Highly Porous Zirconium Metal-Organic Frameworks with β-UH3-like Topology Based on Elongated Tetrahedral Linkers

Shaping the Water-Harvesting Behavior of Metal-Organic Frameworks Aided by Fine-Tuned GPT Models

We construct a data set of metal-organic framework (MOF) linkers and employ a fine-tuned GPT assistant to propose MOF linker designs by mutating and modifying the existing linker structures. This strategy allows the GPT model to learn the intricate language of chemistry in molecular representations, thereby achieving an enhanced accuracy in generating linker structures compared with its base models. Aiming to highlight the significance of linker design strategies in advancing the discovery of water-harvesting MOFs, we conducted a systematic MOF variant expansion upon state-of-the-art MOF-303 utilizing a multidimensional approach that integrates linker extension with multivariate tuning strategies. We synthesized a series of isoreticular aluminum MOFs, termed Long-Arm MOFs (LAMOF-1 to LAMOF-10), featuring linkers that bear various combinations of heteroatoms in their five-membered ring moiety, replacing pyrazole with either thiophene, furan, or thiazole rings or a combination of two. Beyond their consistent and robust architecture, as demonstrated by permanent porosity and thermal stability, the LAMOF series offers a generalizable synthesis strategy. Importantly, these 10 LAMOFs establish new benchmarks for water uptake (up to 0.64 g g-1) and operational humidity ranges (between 13 and 53%), thereby expanding the diversity of water-harvesting MOFs.

Synthesis of hierarchically porous zirconium-based metal-organic framework@silica core-shell stationary phase through etching strategy for liquid chromatography

Metal organic frameworks (MOFs) show promise to be employed as stationary phase for high performance liquid chromatography (HPLC), however, the microporous structures of MOFs seriously restrict the diffusion and mass transfer of solute molecules, leading to a low column efficiency. In this paper, the fabrication of hierarchically porous UiO-66@SiO2 (HP- UiO-66@SiO2) core-shell microspheres via H2O2 etching has been proposed as a viable approach to enhance the separation performance of MOFs-based columns for HPLC. Through the direct treatment of the preliminary prepared UiO-66@SiO2 microspheres with H2O2 etching, HP-UiO-66@SiO2 core-shell microspheres were successfully synthesized with an enlarged pore size of up to 9 nm, facilitating efficient mass transfer in chromatographic separation. The prepared HP-UiO-66@SiO2 core-shell microspheres were then explored as stationary phase in HPLC to separate the nonpolar alkyl benzene homologues, the polar aromatic alcohol homologues and the xylene isomers. The results indicated that the baseline separations of these solutes were achieved successfully with narrow peak width and higher resolution than the UiO-66@SiO2 column. The HP-UiO-66@SiO2 column exhibited superior separation performance, reaching a maximum plate number of 134,459/m for fluorene, and showing good reproducibility. As a result, this template-free approach suggests that the fabrication of hierarchically porous MOFs@silica core-shell microspheres is a successful approach to enhance the column efficiency of MOFs-based columns in HPLC.

Reticular Chemistry in Its Chiral Form: Axially Chiral Zr(IV)-Spiro Metal-Organic Framework as a Case Study

The interplay of primary organic ligands and inorganic secondary building units (SBUs) has led to a continual boom of reticular chemistry, particularly metal-organic frameworks (MOFs). Subtle variations of organic ligands can have a significant impact on the ultimate structural topology and consequently, the material's function. However, the role of ligand chirality in reticular chemistry has rarely been explored. In this work, we report the organic ligand chirality-controlled synthesis of two zirconium-based MOFs (Spiro-1 and Spiro-3) with distinct topological structures as well as a temperature-controlled formation of a kinetically stable phase (Spiro-4) based on the carboxylate-functionalized inherently axially chiral 1,1'-spirobiindane-7,7'-phosphoric acid ligand. Specifically, Spiro-1 is a homochiral framework comprising only enantiopure S-spiro ligands and has a unique 4,8-connected sjt topology with large 3D interconnected cavities, while Spiro-3 contains equal amounts of S- and R-spiro ligands, resulting in a racemic framework of 6,12-connected edge-transitive alb topology with narrow channels. Interestingly, the kinetic product Spiro-4 obtained with racemic spiro ligands is built of both hexa- and nona-nuclear zirconium clusters acting as 9- and 6-connected nodes, respectively, giving rise to a newly discovered azs net. Notably, the preinstalled highly hydrophilic phosphoric acid groups combined with large cavity, high porosity, and outstanding chemical stability endow Spiro-1 with remarkable water vapor sorption performance, whereas Spiro-3 and Spiro-4 show poor performances due to inappropriate pore systems and structural fragility upon the water adsorption/desorption process. This work highlights the important role of ligand chirality in manipulating the framework topology and function and would further enrich the development of reticular chemistry.

Unlocking New Topologies in Zr-Based Metal-Organic Frameworks by Combining Linker Flexibility and Building Block Disorder

The outstanding diversity of Zr-based frameworks is inherently linked to the variable coordination geometry of Zr-oxo clusters and the conformational flexibility of the linker, both of which allow for different framework topologies based on the same linker-cluster combination. In addition, intrinsic structural disorder provides a largely unexplored handle to further expand the accessibility of novel metal-organic framework (MOF) structures that can be formed. In this work, we report the concomitant synthesis of three topologically different MOFs based on the same M₆O₄(OH)₄ clusters (M = Zr or Hf) and methane-tetrakis(p-biphenyl-carboxylate) (MTBC) linkers. Two novel structural models are presented based on single-crystal diffraction analysis, namely, cubic c-(4,12)MTBC-M₆ and trigonal tr-(4,12)MTBC-M₆, which comprise 12-coordinated clusters and 4-coordinated tetrahedral linkers. Notably, the cubic phase features a new architecture based on orientational cluster disorder, which is essential for its formation and has been analyzed by a combination of average structure refinements and diffuse scattering analysis from both powder and single-crystal X-ray diffraction data. The trigonal phase also features structure disorder, although involving both linkers and secondary building units. In both phases, remarkable geometrical distortion of the MTBC linkers illustrates how linker flexibility is also essential for their formation and expands the range of achievable topologies in Zr-based MOFs and its analogues.

Transition-Metal-Free Synthesis of Polyfluoro-Polyarylmethanes via Direct Cross-Coupling of Polyfluoroarenes and Benzyl Chlorides

The transition-metal-free direct cross-coupling between polyfluoroarenes and benzyl chlorides is reported. In this strategy, a variety of polyfluoro di-, tri- and tetra-arylmethanes was efficiently prepared with good to excellent yields in the presence of Mg turnings via a one-pot procedure. Significantly, this method provides a general approach for the synthesis of polyfluorinated polyarylmethanes.

Synthesis and Biomedical Applications of Highly Porous Metal-Organic Frameworks

In this review, aspects of the synthesis, framework topologies, and biomedical applications of highly porous metal-organic frameworks are discussed. The term "highly porous metal-organic frameworks" (HPMOFs) is used to denote MOFs with a surface area larger than 4000 m² g^-1. Such compounds are suitable for the encapsulation of a variety of large guest molecules, ranging from organic dyes to drugs and proteins, and hence they can address major contemporary challenges in the environmental and biomedical field. Numerous synthetic approaches towards HPMOFs have been developed and discussed herein. Attempts are made to categorise the most successful synthetic strategies; however, these are often not independent from each other, and a combination of different parameters is required to be thoroughly considered for the synthesis of stable HPMOFs. The majority of the HPMOFs in this review are of special interest not only because of their high porosity and fascinating structures, but also due to their capability to encapsulate and deliver drugs, proteins, enzymes, genes, or cells; hence, they are excellent candidates in biomedical applications that involve drug delivery, enzyme immobilisation, gene targeting, etc. The encapsulation strategies are described, and the MOFs are categorised according to the type of biomolecule they are able to encapsulate. The research field of HPMOFs has witnessed tremendous development recently. Their intriguing features and potential applications attract researchers' interest and promise an auspicious future for this class of highly porous materials.

Structure Tuning of Hafnium Metal–Organic Frameworks through a Mixed Solvent Approach

The recent development of water-stable metal–organic frameworks (MOFs) has significantly broadened the application scope of this emerging type of porous material. Structure tuning of hafnium MOFs is less studied compared with zirconium MOFs. In this work, we report the synthesis of a mesoporous hafnium MOF, csq-MOF-1, through finely tuning the solvent mixture ratio. The successful synthesis of csq-MOF-1 also relies on the linker flexibility as linker bending and a symmetry decrease were observed in this framework as compared to its structural isomer NPF-300 (Hf). The mesoporous feature and permanent porosity were determined by the N2 adsorption at 77 K. Such a hierarchical pore feature is expected to enable a variety of applications through encapsulation of large functional molecules. The synthetic strategy of utilizing a mixed solvent and flexible linker is expected to inspire the development of new hafnium MOFs with diverse topological structures.

Polyoxometalate-Based Metal-Organic Frameworks as the Solid Support to Immobilize MP-11 Enzyme for Enhancing Thermal and Recyclable Stability

The immobilization of enzymes has received much attention. Metal-organic framework (MOF) as the adsorbent for enzyme encapsulation provides an effective strategy. However, the encapsulation efficacy is not dependent solely on the specific surface area. Though leading into appropriate substrate with negative charge would enhance the encapsulation efficacy. Polyoxometalates (POMs) as the electron sponge would donate electrons without any structural change. In this study, Keggin-type phosphotungstic acid (PW₁₂) was encapsulated in Zirconium metal-organic framework (PW₁₂@UiO-67) as a heterogeneous adsorbent for the encapsulation of enzyme. Our following data proved that this composite cluster could enhance the adsorption of enzyme and the stability of MP-11 was then significantly improved after immobilization.

Ruthenium(II) complexes with phosphonate-substituted 1,10-phenanthroline ligands: synthesis, characterization and use in organic photocatalysis

Ru(II) complexes with polypyridyl ligands play a central role in the development of photocatalytic organic reactions. This work is aimed at the structural modification of such complexes to increase their...

Chiral and robust Zr(IV)-based metal-organic frameworks built from spiro skeletons

Chiral metal-organic frameworks (CMOFs) have emerged as an important subclass of chiral materials; however, their development is hindered substantially by limited enantiopure functional linkers and poor chemical stabilities. Here we report the design and synthesis of a total of five enantiopure spiro-based tetracarboxylate linkers with diverse functionalities and their use in connecting Zr₆ clusters to form an array of highly robust and porous CMOFs. X-ray crystallographic analysis and structure examination unambiguously revealed that the resulting CMOFs possess multifarious three-dimensional networks with novel topologies and pore systems, highlighting the great potential of chiral spiro skeletons in the fabrication of intriguing structures. PXRD and N₂ adsorption experiments validated their exceptional chemical stability towards boiling water as well as aqueous acid and base solutions. Moreover, their potential applications in enantioselective catalysis and separation are also presented.

An uncommon multicentered ZnI-ZnI bond-based MOF for CO2 fixation with aziridines/epoxides

A novel cluster-based MOF with uncommon multicentered Zn^I-Zn^I bonds {[K_1.2Na_2.8Zn^I₈(HL)₁₂]·4H₂O}_n (HL = tetrazole monoanion) (1) was synthesized, which showed higher stability than the reported Zn^I-Zn^I bonded compounds. Moreover, 1 can effectively and circularly catalyze the cyclization of CO₂ and aziridines or epoxides with five substituent groups. Importantly, this is the first time that the catalytic properties of MOFs with multicentered metal-metal bonded clusters as the catalyst have been studied.

Metal-Organic Frameworks in Oxidation Catalysis with Hydrogen Peroxide

In recent years, metal–organic frameworks (MOFs) have received increasing attention as selective oxidation catalysts and supports for their construction. In this short review paper, we survey recent findings concerning use of MOFs in heterogeneous liquid-phase selective oxidation catalysis with the green oxidant–aqueous hydrogen peroxide. MOFs having outstanding thermal and chemical stability, such as Cr(III)-based MIL-101, Ti(IV)-based MIL-125, Zr(IV)-based UiO-66(67), Zn(II)-based ZIF-8, and some others, will be in the main focus of this work. The effects of the metal nature and MOF structure on catalytic activity and oxidation selectivity are analyzed and the mechanisms of hydrogen peroxide activation are discussed. In some cases, we also make an attempt to analyze relationships between liquid-phase adsorption properties of MOFs and peculiarities of their catalytic performance. Attempts of using MOFs as supports for construction of single-site catalysts through their modification with heterometals will be also addressed in relation to the use of such catalysts for activation of H2O2. Special attention is given to the critical issues of catalyst stability and reusability. The scope and limitations of MOF catalysts in H2O2-based selective oxidation are discussed.

Construction of a zeolite A-type multivariate metal–organic framework for selective sensing of Fe3+ and Cr2O72−

A multivariant metal–organic framework (MTV-MOF) BUT-27 with a unique zeolite A structure was synthesized by post-synthetic linker exchange via single-crystal-to-single-crystal transformation.

Remarkable Structural Diversity between Zr/Hf and Rare-Earth MOFs via Ligand Functionalization and the Discovery of Unique (4, 8)-c and (4, 12)-connected Frameworks

Ligand modification in MOFs provides great opportunities not only for the development of functional materials with new or enhanced properties but also for the discovery of novel structures. We report here that a sulfone-functionalized tetrahedral carboxylate-based ligand is capable of directing the formation of new and fascinating MOFs when combined with Zr⁴⁺/Hf⁴⁺ and rare-earth metal cations (RE) with improved gas-sorption properties. In particular, the resulting M-flu-SO₂ (M: Zr, Hf) materials display a new type of the augmented flu-a net, which is different as compared to the flu-a framework formed by the nonfunctionalized tetrahedral ligand. In terms of properties, a remarkable increase in the CO₂ uptake is observed that reaches 76.6% and 61.6% at 273 and 298 K and 1 bar, respectively. When combined with REs, the sulfone-modified linker affords novel MOFs, RE-hpt-MOF-1 (RE: Y³⁺, Ho³⁺, Er³⁺), which displays a fascinating (4, 12)-coordinated hpt net, based on nonanuclear [RE₉(μ₃-Ο)₂(μ₃-ΟΗ)₁₂(-COO)₁₂] clusters that serve as hexagonal prismatic building blocks. In the absence of the sulfone groups, we discovered that the tetrahedral linker directs the formation of new RE-MOFs, RE-ken-MOF-1 (RE: Y³⁺, Ho³⁺, Er³⁺, Yb³⁺), that display an unprecedented (4, 8)-coordinated ken net based on nonanuclear RE₉-clusters, to serve as bicapped trigonal prismatic building units. Successful activation of the representative member Y-ken-MOF-1 reveals a high BET surface area and total pore volume reaching 2621 m² g^-1 and 0.95 cm³ g^-1, respectively. These values are the highest among all RE MOFs based on nonanuclear clusters and some of the highest in the entire RE family of MOFs. The present work uncovers a unique structural diversity existing between Zr/Hf and RE-based MOFs that demonstrates the crucial role of linker design. In addition, the discovery of the new RE-hpt-MOF-1 and RE-ken-MOF-1 families of MOFs highlights the great opportunities existing in RE-MOFs in terms of structural diversity that could lead to novel materials with new properties.

A novel hydrogen-bonded organic framework for the sensing of two representative organic arsenics

A novel fluorescent hydrogen-bonded organic framework with a double fold interpenetrated structure, HOF-22, has been successfully constructed and structurally characterized. HOF-22 is capable of sensitive detection of two representative organic arsenics from aqueous solution.

Topology-Based Functionalization of Robust Chiral Zr-Based Metal-Organic Frameworks for Catalytic Enantioselective Hydrogenation

The design and development of robust and porous supported catalysts with high activity and selectivity is extremely significant but very challenging for eco-friendly synthesis of fine chemicals and pharmaceuticals. We report here the design and synthesis of highly stable chiral Zr(IV)-based MOFs with different topologies to support Ir complexes and demonstrate their network structures-dependent asymmetric catalytic performance. Guided by the modulated synthesis and isoreticular expansion strategy, five chiral Zr-MOFs with a flu or ith topology are constructed from enantiopure 1,1'-biphenol-derived tetracarboxylate linkers and Zr₆, Zr₉, or Zr₁₂ clusters. The obtained MOFs all show high chemical stability in boiling water, strongly acidic, and weakly basic aqueous solutions. The two flu MOFs featuring the dihydroxyl groups of biphenol in open and large cages, after sequential postsynthetic modification with P(NMe₂)₃ and [Ir(COD)Cl]₂, can be highly efficient and recyclable heterogeneous catalysts for hydrogenation of α-dehydroamino acid esters with up to 98% ee, whereas the three ith MOFs featuring the dihydroxyl groups in small cages cannot be installed with P(NMe₂)₃ to support the Ir complex. Incorporation of Ir-phosphorus catalysts into Zr-MOFs leads to great enhancement of their chemical stability, durability, and even stereoselectivity. This work therefore not only advances Zr-MOFs as stable supports for labile metal catalysts for heterogeneous asymmetric catalysis but also provides a new insight into how highly active chiral centers can result due to the framework topology.

Optimization of the Pore Structures of MOFs for Record High Hydrogen Volumetric Working Capacity

Metal-organic frameworks (MOFs) are promising materials for onboard hydrogen storage thanks to the tunable pore size, pore volume, and pore geometry. In consideration of pore structures, the correlation between the pore volume and hydrogen storage capacity is examined and two empirical equations are rationalized to predict the hydrogen storage capacity of MOFs with different pore geometries. The total hydrogen adsorption under 100 bar and 77 K is predicted as n_tot = 0.085× V_p - 0.013× V_p ² for cage-type MOFs and n_tot = 0.076× V_p - 0.011× V_p ² for channel-type MOFs, where V_p is the pore volume of corresponding MOFs. The predictions by these empirical equations are validated by several MOFs with an average deviation of 5.4%. Compared with a previous equation for activated carbon materials, the empirical equations demonstrate superior accuracy especially for MOFs with high surface area (i.e., S_BET over ≈3000 m² g^-1 ). Guided by these empirical equations, a highly porous Zr-MOF NPF-200 (NPF: Nebraska Porous Framework) is examined to possess outstanding hydrogen total adsorption capacity (65.7 mmol g^-1 ) at 77 K and record high volumetric working capacity of 37.2 g L^-1 between 100 and 5 bar at 77 K.

Comparison of Catalytic Activity of ZIF-8 and Zr/ZIF-8 for Greener Synthesis of Chloromethyl Ethylene Carbonate by CO2 Utilization

The catalytic activity of both ZIF-8 and Zr/ZIF-8 has been investigated for the synthesis of chloromethyl ethylene carbonate (CMEC) using carbon dioxide (CO2) and epichlorohydrin (ECH) under solvent-free conditions. Published results from literature have highlighted the weak thermal, chemical, and mechanical stability of ZIF-8 catalyst, which has limited its large-scale industrial applications. The synthesis of novel Zr/ZIF-8 catalyst for cycloaddition reaction of ECH and CO2 to produce CMEC has provided a remarkable reinforcement to this weak functionality, which is a significant contribution to knowledge in the field of green and sustainable engineering. The enhancement in the catalytic activity of Zr in Zr/ZIF-8 can be attributed to the acidity/basicity characteristics of the catalyst. The comparison of the catalytic performance of the two catalysts has been drawn based on the effect of different reaction conditions such as temperature, CO2 pressure, catalyst loading, reaction time, stirring speed, and catalyst reusability studies. Zr/ZIF-8 has been assessed as a suitable heterogeneous catalyst outperforming the catalytic activities of ZIF-8 catalyst with respect to conversion of ECH, selectivity and yield of CMEC. At optimum conditions, the experimental results for direct synthesis of CMEC agree well with similar literature on Zr/MOF catalytic performance, where the conversion of ECH, selectivity and the yield of CMEC are 93%, 86%, and 76%, respectively.

A historical overview of the activation and porosity of metal–organic frameworks

A historical overview of the activation and porosity of MOFs including strategies to design and preserve permanent porosity in MOFs.

Large-Scale Structural Refinement and Screening of Zirconium Metal-Organic Frameworks for H2S/CH4 Separation

Zirconium-based metal-organic frameworks (Zr-MOFs) with Zr₆ inner cores represent a subfamily of nanoporous materials with good physicochemical stabilities, showing significant prospect for practical applications in various fields. Although computational characterization can play an important role that is complementary to experimental efforts, the availability of chemically realistic Zr-MOF structures is one of the prerequisites to accurately evaluate their performance as well as provide valuable insights for guiding material design. In this work, periodic density functional theory (DFT) calculations combined with a molecular mechanics method were performed to optimize the crystalline structures of over 182 experimentally synthesized Zr-MOFs that contain no less than 10-coordinated Zr₆O₈ nodes, leading to a database consisting of the structures having a diversity of topologies, pore sizes, and functionalities. Apart from determination of favorable configurations of organic linkers, rational proton topologies of the 11- and 10-coordinated Zr₆O₈ nodes were also clarified. Computational screening was further conducted to examine the H₂S/CH₄ separation properties of each material in the database. Significant difference were observed by comparing the separation properties of Zr-MOFs with optimized and nonoptimized structures. Some promising candidates with high H₂S adsorption capacity and separation selectivity were identified on the basis of some evaluation metrics, and favorable organic linkers for designing new high-performance Zr-MOFs were also proposed.

Uncovering Structural Opportunities for Zirconium Metal-Organic Frameworks via Linker Desymmetrization

The discovery of metal-organic frameworks (MOFs) mimicking inorganic minerals with intricate topologies requires elaborate linker design guidelines. Herein, the concept of linker desymmetrization into the design of tetratopic linker based Zr-MOFs is applied. A series of bent tetratopic linkers with various substituents are utilized to construct Zr-MOFs with distinct cluster connectivities and topologies. For example, the assembly between a bent linker L-SO2 with C 2v symmetry and an 8-connected Zr6 cluster leads to the formation of an scu topology, while another flu topology can be obtained by the combination of a novel 8-connected Zr6 cluster and a bent linker L-O with C 1 symmetry. Further utilization of restricted bent linker [(L-(CH3)6)] gives rise to a fascinating (4, 6)-c cor net, originated from the corundum lattice, with an unprecedented 6-c Zr6 cluster. In addition, the removal of toxic selenite ions in aqueous solution is performed by PCN-903-(CH3)6 which exhibits rapid and efficient detoxification. This work uncovers new structural opportunities for Zr-MOFs via linker desymmetrization and provides novel design strategies for the discovery of sophisticated topologies for practical applications.

Integration of mesopores and crystal defects in metal-organic frameworks via templated electrosynthesis

Incorporation of mesopores and active sites into metal-organic framework (MOF) materials to uncover new efficient catalysts is a highly desirable but challenging task. We report the first example of a mesoporous MOF obtained by templated electrosynthesis using an ionic liquid as both electrolyte and template. The mesoporous Cu(II)-MOF MFM-100 has been synthesised in 100 seconds at room temperature, and this material incorporates crystal defects with uncoupled Cu(II) centres as evidenced by confocal fluorescence microscopy and electron paramagnetic resonance spectroscopy. MFM-100 prepared in this way shows exceptional catalytic activity for the aerobic oxidation of alcohols to produce aldehydes in near quantitative yield and selectivity under mild conditions, as well as having excellent stability and reusability over repeated cycles. The catalyst-substrate binding interactions have been probed by inelastic neutron scattering. This study offers a simple strategy to create mesopores and active sites simultaneously via electrochemical formation of crystal defects to promote efficient catalysis using MOFs.

Incorporating mesopores and active sites into metal-organic framework materials has proven advantageous for their catalytic application, but remains challenging to achieve. Here the authors obtain mesoporous, defect-rich metal-organic frameworks through templated electrosynthesis using ionic liquids as both electrolyte and template.

Metal-Organic Framework with Rich Accessible Nitrogen Sites for Highly Efficient CO2 Capture and Separation

A novel microporous metal-organic framework (FJU-44), with abundant accessible nitrogen sites on its internal surface, was constructed from the tetrapodal tetrazole ligand tetrakis(4-tetrazolylphenyl)ethylene (H₄TTPE) and copper chloride. Notably, the CO₂ uptake capacity (83.4 cm³/g, at 273 K and 1 bar) in the activated FJU-44a is higher than most of tetrazolate-containing MOF materials. Particularly, FJU-44a exhibits superior adsorption selectivity of CO₂/N₂ (278-128) and CO₂/CH₄ (44-16), which is comparable to some well-known CO₂ capture materials. Furthermore, the fixed-bed breakthrough experiment indicates that the postcombustion flue gas flow over a packed column with FJU-44a adsorbents can be effectively separated.

WO3 in suit embed into MIL-101 for enhancement charge carrier separation of photocatalyst

Compositing nanoparticles photo-catalyst with enormous surface areas metal–organic framework (MOF) will greatly improve photocatalytic performances. Herein, WO₃ nanoparticles are partly embedded into pores of MIL-101 or only supported on the outside of representative MIL-101, which were defined as embedded structure WO₃@MIL-101@WO₃ and coating structure WO₃&MIL-101 respectively. Different pH, concentration and loading percentage were researched. XRD, TEM and BET were carried to analyze the composites. Compared with the pristine WO₃, all WO₃ loaded MOF nanocomposites exhibited remarkable enhancing for the efficiency of photocatalytic degradation methylene blue under visible light. Their activity of the same loading percentage WO₃ in embedded structure and coating structure have increased for 9 and 3 times respectively compared with pure WO₃. The WO₃@MIL-101@WO₃ has 3 times higher efficiency than WO₃&MIL-101, because the shorter electron-transport distance can make a contribution to electron–hole separation. The further mechanism involved has been investigated by radical quantify experiment, XPS and photoluminescence spectroscopy.

A robust and water-stable two-fold interpenetrated metal–organic framework containing both rigid tetrapodal carboxylate and rigid bifunctional nitrogen linkers exhibiting selective CO2 capture

A robust and water-stable two-fold interpenetrated metal–organic framework containing both rigid tetrapodal carboxylate and rigid bifunctional nitrogen linkers exhibiting selective CO₂ capture is reported.

Microwave-assisted activation and modulator removal in zirconium MOFs for buffer-free CWA hydrolysis

A novel, facile and efficient method was developed for the activation of acetic acid modulated zirconium MOFs. The protocol involves briefly heating the material in water using microwave irradiation. MOF-808, DUT-84 and UiO-66 were all activated in this manner to remove the modulator and organic solvent from the framework post synthesis, with retention of MOF integrity post activation. The degree of activation was characterised by the use of TGA and NMR. The catalytic activity of the activated MOFs and their non-activated counterparts was investigated for chemical warfare agent (CWA) hydrolysis. Upon activation, an increase in the rate of hydrolysis was observed in the degradation of CWA simulant dimethyl 4-nitrophenyl phosphate (DMNP). MOF-808 and DUT-84 were also screened as catalysts for the hydrolysis of the V-series agent VM, with remarkable half-lives obtained for MOF-808 in the absence of any buffers. Currently employed MOF activation procedures involve the use of additional organic solvents post synthesis; we believe this method to be ideally efficacious for the organic desolvation of zirconium MOFs and removing modulator additives.

Rational design of a flu-type heterometallic cluster-based Zr-MOF

Following the HSAB principle, the cooperative assembly of tetrahedral [Cu₄I₄(Ina)₄]^4- metalloligands and 8-connecting [Zr₆(μ₃-OH)₈(OH)₈]⁸⁺ building units leads to the first heterometallic cluster-based Zr-MOF (1). The results provide a successful strategy for rational design of heterometallic cluster-based Zr-MOFs.

A mechanistic approach towards the photocatalytic organic transformations over functionalised metal organic frameworks: a review

This review focuses on the possible mechanisms involved in the organic transformations occurring through photocatalysis over functionalised metal–organic frameworks.

Diamondoid architectures from halogen-bonded halides

Halide ions and tetraiodoethynyl-featured tetraphenylmethane are successfully assembled into robust diamond-like networks in the presence of tetraphenylphosphonium cations.