A fluorescent zirconium organic framework displaying rapid and nanomolar level detection of Hg(II) and nitroantibiotics

The solvothermal reaction of ZrCl4 with benzo[1,2-b:4,5-b’]dithiophene-2,6-dicarboxylic acid linker molecule in presence of trifluoro acetic acid modulator afforded the UiO-66 type of metal organic framework (MOF) (IITG-5, IITG = Indian...

Multi-responsive luminescent sensor based on a stable Eu(III) metal-organic framework for sensing Fe3+, MnO4−, and Cr2O72− in aqueous solution

A new water-stable three-dimensional (3D) Eu(III) metal-organic framework with the formula of {[Eu3(BTDC)4(HCOO)(H2O)2]•solvents}n (JXUST-9) was successfully obtained by the solvothermal reaction of 2,1,3-benzothiadiazole-4,7-dicarboxylic acid (H2BTDC) and Eu(NO3)3•6H2O. The PXRD patterns...

Halogen bonding in cadmium(II) MOFs: influence on the structure and on the nitroaldol reaction in aqueous medium

A solvothermal reaction of Cd(II) with the dicarboxyl-functionalized arylhydrazone pro-ligands - 5-(2-(2,4,6-trioxotetrahydro-pyrimidin-5(2H)-ylidene)hydrazineyl)isophthalic acid (H5L1) and 5-(2-(2,4-dioxopentan-3-ylidene)hydrazineyl)isophthalic acid (H3L2), or their halogen bond donor centre(s) decorated versions 2,4,6-triiodo-5-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene)hydrazineyl)isophthalic acid (H5L3) and...

Copper(II)-MOF Containing Glutarate and 4,4′-Azopyridine and Its Antifungal Activity

Antifungal activities of MOFs (metal organic frameworks) have been demonstrated in studies, and improvement in efficiency of fungal inactivation is a critical issue in the application of MOFs. In this study, we employed 4,4′-azopyridine (AZPY) in the construction of MOF to improve its antifungal activity. Three-dimensional (3D) copper metal organic framework containing glutarate (Glu) and AZPY (Cu(AZPY)-MOF) was synthesized by a solvothermal reaction. Glutarates bridge Cu2 dinuclear units to form two-dimensional (2D) layers, and these layers are connected by AZPY to form a 3D framework. When spores of two fungi, Candida albicans and Aspergillus niger, were treated with Cu(AZPY)-MOF for one day, number of CFU (colony forming unit) was continuously reduced over treated MOF concentrations, and maximum 2.3 and 2.5 log10CFU reductions (approximately 99% reduction) were observed in C. albicans and A. niger, respectively. Small amounts of CuII ions and AZPY released from Cu(AZPY)-MOF were not critical for fungal inactivation. Our results indicate that the level of antifungal activity of Cu(AZPY)-MOF is greater than that of Cu-MOF without AZPY constructed in our previous study, and intercalation of AZPY is able to improve the antifungal activity of Cu(AZPY)-MOF.

Facile Construction of Hierarchical TiNb2O7/rGO Nanoflower With Robust Charge Storage Properties for Li Ion Batteries via an Esterification Reaction

TiNb2O7 (TNO) compound has been pursued tremendously due to its high theoretical capacity, high potential, and excellent cycle stability. Unfortunately, an intrinsic low electronic and ionic conductivity feature has restricted its broad applications in electrochemical energy storage fields. Two-dimensional (2D) nanostructures can effectively shorten Li-ion transport path and enhance charge transfer. Here, hierarchical structure TNO was constructed by using ethanol and acetic acid as particularly important organic chemicals of basic raw materials via a simple solvothermal reaction. Ethanol was found to play a critical role in the formation of 2D sheet structure. Meantime, reduced graphene oxide nanosheets can effectively improve electronic conductivity. As-obtained TiNb2O7 were wrapped further by graphene oxide nanosheets through a flocculation process. Their unique structure is beneficial to the final electrochemical performance. This study not only provides a general approach for the design of novel 2D nanomaterials wrapped by graphene because of the advantage of esterification reaction and flocculation reaction, but also improves the electronic and ionic conductivity simultaneously.

A new two-dimensional folding sheet-like coordination polymer assembled from cadmium(II) and (S)-2-(benzylamino)succinic acid: synthesis, structure and properties

A new two-dimensional (2D) coordination polymer, namely, poly[[diaqua[μ3-(S)-2-(benzylamino)succinato-κ4 N,O 1:O 1′:O 4]cadmium(II)] monohydrate], {[Cd(C11H11NO4)(H2O)2]·H2O} n , has been synthesized by the solvothermal reaction of Cd(CH3COO)2·2H2O with the synthesized ligand (S)-2-(benzylamino)succinic acid (H2 L). The title compound has been structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction analysis. In the crystal structure, each CdII cation binds to three carboxylate groups from three symmetry-related L 2− dianions. The tetradentate L 2− ligand links three symmetry-related CdII cations into a 2D folding sheet, which can be simplified as a uninodal (3,3)-connected hcb net with the point symbol (63). In the lattice, all the folding sheets are arranged in an interdigitated fashion and aggregate into zipper-like arrays through interlayer π–π interactions. The large and nonpolar side chain may play an important role in the formation and aggregation of the 2D sheet. The thermal stability and photoluminescence properties of the title compound were investigated, and it exhibits a blue emission with a quantum yield of 8%.

Assembly of cobalt-p-sulfonatothiacalix[4]arene frameworks with phosphate, phosphite and phenylphosphonate ligands

Three cobalt-calixarene coordination frameworks, namely, {[Co4Cl(H4TC4AS)]4(HPO3)8}4− (CIAC-253), {[Co4Cl(H4TC4AS)]4(PO4)8}12− (CIAC-254) and {[Co4Cl(H4TC4AS)]3(Ph-PO3)6}3− (CIAC-255) were obtained by solvothermal reaction of a cobalt salt, sodium p-sulfonatothiacalix[4]arene (Na4H4TC4AS) and phosphate, phosphite and phosphonate ligands. In CIAC-253 and CIAC-254, the shuttlecock-like Co4Cl-(TC4AS) secondary building units (SBUs) are bridged by HPO3 2− or PO4 3− anions into two quadrilateral frameworks while in CIAC-255, the Co4Cl-(TC4AS) SBUs are linked into a triangular framework by phenylphosphonate anions. The supramolecular interactions between the phenyl groups of phosphonate and TC4AS play a crucial role in the formation of the triangle. Magnetic measurements revealed that all the cobalt(II) centers exhibit antiferromagnetic interactions.

Preparation of Eu0.075Tb0.925-Metal Organic Framework as a Fluorescent Probe and Application in the Detection of Fe3+ and Cr2O72−

Luminescent Ln-MOFs (Eu0.075Tb0.925-MOF) were successfully synthesised through the solvothermal reaction of Tb(NO3)3·6H2O, Eu(NO3)3·6H2O, and the ligand pyromellitic acid. The product was characterised by X-ray diffraction (XRD), TG analysis, EM, X-ray photoelectron spectroscopy (XPS), and luminescence properties, and results show that the synthesised material Eu0.075Tb0.925-MOF has a selective ratio-based fluorescence response to Fe3+ or Cr2O72−. On the basis of the internal filtering effect, the fluorescence detection experiment shows that as the concentration of Fe3+ or Cr2O72− increases, the intensity of the characteristic emission peak at 544 nm of Tb3+ decreases, and the intensity of the characteristic emission peak at 653 nm of Eu3+ increases in Eu0.075Tb0.925-MOF. The fluorescence intensity ratio (I653/I544) has a good linear relationship with the target concentration. The detection linear range for Fe3+ or Cr2O72− is 10–100 μM/L, and the detection limits are 2.71 × 10−7 and 8.72 × 10−7 M, respectively. Compared with the sensor material with a single fluorescence emission, the synthesised material has a higher anti-interference ability. The synthesised Eu0.075Tb0.925-MOF can be used as a highly selective and recyclable sensing material for Fe3+ or Cr2O72−. This material should be an excellent candidate for multifunctional sensors.

A New (3, 6)-Connected Heterometallic Coordination Polymer: Therapeutic and Protective Effect on Ischemic Cerebral Infarction

Solvothermal reaction of 4,4’,4’-nitrilotribenzoic acid (H3TCA) with Ca(NO3)2·4H2O and Cd(NO3)2·4H2O successfully afforded a heterometallic compound, that is, [Cd2Ca(TCA)2(DMA)2(H2O)3]n·2n(DMA) (1, DMA = N,N’-dimethylacetamide). The structure of 1 was further characterized through EA, diffraction of single crystal X-ray, and thermogravimetric analysis (TGA) together with powder X-ray diffraction (PXRD). Moreover, complex 1’s luminescent performance in solid state was also discussed at environmental temperature. The applications on the ischemic cerebral infarction therapy were evaluated, and the specific mechanism was investigated at the same time. Firstly, the hypersensitivity C-reactive protein (hs-CRP) content in human brain microvascular endothelial cell (HBMEC) was measured with real-time reverse transcription-polymerase chain reaction (RT-PCR). Then, interleukin-18 and interleukin-1β content released through the HBMEC was detected with enzyme-linked immunosorbent assay (ELISA).

Cu(II) Coordination Polymer Inhibits Liver Cancer Development via Targeting BCL-2 Protein and Activating Apoptotic Pathway

In the current study, a Cu(II) coordination polymer (CP) has been created in success with the solvothermal reaction between an asymmetrical rigid N-heterocyclic carboxylatic acid (HL) and Cu(NO3)2·3H2O in the existence of 1,3-H2bdc, the second assistant ligand (in which 1,3-H2bdc is benzene-1,3-dicarboxylic acid and HL is 1-(4-carboxylphenyl)-3-(prazin-2-yl)-1H-1,2,4-triazole), and the chemical composition of this compound is [Cu2(L)2(1,3-bdc)(H2O)2]n (1). In the biological aspect, we screened the antiproliferation activity of the Cu(II) coordination polymer on five kinds of human cancer cell lines. IC50 and MTT assay results indicated that complex 1 had a spectral antiproliferative activity against liver cancer cells, peculiarly on human HepG2 liver cancer cells. From the data of Annexin V-FITC/PI assay and ROS detection, we can find that complex 1 exerts an antitumor effect by inducing ROS generation and cell apoptosis. Caspase-3 and caspase-9 activity detection revealed that activation of caspase-3 and caspase-9 plays vital roles in HepG2 cell apoptosis. These outcomes indicate that 1 is an excellent compound in treating cancer.