Effective C2H2 Separation and Nitrofurazone Detection in a Stable Indium–Organic Framework

Detection of nitrofurazone with metal-organic frameworks and reduced graphene oxide composites: insights from molecular dynamics simulations

Two-dimensional metal-organic framework (MOF) composites were produced by incorporating Fe-MOFs into reduced graphene oxide (rGO) nanosheets to form Fe-MOF/rGO composites by hydrothermal synthesis. SEM, TEM, XRD, XPS, and measurements of contact angles were used to characterize the composites. TEM studies revealed that the rod-like-shaped Fe-MOFs were extensively dispersed on the rGO sheets. Incorporating Fe-MOF into rGO significantly improves performance due to the large surface area, chemical stability, and high electrical conductivity. The response signals for the electrochemical sensing performance of Fe-MOF/rGO-modified electrodes to nitrofurazone (NFZ) were significantly enhanced. Differential pulse voltammetry was used to detect the NFZ, and the MOF/rGO sensor possesses a lower detection limit (0.77μM) with two dynamic ranges from 0.6-60 to 128-499.3 μM and high sensitivity (1.909 μA·mM^-1·cm^-2). Moreover, the anti-interference properties of the sensor were quite reproducible and stable. To understand the mechanism responsible for the enhanced sensing performance of the composite, grand canonical Monte Carlo calculations were performed for Fe-MOF/rGO composites with five unit cells of Fe-MOF and four layers of rGO. We attributed the improvement to the fact that the interface between the Fe-MOF and rGO absorbed increased NFZ molecules. The findings reported herein confirm that such Fe-MOF/rGO composites have significantly improved electrochemical performance and practical applicability of sensing nitrofurazone.

Mononuclear, hexanuclear and polymeric indium(III) pyrazolido complexes; structural characterization, dynamic solution studies and luminescent properties

A new family of six mononuclear indium(III) complexes of formula mer-[In^IIICl₃(pz*H)₃]-pz*H = pyrazole (pzH), or substituted pyrazoles: 4-Cl-pzH, 4-Br-pzH, 4-I-pzH, 4-Ph-pzH and 3,5-Me₂-pzH-were synthesized by addition reactions of InCl₃ and pz*H and crystallographically characterized. The fluxional behaviour of the complexes, probed by variable temperature ¹H NMR spectroscopy in the 328 K to 173 K range, was attributed to (at least) four simultaneous processes: pyrazole N-H proton dissociation/association, cis/trans-pyrazole exchange, and N¹/N² tautomerization of the cis- and of the trans-pyrazoles. Three novel trianionic hexanuclear complexes of general formula (pipH)₃[In₆Cl₆(μ₃-OH_0.5)₂(μ-OH)₆(μ-pz*)₆]-pz* = pz, 4-Cl-pz and 4-Ph-pz-showing μ-hydroxo and μ-oxo bridges were synthesized from the corresponding mer-[In^IIICl₃(pz*H)₃] and characterized by single crystal X-ray diffraction and ¹H NMR. Under different solvent conditions, multicolour emitting polymeric complexes of general formula [In(μ-pz*)₃]_n-pz* = pz, 4-Cl-pz, 4-I-pz and 4-Ph-pz-were obtained also from mer-[In^IIICl₃(pz*H)₃] after addition of a base. Luminescence and lifetime calculations were performed for all polymers formed.

An anthracene-based Hydrogen-bonded Organic Framework as Bifunctional Fluorescent Sensor for the Detection of γ-Aminobutyric Acid and Nitrofurazone

Intelligent fluorescence detection for disease diagnosis has become a research hotspot. In the era of big data, machine learning (ML) for analyzing data and mining will be widely used in...

Two coordination polymers as multi-responsive luminescent sensors for the detection of UO22+, Cr(vi), and the NFT antibiotic

Two CPs have been synthesized using solvothermal method and can act as multi-responsive luminescent probe to detect UO22+ cation, Cr2O72−/CrO42− anions, and nitrofuran antibiotic in aqueous media with high sensitivity and selectivity.

Metal–organic frameworks (MOFs) as fluorescence sensors: principles, development and prospects

This review classifies the latest developments of MOF-based fluorescence sensors according to the analytes, and discusses the challenges faced by MOF-based fluorescence sensors and promotes some directions for future research.

Metal-Organic Frameworks Featuring 18-Connected Nonanuclear Rare-Earth Oxygen Clusters and Cavities for Efficient C2H2/CO2 Separation

Two rare-earth (RE) metal-organic frameworks (MOFs) formulated as {(Me₂NH₂)₂[RE₉(μ₃-OH)₈(μ₂-OH)₃(DCPB)₆(H₂O)₃]}_n (RE = Y³⁺ and Tb³⁺; termed JXNU-10) built from a triangular 3,5-di(4'-carboxylphenyl)benzoic acid (DCPB^3-) ligand are presented. JXNU-10 features the rarely observed 18-connected nonanuclear [RE₉(μ₃-OH)₈(μ₂-OH)₃] clusters, one-dimensional-nanosized tubular channels, and trigonal-bipyramidal cavities. The presence of the high-nuclear RE-oxo clusters and the robust coordination bonds between the highly charged RE ions and the hard base of the carboxylate/hydroxyl oxygen atoms yielded the water-resistant JXNU-10 materials. JXNU-10 exhibits highly selective sorption of C₂H₂ over CO₂ and highly efficient separation of a C₂H₂ and CO₂ mixture. The carboxylate oxygen atoms and the rich π systems of the organic ligands on the pore walls are the desirable binding sites for a C₂H₂ molecule with acidic hydrogen atoms and an alkyne group, facilitating the excellent efficiency of JXNU-10 for C₂H₂/CO₂ separation demonstrated by breakthrough experiments.

A water-stable multi-responsive luminescent Zn-MOF sensor for detecting TNP, NZF and Cr2O72- in aqueous media

The wide prevalence of organic and inorganic pollutants in water from various industries is responsible for serious environmental problems and endangers human beings. Therefore, the search for effective methods to detect these pollutants has gained great importance. In this work, a new luminescent MOF, {[Zn(L)(bpe)_0.5]·DMF}_n (1) [H₂L = 4,4'-((naphthalene-1,4-dicarbonyl)bis(azanediyl))dibenzoic acid, bpe = 1,2-bis(4-pyridyl)ethene], was solvothermally synthesized and structurally characterized. In this MOF, Zn-SBUs (SBUs = secondary building units) were connected by acylamide-containing dicarboxylate L^2- and nitrogen-containing bpe molecules to yield a 3D porous framework with isolated DMF molecules in the pores. The activated solvent-free MOF sample (denoted as 1a) with good water-stability was obtained by the solvent-exchange and vacuum heat treatment techniques. The luminescence sensing experiments showed that 1a could sensitively, selectively and reversibly detect 2,4,6-trinitrophenol (TNP), nitrofurazone (NZF) and Cr₂O₇^2- in aqueous media, and the corresponding luminescence quenching mechanism has also been discussed. In addition, MOF 1a could quantitatively detect TNP, NZF and Cr₂O₇^2- in tap water samples, indicating that MOF 1a has the potential to detect the aforesaid pollutants in various environmental water matrices.

Luminescence sensing and photocatalytic activities of four Zn(ii)/Co(ii) coordination polymers based on a pyridinephenyl bifunctional ligand

Four Zn(ii)/Co(ii) CPs act as bifunctional materials in the detection of Fe(iii) cation, Cr(vi) anion, and nitrofuran antibiotics and removal of methylene blue in aqueous media.

Selective fluorescence sensing properties of a novel two-fold interpenetrating coordination polymer

One novel 3D interpenetrated Zn(ii) CP acts as multi-functional chemosensors in detection of acetone, Fe³⁺, Cu²⁺, Cr₂O₇²⁻, CrO₄²⁻ and nitrofurantoin (NFT).

A robust 3D In–MOF with an imidazole acid ligand as a fluorescent sensor for sensitive and selective detection of Fe3+ ions

A stable In(iii)-MOF with a versatile 5-(1H-imidazol-1-yl)isophthalic acid ligand can be used as a fluorescent sensor for Fe³⁺ detection.

Metal–organic frameworks for C2H2/CO2 separation

A summary of important advancements in C₂H₂/CO₂ separation using metal-organic frameworks (MOFs) is presented in this perspective article. The structure-activity relationship of MOFs has been discussed in detail.