An Organic Vapor-Responsive Actuator Based on a Novel Urea Macrocycle.

The mechanical actuation of smart materials has garnered considerable attention in biological and medical research due to their ability to mimic biological processes at both molecular level, such as conformational changes in individual compounds, and at the macroscopic level, where polymeric substrates respond to external stimuli. In this study, we present a polymeric composite incorporating a novel urea macrocycle as a filler, forming a soft actuator that responds to various organic solvent vapors. The underlying actuation mechanism is attributed to crystalline phase transition of urea macrocycle, driven by the host-guest interactions with diverse guest molecules.

A Smart Polycage Membrane with Responsive Osmotic Energy Conversion Based on Synchronously Switchable Microporosity and Chargeability.

Membranes with specific pore sizes are widely used in molecular separation, ion transport, and energy conversion. However, the molecular understanding of structure-property performance in membrane science has been an urgent and long-standing problem. A promising but challenging solution lies in the fine-tuning of the membrane microstructure and properties to control membrane performance.

Supramolecular Interfacial Assembly: Integrating Supramolecular Hosts into Polymeric Membranes through an Aqueous Interface.

Efficient incorporation of macrocycles in polymeric membranes can impart the overall matrix with new properties for a range of cutting-edge applications. Here, we introduce a Supramolecular Interfacial Assembly (SIA) method for the fabrication of polymeric membranes featuring embedded macrocycles. Through harnessing the quasi-liquid nature of the concentrated polymer solution, SIA orchestrates the homogeneous spreading of macrocycles in an aqueous layer on its surface, leading to the creation of an interface between "water/water" phases, subsequently forming a cross-linked membrane driven by supramolecular electrostatic interactions.

Inhibition of the Germination of Root Parasitic Plants by Zeolitic Imidazolate Framework-8.

Crystalline ZIF-8 (C-ZIF-8) and amorphous ZIF-8 (Am-ZIF-8) were prepared and investigated to control the germination of Striga hermonthica, a root parasitic plant, which threatens cereal crops production particularly in sub-Saharan Africa. We have demonstrated that Am-ZIF-8 shows a better performance than C-ZIF-8 in inhibiting Striga seeds germination. This efficient performance of Am-ZIF-8 materials can be attributed to the incomplete deprotonation of 2 methylimidazole (2MIM) during amorphization, leading to the presence of unsaturated Zn-N coordination with the uncoordinated -NH groups available to undergo hydrogen bonding with the strigolactone analog GR24 forming a more stable Am-ZIF-8⋅⋅⋅GR24 hydrogen bonded network.

Polar organic cages for efficiently separating azeotropic mixtures.

Dihydroxy-based polar organic cages (DIHO-cages) are reported to selectively separate toluene with 99.5% purity from an equimolar toluene/pyridine mixture, resulting in subsequent superior purification of pyridine. The efficient separation and purification, enhanced by strong and multiple host/guest C-H⋯O interactions between the cage and toluene, showcases DIHO-cages as a suitable candidate for the remarkable separation of such azeotropes on an industrial scale.

Metal-Organic Framework-Mediated Delivery of Nucleic Acid across Intact Plant Cells.

Plant synthetic biology is applied in sustainable agriculture, clean energy, and biopharmaceuticals, addressing crop improvement, pest resistance, and plant-based vaccine production by introducing exogenous genes into plants. This technique faces challenges delivering genes due to plant cell walls and intact cell membranes. Novel approaches are required to address this challenge, such as utilizing nanomaterials known for their efficiency and biocompatibility in gene delivery.

Smart touchless human-machine interaction based on crystalline porous cages.

The rise of touchless technology, driven by the recent pandemic, has transformed human-machine interaction (HMI). Projections indicate a substantial growth in the touchless technology market, nearly tripling from $13.6 billion in 2021 to an estimated $37.

Fluorine-Boosted Kinetic and Selective Molecular Sieving of C6 Derivatives.

Porous molecular sorbents have excellent selectivity towards hydrocarbon separation with energy saving techniques. However, to realize commercialization, molecular sieving processes should be faster and more efficient compared to extended frameworks. In this work, we show that utilizing fluorine to improve the hydrophobic profile of leaning pillararenes affords a substantial kinetic selective adsorption of benzene over cyclohexane (20 : 1 for benzene).

Caging the Hofmeister Effect by a Biomimetic Supramolecular Receptor.

The effect of anions on the solubility and function of proteins was recognized in 1888 and is now termed the Hofmeister effect. Numerous synthetic receptors are known that overcome the associated anion recognition bias. However, we are unaware of a synthetic host being used to overcome Hofmeister effect perturbations to natural proteins.

Vapor-Triggered Mechanical Actuation in Polymer Composite Films Based on Crystalline Organic Cages.

The fabrication of smart materials, which can efficiently mimic biological systems through the introduction of soft components, is of great importance in the emerging fields of sensors and actuators. Herein, a smart composite film that can mechanically respond to vapors trigger then readily restores its original shape upon the removal of the stimuli is reported. This actuating composite film was prepared by mixing the highly elastic poly (vinylidene fluoride) (PVDF) polymer with the flexible and crystalline organic cages (Oba-cage) at variable concentrations.

Highly selective molecular sieving of - over -1,2-dichloroethene isomers.

An intrinsically porous trianglimine macrocycle 1 is reported to display energy-efficient and cost-effective adsorptive properties by selectively separating -1,2-dichloroethene (-DCE) from an equimolar - and -DCE mixture with a purity of over 96%. The selectivity is enhanced by host/guest C-H⋯π intermolecular interactions. Moreover, the macrocycle can be reused many times without any decrease in performance, which further supports the sustainability of using molecular sieves in chemical separation.

Photostable polymorphic organic cages for targeted live cell imaging.

Fluorescent microscopy is a powerful tool for studying the cellular dynamics of biological systems. Small-molecule organic fluorophores are the most commonly used for live cell imaging; however, they often suffer from low solubility, limited photostability and variable targetability. Herein, we demonstrate that a tautomeric organic cage, OC1, has high cell permeability, photostability and selectivity towards the mitochondria.

Pillar[3]trianglamines: deeper cavity triangular macrocycles for selective hexene isomer separation.

The separation of α-olefins and their corresponding isomers continues to be a big challenge for the chemical industry due to their overlapping physical properties and low relative volatility. Herein, pillar[3]trianglamine (P-TA) macrocycles were synthesized for the molecular-sieving-like separation of 1-hexene (1-He) selectively over its positional isomer -3-hexene (trans-3-He) in the vapor and liquid state. This allyl-functionalized macrocycle features a deeper cavity compared to the previously reported trianglamine host molecules.

Tuning the porosity of triangular supramolecular adsorbents for superior haloalkane isomer separations.

Distillation-free separations of haloalkane isomers represents a persistent challenge for the chemical industry. Several classic molecular sorbents show high selectivity in the context of such separations; however, most suffer from limited tunability or poor stability. Herein, we report the results of a comparative study involving three trianglamine and trianglimine macrocycles as supramolecular adsorbents for the selective separation of halobutane isomers.

Coordination-based self-assembled capsules (SACs) for protein, CRISPR-Cas9, DNA and RNA delivery.

Biologics, such as functional proteins and nucleic acids, have recently dominated the drug market and comprise seven out of the top 10 best-selling drugs. Biologics are usually polar, heat sensitive, membrane impermeable and subject to enzymatic degradation and thus require systemic routes of administration and delivery. Coordination-based delivery vehicles, which include nanosized extended metal-organic frameworks (nMOFs) and discrete coordination cages, have gained a lot of attention because of their remarkable biocompatibility, stability, on-demand biodegradability, high encapsulation efficiency, easy surface modification and moderate synthetic conditions.

Selective adsorptive separation of cyclohexane over benzene using thienothiophene cages.

The selective separation of benzene (Bz) and cyclohexane (Cy) is one of the most challenging chemical separations in the petrochemical and oil industries. In this work, we report an environmentally friendly and energy saving approach to separate Cy over Bz using thienothiophene cages (ThT-cages) with adaptive porosity. Interestingly, cyclohexane was readily captured selectively from an equimolar benzene/cyclohexane mixture with a purity of 94%.

A Polymorphic Azobenzene Cage for Energy-Efficient and Highly Selective p-Xylene Separation.

Developing the competence of molecular sorbents for energy-saving applications, such as C8 separations, requires efficient, stable, scalable, and easily recyclable materials that can readily transition to commercial implementation. Herein, we report an azobenzene-based cage for the selective separation of p-xylene isomer across a range of C8 isomers in both vapor and liquid states with selectivity that is higher than the reported all-organic sorbents. The crystal structure shows non-porous cages that are separated by p-xylene molecules through selective CH-π interactions between the azo bonds and the methyl hydrogen atoms of the xylene molecules.

From Capsule to Helix: Guest-Induced Superstructures of Chiral Macrocycle Crystals.

Predicting, controlling, understanding, and elucidating the phase transition from gel to crystal are highly important for the development of various functional materials with macroscopic properties. Here, we show a detailed and systematic description of the self-assembly process of an enantiopure trianglimine macrocyclic host from gel to single crystals. This proceeds via an unprecedented formation of capsule-like or right-handed helix superstructures as metastable products, depending on the nature of the guest molecule.

Reversible thermosalience of 4-aminobenzonitrile.

Crystals of 4-aminobenzonitrile grown by sublimation undergo reversible thermosalient phase changes during cooling and subsequent heating. Single-crystal diffraction studies have been carried out at 20 K intervals during cooling from 300 to 100 K in order to explain the structural change that occurs.

Hand-twistable plastically deformable crystals of a rigid small organic molecule.

4-Bromobenzonitrile was crystallised by sublimation under vacuum. The crystals show highly flexible plastic bending along two perpendicular faces when a mechanical force is applied. The rare occurrence of bending along two perpendicular faces results in twisting or helix formation.

Synthesis of zinc-carboxylate metal-organic frameworks for the removal of emerging drug contaminant (amodiaquine) from aqueous solution.

We herein report the removal of amodiaquine, an emerging drug contaminant from aqueous solution using [Zn(fum)(bpy)] and [ZnO(bdc)] (fum=fumaric acid; bpy=4,4-bipyridine; bdc=benzene-1,4-dicarboxylate) metal-organic frameworks (MOFs) as adsorbents. The adsorbents were characterized by elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, and powder X-ray diffraction (PXRD). Adsorption process for both adsorbents were found to follow the pseudo-first-order kinetics, and the adsorption equilibrium data fitted best into the Freundlich isotherm with the R values of 0.

Hydration-dependent anomalous thermal expansion behaviour in a coordination polymer.

A coordination polymer is shown to possess anomalous anisotropic thermal expansion. Guest water molecules present in the as-synthesised material can be removed upon activation without loss of crystal singularity. The fully dehydrated form shows considerably different thermal expansion behaviour as compared to the hydrate.