Coordination polymers for energy transfer: Preparations, properties, sensing applications, and perspectives

Cadmium–1,4-cyclohexanedicarboxylato coordination polymers bearing different di-alkyl-2,2′-bipyridines: syntheses, crystal structures and photoluminescence studies

Cd(ii) polymers, in acetone, can be used as luminescent materials for detection of CH₃CN.

Ag+-induced photoluminescence enhancement in lanthanide post-functionalized MOFs and Ag+ sensing

Single-phase white-light emitters based on 4d–4f heterometallic co-doped MOFs can be realized, and Sm-MIL-61 shows more highly sensitive and selective sensing towards Ag⁺.

Synthesis and characterization of nano-peanuts of lead(II) coordination polymer [Pb(qcnh)(NO3)2]n with ultrasonic assistance: A new precursor for the preparation of pure-phase nano-sized PbO

A sonochemical method was used to synthesize nano-peanuts of a new lead(II) coordination 1D polymer, [Pb(qcnh)(NO₃)₂]_n (1), where qcnh=2-quinolincarbaldehyde nicotinohydrazide. The compound was characterized by scanning electron microscopy (SEM), elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), and single crystal X-ray analysis. The X-ray structure revealed that the Pb(II) atom is coordinated by one oxygen and three nitrogen atoms from two qcnh ligands and five oxygen atoms from three nitrate ligands in an 8+1 fashion with a PbN₃O₆ donor set. One of the PdN distances in the vicinity of the central atom is a bit longer (Pb1N1=2.939(4) Å), which shows the effect of the 6s² lone electron pair localized within the valence shell of the lead(II) atom. PbO nanoparticles were obtained by thermolysis of 1 at 180°C with oleic acid as a surfactant. The average diameter of the nanoparticles was estimated by XRD to be 28nm. The morphology and size of the prepared PbO nanoparticles were further studied using SEM.

Unique structural micro-adjustments in a new benzothiadiazole-derived Zn(ii) metal organic framework via simple photochemical decarboxylation

Herein, we report the first exploration of structural micro-adjustments via simple photochemical decarboxylation in a new Zn(ii) benzothiadiazole-derived MOF, Zn-BTDC-M1.

An updated roadmap for the integration of metal–organic frameworks with electronic devices and chemical sensors

This review highlights the steps needed to bring the properties of MOFs from the chemical lab to the microelectronics fab.

Synthetic approaches towards structurally-defined electrochemically and (photo)redox-active polymer architectures

This review details synthetic strategies leading to structurally-defined electrochemically and (photo)redox-active polymer architectures,e.g.block, graft and end functionalized (co)polymers.

Sorption and sensing properties of coordination polymers with mixed 1,3,5-tri(1-imidazolyl)benzene and 2,6-naphthalenedicarboxylate ligands

Cd(ii) and Zn(ii) frameworks with mixed dicarboxylate and imidazole-containing ligands show selective adsorption and sensing properties.

A novel one-dimensional double-chain-like ZnIIcoordination polymer: poly[bis(1-benzyl-1H-imidazole-κN3)tris(μ-cyanido-κ2C:N)(cyanido-κC)disilver(I)zinc(II)]

One of most interesting systems of coordination polymers constructed from the first-row transition metals is the porous ZnIIcoordination polymer system, but the numbers of such polymers containingN-donor linkers are still limited. The title double-chain-like ZnIIcoordination polymer, [Ag2Zn(CN)4(C10H10N2)2]n, presents a one-dimensional linear coordination polymer structure in which ZnIIions are linked by bridging anionic dicyanidoargentate(I) units along the crystallographicbaxis and each ZnIIion is additionally coordinated by a terminal dicyanidoargentate(I) unit and two terminal 1-benzyl-1H-imidazole (BZI) ligands, giving a five-coordinated ZnIIion. Interestingly, there are strong intermolecular AgI...AgIinteractions between terminal and bridging dicyanidoargentate(I) units and C—H...π interactions between the phenyl rings of BZI ligands of adjacent one-dimensional linear chains, providing a one-dimensional linear double-chain-like structure. The supramolecular three-dimensional framework is stabilized by C—H...π interactions between the phenyl rings of BZI ligands and by AgI...AgIinteractions between adjacent double chains. The photoluminescence properties have been studied.

Photoluminescent Metal-Organic Frameworks for Gas Sensing

Luminescence of porous coordination polymers (PCPs) or metal-organic frameworks (MOFs) is sensitive to the type and concentration of chemical species in the surrounding environment, because these materials combine the advantages of the highly regular porous structures and various luminescence mechanisms, as well as diversified host-guest interactions. In the past few years, luminescent MOFs have attracted more and more attention for chemical sensing of gas-phase analytes, including common gases and vapors of solids/liquids. While liquid-phase and gas-phase luminescence sensing by MOFs share similar mechanisms such as host-guest electron and/or energy transfer, exiplex formation, and guest-perturbing of excited-state energy level and radiation pathways, via various types of host-guest interactions, gas-phase sensing has its unique advantages and challenges, such as easy utilization of encapsulated guest luminophores and difficulty for accurate measurement of the intensity change. This review summarizes recent progresses by using luminescent MOFs as reusable sensing materials for detection of gases and vapors of solids/liquids especially for O₂, highlighting various strategies for improving the sensitivity, selectivity, stability, and accuracy, reducing the materials cost, and developing related devices.

Chemical Sensors Based on Metal-Organic Frameworks

Metal-organic frameworks (MOFs) as chemical sensors have developed rapidly in recent years. There have been many papers concerning this field and interest is still growing. The reason is that the specific merits of MOFs can be utilized to enhance sensitivity and selectivity by various energy/charge transfers occurring among different ligands, ligand, and metal centers, such as from ligands to metal centers or metal centers to ligands, as well as from MOF skeletons to guest species. This review intends to provide an update on recent progress in various applications of different MOF-based sensors on the basis of their luminescent and electrochemical responses towards small molecules, gas molecules, ions (cations and anions), pH, humidity, temperature, and biomolecules. MOF-based sensors function by utilizing different mechanisms, including luminescent responses of "turn-on" and "turn-off", as well as electrochemical responses.

One-step growth of lanthanoid metal-organic framework (MOF) films under solvothermal conditions for temperature sensing

A one-step direct solvothermal synthesis of an Ln metal-organic framework (MOF) film is reported. The LnHL (Ln = Tb and Gd) films that were deposited on a Gd2O3 subtrate are continuous and smooth. The Gd0.9Tb0.1HL film can be used as a ratiometric thermometer, showing good linear behaviour in the temperature range of 110-250 K with a sensitivity up to 0.8% K(-1).

Novel core-shell structure microspheres based on lanthanide complexes for white-light emission and fluorescence sensing

A series of new core-shell structure materials based on lanthanide complexes [H2NMe2]3[Ln(dpa)3] (Ln = Eu, Tb, Sm, Dy, Nd, and Yb; [H2NMe2](+) = dimethylamino cation; dpa = 2-dipicolinate) and silica microspheres has been prepared under solvothermal conditions. Electron microscopy reveals that the nanosized materials SiO2@Ln-dpa are spherical with a narrow size distribution and a [H2NMe2]3[Ln(L)3] coating was generated on the surface of silica microspheres successfully. The core-shell structure materials exhibit excellent optical performance. The white-light-emitting material SiO2@(Dy:Eu)-dpa has a potential application in the development of a white-light device, as a result of the fact that its CIE chromaticity coordinate is very close to that of pure white. Then, we selected SiO2@Eu-dpa as a representative sample for sensing experiments. Eventually, we found that the core-shell structure sensors are highly selective and sensitive for acetone and Cu(2+) cations. The detection of Cu(2+) in the human body is an important issue. Interestingly, the core-shell structure materials display better selectivity and higher sensitivity than the pure lanthanide complexes in sensing Cu(2+) and the value of the quenching effect coefficient has increased by more than 20%.

Inverted molecular cups: 1-D and 2-D Ag(i) coordination polymers from resorcinarene bis-thiacrowns

Exo-cavity binding into resorcinarene based inverted molecular cups creates 1-D and 2-D silver coordination polymers with argentophilic interactions.

Synthesis and structure characterization of zinc and cadmium dipeptide coordination polymers

A twofold (black, red) interpenetrated network of a Zn(Gly-l-Phe)₂coordination polymer, with hydrogen bonds (green) between neighboring layers.

A responsive MOF nanocomposite for decoding volatile organic compounds

A molecular decoding platform, which recognizes aromatic VOCs with distinctly different 2D readouts, has been developed by a responsive luminescent MOF nanocomposite. The VOC recognition is based on an unprecedented dual-readout orthogonal identification scheme.

3,5-Bis((4′-carboxylbenzyl)oxy)benzoilate-based coordination polymers: their synthesis, structural characterization, and sensing properties

The structural characterization of four 3,5-bis((4′-carboxylbenzyl)oxy)benzoilate-based coordination polymers has been reported, and the sensing ability of 2 and 4 on NB has been investigated.

Exploiting redox activity in metal–organic frameworks: concepts, trends and perspectives

This feature article highlights latest developments in experimental, theoretical and computational concepts relevant to redox-active metal–organic Frameworks.

Color tuning of alternating conjugated polymers composed of pentaazaphenalene by modulating their unique electronic structures involving isolated-LUMOs

Pentaazaphenalene-containing polymers with unique conjugated systems were synthesized. Various colors can be observed from the polymer solutions.

Grinding size-dependent mechanoresponsive luminescent Cd(ii) coordination polymer

A new mechanoresponsive luminescent Cd(ii) coordination polymer exhibits rare grinding size-dependent fluorescence and possesses good crystalline maintenance capability.

Anionic metal–organic framework for high-efficiency pollutant removal and selective sensing of Fe(iii) ions

An anionic metal–organic framework, (DMA)₂[Y₉(μ₃-OH)₈(μ₂-OH)₃BTB₆]_n·(solv)_x, (gea-MOF-1), is a novel rare earth (RE) nonanuclear MOF with an unusual gea topology that can be used as an adsorbent material for efficient removal of cationic dye MB⁺.

Pure white-light and colour-tuning of Eu3+–Gd3+-containing metallopolymer

The first example of Eu³⁺–Gd³⁺-containing metallopolymer Poly(2-co-NVK-co-4) was constructed to exhibit tunable photoluminescence and even direct white-light emission.

A luminescent metal–organic framework for highly selective sensing of nitrobenzene and aniline

A luminescent metal–organic frameworkgea-MOF-1, can act as a fluorescent sensor for sensitive and selective detection of nitrobenzene and aniline. More importantly, the detection limit of nitrobenzene is on the 5–60 ppm scale.

Unraveling a two-step oxidation mechanism in electrochemical Cu-MOF synthesis

To employ the full potential of electrochemical (ec) synthesis to grow metal–organic frameworks (MOFs) in more complex organizations at the mesoscale, it is vital to understand the underlying crystallization reaction pathway.