A Binuclear Cadmium(II) Cluster Based on π···π Stacking and Halogen···Halogen Interactions: Synthesis, Crystal Analysis and Fluorescent Properties

Two Cu(II) and Co(II) Coordination Polymers: Important Values on Colon Cancer Patients by Reducing Insulin Resistance

In the current study, via utilizing H₅L (H₅L = 2,4-di(3',5'-dicarboxylphenyl)benzoic acid), the symmetrical rigid polycarboxylic acid ligand with V-shape geometry, two new coordination polymers containing Cu(II) and Co(II) have been produced, and their chemical formulae respectively are {[Co₅(L)₂(H₂O)₁₂]·6H₂O} _n (1) and {[H₂N(Me)₂][Cu₂(L)(H₂O)]·DMF·H₂O} _n (2), leading to a variety kinds of coordination patterns of H₅L and multifunctional skeletons. Their inhibitory activity on the insulin resistance of colon cancer patients was assessed. In addition, the detailed mechanism of the compound was also investigated. Firstly, the detection of enzyme-linked immunosorbent assay was carried out and the Tumor Necrosis Factor-α (TNF-α) level and the Interleukin-1β (IL-1β) level was detected. Then, the glucose concentration was determined with blood glucose meter. Next, the insulin receptor expression levels of β cells were determined with the real time reverse transcription-polymerase chain reaction assay. Ultimately, the cytotoxicity of compounds 1 and 2 was determined with Cell Counting Kit-8 assay.

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.

A cobalt(II) coordination polymer constructed with the 2-carboxy-phenoxyacetate linker showing a corrugated layer structure: synthesis, structure analysis and magnetic properties

A new binary CoII coordination polymer, [Co(2-cpa)2(H2O)] n (1) has been synthesized by a hydrothermal reaction of cobalt(II) acetate tetrahydrate and 2-carboxy-phenoxyacetic acid (2-H2cpa) in the presence of potassium hydroxide. Structural analysis revealed that the central CoII ion is in an octahedral geometry coordinated with one aqua and five oxygen atoms of three 2-carboxy-phenoxyacetate (2-cpa) ligands. The 2-cpa anions function as pentadentate double bridging chelate-μ 3 linkers binding neighboring CoII ions together, to form an unusual corrugated (4,4)-connected layer. Variable-temperature magnetic susceptibility data in the 2–300 K temperature range indicates a weak antiferromagnetic coupling between adjacent cobalt(II) ions.

Crystal structure of tetraaqua-bis(2-((3,5,6-trichloropyridin-2-yl)oxy)acetato-κO)-nickel(II)—diaqua-bis(2-((3,5,6-trichloropyridin-2-yl)oxy)acetato-nickel(II), C28H24Cl12N4Ni2O18

C28H24Cl12N4Ni2O18, monoclinic, I2/a (no. 15), a = 37.8040(12) Å, b = 6.0860(2) Å, c = 19.3025(6) Å, β = 98.104(3)°, V = 4396.7(2) Å3, Z = 4, Rgt(F) = 0.0498, wRref(F2) = 0.1039, T = 291.8(2) K.

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.

In Situ Assessment of Intrinsic Strength of X-I⋯OA-Type Halogen Bonds in Molecular Crystals with Periodic Local Vibrational Mode Theory

Periodic local vibrational modes were calculated with the rev-vdW-DF2 density functional to quantify the intrinsic strength of the X-I⋯OA-type halogen bonding (X = I or Cl; OA: carbonyl, ether and N-oxide groups) in 32 model systems originating from 20 molecular crystals. We found that the halogen bonding between the donor dihalogen X-I and the wide collection of acceptor molecules OA features considerable variations of the local stretching force constants (0.1–0.8 mdyn/Å) for I⋯O halogen bonds, demonstrating its powerful tunability in bond strength. Strong correlations between bond length and local stretching force constant were observed in crystals for both the donor X-I bonds and I⋯O halogen bonds, extending for the first time the generalized Badger’s rule to crystals. It is demonstrated that the halogen atom X controlling the electrostatic attraction between the σ-hole on atom I and the acceptor atom O dominates the intrinsic strength of I⋯O halogen bonds. Different oxygen-containing acceptor molecules OA and even subtle changes induced by substituents can tweak the n→σ∗(X-I) charge transfer character, which is the second important factor determining the I⋯O bond strength. In addition, the presence of the second halogen bond with atom X of the donor X-I bond in crystals can substantially weaken the target I⋯O halogen bond. In summary, this study performing the in situ measurement of halogen bonding strength in crystalline structures demonstrates the vast potential of the periodic local vibrational mode theory for characterizing and understanding non-covalent interactions in materials.

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.

Multidimensional luminescent cobalt(ii)-coordination polymers as sensors with extremely high sensitivity and selectivity for detection of acetylacetone, benzaldehyde and Cr2O72−

Three new ternary cobalt(ii) CPs were synthesized. 1 exhibits a 3D pcu framework, 2 possesses a 2D hcb layer and 3 is a 1D chain structure. 1, 2, and 3 can be effective luminescent probes for sensing acetylacetone, benzaldehyde and Cr₂O₇²⁻ ions.

Crystal structure of catena-poly[μ2-4,4′-bipyridine-κ2N:N′)-tetrakis(μ2-2-((3,5,6-trichloropyridin-2-yl)oxy)acetato-κ2O:O′)dicobalt(II)], C19H10Cl6CoN3O6

C19H10Cl6CoN3O6, tetragonal, I4̄ (no. 82), a = 13.1152(4) Å, c = 14.2497(6) Å, V = 2451.07(18) Å3, Z = 4, Rgt(F) = 0.0359, wRref(F2) = 0.0843, T = 293.2(3) K.

Two mononuclear zinc(II) complexes constructed by two types of phenoxyacetic acid ligands: syntheses, crystal structures and fluorescence properties

Two new mononuclear complexes, [Zn(3-Hcpa)2(H2O)4] (1) and [Zn(3,5,6-tcpa)2(H2O)4] [Zn(3,5,6-tcpa)2(H2O)2] (2) (3-H2cpa = 3-carboxy-phenoxyacetic acid, 3,5,6-Htcpa = 3,5,6-trichloro pyridine-2-oxyacetic acid), were synthesized and structurally characterized. The single-crystal X-ray diffraction analysis showed that in 1 the ZnII ion lies on an inversion center of an octahedron formed by four aqua ligands and two carboxy oxygen atoms of two unidentate 3-Hcpa− anions in trans-arrangement. Complex 2 is a co-crystal consisting of two discrete and stereochemically different complexes: one with an octahedrally, and the other a tetrahedrally coordinated zinc center. The six-coordination about the first ZnII ion comprises four oxygen atoms from water (H2O) molecules and two from the carboxy groups of monodentate trans-related 3,5,6-tcpa− ligands. The four-coordination about the second ZnII ion is comprised of two H2O ligands and two unidentate carboxy oxygen atoms from 3,5,6-tcpa− ligands. O–HLO hydrogen bond and/or ClLCl halogen bond interactions play an important part in construction of the three-dimensional (3D) networks for 1 and 2. The photoluminescence spectra reveal that both 1 and 2 display luminescent properties in the violet region.