A stable HOF-embedded alginate hydrogel membrane for selective adsorption of cationic dyes.

Targeted at organic dye pollutants, a stable HOF was combined with an alginate (SA) hydrogel to enhance the affinity for cationic dyes. The as-obtained HOF@SA membrane (weight ratio: 1/1) shows a high adsorption capacity (729.21 mg g), adsorption selectivity and good recycling performance towards methylene blue.

Metal-Organic Framework with Space-Partition Pores by Fluorinated Anions for Benchmark CH/CO Separation.

The efficient separation of CH from CH/CO or CH/CO/CH mixtures is crucial for achieving high-purity CH (>99%), essential in producing contemporary commodity chemicals. In this report, we present ZNU-12, a metal-organic framework with space-partitioned pores formed by inorganic fluorinated anions, for highly efficient CH/CO and CH/CO/CH separation. The framework, partitioned by fluorinated SiF anions into three distinct cages, enables both a high CH capacity (176.

Covalent Organic Framework/Graphene Hybrids: Synthesis, Properties, and Applications.

To address current energy crises and environmental concerns, it is imperative to develop and design versatile porous materials ideal for water purification and energy storage. The advent of covalent organic frameworks (COFs), a revolutionary terrain of porous materials, is underscored by their superlative features such as divinable structure, adjustable aperture, and high specific surface area. However, issues like inferior electric conductivity, inaccessible active sites impede mass transfer and poor processability of bulky COFs restrict their wider application.

Dual-Emitting Mixed-Lanthanide Metal-Organic Framework for Ratiometric and Quantitative Visual Detection of 2,6-Pyridine Dicarboxylic Acid.

The detection of the major biomarker of , 2,6-dipicolinic acid (DPA), has attracted great interest in recent years. In this work, mixed-lanthanide metal-organic frameworks (M'LnMOFs), TbEu-cppa (cppa = 5-(5-carboxypyridin-3-yl)isophthalic acid), with different Tb/Eu ratios, were solvothermally synthesized. The results reveal that ratiometric fluorescent probe [TbEu-(Hcppa)(HO)(DMF)]·3HO is water and acid-base stable and exhibits excellent sensitivity (LOD = 2.

Integrating Self-Partitioned Pore Space and Amine Functionality into an Aromatic-Rich Coordination Framework with Ph Stability for Effective Purification of C Hydrocarbons.

A great demand for high-purity C hydrocarbons calls for the development of chemically stable porous materials for the effective isolation of C hydrocarbons from CH and CO. However, such separations are challenged by their similar physiochemical parameters and have not been systematically studied to date. In this work, we reported a cadmium-based rod-packing coordination framework compound of a new 5,6,7-c topology built up from a custom-designed tricarboxylate ligand.

A Multimodal Ratiometric Luminescent Thermometer Based on a Single-Dysprosium Metal-Organic Framework.

The design of high-performance luminescent MOF thermometers with multi-operation modes has been long sought but remains a formidable challenge. In this work, for the first time, we present a multimodal luminescent ratiometric thermometer based on the single-lanthanide metal-organic framework (MOF) DyTPTC-2Me (HTPTC-2Me = 2',5'-dimethyl-[1,1':4',1″-terphenyl]-3,3″,5,5″-tetracarboxylic acid). It not only has the characteristic luminescence of Dy in which the atomic transitions from the I and F states (thermally coupled energy levels, TCELs) are included but also emits ligand fluorescence due to the efficient energy back-transfer of Dy to the ligand, thus allowing accurate non-invasive determination of temperature by different modes.

Ligand Conformation Fixation Strategy for Expanding the Structural Diversity of Copper-Tricarboxylate Frameworks and CH Purification Performance Studies.

Structural and functional expansion of metal-organic frameworks (MOFs) is fundamentally important because it not only enriches the structural chemistry of MOFs but also facilitates the full exploration of their application potentials. In this work, by employing a dual-site functionalization strategy to lock the ligand conformation, we designed and synthesized a pair of biphenyl tricarboxylate ligands bearing dimethyl and dimethoxy groups and fabricated their corresponding framework compounds through coordination with copper(II) ions. Compared to the monofunctionalized version, introduction of two side groups can significantly fix the ligand conformation, and as a result, the dual-methoxy compound exhibited a different network structure from the mono-methoxy counterpart.

Substituent Engineering-Enabled Structural Rigidification and Performance Improvement for C/CO Separation in Three Isoreticular Coordination Frameworks.

Construction of porous solid materials applied to the adsorptive removal of CO from C hydrocarbons is highly demanded thanks to the important role C hydrocarbons play in the chemical industry but quite challenging owing to the similar physical parameters between C hydrocarbons and CO. In particular, the development of synthetic strategies to simultaneously enhance the uptake capacity and adsorption selectivity is very difficult due to the trade-off effect frequently existing between both of them. In this work, a combination of the dicopper paddlewheel unit and 4-pyridylisophthalate derivatives bearing different substituents afforded an isoreticular family of coordination framework compounds as a platform.

Porous metal-organic frameworks for hydrogen storage.

The high gravimetric energy density and environmental benefits place hydrogen as a promising alternative to the widely used fossil fuels, which is however impeded by the lack of safe, energy-saving and cost-effective H storage systems. The use of solid adsorbents as candidate materials offers a less energy-intensive way of storing hydrogen. The exceptional diversity and tunability of the chemical composition, topological structure, and surface chemistry together with large surface area position porous metal-organic frameworks as promising hydrogen storage material candidates.

Amino-Functionalized Single-Lanthanide Metal-Organic Framework as a Ratiometric Fluorescent Sensor for Quantitative Visual Detection of Fluoride Ions.

Excessive content of fluoride ions (F) in water will lead to water pollution and endanger human health, so the research on the method of low-cost, rapid, and efficient detection of F is of particular significance. In this work, an amino-functionalized ligand with an appropriate triplet energy excited state, 2'-amino-[1,1':4',1″-terphenyl]-3,3″,5,5″-tetracarboxylic acid (HTPTC-NH), was selected to construct a luminescent single-lanthanide metal-organic framework, EuTPTC-NH, with uncoordinated amino groups for the detection of F. Based on host-guest interactions, that is, hydrogen bonds formed between the free amino groups and F ions, EuTPTC-NH was developed as a ratiometric fluorescence probe for F detection with good anti-interference ability, low detection limit, high water stability, and selectivity.

Two-Dimensional Metal-Organic Framework with Ultrahigh Water Stability for Separation of Acetylene from Carbon Dioxide and Ethylene.

Highly selective separation and purification of acetylene (CH) from ethylene (CH) and carbon dioxide (CO) are daunting challenges in light of their similar molecule sizes and physical properties. Herein, we report a two-dimensional (2D) stable metal-organic framework (MOF), ([Cu(Hmpba)]·1.5DMF) (Hmpba = 4-(3,5-dimethyl-1-pyrazol-4-yl)benzoic acid), with topology, stacked together through π-π interactions for efficient separation of CH from CH and CO.

Water-Stable Eu-Cluster-Based fcu-MOF with Exposed Vinyl Groups for Ratiometric and Fluorescent Visual Sensing of Hydrogen Sulfide.

Detection of HS in the biological system has attracted enormous attention in recent years. In this work, a new vinyl-functionalized metal-organic framework (MOF), [(MeNH)] [Eu(μ-OH)(BDC-CH═CH)(HO)] (Eu-BDC-CH═CH, BDC-CH═CH = 2-vinylterephthalic acid), was synthesized under solvothermal conditions. The vinyl groups in the ligands can not only modulate the "antenna effect" of the ligand on Eu ions but also serve as an exposed reactive site to allow for the quantitative detection of HS by Eu-BDC-CH═CH.

Recent progress on porous MOFs for process-efficient hydrocarbon separation, luminescent sensing, and information encryption.

Metal-organic frameworks (MOFs), as an emerging class of porous materials, excel in designability, regulatability, and modifiability in terms of their composition, topology, pore size, and surface chemistry, thus affording a huge potential for addressing environment and energy-related challenges. In particular, MOFs can be applied as porous adsorbents for the purification of industrially important hydrocarbons through certain process-efficient separation schemes based on selectivity-reversed adsorption and multicomponent separation. Moreover, the vast combination possibilities and controllable and engineerable luminescent units of MOFs make them a versatile platform to develop functionally tailored materials for luminescent sensing and optical data encryption.

Hydrogen Bond Organic Frameworks as a Novel Electrochemiluminescence Luminophore: Simple Synthesis and Ultrasensitive Biosensing.

Nowadays, continuous efforts have been devoted to searching highly efficient electrochemiluminescence (ECL) emitters for applications in clinical diagnosis and food safety. In this work, triazinyl-based hydrogen bond organic frameworks (Tr-HOFs) were synthesized by N···H hydrogen bond self-assembly aggregation, where 6,6'-(1,4-phenylene)bis(1,3,5-triazine-2,4-diamine) (phenyDAT) was prepared the cyclization reaction and behaved as a novel ligand. Impressively, the resulting Tr-HOFs showed strong ECL responses with highly enhanced ECL efficiency (21.

Improving Ethane/Ethylene Separation Performance of Isoreticular Metal-Organic Frameworks Substituent Engineering.

The preferential capture of ethane (CH) over ethylene (CH) presents a very cost-effective and energy-saving means applied to adsorptive separation and purification of CH with a high product purity, which is however challenged by low selectivity originating from their similar molecular sizes and physical properties. Substituent engineering has been widely employed for selectivity regulation and improvement, but its effect on CH/CH separation has been rarely explored to date. In this work, four isoreticular coordination framework compounds based on 5-(pyridin-3-yl)isophthalate ligands bearing different substituents were rationally constructed.

Lanthanide-Organic Frameworks Featuring Three-Dimensional Inorganic Connectivity for Multipurpose Hydrocarbon Separation.

Implementation of lanthanide-organic frameworks (LOFs) as solid adsorbents has been frequently handicapped by their permanent porosity being difficult to establish owing to the remarkable flexibility and diversity of lanthanide ions in terms of coordination number and geometry. Construction of robust LOFs with permanent porosity for industrially important hydrocarbon separation will greatly expand their application potential. In this work, by distributing N and O donors into an -terphenyl skeleton, we rationally synthesized a heterofunctional linker, and constructed a pair of isostructural LOFs.

A Microporous MOF Constructed by Cross-Linking Helical Chains for Efficient Purification of Natural Gas and Ethylene.

Natural gas (NG) and ethylene (CH) are two raw materials of significant value for manufacturing versatile fine chemicals and/or polymers, and thus the development of solid adsorbing agents such as metal-organic frameworks (MOFs) applied to their depuration is very crucial but remains highly challenging. In this research, we designed and synthesized a ligand containing mixed N and O coordination donors, which was solvothermally assembled with Cu(II) ions to generate a microporous MOF. X-ray crystallography revealed that the title MOF incorporates one-dimensional (1D) homochiral helical chains that are datively cross-linked to form open channels in the three-periodic coordination framework.

Ligand Bent-Angle Engineering for Tuning Topological Structures and Acetylene Purification Performances of Copper-Diisophthalate Frameworks.

To enrich structural chemistry and widen the application prospects of MOFs (metal-organic frameworks), the development of a synthetic strategy to realize structural and functional modulation is highly demanded. By implementation of the linker bent-angle engineering strategy, three banana-like diisophthalate linkers with distinct bent angles were designed and synthesized. The inclusion of the targeted linkers into MOFs through solvothermal assembly with CuCl·2HO under identical conditions yielded three crystalline solids featuring diversified topological structures as revealed by X-ray crystallographic studies.

Interpenetration Symmetry Control Within Ultramicroporous Robust Boron Cluster Hybrid MOFs for Benchmark Purification of Acetylene from Carbon Dioxide.

The separation of C H /CO is an important process in industry but challenged by the trade-off of capacity and selectivity owning to their similar physical properties and identical kinetic molecular size. We report the first example of symmetrically interpenetrated dodecaborate pillared MOF, ZNU-1, for benchmark selective separation of C H from CO with a high C H capacity of 76.3 cm  g and record C H /CO selectivity of 56.

Rational Construction and Performance Regulation of an In(III)-Tetraisophthalate Framework for One-Step Adsorption-Phase Purification of CH from C Hydrocarbons.

The development of porous materials for ethylene (CH) separation and purification, a very important separation process in the chemical industry, is urgently needed but quite challenging. In particular, the realization of selectivity-reversed adsorption (namely, CH is not preferentially adsorbed) and the simultaneous capture of multinary coexisting impurities such as ethane (CH) and acetylene (CH) will significantly simplify process design and reduce energy and cost consumption, but such porous materials are quite difficult to design and have not yet been fully explored. In this work, by employing an aromatic-rich bithiophene-based tetraisophthalate ligand, we solvothermally fabricated an anionic In(III)-based framework termed featuring In(COO) as an inorganic secondary building unit as well as one-dimensional channels.

Modulation of Topological Structures and Adsorption Properties of Copper-Tricarboxylate Frameworks Enabled by the Effect of the Functional Group and Its Position.

To push forward the structural development and fully explore the potential utility, it is highly desired but challenging to regulate in a controllable manner the structures and properties of MOFs. In this work, we reported the structural and functional modulation of Cu(II)-tricarboxylate frameworks by employing a strategy of engineering the functionalities and their positions. Two pairs of unsymmetrical biaryl tricarboxylate ligands modified with a methyl group and a pyridinic-N atom at distinct positions were logically designed and synthesized, and their corresponding Cu(II)-based MOFs were solvothermally constructed.

A Series of Metal-Organic Framework Isomers Based on Pyridinedicarboxylate Ligands: Diversified Selective Gas Adsorption and the Positional Effect of Methyl Functionality.

Solvothermal assembly of copper(II) cations and 5-(pyridine-3-yl)isophthalate linkers bearing different position-substituted methyl groups afforded four ligand-induced metal-organic framework (MOF) isomers as a platform for investigating diverse selective gas adsorption properties and understanding the positional effect of methyl functionality. Single-crystal X-ray diffraction (SCXRD) analyses showed that, when the methyl substituent is at the position with respect to the pyridinic N atom, the resultant framework compound features an -type topology, while the other three solids possess an isoreticular structure with an -type topology when the methyl group is situated at the other positions. As revealed by N physi-adsorption measurements at 77 K, they exhibit moderate specific surface areas ranging from 584 to 1182 m g and distinct degrees of framework flexibility, which are heavily dependent on the methyl position.

Engineering ligand conformation by substituent manipulation towards diverse copper-tricarboxylate frameworks with tuned gas adsorption properties.

To expand the structural diversity and optimize the material performance, it is essential but challenging to regulate MOF structures in a predictable and controllable manner. In this work, by manipulating the substituents to engineer the ligand conformations, we designed and synthesized two asymmetric tricarboxylate ligands, and used them to successfully target two copper-tricarboxylate frameworks with diversified topologies depending on the ligand conformations. Besides, the ligand asymmetry induced the formation of two uncommon kinds of copper-carboxylate clusters, thus greatly expanding the library of copper-carboxylate secondary building units.

An -oxide-functionalized nanocage-based copper-tricarboxylate framework for the selective capture of CH.

The selective capture of C2H2 from C2H2-C2H4 and C2H2-CO2-CH4 mixtures is a very essential but highly challenging process during C2H4 and C2H2 purification in the chemical industry. In this work, by virtue of using oxygen-atom-rich C2H2 recognition sites, we, for the first time, designed and synthesized an N-oxide-functionalized tricarboxylate ligand and utilized it to successfully construct a copper-based MOF. N-Oxide functionalization exerted a significant effect on the ligand conformation, thus resulting in a new topological network that is different from that of the unoxidized parent compound.

Immobilization of N-oxide functionality into NbO-type MOFs for significantly enhanced CH/CH and CO/CH separations.

NbO-type MOFs built up from linear diisophthalate ligands and dicopper paddlewheel-based secondary building units offer an excellent platform to perform pore surface chemistry engineering and understand the structure-property relationship. In this work, we designed and synthesized two N-oxide functionalized linear diisophthalate ligands, and employed them to construct under suitable solvothermal conditions their corresponding NbO-type MOFs termed ZJNU-19 and ZJNU-20. Their gas adsorption properties with respect to C2H2, CO2, and CH4 were systematically measured, and adsorption selectivities of C2H2 and CO2 over CH4 were assayed using a well-known ideal adsorbed solution theory, establishing their promising potential for C2H2/CH4 and CO2/CH4 separations in connection with acetylene and natural gas separation and purification, which were found to be less dependent on the methyl position.