A gas-selective Zn-MOF exhibits selective sensing of Fe3+ ions by doping with Tb3

Here, a new Zn2+ metal organic framework, {[Me2NH2][Zn2(L)(DTZ)]·2DMF·3H2O}n (Zn-MOF), has been synthesized with low-symmetric carboxylic acid ligand 2,6 bis(2',5'-dicarboxyphenyl)pyridine (H4L) as the main ligand and 3,5-diamino-1,2,4-riazole (DTZ) containing an electron-rich N atom as an auxiliary ligand. Because of its high structural stability and adsorption properties, it can be used to efficiently separate CO2/CH4 and C2H2/CH4. In addition, Tb@Zn-MOF was obtained by doping with Tb3+ to partially replace Zn2+. A study of its luminescence sensing performance demonstrated that Tb@Zn-MOF showed intense luminescence properties and can be used for the directional detection of Fe3+ in aqueous solution. Furthermore, PXRD analysis, UV-vis spectroscopy and X-ray photoelectron spectroscopy (XPS) were also used to study possible luminescence sensing mechanisms. The recognition mechanism for Fe3+ ions is believed to be caused by electron transfer.

Zinc(II) Carboxylate Coordination Polymers with Versatile Applications

This review considers the applications of Zn(II) carboxylate-based coordination polymers (Zn-CBCPs), such as sensors, catalysts, species with potential in infections and cancers treatment, as well as storage and drug-carrier materials. The nature of organic luminophores, especially both the rigid carboxylate and the ancillary N-donor bridging ligand, together with the alignment in Zn-CBCPs and their intermolecular interaction modulate the luminescence properties and allow the sensing of a variety of inorganic and organic pollutants. The ability of Zn(II) to act as a good Lewis acid allowed the involvement of Zn-CBCPs either in dye elimination from wastewater through photocatalysis or in pathogenic microorganism or tumor inhibition. In addition, the pores developed inside of the network provided the possibility for some species to store gaseous or liquid molecules, as well as to deliver some drugs for improved treatment.

Recent advances in structures and applications of coordination polymers based on cyclohexanepolycarboxylate ligands

Coordination polymers (CPs) are emerging crystalline materials constructed by metal entities and organic ligands through coordination bonds, containing infinite coordination units in one, two, or three dimensions. Here an overview...

Time-resolved color-changing long-afterglow for security systems based on metal–organic hybrids

Himpc-based phosphors exhibit diverse afterglow performances by modulating molecular aggregation dispositions for anti-counterfeiting application.

Two mesoporous anionic metal-organic frameworks for selective and efficient adsorption of a cationic organic dye

Anionic metal-organic frameworks (MOFs) are beginning to have a great impact in the field of absorption and separation of ionic organic molecules due to the enhanced electrostatic interactions between their anionic frameworks and counter-ionic guests. Herein, the rational design and synthesis of two mesoporous anionic MOFs, [Zn₃(ITTC)₃](Me₂ NH₂)₃·3DMF·H₂O (1) and [Cd₂(ITTC)₃](Me₂NH₂)₅·2DMF (2), where H₃ITTC = 4,4',4''-(1H-imidazole-2,4,5-triyl) tribenzoic acid, is reported. Structural analysis revealed that both materials are anionic MOFs with a 2-fold interpenetrating three dimensional (3D) framework. The cross sectional area of the open one-dimensional rectangular channels is 31.7 Å × 15.6 Å for 1, of which the architecture is indicative of an unprecedented (3,3,4,5)-connection topology. For 2, the diameter of the open one-dimensional regular hexagonal channel is about 34.1 Å, decorated with uncoordinated carboxyl O atoms, and the framework exhibits a (3,4)-connected fcu network. Due to their anionic frameworks and bulky pore window sizes, both MOFs can be employed for absorbing and separating the cationic organic dye methylene blue (MB). The results reveal that both MOFs have better dye adsorption selectivity for MB, than for MO and SDI, because of charge and size-matching effects, enabling them to be potential candidates for use in environmental cleaning. By comparison, 2 presents superior selectivity and adsorptivity for cationic MB which depends on the presence of a basic functionalized pore surface.

Stimuli-Responsive Zinc (II) Coordination Polymers: A Novel Platform for Supramolecular Chromic Smart Tools

The unique role of the zinc (II) cation prompted us to cut a cross-section of the large and complex topic of the stimuli-responsive coordination polymers (CPs). Due to its flexible coordination environment and geometries, easiness of coordination-decoordination equilibria, "optically innocent" ability to "clip" the ligands in emissive architectures, non-toxicity and sustainability, the zinc (II) cation is a good candidate for building supramolecular smart tools. The review summarizes the recent achievements of zinc-based CPs as stimuli-responsive materials able to provide a chromic response. An overview of the past five years has been organised, encompassing 1, 2 and 3D responsive zinc-based CPs; specifically zinc-based metallorganic frameworks and zinc-based nanosized polymeric probes. The most relevant examples were collected following a consequential and progressive approach, referring to the structure-responsiveness relationship, the sensing mechanisms, the analytes and/or parameters detected. Finally, applications of highly bioengineered Zn-CPs for advanced imaging technique have been discussed.

Efficient luminescence sensing in two lanthanide metal–organic frameworks with rich uncoordinated Lewis basic sites

Two novel Ln-MOFs containing uncoordinated Lewis basic sites for sensitive detection of Fe3+ ions and nitrobenzene through fluorescence quenching.

Eight Cd(ii) coordination polymers with persistent room-temperature phosphorescence: intriguing dual emission and time-resolved afterglow modulation

A new series of p-RTP CPs 1–8 were designed and successfully synthesized; 5–8, in particular, exhibited intriguing time-resolved afterglow modulation.

Cobalt(II)-Based 3D Coordination Polymer with Unusual 4,4,4-Connected Topology as a Dual-Responsive Fluorescent Chemosensor for Acetylacetone and Cr2O72

A cobalt(II) coordination polymer with an unusual 4,4,4-connected network was hydrothermally synthesized and observed with high thermal, solvent, and pH stabilities. This polymer can serve as the first dual-responsive fluorescent chemosensor for the selective detection of acetylacetone and Cr₂O₇^2- ion (pH 3.0) in aqueous systems.

Three Anionic Indium-Organic Frameworks for Highly Efficient and Selective Dye Adsorption, Lanthanide Adsorption, and Luminescence Regulation

Through solvothermal reaction of InCl₃ and tetracarboxylate ligands with different substituent groups on diphenyl ethers, three new anionic indium-organic frameworks have been successfully prepared. They are {[(CH₃)₂NH₂]In(G-1)(H₂O)}·9DMF (1), {[(CH₃)₂NH₂]In(G-2)}·15DMF (2), and {[(CH₃)₂NH₂]₂In₂(G-3)₂}·16DMF (3) {DMF = N, N'-dimethylformamide; H₄(G-1) = 5',5″″-oxybis(2'-methoxy[1,1':3',1″-terphenyl]-4,4″-dicarboxylic acid); H₄(G-2) = 5',5″″-oxybis(2'-amino[1,1':3',1″-terphenyl]-4,4″-dicarboxylic acid); H₄(G-3) = 5',5″″-oxybis([1,1':3',1″-terphenyl]-4,4″-dicarboxylic acid)}. Compounds 1-3 can be simplified as unimodal 4-connected frameworks with different topological types: lon, cag, and dia, respectively. Compounds 1 and 3 display 2-fold interpenetrating nets, while compound 2 is non-interpenetrating. Compounds 1 and 3 can adsorb cationic methylene blue (MB) with good capacity and a high adsorption rate due to their anionic frameworks and channel-type voids. In particular, compound 1 exhibits great selectivity for cationic MB in the mixtures of MB and methyl orange. In addition, the adsorption behavior of rare earth ions (Eu³⁺ and Tb³⁺) on compounds 1 and 3 has also been studied. Due to the different structural features and channel sizes of compounds 1 and 3 caused by different substituents on the ligands, the adsorption properties of rare earth ions on the two compounds are different.

Synthesis, structure and selective luminescence sensing for iron(III) ions of a three-dimensional zinc(II) (4,6)-connected coordination network

Coordination polymers constructed from conjugated organic ligands and metal ions with a d¹⁰ electronic configuration exhibit intriguing properties for chemical sensing and photochemistry. A Zn^II-based coordination polymer, namely poly[aqua(μ₆-biphenyl-3,3',5,5'-tetracarboxylato)(μ₂-4,4'-bipyridine)dizinc(II)], [Zn₂(C₁₆H₆O₈)(C₁₀H₈N₂)(H₂O)₂]_n or [Zn₂(m,m-bpta)(4,4'-bipy)(H₂O)₂]_n, was synthesized from a mixture of biphenyl-3,3',5,5'-tetracarboxylic acid [H₄(m,m-bpta)], 4,4'-bipyridine (4,4'-bipy) and Zn(NO₃)₂·6H₂O under solvothermal conditions. The title complex has been structurally characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction analysis, and features a μ₆-coordination mode. The Zn^II ions adopt square-pyramidal geometries and are bridged by two syn-syn carboxylate groups to form [Zn₂(COO)₂] secondary buildding units (SBUs). The SBUs are crosslinked by (m,m-bpta)^4- ligands to produce a two-dimensional grid-like layer that exhibits a stair-like structure along the a axis. Adjacent layers are linked by 4,4'-bipy ligands to form a three-dimensional network with a {4⁴.6¹⁰.8}{4⁴.6²} topology. In the solid state, the complex displays a strong photoluminescence and an excellent solvent stability. In addition, the luminescence sensing results indicate a highly selective and sensitive sensing for Fe³⁺ ions.

Co(ii)-cluster-based metal–organic frameworks as efficient heterogeneous catalysts for selective oxidation of arylalkanes

Three Co-cluster-based metal–organic frameworks were designed and their catalytic activities for the selective oxidation of arylalkanes were explored.

6,6′-(Perfluoropropane-2,2-diyl)bis(2,3-dihydrophthalazine-1,4-dione)-based coordination polymers and their sensing properties towards Cr2O72−

The structures of six new diacylhydrazidate-based coordination polymers were reported. Based on their better photoluminescence properties, their sensing abilities towards Cr2O₇²⁻ were investigated.

Selective recognition of Fe3+ and CrO42− ions using a Zn(ii) metallacycle and a Cd(ii) coordination polymer and their heterogeneous catalytic application

A Zn(ii) metallacycle [Zn₂{(L)₂(DMF)₂(NO₃)₂}]·(NO₃)₂ (1) along with a Cd(ii) coordination polymer [{Cd(L)₂(DMF)₂}·(NO₃)₂]_n (2) have been synthesized, structurally characterized and exploited as a multifunctional material.

Exploring the syntheses, structures, topologies, luminescence sensing and magnetism of Zn(ii) and Mn(ii) coordination polymers based on a semirigid tricarboxylate ligand

Two Zn(ii)-CPs and two Mn(ii)-CPs were constructed from metal salts, H₃cpota and N-heterocyclic group ligands. Their structures, magnetic properties and luminescence sensing properties have been studied in detail.

Two MOFs as dual-responsive photoluminescence sensors for metal and inorganic ion detection

Two MOFs were synthesized and explored as dual-responsive photoluminescent sensors: 1 for Fe³⁺ and Cr₂O₇²⁻ ions, and 2 for Hg²⁺ and Cr₂O₇²⁻ ions.