New 2D and 3D Cd(II) coordination polymers from aromatic dicarboxylate and 1,3-bis(5,6-dimethylbenzimidazol-1-yl)-2-propanol ligands: Syntheses, structures, photocatalytic, and luminescence sensing properties

New Three-Dimensional Supramolecular Framework: Crystal Structure and Photocatalytic Property

In this work, benzimidazole (Hbim) and Cu(II) ions ligands were chosen as building blocks to produce a novel Cu(II) compound (CP) based on {Cu4O}cluster, namely, [Cu4OCl6(Hbim)4]n·n(H2O)·2n(EtOH) (1). The investigation of SCXRD reveals that the CP 1 is a separated 0D structure based on tetrahedral {Cu4O} clusters. Furthermore, this supramolecular frame displayed superior photocatalytic effect on the photodegradation of MB under UV light irradiation.

New Transition Metal Coordination Polymers Derived from 2-(3,5-Dicarboxyphenyl)-6-carboxybenzimidazole as Photocatalysts for Dye and Antibiotic Decomposition

Coordination polymers (CPs) are an assorted class of coordination complexes that are gaining attention for the safe and sustainable removal of organic dyes from wastewater discharge by either adsorption or photocatalytic degradation. Herein, three different coordination polymers with compositions [Ni(HL)(H2O)2·1.9H2O] (1), [Mn3(HL)(L)(μ3-OH)(H2O)(phen)2·2H2O] (2), and [Cd(HL)4(H2O)]·H2O (3) (H3L = 2-(3,5-dicarboxyphenyl)-6-carboxybenzimidazole; phen = 1,10-phenanthroline) have been synthesized and characterized spectroscopically and by single crystal X-ray diffraction. Single crystal X-ray diffraction results indicated that 1 forms a 2D layer-like framework, while 2 exhibits a 3-connected net with the Schläfli symbol of (44.6), and 3 displays a 3D supramolecular network in which two adjacent 2D layers are held by π···π interactions. All three compounds have been used as photocatalysts to catalyze the photodegradation of antibiotic dinitrozole (DTZ) and rhodamine B (RhB). The photocatalytic results suggested that the Mn-based CP 2 exhibited better photodecomposition of DTZ (91.1%) and RhB (95.0%) than the other two CPs in the time span of 45 min. The observed photocatalytic mechanisms have been addressed using Hirshfeld surface analyses.

New 3D Supramolecular Framework: Photocatalytic Property and Therapeutic Activity on Orbital Wall Fracture

Coordination compounds have undergone booming development in the past 20 years for their applications as multifunctional materials in the field of catalysis and biomedicine. To create compounds with both catalytic and bioactive properties, we selected Cu(II) ion and benzimidazole (Hbim) ligand as the building blocks to fabricate a new cluster-based Cu(II) compound [Cu4OCl6(Hbim)4]n·n(H2O)·2n(EtOH) (1). The exploration of single crystal X-ray diffraction exhibits that complex 1 is a 0D isolated structure on the basis of tetrahedral {Cu4O} clusters. Moreover, such supramolecular framework not only shows excellent photocatalytic effect for the MB photodegradation under the irradiation of ultraviolet light but also has the application values against orbital wall fracture. This work gives new insights on the creation of coordination polymers which might be potentially used as photocatalytic and bioactive reagents.

Two chemically robust Cd(II)-frameworks for efficient sensing of levofloxacin, benzaldehyde, and Fe3+ ions

Two luminescent Cd(II)-organic frameworks [Cd2(L1)(tdc)2(H2O)]n (1) and [Cd(L2)0.5(tdc)]n (2) (L1 = 1,5-bis(1-(pyridine-4-ylmethyl)-1H-benzo[d]imidazol-2-yl)pentane, L2 = 1,6-bis(1-(pyridine-4-ylmethyl)-1H-benzo[d]imidazol-2-yl)hexane, and H2tdc = 2,5-thiophenedicarboxylic acid) were hydrothermally synthesized and characterized. 1 displays a rare binodal (3,4)-connected 2D cem-d network, while 2 exhibits a 3D mog (moganite) framework. The two MOFs are highly thermally durable and water-stable in a wide pH range from 3 to 12. Interestingly, 1 and 2 represent the first reported examples of multi-responsive probes based on MOFs for selectively detecting levofloxacin, benzaldehyde, and Fe3+ ions with reusability. The luminescence sensing mechanisms of the two CPs were explored in detail.

Treatment and Nursing Values of Cd(II) Complex with Photocatalytic Activity on Bacterial Infection by Inhibiting the Gram-Positive Bacteria Growth

Presented here is a trinuclear cluster-based Cd(II) compound, namely, {[(CH3)2NH2][Cd6K(bdc)6(btz)3(H2O)6]}n (1 H2bdc = terephthalic acid, Hbtz = 1H-benzotriazole), has been solvothermally prepared and structurally determined by the single crystal X-ray diffraction analysis, elemental analysis, powder X-ray diffraction analysis, and thermogravimetric analysis. Notably, compound 1 shows excellent photocatalytic activity for degradation of MV irradiated by UV light. In addition to this, the biological activity of the new compound on bacterial infection was evaluated, and the corresponding mechanism was also studied. The ELISA assay was used to evaluate the TNF-α and IL-1β released into plasma after compound treatment. Then, the relative expression levels of the bacterial survival gene were measured with real-time RT-PCR.

Six CoII coordination polymers exhibiting UV-light-driven photocatalysis for the degradation of organic dyes

Six different Co^II coordination polymers based on a new bis-pyridyl-bis-amide and polycarboxylates were obtained, showing photocatalytic activity for organic dyes.

Two cadmium(II) coordination polymers as multi-functional luminescent sensors for the detection of Cr(VI) anions, dichloronitroaniline pesticide, and nitrofuran antibiotic in aqueous media

Two ternary cadmium(II) coordination polymers, with the formulas being {[Cd(tptc)_0.5(bpz)(H₂O)]·0.5H₂O}_n (CP 1), and [Cd(tptc)_0.5(bpy)]_n (CP 2), were designed through mixed ligands strategy. Benefiting from the excellent chemical stability and luminescent property, two Cd(II) CPs possessing efficient multi-functional fluorescent responses toward Cr(VI) anions, 2,6-dichloro-4-nitroaniline pesticide, and nitrofuran antibiotic in aqueous media with high sensitivity, selectivity, and excellent recyclable behaviors with the detection limits (LODs) are 235 ppb for CrO₄^2- anion, 343 ppb for Cr₂O₇^2- anion, 112 ppb for DCN pesticide, 62 ppb for NFT antibiotic for CP 1, and 173 ppb for CrO₄^2- anion, 270 ppb for Cr₂O₇^2- anion, 638 ppb for DCN pesticide, 184 ppb for NFT antibiotic for CP 2, respectively. Besides, the mechanisms of luminescence quenching were revealed from the viewpoint of internal filter effect (IFE) and photoinduced electron transfer (PET).

Ln-CPs constructed from unsymmetrical tetracarboxylic acid ligand: Tunable white-light emission and highly sensitive detection of CrO42-, Cr2O72-, MnO4- in water

A series of isostructural lanthanide coordination polymers (Ln-CPs), [Ln(Hbptc)(H₂O)₄]·H₂O [Ln = Er (1), Pr (2), Dy (3), Sm (4), Gd (5), Nd (6) and Tb(7); H₄bptc = 2,3,3',4'-biphenyl tetracarboxylic acid] have been isolated based on an unsymmetrical tetracarboxylic acid. Single-crystal X-ray diffraction analysis reveals that all CPs featured a two dimensional (2D) layer with (6, 6, 6)-connected 6³ topology. Luminescent spectra demonstrate that CPs 1-7 exhibit impressive UV-visible luminescence in the solid state at room temperature. More significantly, a single-component white-light material with International Commission on Illumination (CIE) coordinates of (0.335, 0.334) for 4 (Sm-CP), very closing to the pure white-light of (0.333, 0.333) was obtained by finely tuning of the excitation wavelength. In addition, the luminescent detection for anions of 7 is investigated. Fluorescence measurements show that 7 can detect oxoanion pollutants Cr₂O₇^2-, CrO₄^2-, and MnO₄^- anions in aqueous solutions with high selectivity and sensitivity, which suggests that the Tb-CP is a promising functional luminescence probe for toxic oxoanions. The possible mechanisms of the quenching effect were also discussed in detail.

A dual-responsive luminescent sensor based on a water-stable Cd(ii)-MOF for the highly selective and sensitive detection of acetylacetone and Cr2O72− in aqueous solutions

Two water-stable cadmium(ii) MOFs were synthesized and characterized. 1 is the first dual-function Cd(ii)-MOF luminescent sensor for sensing acetylacetone and Cr₂O₇²⁻ in aqueous solution with high sensitivity and selectivity and good recyclability.

Syntheses of three new isostructural lanthanide coordination polymers with tunable emission colours through bimetallic doping, and their luminescence sensing properties

Tuning the emissive color changes of lanthanide (Ln) complexes is an important and appealing project for promoting the applications of Ln-complexes. A solvothermal reaction of 4-cyano-3-methylbenzoic acid (HL) and Ln(NO3)3·6H2O affords three isostructural Ln-complexes [Eu(L)3(H2O)2]n (1-Ln) (Ln = Eu, Gd and Tb) with one-dimensional chain structures. 1-Eu and 1-Tb show bright red and green emissions with absolute quantum yields of 3.06% and 11.96%, respectively, and the energy transfer was analyzed in detail through combined calculations. Interestingly, a series of heterometallic doped 1-TbxEu1-x coordination polymers were also obtained by mixing different ratios of Eu3+ and Tb3+ ions, which possess continuous luminescent color changes from green to yellow, orange and red. In addition, 1-Eu exhibits high quenching efficiency and low detection limit (∼10-4 M) for the simultaneous sensing of MnO4-, CrO42- and Cr2O72- ions in water.

Syntheses and photocatalytic properties of three new d10-based coordination polymers: effects of metal centres and ancillary ligands

Three d¹⁰-based coordination polymers with three different nitrogen-based ancillary ligands have been synthesized and their photocatalytic properties were explored in the decomposition of methyl violet.

6,6′-(Perfluoropropane-2,2-diyl)bis(2,3-dihydrophthalazine-1,4-dione)-based coordination polymers and their sensing properties towards Cr2O72−

The structures of six new diacylhydrazidate-based coordination polymers were reported. Based on their better photoluminescence properties, their sensing abilities towards Cr2O₇²⁻ were investigated.