Benefits from the pyrazole ligands 4, 5-bis(pyrazole-1-yl) phthalic acid (C14N4O4H10), Co(NO)3·6H2O and Cu(NO)3·3H2O, four 3D supramolecular compounds ([Co(C14N4O4H9)2(H2O)2]∙2H2O (1), [Co2(C16N4O4H13)2(CH3COO)2]·C2H5OH (2), [Co(C14N4O4H9)(CH3COO)(C3H7OH)]·C3H7OH (3)) and [Cu2(C14N4O4H9)2(H2O)2]∙6H2O (4) were synthesized. Among them, the ethanol solution in compound 2 can be used as both solvent and reactant to form 4, 5-bis(pyrazole-1-yl) ethyl phthalate with 4, 5-bis (pyrazole-1-yl) phthalate (C16N4O4H14), which is directly synthesized by a one-step method. This study reports a one-step synthesis method for ester compounds, opening new avenues for the synthesis of ester compounds using solvent. Compounds 1–4 were doped with graphite to prepare a series of composite carbon paste electrodes, and their electrochemical sensing performance toward uric acid, dopamine, and acetaminophen was investigated. Among the four compounds, the modified electrode prepared using 1 and 4 exhibited excellent electrochemical sensing performance, high sensitivity, exceptional selectivity, and remarkable recyclability for detecting uric acid (pH = 7), dopamine (pH = 4) and acetaminophen (pH = 7) in PBS solution.

Abstract There remains much ambiguity regarding the structure of red phosphorus. We report the adsorption and photo-polymerisation of P4 molecules encapsulated in an indium(III)-based metal-organic framework to afford a double-helical chain composite comprising of [P8] units. The similarity between the Raman spectrum of bulk red phosphorus and of the metal-organic framework – (P8)n adduct suggests the presence of such helical chains in the structure of amorphous red phosphorus. This provides crystallographic evidence of the structural building blocks of the red phosphorus allotrope stabilized within the pores of a metal-organic host. The (P8)n inclusion compound is an air-stable semiconductor with a band gap of 2.3 eV, which is relevant for gas detection and photo-catalysis. We demonstrate that this phosphorus adduct demonstrates a 10-fold increase in conversion in the oxidation of methyl orange dye compared with the parent metal-organic framework material.

Coordination polymers [Gd2(5-iip)3(DMF)4]·0.4DMF (1) and [Dy2(5-iip)3DMF2]·0.33DMF (2) (5-iip2−—5-iodoisophthalate) feature two different structural types, as follows from X-ray diffractometry data. We prepared and characterized an extended series of corresponding heterometallic complexes of the composition [GdxDy2−x(5-iip)3DMF2]·0.33DMF and [EuxDy2−x(5-iip)3DMF2]·0.33DMF, where x = 0.2, 0.4…1.8, and examined the changes of their luminescent properties induced by variations of metal composition, finding the promising white emission sources with high light purity.

Four new metal-organic frameworks with the formulae [Sm2(phen)2(NO3)2(chdc)2]2solv, where solv = N,N-dimethylformamide (DMF; 1), N,N-dimethylacetamide (DMA; 2), N,N-diethylformamide (DEF; 3), N-formylpiperidine (NFP; 4), phen = 1,10-phenanthroline and chdc2- = trans-1,4-cyclohexanedicarboxylate were synthesized and structurally characterized. These compounds are based on similar binuclear samarium(iii)-carboxylate blocks, bound by flexible chdc linkers into layered sql-type coordination networks. The amide solvents drive different intralayer block orientations between 1 and 2-4 and different layer-to-layer packings in all the described compounds. A pronounced dependence of the emission color upon the excitation wavelength variation was determined for 1-4, while the relative impacts of Sm3+ and phen emission on overall luminescence were found to depend strongly on these packings, and their reasonable correlation to the distances between the closest pi-pi-stacked phen moieties in the structures was revealed. Phase transitions between compounds 1-4 were studied by means of powder X-ray diffraction. Additionally, bimetallic near-white luminophores were obtained for phases 3 and 4 by doping their synthetic systems with a minor (similar to 5%) Tb3+ additive. In general, this study shows a possibility of tuning the luminescence properties of porous metal-organic frameworks by minor structural differences induced by solvent-driven dynamics with no apparent quenching or other direct impact on the optical properties of the included solvent.

The escalating development of the national industry has led to a growing apprehension regarding water pollution. Therefore, there is an urgent need to develop a rapid, convenient, and highly sensitive method for detecting water pollutants. In this study, we successfully prepared a novel Keggin-type polyacid hybrid material with zerodimensional structure [Zn2(C10H6NO2)2(C10H7NO2)4][ZnCl(C10H7NO2)3]2[HPMo12O40]2 (1) through steam heating using 2,3-quinoline dicarboxylic acid, phosphomolybdic acid and Zn(NO3)2 along as precursors. However, it was observed that 2,3-quinoline dicarboxylic acid (H2L = C11H7NO4) loses a carboxyl group from a new quinoline-3-carboxylic acid ligand (HL1 = C10H7NO2) during the synthesis process of 1. Our investigations have revealed two distinct forms for Zn2+, form A involves coordination with one Zn ion, three ligands and one chloride ion while form B forms a binuclear cluster [Zn2(C10H6NO2)2(C10H7NO2)4]2+ by coordinating with two L1- 1 and four HL1 ligands. These structures are further extended into 3D supramolecular architectures via it-it packing between one-dimensional chains formed by connecting the Keggin-type polyoxometalates through multiple hydrogen bonds. Additionally, we explore the fluorescence and electrochemical properties of compound 1. These results demonstrate its exceptional selectivity and high sensitivity towards Fe3+, HPO42- and CrO42- as a fluorescence probe and excellent electrochemical activity towards NaNO2. Furthermore, the reaction mechanism was thoroughly examined.

Two Cd-based complexes {complex1=Cd2(L1)2.5(NO3)4 and complex2=Cd(HL2)} were synthesized with two nitrogen-containing ligands L1 and H3L2 (L1 = 4,4 '-di(1H-imidazol-1-yl)-1,1 '-biphenyl and H3L2 = 4-(6-Carboxypyridin-3-yl)-isophthalic acid). Both complexes are monoclinic crystal system with P21/c space group, and have good stability. In view of their good stability, complex 1 and complex 2 were employed for fluorescence sensing of amino acids and antibiotics, respectively. Complex 1 can identify tryptophan (Trp) from common amino acids with LOD = 1.72 mu M, and complex 2 can identify chlortetracycline (CTE) and oxytetracycline (OXY) from antibiotics with LOD = 0.89 mu M and 2.89 mu M, respectively. Both complexes exhibit superior anti-interference capabilities, excellent recyclability, and rapid response characteristics. The sensing mechanism of the two complexes on the analytes was also analyzed and explained.

A series of nine 3D metal-organic frameworks based on Ln3+ and 2-diodoterephthalate (2-I-bdc) with general formula{[Ln2(2-I-bdc)3(H2O)]& sdot;xH2O & sdot;yCH3CN} (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Ho, 1 - 9 ) were obtained. According to X-ray diffractometry, all these complexes belong to two structural types (La to Nd and Sm to Ho, respectively). Some of complexes in the 1 - 9 series demonstrate luminescent properties.

New zinc-based luminescent coordination polymer [Zn2(bpy)(H2O)2(LO)2] (Zn-CP, H2LO - 4,7-di(4-carboxypyrazol-1-yl)-2,1,3-benzooxadiazole, bpy - 4,4 '-bipyridine) was synthesized. The compound demonstrated high stability in various organic solvents and excellent luminescent properties with the photoluminescence quantum yield of 57 %. Zn-CP was capable of detecting aluminum, gallium and dihydrogen phosphate ions with the limits of detection 0.10, 0.17 and 0.14 mu M, respectively. The luminescence turn-on upon the addition of these analytes can be detected by the naked eye, making possible the fabrication of express test paper strips. The possibility of using the CP as phosphors in UV-pumped light-emitting diodes was also demonstrated.

Lanthanide metal-organic frameworks combine the luminescent properties of rare earth elements with the structural tunability of molecular frameworks, making them ideal for multifunctional applications, such as luminescence sensing and gas separation. Herein, we report the synthesis of a red luminescent microporous Eu-MOF {[Eu2(H2O)L3]·3H2O}n using 1,2,5-thiadiazole-3,4-dicarboxylic acid (H2L) as the sole ligand. The H2L ligand features an effective antenna effect for energy transfer and structural rigidity, enabling the formation of a robust microporous framework. Detailed structural analysis revealed its highly ordered microporosity. The Eu-MOF exhibited excellent luminescence sensing performance for detecting nitrofuran antibiotics, including nitrofurantoin (NFN) and nitrofurazone (NTZ), demonstrating high selectivity, low detection limits, and short sensing response time (both within 6 s). Furthermore, the microporous structure of Eu-MOF endowed it with exceptional adsorption properties, enabling effective methane-acetylene separation.

Two new Tb(iii) metal-organic frameworks with an aliphatic bis-hydroxamate linker have been synthesized and structurally characterized. The title compounds have [Tb2(H2O)2(OAc)2(L)2]2Solv formulae, where L2- is a deprotonated form of 1,4-dihydroxy-3,3,6,6-tetramethylpiperazine-2,5-dione and Solv is N,N-dimethylacetamide or ethanol. Both compounds possess layered sql-type structures and appear to be solvatomorphic crystal phases, but with a significant change in the pore volume fraction from 35% for the DMA-based structure down to 23% for the EtOH-based one. The activation of the ethanol-based compound led to a porous network demonstrating hysteretic adsorption of carbon dioxide with a BET surface area of 493 m2 g-1. A narrow-banded emission in the green region, typical for Tb(iii)-based metal-organic complexes, was found for both obtained compounds with ca. 1% photoluminescence quantum yields, showing an ability of the first MOF-related example of a non-aromatic bis-hydroxamate strut presented herein to sensitize the phosphorescence of Tb(iii) ions.

For the time being, complexes have limited their application in electrochemistry owing to their poor electrical conductivity, weak structural stability and ease of reunions. In this work, Cd-MOF was hydrothermally synthesized using 5,5 '-(pyridine-2,6-diylbis(oxy))di-isophthalic acid in the environment of Ti3C2 material and CdMOF@Ti3C2 with high stability and conductivity was obtained. Based on the ionic insertion coordination ability between Ti3C2 materials and MOF ligands, Ti3C2 was utilized to immobilize Cd-MOF nanosheets to achieve efficient charge transfer while avoiding the stacking of Cd-MOF nanosheets. In addition, the strong interactions between the organic ligands in Cd-MOF and the functional groups on the Ti3C2 surface reduced the exposure of the Ti3C2 surface groups and delayed the material oxidation, thereby enhancing the electron transfer. The CdMOF@Ti3C2-modified electrode exhibited an ultra-low detection limit (2.46 nM), very high sensitivity and excellent anti-interference ability for rutin by differential pulse voltammetry. The analysis of the actual medicine (rutin tablets) demonstrates the feasibility of the sensor developed based on Cd-MOF@Ti3C2 for practical applications. Furthermore, the Cd-MOF@Ti3C2 material prepared by this method provides a new strategy for the modified loading of complexes, which broadens the horizon for the development of electrochemical sensors.

The rapid advancement of social industrialization and the excessive exploitation and utilization of natural resources have resulted in the increasingly severe issue of water pollution. In this paper, a novel multifunctional photocatalyst, [Co(C22N4H12O4)]& sdot;3DMSO & sdot;2H2O (Co-MOF) (H2L ligand = 2,5-bis-benzoimidazol-1-yl-terephthalic acid, C22N4H14O4) was synthesized via hydrothermal method. X-ray single crystal diffraction analysis, PXRD, FTIR, UV-vis spectroscopy, TGA, SEM imaging and EDS analysis revealed that Co-MOF possesses a threedimensional honeycomb structure with molecular pore channels filled with free DMSO and water molecules. Notably, under visible light irradiation for 100 min, the degradation rates of crystal violet and malachite green using Co-MOF catalyst reached up to 92.97 % and 98.73 %, respectively. The reproducibility as well as the photodegradation mechanism of Co-MOF were also discussed. Future research will concentrate on refining the synthesis process of Co-MOF and enhancing its photocatalytic stability, thereby establishing a robust theoretical foundation for the advancement of highly efficient and recyclable wastewater treatment agents.

A two-dimensional (2D) zinc(II) coordination polymer CP-1, [Zn(im(2)bod)(bdc)](n) (im(2)bod = 4,6-bis(imidazol-1-yl)-2,1,3-benzoxadiazole, bdc(2)- = 1,4-benzenedicarboxylate), was synthesized and fully characterized. CP-1 crystallizes in the monoclinic crystal system, space group P2(1)/n. Zn2+ ions adopt a four-coordinated distorted tetrahedral geometry. The structure of CP-1 comprises a two-dimensional layer consisting Zn2+ cations connected by im(2)bod and bdc(2-) ligands. The adjutant layers participate in pi-pi stacking interactions via the benzene and 2,1,3-benzoxadiazole rings. CP-1 demonstrated a blue emission with the maximum at 490 nm and a photoluminescence quantum yield 24%. Luminescent sensing properties of CP-1 in aqueous suspension toward metal cations were evaluated, and selective emission quenching response was observed toward Ga3+ cations with the limit of detection 10 mu M.

Two heteroleptic Co( ii ) 2,5-diiodoisoterephthalates (2,5-I-bdc) (1 and 2) with a 1,2-bis(4-pyridyl)ethane (bpe) linker, both having the general formula {[Co(2,5-I-bdc)bpe]·XDMF} n , were prepared.

The synthesis of two isomorphic 2D MOFs {[Ln(L)(NO3)(DMF)2] DMF} (Ln = Ho and Er, H2L = 2,5-bis(1,2,4-triazol-1-yl) terephthalic acid) by the solvothermal method enables ratio luminescent sensing of riboflavin (RF), based on the Förster resonance energy transfer (FRET) effect. As sensors for RF, both Ho-MOF and Er-MOF have splendid anti-interference effects, a large Stokes shift with 103 nm, excellent visualization effect, and a low detection limit, as low as 1.72 and 3.90 nM. Ho-MOF, with a better anti-interference capability and a relatively lower detection limit, is selected for further investigations. It possesses the advantages of excellent pH stability in the range of 4-12, rapid response time within 50 s, and even achieving five cycles. Ho-MOF also demonstrates exceptional practical detection potential when tested in real-life environments and samples, with urine and serum exhibiting detection limits of 5.26 and 27.27 nM, respectively, and a recovery range of 96-104% in VB2 tablets. Mechanism research discovers that FRET serves as the primary sensing mechanism with a calculated Forster distance (R0) of 3.7 nm, which is consistent with the required distance (1-10 nm). This study successfully achieves rate-luminescent sensing and monitoring of RF in diverse environments.

ABSTRACT One‐dimensional coordination polymer La‐CP , {[La(H 2 O) 2 (HL O ) (L O )]·H 2 O} n containing a new luminescent ligand 4,7‐di(4‐carboxypyrazol‐1‐yl)‐2,1,3‐benzoxadiazole (H 2 L O ) was synthesized. Upon excitation at 400 nm, the compound shows a strong emission with the maximum at 550 nm with high photoluminescence quantum yield of 43%. La‐CP demonstrates sensing properties toward aluminum and gallium cations, as well as dihydrogen phosphate and sulfate anions through the emission enhancement response. The limits of detection were 0.42, 0.70, 0.37, and 0.40 μM, respectively. La‐CP is the first example of a sensor for sulfate anion among all types of coordination polymers. The uptake of the analytes under the sensing conditions was evaluated, and a strong absorption enhancement as a result of such uptake was proposed as a probable emission response mechanism.

4,7-di(N-morpholyl)-1,10-phenanthroline (morphen) was introduced for the first time as a ligand for the construction of metal–organic frameworks. The obtained MOF compound has the crystallographic formula {[Tb2(morphen)2Br2(chdc)2]}n (1; chdc2− = trans-1,4-cyclohexanedicarboxylate) and is based on binuclear {Tb2(N^N)2Br2(OOCR)4} carboxylate blocks, interlinked by ditopicchdc linkers into a layered coordination network with sql topology. Purity and integrity of the as-synthesized 1 were confirmed by common characterization techniques, such as PXRD, CHN, IR, and TGA. Compound 1 was found to be hydrolytically stable and possessing typical green emission for Tb(III) complexes. Exploiting its high stability, luminescent 1@PVA films were successfully prepared from 1 and polyvinyl alcohol (PVA) through the water solution drying approach.

Ultrathin light sources based on 2D materials are of fundamental importance for the design of planar optical and optoelectronic devices. Next to versatility in fabrication and integration of 2D materials with such devices, the efficiency of light emission at the nanometer scale remains a challenge. Here a geometrical approach is reported on to tune the light emission efficiency of 2D materials by mechanical exfoliation of lanthanide‐based metal‐organic frameworks (Ln‐MOFs). For Ln‐MOF nanosheets of a variable thickness (13.5–500 nm), it is discovered that a decrease in the thickness yields a 10–50 fold increase of photoluminescence (PL), while changing the temperature (300–7 K) additionally leads to a nonlinear growth of PL by 10–20 times. The reported temperature‐ and thickness‐driven light emission by 2D Ln‐MOFs opens prospects to design efficient, robust, and scalable ultrathin MOF‐based light sources and optical sensors.

Xylene isomers are an essential industrial feedstock for producing pharmaceuticals, specialty chemicals, and polymers, for which single isomers of a high purity are usually required. However, similar physical and chemical properties of xylene render conventional separation processes inefficient. Recent advances in separation technology have led to the development of high-performance materials, with metal-organic frameworks (MOFs) being a particularly promising class of crystalline porous adsorbent. The precise engineering of MOFs pore dimensions, chemical tunability and structural versatility enable highly selective molecular recognition, making it ideal for challenging separations. This review systematically examines recent advances in MOM-mediated xylene isomer separation, focusing on the critical role of material composition and pore topology in determining separation selectivity and efficiency.

ABSTRACT Two transition metal complexes (complex 1 = {[Cd (DCPP)·(H 2 O)]·(DMF)} n and complex 2 = {[Ni (DCPP)·(H 2 O)]·(DMF)} n ) with the same structure and different functions were synthesized based on 2,6‐bis(4′‐carboxybenzene)pyrazine ligand (H 2 DCPP) by solvothermal method, and their structure and properties were analyzed and characterized by a variety of characterization methods. Complex 1 was used as a fluorescence sensor to recognize cations and anions in water; it had excellent recognition and anti‐interference ability with Fe 3+ and Cr 2 O 7 2− among cations and anions. Complex 2 ( 2 ‐CPE) was used as electrochemical material to perform electrochemical tests on hydrogen peroxide and sodium nitrite with good electrocatalytic effect. This work provides a synthesis strategy for fluorescence and electrochemical sensing materials, respectively.