Cooperative assembly of three-ring-based zeolite-type metal-organic frameworks and Johnson-type dodecahedra

Tailored Porous Ferrocene-Based Metal-Organic Frameworks as High-Performance Proton Conductors

Although crystalline metal-organic frameworks (MOFs) have gained a great deal of interest in the field of proton conduction in recent years, the low stability and poor proton conductivity (σ) of some MOFs have hindered their future applications. As a result, resolving the issues listed above must be prioritized. Due to their exceptional structural stability, MOFs with ferrocene groups that exhibit particular physical and chemical properties have drawn a lot of attention. This study describes the effective preparation of a set of three-dimensional ferrocene-based MOFs, MIL-53-FcDC-Al/Ga and CAU-43, containing both main group metals and 1,1'-ferrocene dicarboxylic acid (H2FcDC). Multiple measurements, including powder X-ray diffraction (PXRD), infrared (IR), and scanning electron microscopy (SEM), confirmed that the addition of ferrocene groups enhanced the thermal, water, and acid-base stabilities of the three MOFs. Consequently, their proton-conductive behaviors were meticulously measured utilizing the AC impedance approach, and their best proton conductivities are 5.20 × 10-3, 2.31 × 10-3, and 1.72 × 10-4 S/cm at 100 °C/98% relative humidity (RH), respectively. Excitingly, MIL-53-FcDC-Al/Ga demonstrated an extraordinarily ultrahigh σ of above 10-4 S·cm-1 under 30 °C/98% RH. Using data from structural analysis, PXRD, SEM, thermogravimetry (TG), and activation energy, their proton transport mechanisms were thoroughly examined. The fact that these MOFs are notably easy to assemble, inexpensive, toxin-free, and stable will increase the range of practical uses for them.

Hierarchical Self-Assembly of Curved Aromatics: From Donor-Acceptor Porphyrins to Triply Periodic Minimal Surfaces

A saddle-shaped π-extended zinc porphyrin containing a peripheral pyridyl ligand undergoes quantitative self-assembly into a cyclic trimer. The trimer has a prismatic structure with negatively curved side walls, which promote the formation of supramolecular organic frameworks stabilized by dispersion interactions. The first framework type, UWr-1, has the npo topology, with a hexagonal structure analogous to the Schwartz H triply periodic minimal surface. Co-crystallization of the trimer with either C60 and C70 produces the isomorphous cubic UWr-2 and UWr-3 phases, characterized by the ctn network topology and a structural relationship to the Fischer-Koch minimal surface S. All three phases contain complex labyrinths of solvent-filled channels, corresponding to very large probe-accessible volumes (68 % to 76 %). The UWr-2 network could be partly desolvated while retaining its long range dimensional order, indicating remarkable strength of the dispersion interactions in the crystal. A theoretical analysis of noncovalent interactions shows the role of geometrical matching between the negatively curved porphyrin units and positively curved fullerenes.

Building Unit Extractor for Metal-Organic Frameworks

Metal-organic frameworks (MOFs) have relevance in extensive applications such as gas adsorption, separation, and energy storage. The tunability demonstrated by MOFs has encouraged research on MOF database generation via distinct methodologies. One of the crucial stages of these procedures is pre-processing, which often includes extraction of the building units (BUs). The process of BU extraction is intricate, and it is further amplified with the presence of solvent molecules/ions in the structure. This work presents MOF BU developer (mBUD), a platform to deconstruct the BUs, such as metal nodes, organic linkers, and functional groups of the MOF structure. The deconstruction algorithm has been assessed on the MOF structures of the CoRE MOF 2019 database. A total of 2,580 BUs have been extracted and provided as a database. This platform has been utilized to create a ready-to-use database of unique BUs deconstructed from the CoRE MOF database. We have also provided the web version of mBUD that can be easily used to extract BUs. These BUs can be employed to develop hypothetical MOF structures. It is envisaged that the BU database built with the deconstruction platform will aid the design of novel application-specific MOFs.

Recent progress and perspectives on the structural design on metal-organic zeolite (MOZ) frameworks

As a typical group of coordination polymers, metal-organic zeolite (MOZs) frameworks inherit the topological and structural advantages of inorganic zeolites and display great application potential in many areas, including gas adsorption/separation, catalysis, luminescence and chemical sensing. In this review, we outline the recent progress in the synthesis, functionalization and application of metal-organic zeolite frameworks, mainly focusing on the basic structural design principle and synthesis strategy on 4-connect inorganic nodes and 2-connect organic linkers. Employing different valent metals, small inorganic TO₄^2- units and high-nuclear clusters as 4-connect nodes, we derived multi-types of MOZs with a modified framework charge, improved stability and enhanced photo-/eletrocatalytic activity. Besides, the selection, functionalization and defect-engineering on the 2-connect ligands generated different topological and functional MOZs. Finally, the future trends and some perspectives in this area are outlined.

Creative Construction of a Series of Chiral 3D Indium-Organic Frameworks with a umy Topology

Using 2,2'-R₂-biphenyl-4,4'-dicarboxylic acid to bind with a cis-[InO₄(μ₂-OH)₂] octahedron, three novel chiral 3D indium-organic frameworks, [In(μ₂-OH)L] [1, L¹, R = N(CH₃)₂; 2, L², R = OCH₃; 3, L³, R = CH₃], have been hydrothermally synthesized without chiral reagents. Crystal structure analyses reveal that 1-3 show an unprecedented 4-connected umy topology with the Schläfli symbol (4²·6⁴). 1 exhibits high water stability and good sorption selectivity of CO₂ over N₂, while 3 displays high C₂H₂, C₂H₄, and C₂H₆ uptake capacity at 273 K.

Recent progress in the design and synthesis of zeolite-like metal–organic frameworks (ZMOFs)

ZMOFs are a subset of MOFs that exhibit zeolite-like topologies. Using molecular building block strategy, many ZMOFs with high stability and excellent performance can be rationally designed and synthesized using different secondary building units.

Metal–organic frameworks with different spatial dimensions for supercapacitors

Recent progress in MOF materials for SCs with different spatial dimensions, such as 2D MOFs, including conductive MOFs and nanosheets, and 3D MOFs, categorized as single metallic and multiple metallic MOFs, are reviewed.

Inorganic-Organic Hybrid Polyoxoniobates: Polyoxoniobate Metal Complex Cage and Cage Framework

The combination of polyoxoniobates (PONbs) with 3d metal ions, azoles, and organoamines is a general synthetic procedure for making unprecedented PONb metal complex cage materials, including discrete molecular cages and extended cage frameworks. By this method, the first two PONb metal complex cages K₄ @{[Cu₂₉ (OH)₇ (H₂ O)₂ (en)₈ (trz)₂₁ ][Nb₂₄ O₆₇ (OH)₂ (H₂ O)₃ ]₄ } and [Cu(en)₂ ]@{[Cu₂ (en)₂ (trz)₂ ]₆ (Nb₆₈ O₁₈₈ )} have been made. The former exhibits a huge tetrahedral cage with more than 120 metal centers, which is the largest inorganic-organic hybrid PONb known to date. The later shows a large cubic cage, which can act as building blocks for cage-based extended assembly to form a 3D cage framework {[Cu(en)₂ ]@{[Cu₂ (trz)₂ (en)₂ ]₆ [H₁₀ Nb₆₈ O₁₈₈ ]}}. These materials exhibit visible-light-driven photocatalytic H₂ evolution activity and high vapor adsorption capacity. The results hold promise for developing both novel cage materials and largely unexplored inorganic-organic hybrid PONb chemistry.

Two polyoxovanadate-based metal-organic polyhedra with undiscovered "near-miss Johnson solid" geometry

Newfangled frangipani-like [MV₅O₆(μ₃-O)₅(SO₄)(COO)₅] (M = Nb/W) polyanions served as 5-connected molecular building blocks (MBBs) that simultaneously assembled with 4-connected [V₅O₉Cl] MBBs and tricarboxylate ligands (H₃BTC) to form two new polyoxovanadate-based metal-organic polyhedra {[MV₅O₆(μ₃-O)₅(SO₄)]₄[V₅O₉Cl]₄(BTC)₁₂} with undiscovered "near-miss Johnson solid" geometry. Moreover, the variable-temperature magnetic susceptibilities were investigated.

Amide-functionalized ionic indium–organic frameworks for efficient separation of organic dyes based on diverse adsorption interactions

Two amide groups functionalized anionic indium–organic frameworks demonstrated efficient separation of organic dyes based on diverse adsorption interactions, and can be potentially applicable in column-chromatographic separation of dyes.

Design and synthesis of multifunctional metal-organic zeolites

Metal-organic zeolites (MOZs) are an important branch of metal-organic frameworks (MOFs) and combine the advantages of zeolites and MOFs, such as high surface area and porosity as well as the exceptional stability of zeolites, which would have a significant impact on catalysis chemistry, inorganic chemistry, coordination chemistry, materials science and other areas. In this review, we focus on the recent advances in MOZs with a brief outline of the most prominent examples. In particular, we highlight the basic principles of the design and synthesis approaches toward the construction of MOZs. Obeying the principle of charge matching, tuning tetrahedral metal centers, using enlarged tetrahedral building units as clusters, introducing functional groups into ligands, and combining traditional inorganic TO₄ sites in MOZs enable the final materials with diverse topological structures to exhibit superior performance for various applications, such as gas sorption/separation, catalysis, enantio-selectivity, luminescence, etc.

A new strategy for constructing a disulfide-functionalized ZIF-8 analogue using structure-directing ligand–ligand covalent interaction

Inter-ligand –S–S– covalent interaction plays a key role in the synthesis of a ZIF-8 analogue CPM-8S.

2D and 3D lanthanide metal–organic frameworks constructed from three benzenedicarboxylate ligands: synthesis, structure and luminescent properties

Nineteen Ln-MOFs with four different crystal structures were prepared and the luminescence was studied.

Synthesis of zeolitic tetrazolate-imidazolate frameworks (ZTIFs) in ethylene glycol

Ethylene glycol (EG) as a universal solvent is used to reproducibly synthesize zeolitic tetrazolate imidazolate frameworks (ZTIF-11 to 13) in high yields, among which the frl-type ZTIF-11 shows high chemical stability and porosity as well as remarkable CO₂ gas separation.

A highly flexible inorganic framework with amphiphilic amine assemblies as templates

A zinc phosphite-phosphate framework, (HA)₂[Zn₃(HPO₃)_4-x(HPO₄)_x] (1; A = cha, coa, iba, pa, and ha; x = 0.3-1) with nanometer-scale channels was prepared. The framework exhibited an extraordinarily high flexibility, 13% expansion at ambient pressure and 27% contraction under a high pressure of over 2.3 GPa without undergoing any phase transformation. The volume changes in the compression-decompression process are reversible. Such unusual adaptability is rare in pure inorganic networks. The molecular volumes of templates range from 165 ų to 228 ų, which allows to vary channel aperture increasingly from 13.02 to 15.34 Å. Remarkably, three types of organic amine template assemblies, captured in inorganic frameworks, were identified in this study. Presented herein is the first example that demonstrates a successfully controlled template assembly that helps to obtain a flexible inorganic framework with nanosized pores in a systematic manner.

Multifunctional indium complexes with fluorescent sensing and selective adsorption dye properties

Four new complexes [InCl₂(Hphth)(4,4′-bipy)_0.5(H₂O)]·2H₂O (H₂phth = phthalic acid, 4,4′-bipy = 4,4′-bipyridine) (1), [InCl₄(4,4′-bipyH)(H₂O)] (2), [InCl(Hphth)(nia)(H₂O)₂] (Hnia = nicotinic acid) (3), [InCl(Hnia)₂(Hox)₂]·3H₂O (H₂ox = oxalic acid) (4) were synthesized by the reaction of Indium chloride (InCl₃) with H₂phth, Hnia, 4,4′-bipy and H₂ox as the ligands.

Rigid versus semi-rigid bis(imidazole) ligands in the assembly of two Co(ii) coordination polymers: structural variability, electrochemical properties and photocatalytic behavior

Two Co(ii) complexes with 1,2,4,5-cyclohexanetetracarboxylate, rigid or semi-rigid bis(imidazole) ligands were hydrothermally synthesized. Both compounds showed high photocatalytic activity for MB degradation.

A multifunctional Ni(ii) coordination polymer: synthesis, crystal structure and applications as a luminescent sensor, electrochemical probe, and photocatalyst

A new Ni(ii) complex containing 2,5-dichloroterephthalate and rigid bis(imidazole) ligands, which manifests multifunctional properties, has been synthesized and characterized.

A robust indium–porphyrin framework for CO2 capture and chemical transformation

A robust indium–porphyrin framework based on amido-decorated porphyrin ligands is used for CO₂ capture and chemical fixation, showing good catalytic activity and recyclability.

Two copper(i) cyanide coordination polymers modified by semi-rigid bis(benzimidazole) ligands: syntheses, crystal structures, and electrochemical and photocatalytic properties

Two Cu(i) cyanide complexes with semi-rigid bis(benzimidazole) ligands were synthesized and characterized. Both complexes manifest photocatalytic activities for the degradation of methylene blue.

An anionic zeolite-like metal–organic framework (AZMOF) with a Moravia network for organic dye absorption through cation-exchange

We have synthesized a new anionic zeolite-like metal–organic framework (AZMOF) with a twisted partially augmentedthenet, known as the “Moravia” net which is able to selectively adsorb organic cationic dyes (BR, RB, CV and MB) through cation-exchange.

Charge-tunable indium–organic frameworks built from cationic, anionic, and neutral building blocks

Three different indium building blocks, from a positive trimer to a negative monomer, lead to In-MOFs with tunable framework charge.

Versatile structures of group 13 metal halide complexes with 4,4′-bipy: from 1D coordination polymers to 2D and 3D metal–organic frameworks

The nature of the group 13 metal halides strongly affects the structure of their complexes with 4,4′-bipy.