This study presents the synthesis and characterization of three coordination polymers (CPs 1 - 3 ) based on zinc and various ligands, including 5-(4 '-carboxylphenoxy) isophthalic acid (H3L), 1,4-bis(1-imidazoly)-2,5-dimethylbenzene (bid), and Bis(4-pyridyl) amine (bpa) derivatives. The compounds were synthesized under hydrothermal conditions, yielding white and colorless crystals with high yields. Structural analyses, confirmed by single-crystal X-ray diffraction, reveal distinct coordination geometries and robust supramolecular frameworks that exhibit significant thermal stability. The thermal gravimetric analysis (TGA) demonstrates stability up to 403 degrees C, followed by degradation linked to organic ligand breakdown. Moreover, 1 - 3 display pronounced luminescence, making them potential candidates for sensing applications. The study highlights the exceptional sensitivity of 1 for detecting dopamine (DA) and ferric ions (Fe3+) through fluorescence quenching, with 1 exhibiting a low detection limit of DA:1.47 x 10-3 mol/L for DA and Fe3+: 4.88 x 10-6 mol/L for Fe3+. A luminescence test paper was developed for real-time monitoring of DA and Fe3+ in water samples, demonstrating practical applications for environmental monitoring. Additionally, the effect of pH on fluorescence efficiency was evaluated, revealing optimal luminescence in near-neutral conditions. This research emphasizes the structural, thermal, and luminescent properties of 1 - 3 , underscoring their potential in biomolecule and metal ion sensing applications.

Photocatalytic production of hydrogen peroxide (H2O2) from solar energy, oxygen and water is an environmentally friendly and sustainable approach. However, the efficiency is highly restricted by the limited light absorption, charge separation and oxygen capture of the active centers. In this study, a novel hydrophilic o-phenanthroline-based covalent organic polymer (COP) with a reversible iminol-to-ketoenamine tautomeric structure was successfully prepared through the Schiff base reaction. The highly conjugated structure significantly enhances its visible light absorption and accelerates the separation and migration of photogenerated charges. Furthermore, the o-phenanthroline linker facilitates the adsorption and activation of oxygen molecules, and the hydrophilicity is highly advantageous for the rapid photocatalytic reactions. Therefore, the as-prepared COP exhibits excellent photocatalytic H2O2 production performance (814 mu mol g-1 h-1) without the addition of any cocatalysts or sacrificial agents. This work provides a new example for the design of photocatalysts based on covalent organic polymers towards H2O2 production.

Three CPs [Zn2(PDA)2(BMIOPE)2·3H2O]n (1), [Co(Br-BDC)(BMIOPE)]n (2) and [Co(MIP)(BMIOPE)]n (3) were synthesized by solvothermal method based on dual-ligand strategy (H2PDA, Br-H2BDC, BMIOPE and H2MIP are 1,3-phenylenediacetic acid, 5-bromo-isophthalic acid, 4,4′-bis(2-methylimidazol-1-yl)diphenyl ether and 5-methylisophthalic acid, respectively). Complexes 1 and 3 exhibit twofold parallel interwoven sql nets. Complex 2 is 2D layer structure. The luminescence property investigations showed that complexes 1–3 could act as multi-responsive fluorescent sensors to detect UO22+, Cr2O72− and CrO42− and nitrofurantoin (NFT) through fluorescence turn-off process, presenting excellent sensitivity and selectivity. Finally, the possible fluorescent quenching mechanisms of complexes 1–3 toward the above pollutants are also further investigated by employing spectroscopic methods and quantum chemical calculations. The fluorescence lifetime measurements manifest the mechanism of fluorescence quenching is static quenching process.

Two new Cd(II) metal-organic frameworks (MOFs) with the formula [Cd (TA) (L) (H2O)& sdot;DMF]n (1) and [Cd3(BTA)2(L)2(H2O)4(NO3)2]n (2) based on terephthalic acid (H2TA) and 2-bromoterephthalic acid (H2BTA) have been successfully synthesized using semi-rigid N-donor 3,5-di (1H-imidazole-1-yl)pyridine (L). The sensing results illustrated that both of them could be prospective candidates for developing luminescent sensors for the probing of Fe3+ and Cr2O72- .The probe effects remained highly selective to the Fe3+ and Cr2O72- ions even if there are other interfering ions. This may be attributed to the accessible open Lewis-base sites and uncoordinated pyridyl which make it simple to recognize diverse analytes. The detection limits for Fe3+, and Cr2O72- are 4.459 ppm and 1.486 ppm respectively. At further optimized concentrations of Fe3+ and Cr2O72- , the fluorescence "turn off-on" technique exhibits outstanding selectivity and sensitivity, and low detection limit for detecting 4-hydroxy acid and 2-hydroxy acid. Hirshfeld surfaces and fingerprint plots are extensively used to investigate intermolecular interactions, which play a crucial role in creating diverse supramolecular designs that can be compared.

In this study, we synthesized two new coordination polymers (CPs), [Cd2(bbpy)(L)2(DMF)2]n (1) and [Zn2(bbpy)(L)2(DMF)2]n (2) ((bbpy = 3,5-bis(benzoimidazo-2-ly)pyridine and H2L = 4,4′-((1,2-phenylenebis(methylene) bis(oxy))dibenzoic acid)), using a solvothermal method. The optical band gaps of CP 1 and 2, determined using UV–visible spectroscopy, were 2.3 eV and 2.1 eV, respectively. Both CPs demonstrated strong photocatalytic activity for the degradation of various antibiotic pollutants under UV light, with CP 2 showing superior efficiency, particularly for metronidazole (MDZ), achieving 90.89 % degradation. The optimal photocatalytic conditions for CP 2 were a catalyst dosage of 5 mg/L, an MDZ concentration of 40 ppm, and a neutral pH. The stability and reusability of the photocatalyst were confirmed through multiple cycles of use. Radical trapping experiments identified superoxide radicals (O2̇−) as the primary active species in the photocatalytic process. The photocatalytic efficiency of CP 2 was further tested in different water sources, with degradation rates of 87.99 % in tap water, 80.49 % in river water, and 92.13 % in deionized water. The presence of inorganic anions such as Cl−, NO3−, and CO32− was also studied, with CO32− having the most significant inhibitory effect on the degradation efficiency. These results suggest that CP 2 is a promising candidate for practical wastewater treatment applications.

A new Ni coordination polymer [Ni(MIP)(BMIOPE)]n (1) was constructed (BMIOPE = 4,4′-bis(2-methylimidazol-1-yl)diphenyl ether, and H2MIP = 5-methylisophthalic acid), possessing two-dimensional (2D) twofold parallel interwoven net structure with a 44∙62 point symbol. Complex 1 has been successfully obtained based on mixed-ligand strategy. The fluorescence titration experiments revealed that complex 1 could act as multifunctional luminescent sensor to simultaneously detect UO22+, Cr2O72− and CrO42−, and NFT (nitrofurantoin). The limit of detection (LOD) values for complex 1 are 2.86 × 10−5, 4.09 × 10−5, 3.79 × 10−5 and 9.32 × 10−5 M for UO22+, Cr2O72−, CrO42− and NFT. The Ksv values are 6.18 × 103, 1.44 × 104, 1.27 × 104 and 1.51 × 104 M−1 for NFT, CrO42−, Cr2O72− and UO22+. Finally, the mechanism of its luminescence sensing is studied in detail. These results manifest that complex 1 is a multifunctional sensor for sensitive fluorescent UO22+, Cr2O72−, CrO42− and NFT detection.

A new three-dimensional Zn(II) complex named [Zn(1,3-BMIB)(TBIP)⋅2H 2 O][Formula: see text] (1) (containning 1,3-BMIB = 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene, H 2 TBIP=5-tert-butyl isophthalic acid) had been prepared by hydrothermal synthesis. Systematic structural characterization, especially the single crystal X-ray diffraction method, discreetly reveal the complex 1 exhibits three-dimensional (3D) framework with CdSO 4 topology. The 3D crystrals 1 display solid-state fluorescence behavior at room temperature, indicating the potential of the candidate materials for absorbing and using visible light. The photocatalytic properties of compound 1 were estimated through the model photodecomposition dye pollutants using methylene blue (MB) and rhodamine B (RhB) under visible light irradiation.

Two Cd-CPs [Cd(MIP)(BMIOPE)]n (1) and [Cd(NO2-BDC)(BMIOPE)]n (2) were constructed (H2MIP, NO2-H2BDC and BMIOPE are 5-methylisophthalic acid, nitroterephthalic acid and 4,4 '-bis(2-methylimidazol-1-yl)diphenyl ether). Complex 1 shows two-fold 2D-)2D interpenetrating structures with 4-c sql topological net and complex 2 is five-fold 3D-)3D interpenetrated structures with 4-c unc topological net. The luminescence sensing experi-ments revealed that complexes 1 and 2 could simultaneously detect UO22+, Cr2O72-and CrO42-, and NFT (nitro-furantoin) in aqueous solution with excellent selectivity and sensitivity. The limit of detection (LOD) values for complex 1 are 6.78 x 10-5 M for UO22+, 2.22 x 10-6 M for Cr2O72-, 1.83 x 10-5 M for CrO42-and 1.15 x 10- 5 M for NFT. The above values of complex 2 are 1.11 x 10-4, 1.17 x 10-4, 2.81 x 10-5, 6.32 x 10-5. Finally, the luminescent quenching mechanism is investigated in detail.

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.

A novel three-dimensional CdII coordination framework, namely, poly[{μ-bis[4-(2-methylimidazol-1-yl)phenyl] ether-κ2N3:N3'}(μ-naphthalene-1,4-dicarboxylato-κ3O1:O4,O4')cadmium(II)], [Cd(C12H6O4)(C20H18N4O)]n or [Cd(1,4-NDC)(BMIOPE)]n, where 1,4-H2NDC is naphthalene-1,4-dicarboxylic acid and BMIOPE is bis[4-(2-methylimidazol-1-yl)phenyl] ether, has been prepared and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis. The compound displays a novel fourfold interpenetrating diamond-like network. In addition, it not only shows a strong fluorescence emission in the solid state, but also exhibits excellent photocatalytic activity for the degradation of methylene blue (MB) at room temperature.

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.

Two families of Ln-based MOFs with 3D structures have been synthesized under solvothermal conditions. Eu-MOF (4) can act as a multi-responsive luminescent probe in water systems and Dy-MOF (6) shows slow magnetic relaxation behaviors.

Abstract A new 2-dimensional (2D) zinc(II) coordination polymer based on a flexible bis(imidazole) ligand, namely, [Zn2(BIBP)(BPDC)2·DMF]n (1) BIBP is 1,4-bis(4-(imidazole-1-yl)benzyl)piperazine and H2BPDC is benzophenone-2,4′-dicarboxylic acid), has been synthesized and characterized through single-crystal X-ray diffraction, infrared (IR) spectroscopy, and elemental and thermal gravimetric analysis. Complex 1 exhibits a 2D framework oriented parallel to [0 2 1] based on [Zn(BPDC)]n chains. The fluorescence and catalytic properties of complex 1 for the photodegradation of methylene blue were investigated.

A new zinc(II)-coordination polymer, [Zn(5-AIP)(BMIOPE)and#183;2H2O]n (1) (BMIOPE=4,4and#39;-bis (2-methylimidazol-1-yl) diphenyl ether, 5-H2AIP=5-aminoisophthalic acid) were hydrothermally synthesized. 1 possesses a 2D layer based on opposite-handed helical chains. Furthermore, 1 displays good photocatalytic degradation of Rhodamine B (RhB).

A one-dimensional Co(II) complex {[Co2(TIMB)(NO2—IPA)2(H2O)2]·H2O}n (1) (TIMB = 1,3,5-tris(2-methylimidazol-1-yl)benzene, NO2—H2IPA = 5-nitro-1,3-benzenedicarbo­xylic acid) is synthesized and characterized using single crystal X-ray diffraction, IR spectroscopy, and the elemental analysis. The single crystal X-ray diffraction analysis reveals that 1 is a 1D polymeric loop chain based on [Co4(NO2—IPA)4] and [Co2(TIMB)2] loops. Complex 1 exhibits an emission band at 358 nm (λex = 322 nm) and good catalytic photodegradation of RhB. Furthermore, there are antiferromagnetic interactions between the magnetic Co(II) centers in 1.

A new Cu(II) metal-organic framework, [Cu(BMIOPE)(Br-BDC)](n) (1) [Br-H2BDC=5-bromo-isophthalic acid, BMIOPE =4,4'-bis(2-methylimidazol-1-yl) diphenyl ether], has been hydrothermally synthesized and characterized through IR spectroscopy, elemental and thermal analysis, and single-crystal X-ray diffraction. Complex 1 possesses a unique two-fold interpenetrating two-dimensional framework with sql topology. The photocatalytic property of complex 1 for oxidative degradation of methyl orange and methylene blue with hydrogen peroxide was examined under UV irradiation.

A two-dimensional Zn(II) complex {[Zn(BMIOPE)(TBIP)]center dot H2O}(n) (1) (BMIOPE = 4,4 '-bis(2-methylimidazol-1-yl)diphenyl ether, H2TBIP = 5-tert-butyl isophthalic acid) has been synthesized and characterized using single crystal X-ray diffraction, IR and elemental analysis. Single-crystal X-ray diffraction analysis reveals that complex 1 is a two-dimensional (4, 4) layer. The thermal stability, solid-state photoluminescence properties and photocatalytic properties of complex 1 have been investigated.

Three 3D ZnII/CdII CPs were synthesized to act as multiresponsive luminescent sensors for Fe3+, Cr2O72− and NZF antibiotic. The photocatalytic studies indicate that the CPs 1–3 have good photocatalytic capability in degradation of MB.

A series of 2D isomorphous MOFs [M (HBTC)(BMIOPE)·DMF·H2O]n (M = Zn (1), Zn0.7Co0.3 (2), Zn0.5Co0.5 (3), Zn0.3Co0.7 (4), Co (5), H3BTC = 1,3,5‐benzenetricarboxylic acid, BMIOPE = 4,4′‐bis(2‐methylimidazol‐1‐yl)diphenyl ether) were synthesized to investigate the correction between the center metal ions and the photocatalytic behaviors. The photocatalytic results show that with the increase of Co2+ content, the photodegradation properties are continuously improved from 1 to 5, which fully indicate that only changing metal ions could regulate the photodegradation properties. In detail, 1 is an inactive photocatalyst to degrade methylene blue (MB), while 5 exhibits preeminent photocatalytic properties under visible light irradiation. Moreover, 1 shows good selective sensing toward Fe3+, Cr3+, UO22+, CrO42− and Cr2O72− ions in aqueous solution. To the best of our knowledge, 1 is the first MOF example for the optical detection of Fe3+, Cr3+, UO22+, CrO42− and Cr2O72− ions in aqueous solution.