Three coordination polymers based on 4,4'-bis(2-methylimidazol-1-yl)diphenyl ether: Synthesis, structure and selective fluorescent sensing properties

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.

A Ni(II) Coordination Polymer as a Multifunctional Luminescent Sensor for Detection of UO22+, Cr2O72-, CrO42- and Nitrofurantoin

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⁺, Cr₂O₇^2- and CrO₄^2-, 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⁺, Cr₂O₇^2-, CrO₄^2- and NFT. The K_sv values are 6.18 × 10³, 1.44 × 10⁴, 1.27 × 10⁴ and 1.51 × 10⁴ M^-1 for NFT, CrO₄^2-, Cr₂O₇^2- 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⁺, Cr₂O₇^2-, CrO₄^2- and NFT detection.

Electrochemical and fluorescence sensing performance of four new coordination polymers tuned by different metal ions and dicarboxylic acids

Four new ZnII, CdII, CoII, and NiII coordination polymers (CPs) were successfully prepared from a bis-pyridyl–bis-amide and various dicarboxylate mixed ligands, which show good electrochemical and fluorescence sensing performance.

A new two-dimensional cadmium(II) coordination polymer based on the asymmetric dicarboxylic acid homophthalic acid: synthesis, structure and properties

A new coordination polymer poly[[μ2-4,4′-bis(2-methylimidazol-1-yl)biphenyl-κ2 N 3:N 3′]bis[μ3-2-(2-carboxylatophenyl)acetato-κ5 O,O′:O′,O′′:O′′]dicadmium(II)], [Cd(C9H6O4)(C20H18N4)0.5] n or [Cd(HMPH)(4,4′-BMIBP)0.5] n [H2HMPH is homophthalic acid and 4,4′-BMIBP is 4,4′-bis(2-methylimidazol-1-yl)biphenyl], (I), was synthesized by the solvothermal method and was structurally characterized by means of single-crystal X-ray diffraction, IR spectroscopy and elemental analysis. Coordination polymer (I) exhibits a two-dimensional layer based on one-dimensional [Cd(HMPH)] n chains. Remarkably, photocatalytic degradation experiments on methylene blue (MB) indicated that (I) exhibits an obvious degradation effect. Moreover, an investigation of the luminescence properties of (I) revealed that it could be considered as a potential highly selective luminescence sensor for nitrofurantoin (NFT).

A four-fold three-dimensional zinc(II) coordination polymer based on 4,4′-bis(2-methyl-imidazolyl)biphenyl and 5-sulfoisophthalate ligands: synthesis, structure and properties

A Zn(II) coordination polymer, [Zn3(4,4′-BMIBP)3(SIP)2] n (1) (4,4′-BMIBP = 4,4′-bis(2-methyl-imidazolyl)biphenyl, H3SIP = 5-sulfoisophthalic acid) was hydrothermally synthesized and structurally characterized. Complex 1 has a (3,4)-connected binodal four-fold three-dimensional topology with a point symbol of {4·62·82·10}2{4·62}2{64·102}. It shows strong fluorescence emission in the solid state and efficient photocatalytic performances to degrade methylene blue (MB) under UV irradiation, the degradation of MB reaching 88% after 50 min.

A new two-dimensional cadmium(II) coordination polymer based on Cd6(CHADC)6 clusters (H2CHADC is cyclohexane-1,2-dicarboxylic acid): synthesis, structure and properties

The highly effective recognition and detection of metal ions and anions in water has attracted much attention with respect to environmental safety. Herein, a novel Cd-based coordination polymer, poly[[4,4'-bis(2-methylimidazol-1-yl)biphenyl]bis(cyclohexane-1,2-dicarboxylato)dicadmium(II)], [Cd₂(C₈H₁₀O₄)₂(C₂₀H₁₈N₄)]_n or [Cd(CHADC)(4,4'-BMIBP)_0.5]_n, (I), has been synthesized employing cis-cyclohexane-1,2-dicarboxylic acid (H₂CHADC) and 4,4'-bis(2-methyl-1H-imidazol-1-yl)biphenyl (4,4'-BMIBP). Single-crystal X-ray analysis reveals that (I) presents a 6-connected hxl two-dimensional layer based on Cd₆(CHADC)₆ clusters with the point symbol (3⁶·4⁶·5³). Furthermore, (I) has been characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and fluorescence spectroscopy, and exhibits good stability and excellent photoluminescence properties. Coordination polymer (I) was chosen as a fluorescent probe to sense different target analytes and shows an obvious selective recognition response to Fe³⁺ cations and Cr₂O₇^2-/CrO₄^2- anions through luminescence-quenching effects in aqueous solution. The sensing mechanism was investigated and showed that the detection mechanism was resonance energy transfer between (I) and the Fe³⁺, Cr₂O₇^2- and CrO₄^2- ions.

A new three-dimensional cadmium(II) coordination polymer based on bis[4-(2-methylimidazol-1-yl)phenyl]methanone: synthesis, structure and properties

A novel three-dimensional CdII coordination polymer, namely, poly[[(μ3-benzene-1,4-diacetato)(μ2-benzene-1,4-diacetato)bis{μ2-bis[4-(2-methylimidazol-1-yl)phenyl]methanone}dicadmium(II)] tetartohydrate], {[Cd(C10H8O4)(C21H18N4O)]·0.25H2O} n or {[Cd(PBEA)(MIPMO)]·0.25H2O} n , (I), was synthesized by the hydrothermal method using benzene-1,4-diacetic acid (H2PBEA), bis[4-(2-methylimidazol-1-yl)phenyl]methanone (MIPMO) and Cd(NO3)2·6H2O. The title compound was structurally characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis, and exhibits a three-dimensional pillar–layer framework based on CdII–PBEA layers and MIPMO pillars, which can be simplified into a pcu topological network. The title compound displays a highly selective and sensitive sensing for Fe3+ ions in aqueous solution. In addition, it displays a high photocatalytic activity for the degradation of methylene blue (MB) in water under UV light irradiation.

Sensing and photocatalytic properties of a new 3D Co(ii) coordination polymer based on 1,1′-di(p-carboxybenzyl)-2,2′-biimidazole

One novel 3D interpenetrated Co(ii) CP acts as multi-functional chemosensors in detection of Fe3+, Cr2O72−, CrO42− and nitrofurantoin and is an effective and stable photocatalyst and displays excellent photo-catalytic properties.

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.

A cadmium(II) coordination polymer with a fivefold interpenetrating diamondoid three-dimensional framework: synthesis, crystal structure, luminescence and photocatalytic properties

A novel three-dimensional (3D) Cd^II coordination polymer, namely, poly[[μ₂-4,4'-bis(2-methylimidazol-1-yl)-[1,1'-biphenyl]](μ₂-5-methylisophthalato)cadmium(II)], [Cd(C₉H₆O₄)(C₂₀H₁₈N₄)]_n or [Cd(MIP)(4,4'-BMIBP)]_n, (I), was synthesized by the hydrothermal method using 5-methylisophthalic acid (H₂MIP), 4,4'-bis(2-methylimidazol-1-yl)-[1,1'-biphenyl] (4,4'-BMIBP) and Cd(NO₃)₂·6H₂O, and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis. Compound (I) exhibits a novel fivefold interpenetrating 3D diamondoid framework. Additionally, it shows fluorescence emission in the solid state and promising photocatalytic activities for the degradation of methylene blue (MB) in water at room temperature.

The crystal structure of catena-poly[diaqua-bis(μ2-2-((2-(2-phenylacetyl)hydrazineylidene)methyl)benzoato-κ2 O:O')zinc(II)], C32H30N4O8Zn

C32H30N4O8Zn, triclinic, P 1 ‾ $P\bar{1}$ (no. 2), a = 4.4080(3) Å, b = 12.1316(10) Å, c = 14.0769(12) Å, α = 102.810(7)°, β = 97.455(7)°, γ = 97.982(7), V = 716.81(10) Å3, Z = 1, R gt (F) = 0.0367, wR ref (F 2) = 0.0761, T = 149.99(10) K.