Effects of binuclear copper(Ⅱ)threonine complex on blood glucose, lipids and protection of the hearts and kidneys in diabetic mice

Aim To study the effects of binuclear copper （Ⅱ） threonine complex （Cu2 （Thr）4） as analogue of superoxide dismutase （SOD） on blood glucose, blood lipids and vessels of hearts and kidneys in diabetic mice. Methods Diabetic mouse model was established by intraperitioneal injection of alloxan. Low, middle, and high doses of Cu2（Thr）4 at 0.002%, 0.02% and 0.1% were given respectively to diabetic mice following lavage. The fasting blood glucose was determined after the diabetic mice were given Cu2 （Thr）4 for 0, 30, and 45 d. The diabetic mice were killed on the 45th day. Then glycosylated hemoglobin （HbAlc） and blood lipids were assayed, and pathologic changes in hearts and kidneys stained with HE were observed. Results Compared with the control group in which the diabetic mice were given distilled water, the value of blood glucose reduced significantly in middle dose group （P 〈 0.01 ）, followed by that in low dose group （P 〈 0.05）. TC level reduced markedly and HDL level increased significantly in all three treatment groups （P 〈 0.05）. Especially in middle dose group, cardiac muscle fibers were neatly arranged, nucleus and cytoplasm well distributed, glomeruli showing normal structure, cells well distributed and staining being normal. Conclusion Cu2 （Thr）4 reduces blood glucose, regulates blood lipids, and play protective action on the vessels of hearts and kidneys in diabetic mice. The effects of it in middle dose were better than those of other doses.

Determination of Ultratrace Amounts of Copper(Ⅱ) in Water Samples by Electrothermal Atomic Absorption Spectrometry After Cloud Point Extraction

A novel approach was developed for the determination of ultratrace amounts of copper in water samples by using electrothermal atomic absorption spectrometry （ETAAS） after cloud point extraction （ CPE ）. 1-（ 2-Pyridylazo ） -2- naphthol was used as the chelating reagent and Triton X-114 as the mieellar-forming surfactant. CPE was conducted in a pH 8. 0 medium at 40 ℃ for 10 rain. After the separation of the phases by contrifugafion, the surfactant-rieh phase was diluted with 1 mL of a methanol solution of 0. 1 mol/L HNO3. Then 20μL of the diluted surfactant-rieh phase was injected into the graphite furnace for atomization in the absence of any matrix modifier. Various experimental conditions that affect the extraction and atomization processes were optimized. A detection limit of 5 ng/L was obtained after preconeentration. The linear dynamic range of the copper mass concentration was found to be 0-2.0 ng/mL, and the relative standard deviation was found to be less than 3. 1% for a sample containing 1.0 ng/mL Cu （ Ⅱ ）. This developed method was successfully applied to the determination of uhratraee amounts of Cu in drinking water, tap water, and seawater samples.

A novel spectrophotometric determination of copper(Ⅱ) with bromosulphonazoⅢ

A novel chromogenic reaction involving copper（Ⅱ） and bromosulphonazo Ⅲ （Br-SAZⅢ） in hexamethylenetetramine- hydrochloric buffer solution was investigated. The results showed that a blue complex of copper（Ⅱ） and bromosulphonazo Ⅲ was formed with a molar ratio of 1：1. The apparent molar absorptivity was 3.3×10^5Lmol-1cm-1 and the maximum absorption peak was at 616.8 nm. The proposed procedure was used for quantitative estimation of Cu（II） in the concentration range of 0-1.024μg/mL with the detection limit （3σ） of 7.03 × 10^-4 μg/mL （n = 20）. The relative standard deviations （RSDs） were 0.56-4.68%. Under the optimized conditions, total copper in the vegetables and tea was successfully determined. 2007 Li Yuan. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Crystal Structure, Electrochemical and Fluorescent Properties of a New Copper(Ⅱ) Coordination Polymer with 2,3-Pyridinedi-carboxylic Acid

A new copper(Ⅱ)coordination polymer[Cu5(Hpt)5(H2O)2(2,3-PCA)2]n·12nH2O(1)has been successfully synthesized under hydrothermal conditions with copper hydroxide,3-(pyridin-2-yl)-1,2,4-triazole(Hpt)and 2,3-pyridinedi-carboxylic acid(2,3-PCA).The structure of the title compound was determined by X-ray diffraction analyses,elemental analyses and IR spectrum.The architecture of 1 consists of one-dimensional sandwich-like chains which are connected by extensive hydrogen bonding interactions.The solid-state photoluminescence displays an obvious emission band at 384 nm upon excitation at 340 nm.In addition,electrochemistry property has also been studied.

Simple, Selective, and Sensitive Spectrophotometric Method for Determination of Trace Amounts of Nickel(Ⅱ), Copper (Ⅱ), Cobalt (Ⅱ), and Iron (Ⅲ) with a Novel Reagent 2-Pyridine Carboxaldehyde Isonicotinyl Hydrazone

A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.

Synthesis,Crystal Structure and Thermal Stability Properties of a Binuclear Copper(Ⅱ) Coordination Polymer {[Cu_2(4,4'-bipy)_2(o-ABA)_4(H_2O)_2][(H_2O)_2]}_n

One-dimensional chain copper（Ⅱ） coordination polymer has been synthesized and characterized in the solvent mixture of water and alcohol with o-acetamidobenzoic acid,4,4＇-bipyridine and copper perchlorate.It is of tetragonal,space group P41212 with a=1.57756（10）,b= 1.57756（10）,c=2.1438（3）nm,V=5.3352（8） nm^3,Dc=1.524 g/cm^3,Z=4,F（000）=2536,R= 0.0479 and wR=0.0979.The crystal structure shows two coordination modes.The copper（1） is coordinated with two nitrogen atoms of one 4,4＇-bipyridine molecule and two oxygen atoms from two o-acetamidobenzoic acid molecules,forming a distorted tetrahedral coordination geometry; the copper（2） is coordinated with two nitrogen atoms of one 4,4＇-bipyridine molecule,four oxygen atoms from two o-acetamidobenzoic acid molecules and two water molecules,generating a distorted octahedral coordination geometry.The result of TG analysis shows that the title complex is stable below 180.0 ℃.

Thermal Behavior, Non-isothermal Decomposition Reaction Kinetics of Copper(Ⅱ) Salt of 4-Hydroxy-3,5-dinitropyridine and Its Application in Propellant

The thermal behavior and kinetic parameters of the major exothermic decomposition reaction of the title compound in a temperature-programmed mode were studied by means of TG-DTG and DSC. The critical temperature of thermal explosion was calculated. The effect of the title compound on the combustion characteristic of composition modifier double base propellant containing RDX was explored with a strand burner. The results show that the kinetic model function in differential forms, the apparent activation energy(E a) and the pre-exponential factor(A) of the major exothermic decomposition reaction are 3(1-α)[-ln(1-α)] 2/3, 190.56 kJ/mol and 10 13.39 s -1, respectively. The critical temperature of thermal explosion of the compound is 353.08 ℃. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as dα/dT=10 14.65(1-α)[-ln(1-α)] 2/3 e -2.2920×104/T. As an auxiliary catalyzer, the title compound can help the main catalyzer of lead salt of 4-hydroxy-3,5-dinitropyridine to accelerate the burning rate and reduce the pressure exponent of RDX-CMDB propellant.

A Novel Copper(Ⅱ) Complex of Asymmetrically N-Functionalized 1,4,7-Triazacyclononane Ligand： Syntheses, Structure, Electrochemical Property and Biological Activities

A novel copper（Ⅱ） complex derived from 1,4,7-triazacyclononane[CuL]_2（PF_6）_3×MeCN×H_2 O was synthesized and crystallographically characterized {L = 1,4-bis（2-carbamoylethyl）-7-benzimidazole-2-yl-methyl-1,4,7-triazacyclononane}. It crystallizes in triclinic, space group P1, with a = 13.2425（13）, b = 14.0807（15）, c = 17.6798（18）, α = 86.296（2）, β = 72.773（2）, γ= 68.905（2）o, V = 2934.5（5）A^3, Z = 2, D_c = 1.611 g/m^3, F（000） = 1456, M_r = 1423.09, m = 0.920 mm^-1. The final R = 0.0671 and wR = 0.1874 for 6501 observed reflections with I 〉 2σ（I）. The structural analysis shows that the complex cation（[CuL]_2^3＋） was formed by two complex cations, namely（[CuL^3]^2＋） and [CuL_（-H）~3]~＋） through a hydrogen bond. In each complex cation, the Cu（Ⅱ） lies in a distorted square pyramidal geometry. The redox behavior was studied by cyclic voltammetry（CV） in aqueous solution which indicates a reversible one electron redox reaction. The result of UV absorption, ethidium bromide（EB） fluorescence spectra indicated that the complex binds to CT-DNA in an intercalative mode. Superoxide dismutase（SOD） activity of the complex was determined by photoreduction of NBT, and the value of IC_（50） is 5.22 μmol·L^-1.

Sorption Kinetic Analysis for the Removal of Copper(Ⅱ) by Using Biofilm

The biosorption of copper(Ⅱ) ions onto biofilm was studied in a batch system with respect to the temperature, initial pH value and biofilm sorbent mass. The biomass exhibited the highest copper(Ⅱ) sorption capacity under the conditions of room temperature, initial pH value of 6.0 and the sorbent mass 8 g. The experimental data were analyzed using four sorption kinetic models, the pseudo-first order, the Ritchie second order, the modified second order and the Elovich equations to determine the best-fit equation for the sorption of metal ions onto biofilm. Comparing with the sum of squared-errors, the results show that both the Ritchie second order and modified second order equations can fit the experimental data very well.

Synthesis,Crystal Structure,Spectroscopic Characterization,Thermal Stability and Magnetic Properties of a Dinuclear Copper(Ⅱ) Complex

A new copper（Ⅱ） complex [Cu2（MNA）2（2,2‘-bipy）2]·2.5H2 O with methy-5-norbornene-2,3-dicarboxylic acid（MNA） and 2,2’-bipyridine as ligands has been synthesized in the mixed solvents of DMF and water.It crystallizes in monoclinic,space group P 1,with a = 10.4191（11）,b = 12.8883（13）,c = 16.1114（16） A,α = 70.8090（10）,β = 80.568（2）,γ = 77.440（2）o,V = 1984.3（4） A^3,Dc = 1.551 g/cm^3,Z = 2,F（000） = 962,the final GOOF = 1.051,R = 0.0431 and w R= 0.0980.The crystal structure shows that the whole molecule consists of two independent dinuclear units,in which two copper ions are bridged by two μ2-η^1：η^0 3-carboxylate groups of MNA^2-.The coordination environment of Cu（Ⅱ） ion is Cu O3N2,giving a distorted square pyramidal geometry.The spectroscopic characterization,thermal stability and magnetic properties of the complex were investigated.

Synthesis,Characterization,and DNA Binding Properties of Dinuclear Copper(Ⅱ) Complex [Cu_2(TATP)_2(L-Leu)_2(ClO_4)_2]_2·2H_2O

A dinuclear copper（Ⅱ） complex[Cu2（TATP）2（L-Leu）2（CIO4）2]2·2H2Owas synthesized and characterized, where, TATP=1,4,8,9-tetraazatriphenylene, and L-Leu=L-leucinate. The complex was crystallized in the triclinic space group P1, with two independent molecules in a unit cell. Two Cu（Ⅱ） ions in each complex [Cu2（TATP）2（L-Leu）2（CIO4）2] molecule were found to be in different coordination geometries, i.e., Cu2 or Cu4 of a distorted square-pyramidal geometry coordinated with two nitrogens of TATP, the amino nitrogen and one carboxylate oxygen of L-Leu and one oxygen of perchlorate, and Cul or Cu3 with an octahedral geometry coordinated with the above stated similar coordinated atoms, and another carboxylate oxygen of L-Leu coordinating to Cu2 or Cu4. The complex can interact with CT-DNA by an intercalative mode and cleave pBR322 DNA in the presence of ascorbate.

Extraction and stripping kinetics of copper(Ⅱ)by N902 using single drop technique

The kinetics of extraction and stripping of copper （Ⅱ） was investigated by the single drop technique with a new extractant N902 （a derivative of the salicylal-doxime） and the rate equations of extraction and stripping were derived, respectively. The apparent activation energies of extraction and stripping were estimated to be 20.14 kJ/mol and 30.0 k J/mol.

Characterization and Crystal Structures of Two Copper(Ⅱ) Complexes Constructed by a Flexible Double Betaine Ligand

A flexible double betaine 1,4-bis（pyridinil-4-carboxylato）-1,4-dimethylbenzene L has been used to generate two Cu（Ⅱ）-containing metal complexes that exhibit different polymeric structures： [Cu（H2O）2 L].2NO3 1 and [Cu（H2O）3 L].2Cl.H2O 2. The crystal structures of 1 and 2 have been determined by single-crystal X-ray diffraction method. Crystal data for 1： triclinic, space group PT, a = 5.253（2）, b = 7.406（3）, c = 14.792（5） A, α = 84.195（5）, β = 80.014（5）, γ = 78.053（5）°, V= 553.2（3）A^3, Z = 1, F（000） = 293, Dc = 1.717 g/cm^3, the final R = 0.0385 and wR = 0.1079 for 1883 observed reflections （I 〉 2σ（I））; and those for 2： monoclinic, space group P21/c, a = 10.222（3）, b = 25.287（7）, c = 9.277（3）A, β = 93.572（5）°, V = 2393.2（12）A^3, Z = 4, F（000） = 1140, Dc = 1.540 g/cm^3, the final R = 0.0472 and wR = 0.0956 for 3204 observed reflections （I 〉2o（/））.

Kinetics and Thermodynamics of the Adsorption of Copper(Ⅱ) onto a New Fe-Si Adsorbent

A new kind of Fe-Si adsorbent was synthesized by iron oxide and diatomite after calcining and hydrothermal process. The influences of the initial Cu2＋ concentration, p H and adsorption time on the Cu2＋ removal efficiency were discussed. Three adsorption empirical kinetics equations and two thermodynamics equations were used to simulate the adsorption process. The microstructures of newly developed copper removal materials and properties of copper removal are characterized in details by SEM and EDS. Adsorption mechanism of the adsorbent was discussed. The suitable p H value for Cu2＋ removal is 5.0 to 6.0 and the adsorption capacity increases with increasing the initial Cu2＋ concentration. The adsorption kinetics of the adsorbent could be better described by pseudo second order kinetic model, whereas the adsorption isotherms highly conform to the Freundlich equation. The main crystalline phase of the adsorbent is Fe（Si O3） which can build porous structures conducive to the Cu2＋ adsorption.

Operando HERFD-XANES and surface sensitive Δμ analyses identify the structural evolution of copper(Ⅱ) phthalocyanine for electroreduction of CO_(2)

The quantitative understanding of how atomic-level catalyst structural changes affect the reactivity of the electrochemical CO_(2)reduction reaction is challenging.Due to the complexity of catalytic systems,conventional in situ X-ray spectroscopy plays a limited role in tracing the underlying dynamic structural changes in catalysts active sites.Herein,operando high-energy resolution fluorescence-detected X-ray absorption spectroscopy was used to precisely identify the dynamic structural transformation of well-defined active sites of a representative model copper(Ⅱ)phthalocyanine catalyst which is of guiding significance in studying single-atom catalysis system.Comprehensive X-ray spectroscopy analyses,including surface sensitive△μspectra which isolates the surface changes by subtracting the disturb of bulk base and X-ray absorption near-edge structure spectroscopy simulation,were used to discover that Cu species aggregated with increasing applied potential,which is responsible for the observed evolution of C_(2)H_(4).The approach developed in this work,characterizing the active-site geometry and dynamic structural change,is a novel and powerful technique to elucidate complex catalytic mechanisms and is expected to con tribute to the rational design of highly effective catalysts.

Synthesis and Conductivity of a One-dimensional Polymer of a Copper(Ⅱ)-porphyrazine with Sulfur Bridges

A novel conjugated polymer which shows sendconductivity at T < 260K and T >286K and metallic conductivity at 260K < T< 286K was syllthesized by reaction of 2, 3, 5, 6-tetracyano1, 4-dithiin and phthalonitrile with CuCl2.2H2O.

Molecular dynamics studies of the inhibitory mechanism of copper(Ⅱ) on aggregation of amyloid β-peptide

The inhibitory mechanism of copper（Ⅱ） on the aggegation of amyloid β-peptide （Aβ） was investigated by molecular dynamics simulations. The binding mode ofcopper（Ⅱ） with Aβ is characterized by the imidazole nitrogen atom, Nπ, of the histidine residue H 13, acting as the anchoring site, and the backbone＇s deprotoned amide nitogen atoms as the main binding sites. Drove by the coordination bonds and their induced hydrogen bond net, the conformations of Aβ converted from β-sheet non-β-sheet conformations, which destabilized the aggregation of Aβ into fibrils.

Synthesis, Crystal Structure and Magnetic Properties of a Novel Azide-bridged Copper(Ⅱ) Coordination Polymers Containing Nitroxy Nitroxide

A novel azide-bridged copper（Ⅱ） coordination polymer, [Cu3（NITpPy）4（N3）6]n （NITpPy = 4-pyridyl-4,4,5,5-tetramethylimidazline-3-oxide-1-oxyl）, was structurally and magnetically characterized. It crystallizes in the triclinic space group P with a = 7.6932（10）, b = 14.5556（19）, c = 16.122（2） , α = 108.443（2）, β = 95.251（2）, γ = 104.236（2）°, V = 1631.7（4） 3, C48H64Cu3N30O8, Mr = 1379.87, Z = 1, Dc = 1.404 g/cm3, μ（MoKα） = 1.041 mm-1, F（000） = 713, the R = 0.0510 and wR = 0.1185 for 4285 observed reflections with I 2σ（I）. X-ray analysis reveals that the Cu（Ⅱ） ions are linked by nitrogen atom of μ1,1 azido ligands to form a Cu-Cu-Cu unit. The units are linked by μ1,3 azido ligands through a bridging style to form a one-dimensional coordination polymer. The variable-temperature magnetic susceptibility data of the complex show ferromagnetic interactions in the complex.

Synthesis, Structure and Magnetic Property of a New Three-dimensional Copper(Ⅱ) Coordination Polymer Constructed from 5-Tert-butyl Isophthalic Acid and N-donor Ligand

A new 3D copper（Ⅱ） coordination polymer, {[Cu_2（tbip）_2（1,3,5-tib）]×2H_2O}n（1, H_2 tbip = 5-tert-butyl isophthalic acid, 1,3,5-tib = 1,3,5-tris（1-imidazolyl）benzene）, has been synthesized by hydrothermal reaction of Cu（OAc）_2·4H_2O, H_2 tbip and 1,3,5-tib. It has been structurally characterized by element analysis, IR and magnetic measurement. X-ray single-crystal analysis was carried out for 1, which crystallizes in the triclinic system, space group P1 with a = 7.822（3）, b = 15.854（6）, c = 17.553（6） ？, a = 113.033（4）, β = 90.694（4）, g = 101.006（4）°, V = 1957.3（12） ？~3, Z = 1, D_c = 1.493 g/cm^3, M_r = 1759.70, F（000） = 908, R = 0.0721 and w R = 0.1978 with I 〉 2s（I）. The single-crystal X-ray diffraction studies reveal that compound 1 exhibits 2D [Cu（tbip）] layers which are further pillared by 1,3,5-tib ancillary ligand with terminal tridentate coordination mode to generate the final 3D structure. Magnetic susceptibility data for 1 have been measured in the range of 2~300 K. There are antiferromagnetic interactions between copper ions of the compound.

Synthesis,Structure and DFT Calculations of a Novel Copper(Ⅱ)Complex Based on Tert-butyl 2-[N-(tert-butyloxycarbonylmethyl)-2-picolyamino]acetate

A novel copper（Ⅱ） complex with tert-butyl 2-[N-（tert-butyloxycarbonylmethyl）-2-picolyamino]acetate（ampy） was synthesized and structurally characterized by elemental analysis, FT-IR spectrum, electrospray ionization-mass spectrometry, UV-vis spectrum and single-crystal X-ray diffraction, respectively. A mononuclear copper（II） complex with ampy, [Cu（ampy）Cl2]（1）, was formed irrespective of the metal-to-ligand molar ratios（[Cu2＋]：[ampy] = 0.5：1, 1：1, and 2：1） as a single product. Complex 1 crystallizes in the orthorhombic system, space group Pbca with a = 12.343（2）, b = 18.928（3）, c = 20.058（4） A, V = 4686.1（14） A3, Z = 8, Dc = 1.3349（4） g/cm3, F（000） = 1920, S = 1.016, R = 0.0693 and w R = 0.1721 for 3151 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that the central copper（II） ion is bound by pyridyl N, tertiary amine N and carbonyl O atoms of the quadridentate ampy as well as two Cl anions, constructing a slightly distorted octahedral geometry. Complex 1 further constructs a stable 3D supramolecular architecture by intermolecular C–H…Cl hydrogen bonds. In addition, the molecular geometry was calculated by density functional theory（DFT/B3LYP） method with the basis sets（6-31＋G（d,p） for H, C, N, O and Cl atoms, and LANL2 DZ for Cu atom, respectively）. The calculated results show that the optimized geometrical parameters are in good agreement with the experimental data. Natural bond orbital（NBO） analysis and frontier molecular orbitals（FMOs） analysis were investigated at the same level.