A fluorescent microporous crystalline dendrimer discriminates vapour molecules

The surprising crystalline self-assembly of a conjugated dendrimer with exciting optical and sensing properties.

Synthesis, structure, and fluorescence properties of a calcium-based metal–organic framework

The solvothermal reaction of a mixture of calcium acetylacetonate and 1,4-naphthalenedicarboxylic acid (H₂NDC) in a solution containing ethanol and distilled water gave rise to a metal–organic framework (MOF), {(H₃O⁺)₂[Ca(NDC)(C₂H₅O)(OH)]}₄·1.1H₂O. This MOF possesses a new structure composed of calcium clusters and H₂NDC linker anions and shows a unique fluorescence property; it exhibits a fluorescence peak at 395 nm (λ_ex = 350 nm) at room temperature, which is blue-shifted compared with that exhibited by the free H₂NDC ligand. One of the possible mechanisms for this fluorescence is likely attributable to a ligand-to-metal charge transfer (LMCT) transition and is the first example of a calcium-based MOF exhibiting blue-shifted fluorescence due to LMCT.

The solvothermal reaction of a mixture of calcium acetylacetonate and 1,4-naphthalenedicarboxylic acid (H₂NDC) in a solution containing ethanol and distilled water gave rise to a metal–organic framework (MOF), {(H₃O⁺)₂[Ca(NDC)(C₂H₅O)(OH)]}₄·1.1H₂O.

A uranyl phosphonate framework with a temperature-induced order–disorder transition and temperature-correlated photoluminescence

UPF-1 experiences a thermally induced order–disorder transition, leading to a negative linear correlation between the photoluminescence intensity and temperature, and may find application as a luminescent thermometer.

A new europium metal–organic framework with both high proton conductivity and highly sensitive detection of ascorbic acid

The highest proton conductivity of the new Eu-MOF reaches up to 1.0 × 10⁻⁴ S cm⁻¹. Furthermore, it is an excellent luminescence-based sensor for detection of ascorbic acid (AA) in aqueous solutions.

Electronic metal–organic framework sensors

This review provides an overview on the different types of electronic MOF sensors used for the detection of molecules in the gas/vapour phase and how to assess their performances.

Coordination supramolecules with oxazoline-containing ligands

This highlight focuses on the recent development of oxazoline-based discrete coordination complexes and coordination polymers.

Operando study of palladium nanoparticles inside UiO-67 MOF for catalytic hydrogenation of hydrocarbons

Formation of Pd nanoparticles inside UiO-67 MOF was monitored by in situ X-ray absorption and diffraction.

Aldehyde-functionalized metal–organic frameworks for selective sensing of homocysteine over Cys, GSH and other natural amino acids

Aldehyde-functionalized luminescent MOFs represent the first example of MOF-implicated sensors for discriminating Hcy from Cys and GSH.

Neutral ligand TIPA-based two 2D metal–organic frameworks: ultrahigh selectivity of C2H2/CH4and efficient sensing and sorption of Cr(vi)

Two 2D porous frameworks are synthesized base on tri(4-imidazolylphenyl)amine. Compound1exhibits that the ultrahigh selectivity of C₂H₂/CH₄, the highest one reported to date. Compound2combines the ultrahigh sensitivity and trapping for Cr₂O₇²⁻in aqueous solution.

Assembly of a series of zinc coordination polymers based on 5-functionalized isophthalic acids and dipyridyl

A series of zinc coordination polymers based on 5-functionalized isophthalate and flexible dipyridyl ligands have been prepared. Their thermal and luminescent properties in the solid state were also investigated.

Luminescence properties of mechanochemically synthesized lanthanide containing MIL-78 MOFs

Solvent-free mechanochemistry is a highly effective route to synthesize MOFs with good luminescent properties as demonstrated in Ln_0.5Gd_0.5{C₆H₃(COO)₃ with a MIL-78 structure.

A pair of polymorphous metal–organic frameworks based on an angular diisophthalate linker: synthesis, characterization and gas adsorption properties

A pair of polymorphous MOFs derived from a bent diisophthalate ligand were synthesized by modulating solvothermal conditions, exhibiting comparable gas adsorption properties with respect to C₂H₂, CO₂ and CH₄.

Metal-Organic Framework-Based Sensors for Environmental Contaminant Sensing

Increasing demand for timely and accurate environmental pollution monitoring and control requires new sensing techniques with outstanding performance, i.e., high sensitivity, high selectivity, and reliability. Metal-organic frameworks (MOFs), also known as porous coordination polymers, are a fascinating class of highly ordered crystalline coordination polymers formed by the coordination of metal ions/clusters and organic bridging linkers/ligands. Owing to their unique structures and properties, i.e., high surface area, tailorable pore size, high density of active sites, and high catalytic activity, various MOF-based sensing platforms have been reported for environmental contaminant detection including anions, heavy metal ions, organic compounds, and gases. In this review, recent progress in MOF-based environmental sensors is introduced with a focus on optical, electrochemical, and field-effect transistor sensors. The sensors have shown unique and promising performance in water and gas contaminant sensing. Moreover, by incorporation with other functional materials, MOF-based composites can greatly improve the sensor performance. The current limitations and future directions of MOF-based sensors are also discussed.

A series of porous interpenetrating metal–organic frameworks based on fluorescent ligands for nitroaromatic explosive detection

Four porous interpenetrated fluorescent MOFs based on π-electron-rich N-donor ligands can effectively detect nitroaromatic explosives and exhibit highly sensitive responses to 2,4,6-trinitrophenol.

Two luminescent lanthanide(iii) metal–organic frameworks as chemosensors for high-efficiency recognition of Cr(vi) anions in aqueous solution

Two 12-connected sqc15 lanthanide(iii) MOFs act as luminescent turn-off chemosensors for high-efficiency recognition of Cr₂O₇²⁻ and CrO₄²⁻ anions in aqueous solution.

A robust Zn(ii)/Na(i)-MOF decorated with [(OAc)2(H2O)2]n2n− anions for the luminescence sensing of copper ions based on the inner filter effect

A robust Zn(ii)/Na(i)-based MOF decorated with [(OAc)₂(H₂O)₂]_n²ⁿ⁻ anions was synthesized and employed as the probe for Cu²⁺ detection.

Selective chiral symmetry breaking and luminescence sensing of a Zn(ii) metal–organic framework

The non-random handedness excess is observed in a chiral metal–organic framework [(CH₃)₂NH₂]₅[Zn_1.5(Zn₃O)(TATAT)₂]·9DMF·17H₂O (1, 1P ≫ 1M) without any chiral sources.

A water stable microporous metal–organic framework based on rod SBUs: synthesis, structure and adsorption properties

A microporous metal–organic framework based on rod SBUs with high water stability and good selectivity for CO₂ separation has been successfully synthesized.

Two luminescent lanthanide–organic frameworks containing bithiophene groups for the selective detection of nitrobenzene and Fe3+

Two isostructural lanthanide–organic frameworks containing bithiophene groups can be used as fast-response fluorescent probes for the sensitive detection of nitrobenzene and Fe³⁺ ions through fluorescence quenching.

From 2D → 3D interpenetration to packing: N coligand-driven structural assembly and tuning of luminescent sensing activities towards Fe3+ and Cr2O72− ions

Three complexes were hydrothermally synthesized and exhibited excellent selectivity towards Fe³⁺ and Cr₂O₇²⁻.

Microwave-assisted dry-gel conversion-a new sustainable route for the rapid synthesis of metal–organic frameworks with solvent re-use

Microwave-assisted dry-gel conversion (MW-DGC) combines the advantages of concentrated reactants in DGC with fast heating by microwave irradiation.

A highly hydrolytically stable lanthanide organic framework as a sensitive luminescent probe for DBP and chlorpyrifos detection

A series of isostructural 3D Ln-MOFs with exceptional hydrolytic stability were synthesized. The Tb³⁺ compound showed excellent sensing ability towards DBP and chlorpyrifos.

Luminescent Zn(ii) coordination polymers as efficient fluorescent sensors for highly sensitive detection of explosive nitroaromatics

Zn CPs 1–3 exhibit strong blue/cyan fluorescence emissions in toluene suspension for highly selective and sensitive detection of explosive nitroaromatics through remarkable fluorescence quenching responses. In addition, the framework Zn²⁺ ions in 3 were partially substituted by Cu²⁺ ions via a single-crystal to single-crystal (SCSC) transformation.

Efficient heterogeneous catalysis by dual ligand Zn(ii)/Cd(ii) MOFs for the Knoevenagel condensation reaction: adaptable synthetic routes, characterization, crystal structures and luminescence studies

Chemically stable Zn(ii)/Cd(ii) MOFs as a heterogeneous catalysts for Knoevenagel condensation.

Photonic functional metal–organic frameworks

The recent progress in photonic MOFs for luminescence sensing, white-light emission, photocatalysis, nonlinear optics, lasing devices, and biomedicine is summarized.

Liquid-free single-crystal to single-crystal transformations in coordination polymers

Single-crystal to single-crystal (SCSC) transformations not only can create new materials, but also provide an opportunity to explore the process of forming a chemical bond. SCSC transformations discussed in this paper are confined to transformationsviaan absolutely liquid-free mode and involve the breakage and formation of new chemical bonds.

A 2D porous pentiptycene-based MOF for efficient detection of Ba2+ and selective adsorption of dyes from water

The 2D MOF (UPC-28) as the water monitor can exhibit efficient detection of Ba²⁺ and perform selective adsorption of dyes from water.

The interlocked in situ fabrication of graphene@prussian blue nanocomposite as high-performance supercapacitor

High-quality graphene@prussian blue (G@PB) nanocomposite sheets fabricated via the one-step in situ hydrothermal method show great promise for energy-storage hybrid electrodes with excellent electrochemical performance.

A bi-metallic MOF catalyst via sensitive detection & adsorption of Fe3+ ions for size-selective reaction prompting

Novel MOF adsorbed Fe³⁺ presents the first example of a bi-metallic Lewis-acid catalyst for the cyanosilylation reaction in a size-selective fashion.

Rational synthesis of a luminescent uncommon (3,4,6)-c connected Zn(ii) MOF: a dual channel sensor for the detection of nitroaromatics and ferric ions

A 3D (3,4,6)-c connected net constructed using a rigid tetracarboxylate ligand and sensing studies to detect nitroaromatics and ferric ion performed.

Phosphorescence emission and fine structures observed respectively under ambient conditions and at ca. 55 K in a coordination polymer of lead(ii)-thiophenedicarboxylate

Under solvothermal conditions, a robust Pb²⁺-based coordination polymer (CP), [Pb(TDC)]_n (1), where H₂TDC is thiophenedicarboxylic acid, has been achieved.

Biocarbon-templated synthesis of porous Ni–Co-O nanocomposites for room-temperature NH3 sensors

Mesoporous nickel–cobalt oxide (Ni–Co-O) nanocomposites were fabricated using a mesoporous biocarbon material (BCM), resulting from hemp stem, as a template.

Utilizing an effective framework to dye energy transfer in a carbazole-based metal–organic framework for high performance white light emission tuning

By introducing dyes into a MOF, a white-light-emitting luminophor was obtained based on effective framework to dye energy transfer mechanism.

Luminescent metal–organic frameworks as chemical sensors: common pitfalls and proposed best practices

In this review we approach the emerging field of sensors based on luminescent metal–organic frameworks from the perspective of the most commonly encountered pitfalls and we suggest best practices so that they can be avoided.

A Co(ii) framework derived from a tris(4-(triazol-1-yl)phenyl)amine redox-active linker: an electrochemical and magnetic study

This is a rare case of a solid-state electrochemical and spectroelectrochemical study of coordination polymers. Furthermore, the framework exhibits an interesting field-induced magnetic spin-flop transition.

Chiral coordination polymers based on d10 metals and 2-aminonicotinate with blue fluorescent/green phosphorescent anisotropic emissions

Two isostructural and chiral 2D-layered coordination polymers present bright blue steady-state fluorescence that turns into pale green long-lasting phosphorescence.

Selective and reversible adsorption of cationic dyes by mixed ligand Zn(ii) coordination polymers synthesized by reactant ratio modulation

2D/3D luminescent Zn(ii)-based coordination polymers CP1 and CP2 have been synthesized by reactant ratio modulation. Photoluminescence studies of both CPs; selective and reversible adsorption/separation of cationic dyes by CP1 in the aqueous medium has been investigated.

A luminescent turn-up metal–organic framework sensor for tryptophan based on singlet–singlet Förster energy transfer

A highly stable MOF, ZJU-108, was synthesized with Zn²⁺ and 6-(4-pyridyl)-terephthalic acid (H₂pta) as construction units, and it exhibits an impressive turn-on luminescence enhancement response to tryptophan.

Acid and Base Resistant Zirconium Polyphenolate-Metalloporphyrin Scaffolds for Efficient CO2 Photoreduction

A series of zirconium polyphenolate-decorated-(metallo)porphyrin metal-organic frameworks (MOFs), ZrPP-n (n = 1, 2), featuring infinite Zr^IV -oxo chains linked via polyphenolate groups on four peripheries of eclipse-arranged porphyrin macrocycles, are successfully constructed through a top-down process from simulation to synthesis. These are the unusual examples of Zr-MOFs (or MOFs in general) based on phenolic porphyrins, instead of commonly known carboxylate-based types. Representative ZrPP-1 not only exhibits strong acid resistance (pH = 1, HCl) but also remains intact even when immersed in saturated NaOH solution (≈20 m), an exceptionally large range of pH resistance among MOFs. The metallation at the porphyrin core gives rise to materials with enhanced sorption and catalytic properties. In particular, ZrPP-1-Co, with precise and uniform distribution of active centers, exhibits not only high CO₂ trapping capability (≈90 cm³ g^-1 at 1 atm, 273 K, among the highest in Zr-MOFs) but also high photocatalytic activity for reduction of CO₂ into CO (≈14 mmol g^-1 h^-1 ) and high selectivity over CH₄ (>96.4%) without any cocatalyst under visible-light irradiation (λ > 420 nm). Given the strong chemical resistance under extreme alkali conditions, these catalysts can be recycled without appreciable loss of activity. The possible mechanism for photocatalytic reduction of CO₂ -to-CO over ZrPP-1-Co is also proposed.

Highly selective and sensitive detection of Hg2+, Cr2O72−, and nitrobenzene/2,4-dinitrophenol in water via two fluorescent Cd-CPs

Taking advantage of fluorescent Cd-CPs with 3,3′-thiodipropionic acid and imidazole ligands, herein, we demonstrate the synthesis of functional CPs, and develop two Cd-CP fluorescence sensing materials with highly selective and sensitive detection of Hg²⁺, Cr₂O₇²⁻, NB,/2,4-DNP in water.

Novel 1D coordination polymers built from acyclic cryptate containing bis(1H-1,2,4-triazole) ligands and featuring coordinated counteranions

Two new coordination polymers, namely, ZnL₂(BF₄)₂ (1) and CuL₂(NO₃)₂ (2) were constructed from a new flexible acyclic cryptate-bis(1H-1,2,4-triazole) ligand.

Synthesis, structure and temperature sensing of a lanthanide-organic framework constructed from a pyridine-containing tetracarboxylic acid ligand

A high sensitive, thermostable mixed lanthanide metal–organic framework, Eu_0.19Tb_0.81PDDI, was developed as a self-calibrated thermometer effective in the high temperature range of 313 to 473 K.

Bulky substituent and solvent-induced alternative nodes for layered Cd–isophthalate/acylhydrazone frameworks

A series of three layered cadmium–organic frameworks containing acylhydrazone and (un)substituted isophthalates have been prepared and characterised.

Synthesis of tetraphenylethylene-based conjugated microporous polymers for detection of nitroaromatic explosive compounds

Conjugated microporous polymers (CMPs) containing tetraphenylethylene (TPE) were synthesized via the Suzuki coupling polymerization.

A series of Ln4III clusters: Dy4 single molecule magnet and Tb4 multi-responsive luminescent sensor for Fe3+, CrO42−/Cr2O72− and 4-nitroaniline

Five tetranuclear lanthanide clusters were synthesized. Dy₄ complex exhibits single molecule magnet (SMM) behavior and Tb₄ compound shows sensing properties towards Fe³⁺, CrO₄²⁻, Cr₂O₇²⁻ and 4-nitroaniline (4-NA).

Direct synthesis of functionalized PCN-333 via linker design for Fe3+ detection in aqueous media

Functionalized PCN-333 was synthesized for Fe³⁺ ion detection via one-pot solvothermal reaction.

Three ligand-originated MOF isomers: the positional effect of the methyl group on structures and selective C2H2/CH4 and CO2/CH4 adsorption properties

The positional effect of the methyl group on structures and gas adsorption properties was explored in a copper-based MOF platform constructed from bent diisophthalate ligands bearing the methyl group at different positions.