Ultrastable Imidazole-linked Porous Organic Cages for Ammonia Capture and Detection.

Here, we report the facile synthesis of imidazole-linked porous organic cages (IPOCs) via an in situ cyclization reaction protocol. Specifically, three IPOCs with [2+4] lantern-like structures and one with a [3+6] triangular prism structure were successfully prepared through condensation reactions between tetraformyl-functionalized calix[4]arene and bis(o-phenylenediamine) monomers in a single pot. Notably, these IPOCs exhibit high porosity, with Brunauer-Emmett-Teller (BET) specific surface areas reaching up to 1162 m g.

Metal-Organic Framework with Open Metal Sites for D/H Separation.

The separation of hydrogen isotopes remains a significant challenge due to their nearly identical physicochemical properties. Recently, metal-organic frameworks employing the chemical affinity quantum sieving effect have garnered increasing attention for hydrogen isotope separation. In this study, with open metal sites was synthesized and demonstrated high hydrogen isotope adsorption capacities of 266 cm/g for H and 288 cm/g for D.

Improving the Cellular Internalization of Zr(IV) Nanocages by Tuning Hydrophilicity and Lipophilicity.

Nanoscale molecular materials have emerged as a new class of compounds at the nanometer scale with well-defined chemical structures, remarkable uniformity and high reproducibility. Among these materials, zirconium-based metal-organic cages (MOCs) have attracted significant attention due to their exceptional stability and applications in catalysis, recognition and separation and so on. However, their poor water solubility impedes their biomedical applications.

Stable Porous Organic Cage Nanocapsules for pH-Responsive Anticancer Drug Delivery for Precise Tumor Therapy.

The search for drug nanocarriers with stimuli-responsive properties and high payloads for targeted drug delivery and precision medicine is currently a focal point of biomedical research, but this endeavor still encounters various challenges. Herein, a porous organic cage (POC) is applied to paclitaxel (PTX) drug delivery for cancer therapy for the first time. Specifically, water-soluble, stable, and biocompatible POC-based nanocapsules (PTX@POC@RH40) with PTX encapsulation efficiency over 98% can be synthesized by simply grafting nonionic surfactant (Polyoxyl 40 hydrogenated castor oil, RH40) on the POC surface.

Construction of stable porous organic cages: from the perspective of chemical bonds.

Porous organic cages (POCs) are constructed from purely organic synthons by covalent linkages with intrinsic cavities and have shown potential applications in many areas. However, the majority of POC synthesis methods reported thus far have relied on dynamically reversible imine linkages, which can be metastable and unstable under humid or harsh chemical conditions. This instability significantly hampers their research prospects and practical applications.

Hierarchical Self-Assembly of Capsule-Shaped Zirconium Coordination Cages with Quaternary Structure.

Biological macromolecules exhibit emergent functions through hierarchical self-assembly, a concept that is extended to design artificial supramolecular assemblies. Here, the first example of breaking the common parallel arrangement of capsule-shaped zirconium coordination cages is reported by constructing the hierarchical porous framework ZrR-1. ZrR-1 adopts a quaternary structure resembling protein and contains 12-connected chloride clusters, representing the highest connectivity for zirconium-based cages reported thus far.

Effect of Functional Groups on Low-Concentration Carbon Dioxide Capture in -Type Metal-Organic Frameworks.

The selective capture of low-concentration CO from air or confined spaces remains a great challenge. In this study, various functional groups were introduced into to generate functionalized derivatives (, = , , , and ), aiming at significantly enhancing CO adsorption and separation efficiency. More significantly, and with high polarity exhibit exceptional CO affinity and optimal separation characteristics in mixed CO/O/N (1:21:78).

Chiral proline-substituted porous organic cages in asymmetric organocatalysis.

The efficient preparation of chiral porous organic cages (POCs) with specific functions is challenging, and their application in asymmetric catalysis has not previously been explored. In this work, we have achieved the construction of chiral POCs based on a supramolecular tetraformyl-resorcin[4]arene scaffold with different chiral proline-modified diamine ligands and utilizing dynamic imine chemistry. The incorporation of V-shaped or linear chiral diamines affords the [4 + 8] square prism and [6 + 12] octahedral POCs respectively.

Water-stable hydrazone-linked porous organic cages.

Although porous organic cages (POCs), particularly imine-linked (C[double bond, length as m-dash]N) ones, have advanced significantly over the last few decades, the reversible nature of imine linkages makes them prone to hydrolysis and structural collapse, severely limiting their applications under moist or water conditions. Herein, seven water-stable hydrazone-linked (C[double bond, length as m-dash]N-N) POCs are prepared through a simple coupling of the same supramolecular tetraformylresorcin[4]arene cavitand with different dihydrazide linkers. Their structures are all determined by single-crystal X-ray crystallography, demonstrating rich structural diversity from the [2 + 4] lantern, [3 + 6] triangular prism, and unprecedented [4 + 8] square prism to the extra-large [6 + 12] octahedron.

Efficient ethylene purification by a robust ethane-trapping porous organic cage.

The removal of ethane (CH) from its analogous ethylene (CH) is of paramount importance in the petrochemical industry, but highly challenging due to their similar physicochemical properties. The use of emerging porous organic cage (POC) materials for CH/CH separation is still in its infancy. Here, we report the benchmark example of a truncated octahedral calix[4]resorcinarene-based POC adsorbent (CPOC-301), preferring to adsorb CH than CH, and thus can be used as a robust absorbent to directly separate high-purity CH from the CH/CH mixture.

Solvatomorphism Influence of Porous Organic Cage on CH/CO Separation.

Porous organic molecular (POM) materials can exhibit solvatomorphs via altering their crystallographic packing in the solid state, but investigating real gas mixture separation by porous materials with such a behavior is still very rare. Herein, we report that a lantern-shaped calix[4]resorcinarene-based porous organic cage (POC, namely, ) can exhibit eight distinct solid-state solvatomorphs via crystallization in different solvents. This POC solvatomorphism has a significant influence on their gas sorption capacities as well as separation abilities.

Reticular Chemistry in the Construction of Porous Organic Cages.

Reticular chemistry offers the possibility of systematic design of porous materials with different pores by varying the building blocks, while the emerging porous organic cage (POC) system remains generally unexplored. A series of new POCs with dimeric cages with odd-even behaviors, unprecedented trimeric triangular prisms, and the largest recorded hexameric octahedra have been prepared. These POCs are all constructed from the same tetratopic tetraformylresorcin[4]arene cavitand by simply varying the diamine ligands through Schiff-base reactions and are fully characterized by X-ray crystallography, gas sorption measurements, NMR spectroscopy, and mass spectrometry.

Structural and Morphological Conversion between Two Co-Based MOFs for Enhanced Water Oxidation.

The rapid development of suitable and cheap water oxidation catalysts is of great significance in energy conversion and storage. In this context, herein we have synthesized two different types of metal-organic frameworks (MOFs, denoted as and ) constructed from the same metal salts (cobalt nitrate) and organic linkers (HBPTC) at the similar solvothermal conditions. Interestingly, we learned that both crystalline materials can be conveniently converted into each other by a single-crystal-to-single-crystal transformation method at their corresponding synthetic conditions.

A Reusable MOF-Supported Single-Site Zinc(II) Catalyst for Efficient Intramolecular Hydroamination of o-Alkynylanilines.

The exploitation of new and active earth-abundant metal catalysts is critical for sustainable chemical production. Herein, we demonstrate the design of highly efficient, robust, and reusable Zn -bipyridine-based metal-organic framework (MOF) catalysts for the intramolecular hydroamination of o-alkynylanilines to indoles. Under similar conditions homogeneous catalytic systems mainly provide hydrolysate.

Interconvertible vanadium-seamed hexameric pyrogallol[4]arene nanocapsules.

Research into stimuli-responsive controlled self-assembly and reversible transformation of molecular architectures has received much attention recently, because it is important to understand and reproduce this natural self-assembly behavior. Here, we report two coordination nanocapsules with variable cavities: a contracted octahedral V capsule and an expanded ball-shaped V capsule, both of which are constructed from the same number of subcomponents. The assemblies of these two V capsules are solvent-controlled, and capable of reversible conversion between contracted and expanded forms via control of the geometries of the metal centers by association and dissociation with axial water molecules.

A monomeric bowl-like pyrogallol[4]arene Ti coordination complex.

Herein, an unprecedented monomeric bowl-like coordination complex, TiPgC (PgC = C-propylpyrogallol[4]arene), has been successfully synthesized. To the best of our knowledge, TiPgC not only presents the first pyrogallol[4]arene-based titanium coordination complex, but also the highest nuclearity titanium coordination complex in the metal-calixarene system. In addition, this titanium coordination complex can effectively degrade the methylene blue (MB) dye under sunlight.

Controlled Orthogonal Self-Assembly of Heterometal-Decorated Coordination Cages.

Multiple orthogonal coordinative interactions were utilized to construct heterometal-decorated tetrahedral cages from in situ formed trinuclear Zr clusters through the combination with other metal ions such as Cu or Pd . Through effective use of the hard/soft acid/base principle, the orthogonal self-assembly process of Zr-bpydc-CuCl (H bpydc=2,2-bipyridine-5,5-dicarboxylic acid) can be finely controlled using three strategies: post-synthetic metallization, a stepwise metalloligand approach, or a one-pot reaction.

Cuboctahedron-based indium-organic frameworks for gas sorption and selective cation exchange.

[Me2NH2]3[In3(BTB)4]·2DMF·2DMA·28H2O (InOF-9) is an anionic indium-organic framework based on nanosized cuboctahedrons, which is sustained by tetrahedral [In(COO)4] nodes and 3-connected tricarboxylates. Although InOF-9 is structurally unstable when exposed to air, it exhibits excellent gas sorption capacity through a supercritical carbon dioxide activation process and selectively encapsulates guest methylene blue cations.

Visualizing the Dynamics of Temperature- and Solvent-Responsive Soft Crystals.

We demonstrate that three flexible MOFs termed FJI-H11-R (FJI-H=Hong's group in Fujian Institute of Research on the Structure of Matter, R=Me, Et, (i) Pr) can reversibly respond to temperature and solvents via structural transformations, which can be visualized by in situ single-crystal X-ray snapshot analyses. FJI-H11-R exhibit colossal anisotropic thermal expansion, with a record-high uniaxial positive thermal-expansion coefficient of 653.2×10(-6)  K(-1) observed in FJI-H11-Me.

A porous metal-organic framework with ultrahigh acetylene uptake capacity under ambient conditions.

Acetylene, an important petrochemical raw material, is very difficult to store safely under compression because of its highly explosive nature. Here we present a porous metal-organic framework named FJI-H8, with both suitable pore space and rich open metal sites, for efficient storage of acetylene under ambient conditions. Compared with existing reports, FJI-H8 shows a record-high gravimetric acetylene uptake of 224 cm(3) (STP) g(-1) and the second-highest volumetric uptake of 196 cm(3) (STP) cm(-3) at 295 K and 1 atm.

Self-assembly of polyhedral indium-organic nanocages.

A synthetic strategy to construct discrete indium-organic polyhedra has been illustrated based on small three-membered windows from a 2,5-pyridinedicarboxylate (PDC) ligand with an angle of 120°. [Et2NH2]6[In6(PDC)12] (InOF-10) is a high-symmetry octahedron with eight three-membered windows, and [Et2NH2]18[In18(BPDC)6(PDC)30] (InOF-11) is a complex polyhedron derived from 3-edge-removed octahedra with an auxiliary biphenyl-3,3'-dicarboxylate (BPDC) ligand. Moreover, the sorption behavior of the latter is also well investigated.

Heterometallic cluster-based indium-organic frameworks.

With the help of the ligand-oriented method, we have successfully embedded independent copper-based units into the indium-organic framework system for the first time, in which the Cu4I4 clusters and In3O(CO2)6 clusters coexist. This heterometallic cluster-based framework has a large porosity with extra-open channels along the c-axis, and its sorption capacity has also been investigated.

Coexistence of cages and one-dimensional channels in a porous MOF with high H(2) and CH(4) uptakes.

A porous metal-organic framework with high surface area was designedly synthesized, in which polyhedral cages and one-dimensional channels coexist. It shows a total gravimetric H2 uptake of 11.35 wt% at 77 K and 90 bar and a total CH4 uptake of 305.