing application, as demonstrated here for pressure, anion and gas sensing. [ABSTRACT FROM AUTHOR]

A viologen-based Borromean entangled porous framework was found to be sensitive to both CuKα and MoKα X-ray sources, showing rapid photochromic response and recovery within one minute. The X-ray-induced photochromic process is accompanied by a reversible single-crystal-to-single-crystal (SC-SC) structural transformation, an unprecedented phenomenon for X-ray sensitive materials. The complex can be further processed into portable thin films for detecting the dose of the X-ray exposure. Moreover, the photochromism can occur over a broad temperature range of 100-333 K, both in the form of single crystals and thin films, making it a potential candidate for practical indoor and outdoor applications. [ABSTRACT FROM AUTHOR]

A viologen-based Borromean entangled porous framework was found to be sensitive to both CuKα and MoKα X-ray sources, showing rapid photochromic response and recovery within one minute. The X-ray-induced photochromic process is accompanied by a reversible single-crystal-to-single-crystal (SC-SC) structural transformation, an unprecedented phenomenon for X-ray sensitive materials. The complex can be further processed into portable thin films for detecting the dose of the X-ray exposure. Moreover, the photochromism can occur over a broad temperature range of 100-333 K, both in the form of single crystals and thin films, making it a potential candidate for practical indoor and outdoor applications. [ABSTRACT FROM AUTHOR]

The past decade has witnessed rapid progress in the synthesis of nanoporous organic networks or polymer frameworks for various potential applications. Generally speaking, functionalization of porous networks to add extra properties and enhance materials performance could be achieved either during the pore formation (thus a concurrent approach) or by post-synthetic modification (a sequential approach). Nanoporous organic networks which include ion pairs bound in a covalent manner are of special importance and possess extreme application profiles. Within these nanoporous ionic organic networks (NIONs), here with a pore size in the range from sub-1 nm to 100 nm, we observe a synergistic coupling of the electrostatic interaction of charges, the nanoconfinement within pores and the addressable functional units in soft matter resulting in a wide variety of functions and applications, above all catalysis, energy storage and conversion, as well as environment-related operations. This review aims to highlight the recent progress in this area, and seeks to raise original perspectives that will stimulate future advancements at both the fundamental and applied level. [ABSTRACT FROM AUTHOR]

B-doped porous carbons have attracted attention in energy applications including gas and energy storage due to the increase of binding energy for H2 and lowering the Fermi level. However, B-doped carbons are usually microporous materials, which show low surface areas. Herein, for the first time, hierarchically porous B-doped carbons derived from COF-5 have been obtained via a molten-salt (MS) approach. The carbons with micro–meso–macro-porous architectures exhibit enhanced supercapacitive performance and H2 storage properties. The methodology described may open up a new avenue towards the synthesis of distinct carbon materials in liquid media. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) as newly emerged materials have experienced rapid development in the last few years. The modular synthesis procedure allows integrating functional groups in their frameworks with varied applications. Due to the easy modification of the backbone and highly charged characteristics with interesting electron-active properties, the use of bipyridinium derivatives as synthons for the fabrication of functional metal–bipyridinium frameworks (MBPFs) has attracted increased interest over the past few years. Various bipyridinium-bearing ligands have been designed for the construction of functional MBPFs, and some of them present intriguing properties for potential applications including photochromism and photoswitching, sensing, molecule adsorption and separation. This perspective aims to highlight the recent progress in this area, and seeks to uncover promising ideas that will underscore future advancements at both the fundamental and applied levels. [ABSTRACT FROM AUTHOR]

For the first time, high surface-area hierarchical hollow octahedral carbon cages have been successfully fabricated by carbonization of a metal–organic framework, MIL-100(Al), followed by subsequent controlled acid etching, which exhibit significant CO2 and H2 adsorption capacities. [ABSTRACT FROM AUTHOR]

Well-dispersed PtNi nanoparticles (NPs) grown on carbon nanodots (CNDs) derived from a metal-organic framework (ZIF-8) are synthesized by a simple reduction of metal precursors in the presence of CNDs, wherein the CNDs prove to be a powerful dispersion agent and distinct support for the PtNi NPs. The resultant PtNi-CND catalyst exerts almost 100 % H2 selectivity and a high activity for the decomposition of hydrous hydrazine at room temperature. This excellent catalytic performance might be a result of the synergistic effect of the CND support and the PtNi NPs. The utilization of CNDs as a support to anchor the active component NPs and thus to facilitate the electron transfer and mass transport kinetics during the catalytic reaction process opens up new avenues to design high-performance catalysts. [ABSTRACT FROM AUTHOR]

A series of nanoporous frameworks constructed by a polycatenated isoreticular 1D ribbon of rings have been developed. The orientation of catenated ribbons can be fine tuned by varying counter anions, which allows both pore size and shape to be systematically adjusted in a pre-synthetic process. Distinct from conventional pore construction modes in which the organic linkers are alternately connected by metal nodes into a 3D periodic arrangement, the present polycatenation approach represents an alternative for constructing soft porous materials with tunable pore metrics and functions. Furthermore, these porous structures can interconvert into each other based on an anion-exchange process, accompanied by the transformation of the interpenetrating structures in different dimensional networks, which is unusual in porous frameworks. In addition, such a porous framework can be post-synthetically modified by a photoinduced [2+2] cycloaddition reaction, which not only achieves the surface modification (from conjugated to non-conjugated inner surface), but also triggers the structural transformation from low dimension to high dimension. Such a post-modification process reinforces the pore architecture through a covalent locking effect and has a great impact on the adsorption properties. [ABSTRACT FROM AUTHOR]

Rolled‐up crystals: Photoinduced bending of large single crystals has been realized based on a simple organic small molecule (see picture). The bending process is accompanied with high visual fluorescence contrast, which is essential for remote detection of photomechanical work. [ABSTRACT FROM AUTHOR]

Krumme Kristalle: Große Einkristalle eines einfachen organischen kleinen Moleküls gehen ein lichtinduziertes Verbiegen ein (siehe Bild). Der Biegeprozess wird von einem starken visuellen Fluoreszenzkontrast begleitet, was für die Ferndetektion photomechanischer Arbeit genutzt werden kann. [ABSTRACT FROM AUTHOR]

A study of the supramolecular isomer-dependent photoresponse and emission behaviors of a carboxybenzyl-substituted bipyridinium salt in the solid state is presented. Two supramolecular isomers (A1and A2) are obtained by self-assembly with the same starting materials at different concentrations. The flexible conformation of the bipyridinium molecule results in different crystal packing geometries, which further influence and alter their photochromic behaviors owing to the crucial differences in the distance and orientation between the donor and acceptor moieties. Remarkably, the introduction of carboxyl groups into the bipyridinium molecule leads to intramolecular charge transfer (ICT) emissions in the visible region. A strong fluorescence emission can be detected in A1, and reversible on/off and multicolor (yellow, olivine and green) fluorescence switching, viaphoto-irradiation in the solid state, has been observed. Considering the easy chemical modification and the intriguing multicolor photoswitching properties, the present system shows great potential for use in solid photonic devices. [ABSTRACT FROM AUTHOR]

A bipyridinium ligand with a charge separated skeleton has been introduced into a metal–organic framework to yield a porous material with charge-polarized pore space, which exhibits selective adsorption for polar guest molecules and can be further used in gas chromatography for the separation of alcohol–water mixtures. [ABSTRACT FROM AUTHOR]

Eu(iii) ions have been introduced into a photoactive viologen system to yield a polyrotaxane-like metal–organic framework, which exhibits reversible photochromism and luminescence modulation with a non-destructive readout capability in the solid state. [ABSTRACT FROM AUTHOR]

Two Mn(ii) coordination complexes with considerable difference in photochromism and chirality have been constructed from the photoactive 1-(4-carboxybenzyl)-4,4′-bipyridinium ligand upon adjusting the reaction solvents. [ABSTRACT FROM AUTHOR]

A series of nanoporous frameworks  with tunable pore metrics and functions has been prepared using a polycatenation approach. As described in the Full Paper by J. Zhang et al. on p. 2488 ff., these unique porous structures can interconvert through an anion‐exchange process and can be post‐synthetically photomodified, which resulted in a significant effect on the adsorption properties. [ABSTRACT FROM AUTHOR]