An asymmetric mononuclear cobalt(II) compound derived from 3-bromo-pyridine-2,6-dicarboxylic acid involving in-situ hydrothermal decarboxylation: structure, magnetic property and Hirshfeld surface analysis

A new cobalt(II) compound with the formula [Co(5-Br-pyc)(2,2′-bipy)(H2O)(Cl)]·2H2O (1·H2O) (5-Br-Hpyc = 5-bromo-pyridine-2-carboxylic acid, 2,2′-bipy = 2,2′-bipyridine) has been hydrothermally synthesized and well characterized. The X-ray single-crystal diffraction analysis showed that 1⋅2H2O has crystallizes in the monoclinic system, space group P21/c (no. 14). The Co(II) center was octahedrally bonded by one bidentate chelate 5-Br-pyc anion and one 2,2′-bipy, one water molecule as well as one chloride anion to form the mononuclear structure of 1⋅2H2O. Complex 1⋅2H2O forms a 3D network through abundant O–H⋅⋅⋅O hydrogen bonds and π⋅⋅⋅π stacking interactions. Notably, the 5-Br-Hpyc ligand was in situ generated by decarboxylation of the 3-bromo-pyridine-2,6-dicarboxylic acid (3-Br-H2pydc) precursor selectively on 2-position under hydrothermal conditions. The magnetic properties, the Hirshfeld surface structure and the synthetic process for 1⋅2H2O have been carefully described and discussed.

The synthesis, crystal structure and conformation analysis of triclopyr ethyl ester

Triclopyr ethyl ester (1) has been co-synthesized through one-pot solvothermal reaction and the crystal structure has been determined by single crystal X-ray structure analysis. The compound C18H16Cl6N2O6 crystallizes in the monoclinic crystal system, P21/c space group with unit-cell parameters: a = 4.9615(2) Å, b = 30.9297(14) Å, c = 15.9155(10) Å, β = 91.466(4)° and Z = 4. Each unit cell is composed of two discrete, similar but reversely arranged triclopyr ethyl ester organic molecules. In the 3D packing plot, 1 is further assembled into a network structure via rich Cl⋯Cl halogen bond interactions. In addition, the crystal structure, the flexible conformation of phenoxy methylene group of 1 has been carefully compared and discussed with those of triclopyr acid.

THE SYNTHESIS AND PROPERTIES OF A SODIUM SUPRAMOLECULAR CRYSTAL NETWORK CONSTRUCTED WITH FUNCTIONAL PYRAZINE SULFONIC ACID

Sulfonic acid groups with C_3ν symmetry can coordinate with metal ions to produce multidimensional structures due to their flexible coordination modes. They can also penetrate into supramolecular structures through an intriguing bridging pattern and weak interactions. Herein, a novel heterocyclic sodium sulfonate supramolecular structure, namely [Na(Pyr-SO₃)(H₂O)]_n where Pyr-SO₃H is pyrazine sulfonic acid, is synthesized by utilizing NaBF₄ to coordinate with the P–SO₃H ligand through the solvent evaporation method. The single crystal X-ray diffraction (XRD) data indicate that the as-formed structure belongs to the Pbca space group. Additional properties are characterized by powder XRD, thermal analysis, and solid-state fluorescence. In particular, the introduction of a soft alkali metal ion can coordinate with the oxygen atom of the sulfonate ligand and form a Na–O bridging configuration that can not only significantly improve the pyrazine sulfonic acid ligand coordination ability, but also provide a reference for the extended study of functional sulfonate polymers in the future.

A (4,4)-connected zinc(II) coordination polymer constructed with the flexible 2-carboxy phenoxyacetate ligand: synthesis, conformation alteration and fluorescent properties

A new binary ZnII coordination polymer, [Zn(2-cpa)(H2O)] n (2D-Zn) has been prepared by a 120 °C hydrothermal reaction of zinc(II) sulfate heptahydrate and 2-carboxy phenoxyacetic acid (2-H2cpa) in the presence of potassium hydroxide. Single-crystal X-ray diffraction analysis shows that the ZnII ion is located in a deformed ZnO6 octahedron bonded by one water and three 2-carboxy phenoxyacetate (2-cpa) ligands. The 2-cpa exhibits pentadentate double bridging chelate-μ 3 coordination mode and connects adjacent ZnII ions to generate a corrugated (4,4)-connected layer structure. The structures, conformation of 2-cpa and photoluminescence spectra for 2D-Zn have been carefully analyzed and compared with its two closely related compounds ̶ 1D [Zn(2-cpa)(H2O)] n (1D-Zn) and mononuclear [Zn(2-cpa)(H2O)3] (0D-Zn). The results showed that the conformation of 2-cpa in 2D-Zn has the maximum alteration and the corresponding fluorescence emission peak of 2D-Zn has the largest red-shift of 62 nm compared with that of free 2-H2cpa.

Two Metal Complexes: Selective Detection of Fe3+ Ion and Promotion Activity on Mesenchymal Stem Cells Differentiate Into Vascular Endothelial Cells

With the aid of 1,2-bis(4-pyridyl)ethane (bpee), a nitrogen-donor ligand and 1,3,5-tris(carboxymethoxy)benzene (H3TCMB), a tripodal ether-connector tricarboxylate ligand, two novel transition metal coordination polymers (CPs) have been synthesized via the reaction of Zn(NO3)2·6H2O or Cu(NO3)2·3H2O with the ligands of H3TCMB and bpee ligands with similar reactions under slightly distinct temperatures (80℃ for 1 and 120℃ for 2), and their chemical formula are [Cu4(TCMB)2(bpee)2(µ3-OH)2(H2O)2]n·12nH2O (1) and [Zn4(TCMB)2(bpee)2(µ3-OH)2(H2O)2]n·12nH2O (2). Complex 2 can be utilized as a super sensitive fluorescence quenching sensor to determine the Fe3+ ions. The effect of these two compounds on the differentiation of mesenchymal stem cells (MSCs) into the cells of vascular endothelial was further explored.

A Bifunctional Coordination Polymer for Al3+ Ion Detection and its Treatment Effect on Nonalcoholic Fatty Liver Disease by Promoting Lipoxygenases and Reducing Intrahepatic Triglyceride Content

In this study, a new Cd(II)-bearing coordination polymer with the chemical formula of {[Cd4(meda)3(dpe)4(H2O)4]·(NO3)2·2(H2O)}n (1, H2meda = 3,3'-methylenedibenzoic acid, dpe = 1,2-di(pyridin-4-yl)ethane) has been successfully prepared by reaction of Cd(NO3)·4H2O with a V-shape carboxyl ligand H2meda along with the linear dipyridine ligand dpe under the hydrothermal conditions. Due to its intensive luminescence, complex 1 could be utilized as the sensor of detecting Al3+ ion, and its detection limit is 4 × 10-6 M. Firstly, the toxicity of the compound on the normal liver cells was determined with Cell Counting Kit-8 detection kit. The triglyceride in liver cells was detected by detection kit after compound treatment and the relative expression of 15-lox and 12-lox in L02 cells was also measured by RT-PCR after compound treatment. In addition, multiple functional groups that provided by the synthesized Cd(II) complex have been studied by using molecular docking simulation for the confirmation of possible binding modes that formed between ligand and receptor.

The syntheses, structures, and magnetic properties of two mononuclear manganese(II) complexes involving in situ hydrothermal decarboxylation

Two new mononuclear compounds [Mn(3-Br-pydc)(H2O)3] (1) and {[Mn(5-Br-pyc)(bipy)(H2O)(Cl)]·2H2O (2) (3-Br-H2pydc = 3-Br-pyridine-2,6-dicarboxylic acid, 5-Br-Hpyc = 5-Br-pyridine-2-carboxylic acid, bipy = 2,2′-bipyridine) have been synthesized by traditional solution reaction and hydrothermal reaction, respectively. In both compounds, the MnII center is six-coordinated in a distorted octahedral geometry, formed by one tridentate chelate 3-Br-pydc dianion and three water molecules in 1, while the coordination sphere consists of one bidentate chelate 5-Br-pyc anion, one bipy, one water molecule, and one chloride anion in 2 (MnNO5 for 1 and MnN3O2Cl for 2). O–H⋯O hydrogen bonds, Br⋯O halogen bonds, and/or π-π stacking assist in the construction of the three-dimensional (3D) network structures of 1 and 2. Notably, the 5-Br-Hpyc ligand was generated in situ by decarboxylation of the 3-Br-H2pydc precursor under hydrothermal conditions. Variable-temperature magnetic susceptibility data in the 2–300 K temperature range indicate weak antiferromagnetic coupling in both 1 and 2.

The crystal structure of catena-poly[(μ2-4,4′-dipyridine-κ2N,N′)-bis(3,5,6-trichloropyridine-2-oxyacetato-κO)-bis(ethanol-κO)nickel(II)], C28H26Cl6N4NiO8

C28H26Cl6N4NiO8, monoclinic, I2/a (no. 15), a = 15.7577(10) Å, b = 12.6174(7) Å, c = 16.7333(10) Å, β = 99.609(6)Å, V = 3280.3(3) Å3, Z = 4, Rgt(F) = 0.0674, wRref(F2) = 0.1665, T = 291.2(3) K.

Preparation and Characterization of Epoxy Resin Filled with Ti3C2Tx MXene Nanosheets with Excellent Electric Conductivity

MXene represents new kinds of two-dimensional material transition metal carbides and/or carbonitrides, which have attracted much attention in various applications including electrochemical storage devices, catalysts, and polymer composite. Here, we report a facile method to synthesize Ti3C2Tx MXene nanosheets and prepare a novel electrically conductive adhesive based on epoxy resin filled with Ti3C2Tx MXene nanosheets by solution blending. The structure, morphology, and performance of Ti3C2Tx MXene nanosheets and epoxy/Ti3C2Tx MXene nanosheets composite were investigated. The results show that Ti3C2Tx MXene possesses nanosheet structure. Ti3C2Tx MXene nanosheets were homogeneously dispersed in epoxy resin. Electrical conductivity and mechanical properties measurements reveal that the epoxy/Ti3C2Tx MXene nanosheet composite exhibited both good electrical conductivity (4.52 × 10-4 S/m) and favorable mechanical properties (tensile strength of 66.2 MPa and impact strength of 24.2 kJ/m2) when the content of Ti3C2Tx MXene nanosheets is 1.2 wt %. Thus, Ti3C2Tx MXene is a promising filler for electrically conductive adhesive with high electric conductivity and high mechanical performance.