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Sample records for copper ii sulfate

  1. Decomposition of Copper (II) Sulfate Pentahydrate: A Sequential Gravimetric Analysis.

    ERIC Educational Resources Information Center

    Harris, Arlo D.; Kalbus, Lee H.

    1979-01-01

    Describes an improved experiment of the thermal dehydration of copper (II) sulfate pentahydrate. The improvements described here are control of the temperature environment and a quantitative study of the decomposition reaction to a thermally stable oxide. Data will suffice to show sequential gravimetric analysis. (Author/SA)

  2. Spectroscopic study of copper(II) complexes with carboxymethyl dextran and dextran sulfate

    NASA Astrophysics Data System (ADS)

    Glišić, S.; Nikolić, G.; Cakić, M.; Trutić, N.

    2015-07-01

    The copper(II) ion complexes with carboxymethyl dextran (CMD) and dextran sulfate (DS) were studied by different methods. Content of copper was determined by atomic absorption spectroscopy. It was found that copper : ligand mole ratio (Cu : CMD) is 1 : 2, and Cu : DS is 1 : 1 by mole ratio method. Spectrophotometric parameters of synthesized compounds are characteristic for Cu(II) ion in octahedral ( O h ) coordination. Analyzing of FTIR spectra in ν(C=O) vibration region has showed that -COOH group acts as bidentate ligand, while the compounds of Cu(II) with DS copper ions are in the region of four oxygen atoms of two adjacent sulfo groups. The presence of crystalline water was determined by isotopic substitution of H2O molecules with D2O molecules. Comparison of spectra recorded at room (RT) and liquid nitrogen temperature (LNT) has enabled detection bands of water molecules libration indicating that they are coordinated complementing coordination sphere of Cu(II) ions to six. The complexes are of Cu(II) · (CMD)2 · (H2O)2 or Cu(II) · DS · (H2O)2 type. The similarities of the γ(C-H) range in a part of FTIR spectra indicate that there is no difference in the conformation of the 4 C 1 glucopyranose (Glc) unit CMD and DS synthesized Cu(II) complexes.

  3. Tris(2,2'-bipyridyl-κN,N')copper(II) sulfate 7.5-hydrate.

    PubMed

    Xu, Feng; You, Wei; Huang, Wei

    2009-01-01

    The title compound, [Cu(C(10)H(8)N(2))(3)]SO(4)·7.5H(2)O, is a six-coordinate copper(II) complex with a slightly elongated octa-hedral coordination geometry. The pyridyl rings of the three bipyridyl ligands are not coplanar, making dihedral angels of 9.5 (5), 5.2 (4) and 5.8 (5)°. In the crystal, several O-H⋯O and C-H⋯O hydrogen-bonding inter-actions are observed due to the existance of a large number of water mol-ecules and the sulfate dianions. PMID:21581747

  4. Sulfate-bridged dimeric trinuclear copper(II)–pyrazolate complex with three different terminal ligands

    PubMed Central

    Mezei, Gellert

    2016-01-01

    The reaction of CuSO4·5H2O, 4-chloro­pyrazole (4-Cl-pzH) and tri­ethyl­amine (Et3N) in di­methyl­formamide (DMF) produced crystals of di­aqua­hexa­kis­(μ-4-chloro­pyrazolato-κ2 N:N′)bis­(N,N-di­methyl­formamide)di-μ3-hydroxido-bis­(μ4-sulfato-κ4 O:O′:O′′:O′′)hexa­copper(II) N,N-di­methyl­formamide tetra­solvate dihydrate, [Cu3(OH)(SO4)(C3H2ClN2)3(C3H7NO)(H2O)]2·4C3H7NO·2H2O. The centrosymmetric dimeric molecule consists of two trinuclear copper–pyrazolate units bridged by two sulfate ions. The title compound provides the first example of a trinuclear copper–pyrazolate complex with three different terminal ligands on the Cu atoms, and also the first example of such complex with a strongly binding basal sulfate ion. Within each trinuclear unit, the CuII atoms are bridged by μ-pyrazolate groups and a central μ3-OH group, and are coordinated by terminal sulfate, H2O and DMF ligands, respectively. Moreover, the sulfate O atoms coordinate at the apical position to the Cu atoms of the symmetry-related unit, providing square–pyramidal coordination geometry around each copper cation. The metal complex and solvent mol­ecules are involved in O—H⋯O hydrogen bonds, leading to a two-dimensional network parallel to (10-1). PMID:27536383

  5. In vitro Solubility of Copper(II) Sulfate and Dicopper Chloride Trihydroxide for Pigs

    PubMed Central

    Park, C. S.; Kim, B. G.

    2016-01-01

    This study was conducted to determine the solubility of copper (Cu) in two sources of copper(II) sulfate (CuSO4) including monohydrate and pentahydrate and three sources of dicopper chloride trihydroxide (dCCTH) including α-form (dCCTH-α), β-form (dCCTH-β), and a mixture of α- and β-form (dCCTH-αβ) at different pH and a 3-step in vitro digestion assay for pigs. In Exp. 1, Cu sources were incubated in water-based buffers at pH 2.0, 3.0, 4.8, and 6.8 for 4 h using a shaking incubator at 39°C. The CuSO4 sources were completely dissolved within 15 min except at pH 6.8. The solubility of Cu in dCCTH-α was greater (p<0.05) than dCCTH-β but was not different from dCCTH-αβ during 3-h incubation at pH 2.0 and during 2-h incubation at pH 3.0. At pH 4.8, there were no significant differences in solubility of Cu in dCCTH sources. Copper in dCCTH sources were non-soluble at pH 6.8. In Exp. 2, the solubility of Cu was determined during the 3-step in vitro digestion assay for pigs. All sources of Cu were completely dissolved in step 1 which simulated digestion in the stomach. In Exp. 3, the solubility of Cu in experimental diets including a control diet and diets containing 250 mg/kg of additional Cu from five Cu sources was determined during the in vitro digestion assay. The solubility of Cu in diets containing additional Cu sources were greater (p<0.05) than the control diet in step 1. In conclusion, the solubility of Cu was influenced by pH of digesta but was not different among sources based on the in vitro digestion assay. PMID:27456425

  6. Tris(2,2′-bipyridyl-κ2 N,N′)copper(II) sulfate 7.5-hydrate

    PubMed Central

    Xu, Feng; You, Wei; Huang, Wei

    2009-01-01

    The title compound, [Cu(C10H8N2)3]SO4·7.5H2O, is a six-coordinate copper(II) complex with a slightly elongated octa­hedral coordination geometry. The pyridyl rings of the three bipyridyl ligands are not coplanar, making dihedral angels of 9.5 (5), 5.2 (4) and 5.8 (5)°. In the crystal, several O—H⋯O and C—H⋯O hydrogen-bonding inter­actions are observed due to the existance of a large number of water mol­ecules and the sulfate dianions. PMID:21581747

  7. Catalytic-Oxidative Leaching of Low-Grade Complex Zinc Ore by Cu (II) Ions Produced from Copper Ore in Ammonia-Ammonium Sulfate Solution

    NASA Astrophysics Data System (ADS)

    Liu, Zhi Xiong; Yin, Zhou Lan; Hu, Hui Ping; Chen, Qi Yuan

    2012-10-01

    The catalytic-oxidative leaching of a mixed ore, which consists of low-grade oxide copper ore and oxide zinc ore containing ZnS, was investigated in ammonia-ammonium sulfate solution. The effect of the main parameters, such as mass ratio of copper ore to zinc ore, liquid-to-solid ratio, concentration of lixivant, leaching time, and temperature, was studied. The optimal leaching conditions with a maximum extraction of Cu 92.6 pct and Zn 85.5 pct were determined as follows: the mass ratio of copper ore to zinc ore 4/10 g/g, temperature 323.15 K (50 °C), leaching time 6 hours, stirring speed 500 r/min, liquid-to-solid ratio 3.6/1 cm3/g, concentration of lixivant including ammonia 2.0 mol/dm3, ammonium sulfate 1.0 mol/dm3, and ammonium persulfate 0.3 mol/dm3. It was found that ZnS in the oxide zinc ore could be extracted with Cu(II) ion, which was produced from copper ore and was used as the catalyst in the presence of ammonium persulfate.

  8. A new copper(II) chelate complex with tridentate ligand: Synthesis, crystal and molecular electronic structure of aqua-(diethylenetriamine-N, N‧, N‧‧)-copper(II) sulfate monohydrate and its fire retardant properties

    NASA Astrophysics Data System (ADS)

    Lavrenyuk, H.; Mykhalichko, O.; Zarychta, B.; Olijnyk, V.; Mykhalichko, B.

    2015-09-01

    The crystals of a new aqua-(diethylenetriamine-N, N‧, N‧‧)-copper(II) sulfate monohydrate have been synthesized by direct interaction of solid copper(II) sulfate pentahydrate with diethylenetriamine (deta). The crystal structure of [Cu(deta)H2O]SO4ṡH2O (1) has been determined by X-ray diffraction methods at 100 K and characterized using X-ray powder diffraction pattern: space group P 1 bar, a = 7.2819(4), b = 8.4669(4), c = 8.7020(3) Å, α = 83.590(3), β = 89.620(4), γ = 84.946(4)°, Z = 2. The environment of the Cu(II) atom is a distorted, elongated square pyramid which consists of three nitrogen atoms of the deta molecule and oxygen atom of the water molecule in the basal plane of the square pyramid (the average lengths of the in-plane Cu-N and Cu-O bonds are 2.00 Å). The apical position of the coordination polyhedron is occupied by complementary oxygen atom of the sulfate anion (the length of the axial Cu-O bond is 2.421(1) Å). The crystal packing is governed by strong hydrogen bonds of O-H⋯O and N-H⋯O types. The ab initio quantum-chemical calculations have been performed by the restricted Hartree-Fock method with a basis set 6-31∗G using the structural data of [Cu(deta)H2O]SO4ṡH2O. It has been ascertained that the degenerate d-orbitals of the Cu2+ ion split under the co-action of both the square-pyramidal coordination and the chelation. It is significant that visually observed crystals color (blue-violet) of the [Cu(deta)H2O]SO4ṡH2O complex is in good agreement with the calculated value of wavelength of visible light (λ = 5735 Å) which is closely related to the energy of the absorbed photon (Δ = 2.161 eV). Furthermore, the stereo-chemical aspect of influence of the CuSO4 upon combustibility of modified epoxy-amine polymers has been scrutinized.

  9. Acid copper sulfate plating bath: Control of chloride and copper

    SciTech Connect

    Borhani, K.J.

    1992-08-01

    Plated-through holes in high-reliability printed wiring boards require a ductile copper plate of uniform consistency. The level of control of the chemical constituents in the electroplating solutions dictates the physical properties of the copper plate. To improve the control of the chemical bath constituents, in-situ methods for electrochemically determining copper and chloride in acid copper sulfate baths were developed. A solid-state ion-selective electrode was used for the chloride ion and proved to be more reproducible than conventional silver chloride turbidimetric methods. The use of a copper solid-state ion-selective electrode in-situ was also successful in this application.

  10. Status of copper sulfate research at SNARC

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An overview of the Technical Sections completed and being worked on for the New Animal Drug Application (NADA) for copper sulfate will be given. The change in Sponsorship will also be discussed. The Initial label claim will be “For the treatment of ichthyophthiriasis (Ichthyophthirius multifiliis)...

  11. Minnows get columnaris too; copper sulfate works!

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to compare the therapeutic effects of copper sulfate (CuSO4), when delivered in either a flow-through or static system, on the survival of golden shiner (Notemigonus crysoleucas; Fig. 1A) and fathead minnow (Pimephales promelas; Fig. 1B) infected with Flavobacterium columnare (...

  12. 21 CFR 184.1261 - Copper sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the...) of this chapter. (2) The ingredient is used in food at levels not to exceed current good... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Copper sulfate. 184.1261 Section 184.1261 Food...

  13. 21 CFR 184.1261 - Copper sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the...) of this chapter. (2) The ingredient is used in food at levels not to exceed current good... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Copper sulfate. 184.1261 Section 184.1261 Food...

  14. 21 CFR 184.1261 - Copper sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the...) of this chapter. (2) The ingredient is used in food at levels not to exceed current good... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Copper sulfate. 184.1261 Section 184.1261 Food...

  15. 21 CFR 184.1261 - Copper sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the...) of this chapter. (2) The ingredient is used in food at levels not to exceed current good... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Copper sulfate. 184.1261 Section 184.1261 Food...

  16. Copper sulfate: Liquid or crystals?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two separate experiments were conducted to evaluate copper toxicity to channel catfish and free-swimming Ichthyophthirius multifiliis or Ich (the stage of Ich that can be treated); the compounds we used were CuSO4 crystals and a non-chelated liquid CuSO4 product. In 96 hr tests conducted in aquaria...

  17. Comparative studies of the effects of copper sulfate and zinc sulfate on serum albumins

    NASA Astrophysics Data System (ADS)

    Plotnikova, O. A.; Melnikov, G. V.; Melnikov, A. G.; Kovalenko, A. V.

    2016-04-01

    The work is devoted to the study of the interaction of heavy metals with bovine serum albumin (BSA) and human serum albumin (HSA), by quenching of the intrinsic fluorescence of proteins and fluorescent probe pyrene by heavy metal ions. Sulfates of copper and zinc (CuSO4, ZnSO4) were taken as the metal salts. The value of the Stern-Volmer constants of quenching of intrinsic fluorescence of proteins and fluorescence probe pyrene reduced from Cu (II) to the Zn (II). It was experimentally found that the copper ions have a greater ability to fluorescence quenching, which is probably associated with the greater availability of protein chromophore groups to copper ions and with adsorbed fluorescent probe pyrene in the protein globule.

  18. Uncovering the Terahertz Spectrum of Copper Sulfate Pentahydrate.

    PubMed

    Ruggiero, Michael T; Korter, Timothy M

    2016-01-21

    Terahertz vibrational spectroscopy has evolved into a powerful tool for the detection and characterization of transition metal sulfate compounds, specifically for its ability to differentiate between various hydrated forms with high specificity. Copper(II) sulfate is one such system where multiple crystalline hydrates have had their terahertz spectra fully assigned, and the unique spectral fingerprints of the forms allows for characterization of multicomponent systems with relative ease. Yet the most commonly occurring form, copper(II) sulfate pentahydrate (CuSO4·5H2O), has proven elusive due to the presence of a broad absorption across much of the terahertz region, making the unambiguous identification of its spectral signature difficult. Here, it is shown that the sub-100 cm(-1) spectrum of CuSO4·5H2O is obscured by absorption from adsorbed water and that controlled drying reveals sharp underlying features. The crystalline composition of the samples was monitored in parallel by X-ray diffraction as a function of drying time, supporting the spectroscopic results. Finally, the terahertz spectrum of CuSO4·5H2O was fully assigned using solid-state density functional theory simulations, helping attribute the additional absorptions that appear after excessive drying to formation of CuSO4·3H2O. PMID:26730508

  19. A Copper-Sulfate-Based Inorganic Chemistry Laboratory for First-Year University Students That Teaches Basic Operations and Concepts.

    ERIC Educational Resources Information Center

    Rodriguez, Emilio; Vicente, Miguel Angel

    2002-01-01

    Presents a 10-hour chemistry experiment using copper sulfate that has three steps: (1) purification of an ore containing copper sulfate and insoluble basic copper sulfates; (2) determination of the number of water molecules in hydrated copper sulfate; and (3) recovery of metallic copper from copper sulfate. (Author/YDS)

  20. [(1,4,8,11-Tetraazacyclotetradeca-1,4,8,11-tetrayl)tetraacetamide-kappa6N1,N4,N8,N11,O1,O8]copper(II) sulfate 4.5-hydrate.

    PubMed

    Espinosa, Enrique; Meyer, Michel; Berard, David; Guilard, Roger

    2002-02-01

    The crystal structure of the title copper(II) complex, [Cu(C(18)H(36)N(8)O(4))]SO(4).4.5H(2)O, formed with the tetraamide cyclam derivative 2-(4,8,11-triscarbamoylmethyl-1,4,8,11-tetraazacyclotetradec-1-yl)acetamide (TETAM), is described. The macrocycle lies on an inversion centre occupied by the hexacoordinated Cu atom. The four macrocyclic tertiary amines form the equatorial plane of an axially Jahn-Teller elongated octahedron. Two O atoms belonging to two diagonally opposite amide groups occupy the apical positions, giving rise to a trans-III stereochemistry, while both the remaining pendant side arms extend outwards from the macrocyclic cavity and are engaged in hydrogen bonds with sulfate anions and co-crystallized water molecules. PMID:11828099

  1. Electrochemical control of brightener in acid copper sulfate plating solutions

    SciTech Connect

    Bronson, M.J. . Kansas City Div.); Hawley, M.D. )

    1990-11-01

    Electrochemical methods have been evaluated that attempt the indirect measurement of the effective concentration of a brighter additive in acid copper sulfate plating baths. The procedures all employed electrodeposition of copper on a platinum working electrode under carefully controlled conditions of mass transport, time, temperature, and potential, followed by the measurement of the charge that was required to strip the copper deposit from the working electrode. The amount of charge that was required to strip the copper deposit at a given concentration of additive varied significantly from fresh to production baths and from lot to lot of the additive. The feasibility of using electrochemical methods to control brightener additive in acid copper sulfate plating baths is discussed. 3 figs., 11 refs.

  2. Analysis of Saprolegnia parasitica Transcriptome following Treatment with Copper Sulfate

    PubMed Central

    Ye, Xin; Sun, Qi; Yuan, Hai-Lan; Liang, Nan; Fang, Wen-Hong; Li, Hao-Ran; Yang, Xian-Le

    2016-01-01

    Background Massive infection caused by oomycete fungus Saprolegnia parasitica is detrimental to freshwater fish. Recently, we showed that copper sulfate demonstrated good efficacy for controlling S. parasitica infection in grass carp. In this study, we investigated the mechanism of inhibition of S. parasitica growth by copper sulfate by analyzing the transcriptome of copper sulfate—treated S. parasitica. To examine the mechanism of copper sulfate inhibiting S. parasitica, we utilized RNA-seq technology to compare differential gene expression in S. parasitica treated with or without copper sulfate. Results The total mapped rates of the reads with the reference genome were 90.50% in the control group and 73.50% in the experimental group. In the control group, annotated splice junctions, partial novel splice junctions and complete novel splice junctions were about 83%, 3% and 14%, respectively. In the treatment group, the corresponding values were about 75%, 6% and 19%. Following copper sulfate treatment, a total 310 genes were markedly upregulated and 556 genes were markedly downregulated in S. parasitica. Material metabolism related GO terms including cofactor binding (33 genes), 1,3-beta-D-glucan synthase complex (4 genes), carboxylic acid metabolic process (40 genes) were the most significantly enriched. KEGG pathway analysis also determined that the metabolism-related biological pathways were significantly enriched, including the metabolic pathways (98 genes), biosynthesis of secondary metabolites pathways (42 genes), fatty acid metabolism (13 genes), phenylalanine metabolism (7 genes), starch and sucrose metabolism pathway (12 genes). The qRT-PCR results were largely consistent with the RNA-Seq results. Conclusion Our results indicate that copper sulfate inhibits S. parasitica growth by affecting multiple biological functions, including protein synthesis, energy biogenesis, and metabolism. PMID:26895329

  3. 21 CFR 184.1261 - Copper sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... crystals; as blue granules, or as a light blue powder. The ingredient is prepared by the reaction of sulfuric acid with cupric oxide or with copper metal. (b) The ingredient must be of a purity suitable...

  4. Copper accumulation in channel catfish (Ictalurus punctatus) exposed to water borne copper sulfate

    SciTech Connect

    Hobbs, M.; Griffin, B.; Schlenk, D.; Kadlubar, F.; Brand, C.D.

    1995-12-31

    Liver and axial muscle of channel catfish (Ictalurus punctatus) was analyzed for residual copper after exposure to water borne copper sulfate. Copper sulfate was continuously introduced into well water in three fiber glass tanks to achieve 1.7 mg/L, 2.7 mg/L and 3.6 mg/L copper sulfate concentrations in exposure waters. Milli-Q quality water was metered into a fourth tank at the same rate for unexposed fish. Actual levels of copper in exposure waters were determined by daily sampling and analysis by graphite furnace atomic absorption spectrophotometry (GFAA). Tissue samples were taken from six fish from each of the exposed and unexposed tanks at two-week intervals, Samples were collected until tissue analysis indicated an equilibrium had been established between the uptake and elimination in both the muscle and liver tissue. Elimination was followed until a clear rate of deputation could be established. Samples were digested in nitric acid in a micro wave digestor and analyzed by GFAA. Results of tissue analysis will be presented to demonstrate bioaccumulation and the effect of copper concentration, length of copper exposure, and gender on copper uptake, establishment of tissue:environmental copper equilibrium, and rate of copper elimination following exposure.

  5. Acid copper sulfate plating bath: Control of chloride and copper. Final report

    SciTech Connect

    Borhani, K.J.

    1992-08-01

    Plated-through holes in high-reliability printed wiring boards require a ductile copper plate of uniform consistency. The level of control of the chemical constituents in the electroplating solutions dictates the physical properties of the copper plate. To improve the control of the chemical bath constituents, in-situ methods for electrochemically determining copper and chloride in acid copper sulfate baths were developed. A solid-state ion-selective electrode was used for the chloride ion and proved to be more reproducible than conventional silver chloride turbidimetric methods. The use of a copper solid-state ion-selective electrode in-situ was also successful in this application.

  6. Practical use of copper sulfate in catfish production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copper sulfate has been used in aquaculture for many years to control weeds, algae, snails (which carry catfish trematode), and ecto-parasitic organisms in catfish production. Our research has also shown it to be safe and effective to treat fungus on various fish eggs (catfish, hybrid striped bass,...

  7. Environmental assessment of copper sulfate use in channel catfish ponds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copper sulfate (CuSO4) is used worldwide as a waterborne disease therapeutant in commercial and ornamental fish culture. However, it is not approved by the U.S. Food and Drug Administration (FDA) for therapeutic use in aquaculture; regulatory action on the use of CuSO4 has been deferred pending the...

  8. Control of Saprolegniasis on sunshine bass eggs with copper sulfate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major obstacle to successful hatchery production is water-mould (Saprolegniasis) growth on eggs. Copper sulfate (CuSO4) is commonly used to control Saprolegnia species in channel catfish hatcheries that use troughs, but the effectiveness of it on fish eggs hatched using different systems was not ...

  9. 21 CFR 864.9320 - Copper sulfate solution for specific gravity determinations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Copper sulfate solution for specific gravity... Establishments That Manufacture Blood and Blood Products § 864.9320 Copper sulfate solution for specific gravity determinations. (a) Identification. A copper sulfate solution for specific gravity determinations is a...

  10. 21 CFR 864.9320 - Copper sulfate solution for specific gravity determinations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Copper sulfate solution for specific gravity... Establishments That Manufacture Blood and Blood Products § 864.9320 Copper sulfate solution for specific gravity determinations. (a) Identification. A copper sulfate solution for specific gravity determinations is a...

  11. 21 CFR 864.9320 - Copper sulfate solution for specific gravity determinations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Copper sulfate solution for specific gravity... Establishments That Manufacture Blood and Blood Products § 864.9320 Copper sulfate solution for specific gravity determinations. (a) Identification. A copper sulfate solution for specific gravity determinations is a...

  12. 21 CFR 864.9320 - Copper sulfate solution for specific gravity determinations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Copper sulfate solution for specific gravity... Establishments That Manufacture Blood and Blood Products § 864.9320 Copper sulfate solution for specific gravity determinations. (a) Identification. A copper sulfate solution for specific gravity determinations is a...

  13. 21 CFR 864.9320 - Copper sulfate solution for specific gravity determinations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Copper sulfate solution for specific gravity... Establishments That Manufacture Blood and Blood Products § 864.9320 Copper sulfate solution for specific gravity determinations. (a) Identification. A copper sulfate solution for specific gravity determinations is a...

  14. Heparin cofactor II is degraded by heparan sulfate and dextran sulfate.

    PubMed

    Saito, Akio

    2015-02-20

    Heparan sulfate normally binds to heparin cofactor II and modulates the coagulation pathway by inhibiting thrombin. However, when human heparin cofactor II was incubated with heparan sulfate, heparin cofactor II became degraded. Other glycosaminoglycans were tested, including hyaluronic acid, chondroitin sulfates, dermatan sulfate, and heparin, but only dextran sulfate also degraded heparin cofactor II. Pretreatment of heparan sulfate with heparinase reduced its heparin cofactor II-degrading activity. Heparan sulfate and dextran sulfate diminished the thrombin inhibitory activity of heparin cofactor II. Other serpins, including antithrombin III and pigment epithelium-derived factor, were also degraded by heparan sulfate. This is the first evidence of acidic polysaccharides exhibiting protein-degrading activity without the aid of other proteins.

  15. Reaction of Molecular Hydrogen with Tetraaminecopper(II) Sulfate Monohydrate

    NASA Astrophysics Data System (ADS)

    Kanda, Seiichi; Kori, Toshinari; Kida, Sigeo

    1994-02-01

    The reaction of tetraammincopper(II) sulfate monohydrate in a solid state with H 2 (10 MPa) was studied. The Cu(II) ion in the complex was reduced to Cu(0). The final product was a mixture of (NH 4) 2SO 4 and colloidal black Cu(0) which showed a remarkable reactivity as follows. In thermogravimetric analysis up to 440°C under nitrogen atmosphere, the above product reacted between the components very much differently from a control sample with the same composition. The six intermediate samples, taken at successive reaction times, were examined by powder diffraction method. As one of the intermediates, the copper double salt, (NH 4) 2Cu(SO 4) 2, was identified.

  16. Observations on Diseased Pigs with High Sulfate Intake and Normal Tissue Copper Levels

    PubMed Central

    Jericho, K. W. F.; Strausz, K. I.; Martin, P. J.

    1973-01-01

    Disease in a large pig herd reared intensively and kept on sulfate-rich drinking water is described. It is the first report of diseased progeny of sows with high sulfate intake. Results of two surveys are presented, one for water with sulfate in excess of 2000 ppm and one for water with less than 1000 ppm. The management practices are described in detail. Disease of Survey I was manifested by high morbidity and mortality (50% of 600) in piglets, incoordination in piglets and some adult stock and osteopathy in piglets and weaners. In Survey II disease was less severe and restricted to piglets. Detailed histopathological studies revealed myelin deficiency in brain and spinal cord of sows and piglets, interferred endochondreal ossification of long bones of piglets and weaners, fatty changes of livers and interstitial nephritis in piglets and weaners. The changes in the nervous tissue were considered due to delayed fixation as tissue was only immersed in fixative and not perfused with it immediately after death. Similar changes have been described for pigs deficient in copper. Copper content of tissue and body fluids of pigs of this study were normal, as were the serum inorganic phosphate and total calcium levels. The bone changes observed have also been reported for rats given dextran sulfate injections, for pigs on experimental low-copper sulfate-enriched diet and for pigs reported low in copper and fed a diet supplemented with sulfide. The cause of the locomotor disturbance and mortality in piglets was not established. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4.Fig. 5.Fig. 6.Fig. 7. PMID:4270430

  17. Magnetic field effects on copper metal deposition from copper sulfate aqueous solution.

    PubMed

    Udagawa, Chikako; Maeda, Aya; Katsuki, Akio; Maki, Syou; Morimoto, Shotaro; Tanimoto, Yoshifumi

    2014-05-01

    Effects of a magnetic field (≤0.5 T) on electroless copper metal deposition from the reaction of a copper sulfate aqueous solution and a zinc thin plate were examined in this study. In a zero field, a smooth copper thin film grew steadily on the plate. In a 0.38 T field, a smooth copper thin film deposited on a zinc plate within about 1 min. Then, it peeled off repeatedly from the plate. The yield of consumed copper ions increased about 2.1 times compared with that in a zero field. Mechanism of this magnetic field effect was discussed in terms of Lorentz force- and magnetic force-induced convection and local volta cell formation.

  18. Short communication: Efficacy of copper sulfate hoof baths against digital dermatitis--Where is the evidence?

    PubMed

    Thomsen, Peter T

    2015-04-01

    Digital dermatitis is a major problem in modern dairy production because of decreased animal welfare and financial losses. Individual cow treatments are often seen as too time consuming by farmers, and walk-through hoof baths have therefore been used extensively to control digital dermatitis. For decades, copper sulfate hoof baths have been used to treat and prevent digital dermatitis. Copper sulfate has been referred to as the industry gold standard when it comes to hoof-bath chemicals. In several scientific studies testing the efficacy of other hoof-care products, copper sulfate has been used as a positive control, thereby indicating that copper sulfate has a known positive effect. However, this may not be the case. A dilemma may exist between (1) copper sulfate generally being perceived as being effective against digital dermatitis and (2) a possible lack of well-documented scientific evidence of this effect. The objective of this study was to evaluate the existing scientific literature to determine whether the efficacy of copper sulfate used in hoof baths against digital dermatitis has in fact been demonstrated scientifically. A systematic literature search identified 7 peer-reviewed journal articles describing the efficacy of copper sulfate in hoof baths as treatment or prevention of bovine digital dermatitis. Only 2 of the 7 studies compared copper sulfate to a negative control; most studies were relatively small, and often no clear positive effect of copper sulfate was demonstrated. In conclusion, the frequent claim that copper sulfate is widely reported to be effective is supported by little scientific evidence. Well-designed clinical trials evaluating the effect of copper sulfate against digital dermatitis compared with a negative control are needed. Until such studies have been made, the efficacy of copper sulfate in hoof baths against digital dermatitis remains largely unproven.

  19. Copper sulfates as cathode materials for Li batteries

    NASA Astrophysics Data System (ADS)

    Schwieger, Jonathan N.; Kraytsberg, Alexander; Ein-Eli, Yair

    As lithium battery technology sets out to bridge the gap between portable electronics and the electrical automotive industry, cathode materials still stand as the bottleneck regarding performances. In the realm of highly attractive polyanion-type structures as high-voltage cathode materials, the sulfate group (SO 4) 2- possesses an acknowledged superiority over other contenders in terms of open circuit voltage arising from the inductive effect of strong covalent S-O bonds. In parallel, novel lithium insertion mechanisms are providing alternatives to traditional intercalation, enabling reversible multi-electron processes securing high capacities. Combining both of these advantageous features, we report here the successful electrochemical reactivity of copper sulfate pentahydrate (CuSO 4·5H 2O) with respect to lithium insertion via a two-electron displacement reaction entailing the extrusion of metallic copper at a dual voltage of 3.2 V and 2.7 V followed by its reversible insertion at 3.5 V and 3.8 V. At this stage, cyclability was still shown to be limited due to the irreversible degradation to a monohydrate structure owing to constitutional water loss.

  20. A hybrid water-splitting cycle using copper sulfate and mixed copper oxides

    NASA Technical Reports Server (NTRS)

    Schreiber, J. D.; Remick, R. J.; Foh, S. E.; Mazumder, M. M.

    1980-01-01

    The Institute of Gas Technology has derived and developed a hybrid thermochemical water-splitting cycle based on mixed copper oxides and copper sulfate. Similar to other metal oxide-metal sulfate cycles that use a metal oxide to 'concentrate' electrolytically produced sulfuric acid, this cycle offers the advantage of producing oxygen (to be vented) and sulfur dioxide (to be recycled) in separate steps, thereby eliminating the need of another step to separate these gases. The conceptual process flow-sheet efficiency of the cycle promises to exceed 50%. It has been completely demonstrated in the laboratory with recycled materials. Research in the electrochemical oxidation of sulfur dioxide to produce sulfuric acid and hydrogen performed at IGT indicates that the cell performance goals of 200 mA/sq cm at 0.5 V will be attainable using relatively inexpensive electrode materials.

  1. Are you keeping all your eggs in one basket? Think copper sulfate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    SNARC has been involved with research on copper sulfate for several proposed label claims; this presentation will be about one of the claims, fungus on catfish eggs. A major obstacle in fish hatcheries is the inevitable fungal growth on eggs. Copper sulfate is commonly used for fungus control in c...

  2. Di-sulfated Keratan Sulfate as a Novel Biomarker for Mucopolysaccharidosis II, IVA, and IVB.

    PubMed

    Shimada, Tsutomu; Tomatsu, Shunji; Mason, Robert W; Yasuda, Eriko; Mackenzie, William G; Hossain, Jobayer; Shibata, Yuniko; Montaño, Adriana M; Kubaski, Francyne; Giugliani, Roberto; Yamaguchi, Seiji; Suzuki, Yasuyuki; Orii, Kenji E; Fukao, Toshiyuki; Orii, Tadao

    2015-01-01

    Keratan sulfate (KS) is a storage material in mucopolysaccharidosis IV (MPS IV). However, no detailed analysis has been reported on subclasses of KS: mono-sulfated KS and di-sulfated KS. We established a novel method to distinguish and quantify mono- and di-sulfated KS using liquid chromatography-tandem mass spectrometry and measured both KS levels in various specimens.Di-sulfated KS was dominant in shark cartilage and rat serum, while mono-sulfated KS was dominant in bovine cornea and human serum. Levels of both mono- and di-sulfated KS varied with age in the blood and urine from control subjects and patients with MPS II and IVA. The mean levels of both forms of KS in the plasma/serum from patients with MPS II, IVA, and IVB were elevated compared with that in age-matched controls. Di-sulfated KS provided more significant difference between MPS IVA and the age-matched controls than mono-sulfated KS. The ratio of di-sulfated KS to total KS in plasma/serum increased with age in control subjects and patients with MPS II but was age independent in MPS IVA patients. Consequently, this ratio can discriminate younger MPS IVA patients from controls. Levels of mono- and di-sulfated KS in urine of MPS IVA and IVB patients were all higher than age-matched controls for all ages studied.In conclusion, the level of di-sulfated KS and its ratio to total KS can distinguish control subjects from patients with MPS II, IVA, and IVB, indicating that di-sulfated KS may be a novel biomarker for these disorders.

  3. Photochemical properties of copper(II)-amino acid complexes

    SciTech Connect

    Natarajan, P.; Ferraudi, G.

    1981-11-01

    The photochemistry of copper(II)-amino acid complexes (amino acid = glutamic acid, ..beta..-alanine, or glycine) has been investigated by continuous and flash photolysis. The charge-transfer irradiations induce the oxidation of the ligand and the reduction of copper(II) to copper(I). Transients observed in flash photolysis have been assigned as copper-alkyl complexes. Moreover, other copper-alkyl species are produced when carbon-centered radicals react with excess of copper(II) complexes. The photochemical properties of the copper(II)-amino acid complexes are discussed in terms of population of charge transfer to copper excited states.

  4. DNA damage in leukocytes of mice treated with copper sulfate.

    PubMed

    Saleha Banu, B; Ishaq, Mohd; Danadevi, K; Padmavathi, P; Ahuja, Y R

    2004-12-01

    Single stranded DNA breaks induced by copper sulfate (CuSO(4)) in mice has been studied in vivo using Alkaline Single Cell Gel Electrophoresis (Comet assay). Mice were administered orally with doses of 0, 1.25, 2.50, 5.00, 7.50, 10.00 and 12.50 mg/kg body weight (b.wt.) of CuSO4 respectively. The samples of whole blood were collected at 24, 48, 72 h, first week and second week post-treatment and the assay was carried out to determine single strand DNA breaks as represented by comet tail-length. In addition, the sample was used to study the repair efficiency by incubating the samples with RPMI medium for 2 h. Results indicated a significant DNA damage at all the doses after treatment with CuSO4 when compared to controls showing a clear dose-dependent response (p < 0.05). A gradual decrease in the tail-lengths from 48 h post-treatment was observed and by second week, the values returned to control levels at all doses. The study on the repair efficiency indicated that mice treated with all the doses of CuSO4 showed decrease in mean comet tail-length indicating repair efficiency capacity but less when compared to those of controls. The study also reveals that comet assay is a sensitive and rapid method for detecting DNA damage caused by trace metals such as copper (Cu). PMID:15500930

  5. Copper(II) thiaethyneporphyrin and copper(II) 21-phosphoryl N-confused porphyrin hybrids. intramolecular copper(II)-carbon interaction inside of a porphyrinoid surrounding.

    PubMed

    Grzegorzek, Norbert; Nojman, Elżbieta; Szterenberg, Ludmiła; Latos-Grażyński, Lechosław

    2013-03-01

    Stabilization of unusual organocopper(II) species via the very efficient protection of the copper(II)-carbon bond has been achieved encapsulating the copper(II) center in the coordination core of suitably constructed carbaporphyrinoids. Copper(II) was inserted into hybrid N-confused porphyrins which contain 21-diphenylphosphoryl-, 21-diphenylthiophosphoryl-, or 21-phosphinodithioic substituents or into 20-thiaethyneporphyrin, an aromatic porphyrinoid, which combines two structural motifs of 21-thiaporphyrin and ethyne. Two distinctly different types of the copper(II)-carbon bond have been detected. Copper(II) hybrid N-confused porphyrins reveal the η(1)-C(21) side-on coordination. The unprecedented equatorial metal(II)···η(2)-CC interaction has been trapped in a copper(II) thiaethyneporphyrin surrounding.

  6. Copper(II)-quenched oligonucleotide probes for fluorescent DNA sensing.

    PubMed

    Brunner, Jens; Kraemer, Roland

    2004-10-27

    A copper(II)-quenched molecular beacon was prepared by attaching fluorescein to the 3'-end and a copper(II) complex to the 5'-end of DNA. In the presence of complementary DNA, copper(II) and dye are spatially separated in the duplex and fluorescence increases up to 15-fold, with excellent discrimination of single base mismatches.

  7. Side effects of 58 years of copper sulfate treatment of the Fairmont Lakes, Minnesota

    SciTech Connect

    Hanson, M.J.; Stefan, H.G.

    1984-12-01

    The shallow Fairmont Lakes in Southern Minnesota have been treated with copper sulfate for 58 years to reduce excessive algal growth. Copper sulfate was applied to five lakes at cumulative rates up to 1647 kg/ha (1470 lb/acre), totaling 1.5 million kilograms. Data collected since treatment of the Fairmont Lakes began in 1921 provide alarming insights into lake responses to sustained chemical treatment with copper sulfate. Short-term and long-term effects have occurred. Short-term effects include: a) the intended temporary killing of algae, b) dissolved oxygen depletion by decomposition of dead algae, c) accelerated phosphorus recycling from the lake bed and recovery of the agal population within 7 to 21 days, and d) occasional fish kills due to oxygen depletion or copper toxicity or both. Long-term effects are shown to include: a) copper accumulation in the sediments, b) tolerance adjustments of certain species of algae to higher copper sulfate dosages, c) shift of species from green to blue-green algae and from game fish to rough fish, d) disappearance of macrophytes, and e) reductions in benthic macroinvertebrates. The conclusion is that while copper sulfate treatments enjoy great popularity because they kill and remove algae almost instantaneously, other immediate or cumulative side effects can be harmful to many other aquatic organisms.

  8. Induction of phase II enzymes and hsp70 genes by copper sulfate through the electrophile-responsive element (EpRE): insights obtained from a transgenic zebrafish model carrying an orthologous EpRE sequence of mammalian origin.

    PubMed

    Almeida, Daniela Volcan; Nornberg, Bruna Félix da Silva; Geracitano, Laura A; Barros, Daniela Martí; Monserrat, José Maria; Marins, Luis Fernando

    2010-09-01

    We have evaluated the homology of the electrophile-responsive element (EpRE) core sequence, a binding site for the Nrf2 transcription factor, in the proximal promoters of the mouse and zebrafish glutathione-S-transferase (gst), glutamate cysteine ligase catalytic subunit (gclc) and heat shock protein 70 (hsp70) genes. The EpRE sites identified for both species in the three analyzed genes showed a high similarity with the putative EpRE core sequence. We also produced a transgenic zebrafish model carrying a transgene comprised of the luciferase (luc) reporter gene under transcriptional control of a mouse EpRE sequence. This transgenic model was exposed to copper sulfate, and the reporter gene was significantly activated. The endogenous gst, gclc and hsp70 zebrafish genes were analyzed in the EpRE-Luc transgenic zebrafish and showed an expression pattern similar to that of the reporter transgene used. Our results demonstrate that EpRE is conserved between mouse and zebrafish for detoxification-related genes and that the development of genetically modified models using this responsive element to drive the expression of reporter genes can be an important tool in understanding the action mechanism of aquatic pollutants. PMID:19116768

  9. trans-Bis(hexafluoroantimonato)(phthalocyaninato)copper(II).

    PubMed

    Gardberg, A S; Ibers, J A

    2001-05-01

    The title compound, trans-bis(hexafluoroantimonato-F)(phthalocyaninato-kappa(4)N(29,30,31,32))copper(II), [Cu(SbF(6))(2)(C(32)H(16)N(8))] or Cu(pc)(SbF(6))(2) (pc is phthalocyaninate), comprises a six-coordinate Cu atom, lying on an inversion center, bonded to four N atoms of a phthalocyanine ring and to F atoms of two trans SbF(6)(-) groups. The compound is presumed to consist of a Cu(II) center and a doubly oxidized phthalocyanine ring, by analogy with Cu(pc)(ReO(4))(2).

  10. Toxicity of copper sulfate and rotenone to Chinese mystery snail (Bellamya chinensis)

    USGS Publications Warehouse

    Haak, Danielle M.; Stephen, Bruce J.; Kill, Robert A.; Smeenk, Nicholas A.; Allen, Craig R.; Pope, Kevin L.

    2014-01-01

    The Chinese mystery snail (Bellamya chinensis) is a freshwater snail native to Southeast Asia, Japan, and Russia and is currently classified as an invasive species in at least 27 states in the USA. The species tolerates a wide range of environmental conditions, making management of established populations difficult. We tested the efficacy of two traditional chemical treatments, rotenone and copper sulfate, on the elimination of adult Chinese mystery snails in laboratory experiments. All snails (N=50) survived 72-hour exposure to rotenone-treated lake water, and 96% (N=25) survived 72-hour exposure to pre-determined rotenone concentrations of 0.25, 2.5, and 25.0 mg/L. All snails (N=10) survived exposure to 1.25 mg/L copper sulfate solution, 90% (N=10) survived exposure to 2.50 mg/L copper sulfate solution, and 80% (N=5) survived exposure to 5.0 mg/L copper sulfate solution. Neither rotenone nor copper sulfate effectively killed adult Chinese mystery snails in laboratory experiments, most likely due to their relatively large size, thick shell, and operculum. Therefore, it appears that populations will be very difficult to control once established, and management should focus on preventing additional spread or introductions of this species.

  11. Synergistic effects between sodium tripolyphosphate and zinc sulfate in corrosion inhibition for copper in neutral tap water

    SciTech Connect

    Feng, Y.; Siow, K.S.; Teo, W.K.; Tan, K.L.; Hsieh, A.K.

    1997-07-01

    The corrosion inhibition behavior of sodium tripolyphosphate (Na{sub 5}P{sub 3}O{sub 10}, or TPP) and zinc sulfate and the synergistic effects between them were studied for copper in neutral simulated tap water using electrochemical methods, x-ray photoelectron spectroscopy, and scanning electron microscopy. Zn{sup 2+} alone showed few inhibiting effects on copper corrosion. The film formed in the presence of Zn{sup 2+} was porous and composed mainly of cuprous oxide, which was similar in morphology and composition to films formed in the absence of the inhibitor. In the presence of TPP, a smooth and compact film, believed to be of Cu(II)-TPP compounds, formed on the copper surface. More protective films were formed in solutions containing TPP and Zn{sup 2+} as a blend. High zinc content (15% to 19%) was detected by XPS. Synergistic effects of TPP and Zn{sup 2+} were believed to result from formation of Zn(II)-TPP compounds that incorporated in the films, with Cu(II)-TPP in the upper layer and Cu{sub 2}O in the inner layer. The zinc compounds increased the anodic diffusion resistance of copper ions in the films and enhanced polarization of the cathodic reduction of dissolved oxygen.

  12. A Copper-Sulfate-Based Inorganic Chemistry Laboratory for First-Year University Students That Teaches Basic Operations and Concepts

    NASA Astrophysics Data System (ADS)

    Rodríguez, Emilio; Vicente, Miguel Angel

    2002-04-01

    An integrated inorganic chemistry laboratory experiment for first-year students in Chemistry and Chemical Engineering is presented. It is based on copper sulfate and structured for a duration of about 10 hours, and has three steps: purification of a natural ore containing copper sulfate and insoluble basic copper sulfates, determination of the number of water molecules in hydrated copper sulfate, and recovery of metallic copper from copper sulfate. Many basic operations and concepts related to this experiment are studied: weighing; heating; filtration (simple and vacuum-assisted); purification; crystallization; pure compounds and mixtures; hydrated and anhydrous salts; solubility; unsaturated (dilute and concentrated), saturated, and supersaturated solutions; adsorbed and crystallization water; reversible dehydration; redox reaction; electrode potential; free energy; spontaneity; and catalysis.

  13. Anodonta imbecillis copper sulfate reference toxicant test, Clinch River - Environmental Restoration Program (CR-ERP)

    SciTech Connect

    Simbeck, D.J.

    1997-06-01

    Reference toxicant testing using juvenile freshwater mussels was conducted as part of the CR-ERP biomonitoring study of Clinch River sediments to assess the sensitivity of test organisms and the overall performance of the test. Tests were conducted using moderately hard synthetic water spiked with known concentrations of copper as copper sulfate. Toxicity testing of copper sulfate reference toxicant was conducted from May 12-21, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Results from this test showed an LC{sub 50} value of 1.12 mg Cu/L which is lower than the value of 2.02 mg Cu/L obtained in a previous test. Too few tests have been conducted with copper as the toxicant to determine a normal range of values.

  14. Effects of copper sulfate supplement on growth, tissue concentration, and ruminal solubilities of molybdenum and copper in sheep fed low and high molybdenum diets

    SciTech Connect

    Ivan, M.; Veira, D.M.

    1985-01-01

    Each of four groups of six wethers were fed one of a low molybdenum, high molybdenum, high molybdenum plus copper sulfate, or high molybdenum plus copper sulfate corn silage-based diet for ad libitum intake for 221 days. Average daily gains and ratios of feed/gain were depressed for the high molybdenum diet as compared with the low molybdenum diet suggesting molybdenum toxicity in sheep fed the high molybdenum diet. This was alleviated partly by the copper sulfate supplement. The supplement also decreased solubility of both copper and molybdenum in the rumen but had no effect on copper concentration in blood plasma. Concentration of molybdenum was higher in both liver and kidney in sheep fed high-molybdenum diets as compared with low-molybdenum diets. Copper concentration was higher in kidneys of sheep fed high-molybdenum diets, but no difference was significant in liver copper between sheep fed diets high or low in molybdenum.

  15. Nickel, manganese and copper removal by a mixed consortium of sulfate reducing bacteria at a high COD/sulfate ratio.

    PubMed

    Barbosa, L P; Costa, P F; Bertolino, S M; Silva, J C C; Guerra-Sá, R; Leão, V A; Teixeira, M C

    2014-08-01

    The use of sulfate-reducing bacteria (SRB) in passive treatments of acidic effluents containing heavy metals has become an attractive alternative biotechnology. Treatment efficiency may be linked with the effluent conditions (pH and metal concentration) and also to the amount and nature of the organic substrate. Variations on organic substrate and sulfate ratios clearly interfere with the biological removal of this ion by mixed cultures of SRB. This study aimed to cultivate a mixed culture of SRB using different lactate concentrations at pH 7.0 in the presence of Ni, Mn and Cu. The highest sulfate removal efficiency obtained was 98 %, at a COD/sulfate ratio of 2.0. The organic acid analyses indicated an acetate accumulation as a consequence of lactate degradation. Different concentrations of metals were added to the system at neutral pH conditions. Cell proliferation and sulfate consumption in the presence of nickel (4, 20 and 50 mg l(-1)), manganese (1.5, 10 and 25 mg l(-1)) and copper (1.5, 10 and 25 mg l(-1)) were measured. The presence of metals interfered in the sulfate biological removal however the concentration of sulfide produced was high enough to remove over 90 % of the metals in the environment. The molecular characterization of the bacterial consortium based on dsrB gene sequencing indicated the presence of Desulfovibrio desulfuricans, Desulfomonas pigra and Desulfobulbus sp. The results here presented indicate that this SRB culture may be employed for mine effluent bioremediation due to its potential for removing sulfate and metals, simultaneously.

  16. Nickel, manganese and copper removal by a mixed consortium of sulfate reducing bacteria at a high COD/sulfate ratio.

    PubMed

    Barbosa, L P; Costa, P F; Bertolino, S M; Silva, J C C; Guerra-Sá, R; Leão, V A; Teixeira, M C

    2014-08-01

    The use of sulfate-reducing bacteria (SRB) in passive treatments of acidic effluents containing heavy metals has become an attractive alternative biotechnology. Treatment efficiency may be linked with the effluent conditions (pH and metal concentration) and also to the amount and nature of the organic substrate. Variations on organic substrate and sulfate ratios clearly interfere with the biological removal of this ion by mixed cultures of SRB. This study aimed to cultivate a mixed culture of SRB using different lactate concentrations at pH 7.0 in the presence of Ni, Mn and Cu. The highest sulfate removal efficiency obtained was 98 %, at a COD/sulfate ratio of 2.0. The organic acid analyses indicated an acetate accumulation as a consequence of lactate degradation. Different concentrations of metals were added to the system at neutral pH conditions. Cell proliferation and sulfate consumption in the presence of nickel (4, 20 and 50 mg l(-1)), manganese (1.5, 10 and 25 mg l(-1)) and copper (1.5, 10 and 25 mg l(-1)) were measured. The presence of metals interfered in the sulfate biological removal however the concentration of sulfide produced was high enough to remove over 90 % of the metals in the environment. The molecular characterization of the bacterial consortium based on dsrB gene sequencing indicated the presence of Desulfovibrio desulfuricans, Desulfomonas pigra and Desulfobulbus sp. The results here presented indicate that this SRB culture may be employed for mine effluent bioremediation due to its potential for removing sulfate and metals, simultaneously. PMID:24710619

  17. Bioremediation of copper-containing wastewater by sulfate reducing bacteria coupled with iron.

    PubMed

    Bai, He; Kang, Yong; Quan, Hongen; Han, Yang; Sun, Jiao; Feng, Ying

    2013-11-15

    In order to treat copper-containing wastewater effectively using sulfate reducing bacteria (SRB), iron (Fe(0)) was added to enhance the activity of SRB. The SRB system and the SRB + Fe(0) system were operated under continuous operation. The sulfate reduction efficiency of the SRB + Fe(0) system was twice as much as that of the SRB system with the sulfate loading rate at 125  mg L(-1) h(-1). The effect of COD/SO4(2-) on sulfate reduction indicates an enhanced activity of SRB by adding Fe(0). 99% of total sulfate was deducted in both systems at pH 4.0-7.0, and temperature slightly influenced the removal of sulfate in the SRB + Fe(0) system. In the copper-containing wastewater treatment, the SRB + Fe(0) system shows a better performance since sulfate removal in this system was higher than the SRB system, and the removal ratio of Cu(2+) was held above 95% in SRB + Fe(0) system at all influent Cu(2+) concentrations.

  18. Egg saprolegniasis in a commercial sunshine bass hatchery: Control regime developed using copper sulfate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An obstacle to sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) larval production is fungal growth on eggs caused by the water-mold Saprolegnia spp. Copper sulfate (CuSO4) is commonly used for fungus control in troughs of catfish hatcheries, but the effectiveness o...

  19. Use of copper sulfate to control Saprolegniasis at a commercial sunshine bass hatchery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An obstacle to sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) larval production is fungal growth on eggs caused by the water-mold Saprolegnia spp. Copper sulfate (CuSO4) is commonly used for fungus control in troughs of catfish hatcheries, but the effectiveness o...

  20. The effect of copper sulfate, potassium permanganate, and peracetic acid on Ichthyobodo necator in channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ichthyobodo necator is a single celled biflagellate that can cause significant mortalities in fish, particularly young, tank-reared fish. Copper sulfate (CuSO4), potassium permanganate (KMnO4) and peracetic acid (PAA) were evaluated for effectiveness against Ichthybodosis in juvenile channel catfis...

  1. DEVELOPMENTAL TOXICITY OF COPPER SULFATE AND METHYLENE CHLORIDE TO SHRIMP EMBRYOS

    EPA Science Inventory

    The embryos of the grass shrimp (Palaemonetes pugio) have shown sensitivity to the water-soluble fraction of Number 2 fuel oil which indicates they may be a useful test species in estuarine developmental toxicity tests. Detailed concentration-response curves for copper sulfate an...

  2. Use of copper sulfate and peracetic acid as therapeutants on fish: can these replace formalin?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copper sulfate (CuSO4) and peracetic acid (PAA) are compounds that have been found to be useful in several areas of aquaculture around the world. In the United States, CuSO4 is used for treatment of an ectoparasite (Ichthyophthirius multifiliis) on fish (Straus 1993; Tieman and Goodwin 2001), and s...

  3. Treating sunshine bass eggs with copper sulfate controls fungus and increases survival

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major obstacle to sunshine bass production is fungal growth on eggs. Copper sulfate (CuSO4) is commonly used for fungus control in channel catfish hatcheries that use troughs, but the effectiveness of it on fish eggs hatched using different systems was not known. Female white bass Morone chrysop...

  4. Copper sulfate controls fungus on sunshine bass eggs and increases survival

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major obstacle to sunshine bass production is fungal growth on eggs. Copper sulfate (CuSO4) is commonly used for fungus control in channel catfish hatcheries that use troughs, but the effectiveness of it on fish eggs hatched using different systems was not known. Female white bass Morone chrysop...

  5. Using copper sulfate on hybrid striped bass eggs to control fungus and increase survival

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major obstacle in fish hatcheries is the inevitable fungal growth on eggs. Copper sulfate (CuSO4) is commonly used for fungus control in channel catfish hatcheries that use troughs, but effectiveness on fish eggs hatched using different systems has only recently been investigated. Fish were spawn...

  6. Using copper sulfate on hybrid striped bass eggs to control fungus and increase survival

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major obstacle in fish hatcheries is reduced hatch rates due to fungal growth on eggs. Copper sulfate (CuSO4) is commonly used for fungus control in catfish hatcheries that use troughs, but effectiveness on other species of fish eggs in different hatching systems has only recently been investigat...

  7. Impact of Copper Sulfate on Plankton in Channel Catfish Nursery Ponds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many fish culturists are interested in applying copper sulfate pentahydrate (CSP) to channel catfish, Ictalurus punctatus, nursery ponds as a prophylactic treatment for trematode infection and proliferative gill disease by killing snails and Dero sp., respectively, before stocking fry. However, copp...

  8. Using copper sulfate to control egg fungus at Keo Fish Farm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keo Fish Farm is the biggest producer of hybrid striped bass fry in the world. The hatchery manager asked about treatments to control fungus on eggs which occurred fairly often. Our lab has been working on gaining FDA-approval to use copper sulfate to control fungus on catfish eggs, so we were con...

  9. The use of copper sulfate in catfish hatcheries: safety and effectiveness

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copper sulfate (CuSO4) is cheap, safe to the applicator and effective for controlling fungus on catfish eggs. Several studies were designed to determine the effectiveness and safety of CuSO4 to channel catfish eggs in pursuit of an FDA approval. In an effectiveness study for the FDA, we found that ...

  10. Copper sulfate toxicity to two isolates of Ichthyophthirius multifiliis relative to alkalinity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Theronts from two different strains of Ichthyophthirius multifiliis (AR1 and G5) were exposed to copper sulfate in waters of different total alkalinities and observed for 4 h to determine relative toxicity and kinetics of parasite mortality. Consistent with the known solubility properties of the me...

  11. Using a computer model to calculate copper sulfate treatments for Ich

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copper sulfate (CuSO4) is often used to control infestations of Ichthyophthirius multifiliis (Ich) in pond aquaculture in the United States. In this study, we determined the acute toxicity of CuSO4 to the free-swimming theronts of Ich in reconstituted waters. Water chemistry characteristics, inclu...

  12. Novel copper (II) alginate hydrogels and their potential for use as anti-bacterial wound dressings.

    PubMed

    Klinkajon, Wimonwan; Supaphol, Pitt

    2014-08-01

    The incorporation of a metal ion, with antimicrobial activity, into an alginate dressing is an attractive approach to minimize infection in a wound. In this work, copper (II) cross-linked alginate hydrogels were successfully prepared using a two-step cross-linking procedure. In the first step, solid alginate films were prepared using a solvent-casting method from soft gels of alginate solutions that had been lightly cross-linked using a copper (II) (Cu(2+)) sulfate solution. In the second step, the films were further cross-linked in a corresponding Cu(2+) sulfate solution using a dipping method to further improve their dimensional stability. Alginate solution (at 2%w/v) and Cu(2+) sulfate solution (at 2%w/v) in acetate buffer at a low pH provided soft films with excellent swelling behavior. An increase in either Cu(2+) ion concentration or cross-linking time led to hydrogels with more densely-cross-linked networks that limited water absorption. The hydrogels clearly showed antibacterial activity against Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis and Streptococcus pyogenes, which was proportional to the Cu(2+) ion concentration. Blood coagulation studies showed that the tested copper (II) cross-linked alginate hydrogels had a tendency to coagulate fibrin, and possibly had an effect on pro-thrombotic coagulation and platelet activation. Conclusively, the prepared films are likely candidates as antibacterial wound dressings.

  13. Novel copper (II) alginate hydrogels and their potential for use as anti-bacterial wound dressings.

    PubMed

    Klinkajon, Wimonwan; Supaphol, Pitt

    2014-08-01

    The incorporation of a metal ion, with antimicrobial activity, into an alginate dressing is an attractive approach to minimize infection in a wound. In this work, copper (II) cross-linked alginate hydrogels were successfully prepared using a two-step cross-linking procedure. In the first step, solid alginate films were prepared using a solvent-casting method from soft gels of alginate solutions that had been lightly cross-linked using a copper (II) (Cu(2+)) sulfate solution. In the second step, the films were further cross-linked in a corresponding Cu(2+) sulfate solution using a dipping method to further improve their dimensional stability. Alginate solution (at 2%w/v) and Cu(2+) sulfate solution (at 2%w/v) in acetate buffer at a low pH provided soft films with excellent swelling behavior. An increase in either Cu(2+) ion concentration or cross-linking time led to hydrogels with more densely-cross-linked networks that limited water absorption. The hydrogels clearly showed antibacterial activity against Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis and Streptococcus pyogenes, which was proportional to the Cu(2+) ion concentration. Blood coagulation studies showed that the tested copper (II) cross-linked alginate hydrogels had a tendency to coagulate fibrin, and possibly had an effect on pro-thrombotic coagulation and platelet activation. Conclusively, the prepared films are likely candidates as antibacterial wound dressings. PMID:25029588

  14. Metallothionein (MT) induction in channel catfish following treatment with therapeutic levels of copper sulfate

    SciTech Connect

    Schlenk, D.; Perkins, E.J.; Griffin, B.

    1995-12-31

    Copper sulfate is regularly used in the aquaculture industry for the treatment of various ectoparasitic infestations. Male and female Channel catfish (Ictlurus punctatus) were treated for 8 weeks with three therapeutic doses of copper sulfate (1.7, 2.7 and 3.6 mg/L). Liver, gill, spleen, and gonads were dissected from 6 fish sampled at two week intervals. Samples were frozen and will be analyzed for MT in each tissue. Total MT will be measured by ELISA using antibodies raised against the first 10 amino acid residues which are conserved in fish. MT mRNA will also be measured in each tissue by the Ribonuclease Protection Assay using winter flounder CDNA and compared to protein measurements during the exposure period. MT levels also will be compared to total copper accumulation levels in each fish.

  15. Comparison of the toxicity of two chelated copper algaecides and copper sulfate to non-target fish.

    PubMed

    Closson, K R; Paul, E A

    2014-12-01

    New pesticide products are reviewed by the United States Environmental Protection Agency for possible effects to non-target aquatic organisms. The required toxicity data are for the active ingredient only, and fail to include toxicity of the mixture of other ingredients found in these pesticides. These ingredients may increase the toxicity of the active ingredient to non-target organisms. Our study compares the toxicity of two formulations of chelated copper algaecides with each other, and to a copper sulfate algaecide. We were particularly interested in the effects of a surfactant that is present in one of the formulations. We found that copper becomes less toxic to fish (e.g. fathead minnow 48-h LC50 = 0.90 mg/L) when it is chelated, providing an additional margin of safety to non-target fish compared to copper sulfate. However, inclusion of a surfactant to the formulation resulted in increased toxicity (e.g. fathead minnow 48-h LC50 = 0.30 mg/L).

  16. Effects of copper sulfate on seedlings of Prosopis pubescens (screwbean mesquite).

    PubMed

    Zappala, Marian N; Ellzey, Joanne T; Bader, Julia; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge

    2014-01-01

    Phytoextraction is an established method of removal of heavy metals from contaminated soils worldwide. Phytoextraction is most efficient if local plants are used in the contaminated site. We propose that Prosopis pubescens (Screw bean mesquite) would be a successful phytoextractor of copper in our local soils. In order to determine the feasibility of using Screw bean mesquite, we utilized inductively-coupled plasma-optical emission spectroscopy (ICP-OES) and elemental analysis to observe the uptake of copper and the effects on macro and micro nutrients within laboratory-grown seedlings. We have previously shown that P. pubescens is a hyperaccumulator of copper in soil-grown seedlings. Light and transmission electron microscopy demonstrated death of root cells and ultrastructural changes due to the presence of copper from 50 mg/L - 600 mg/L. Ultrastructural changes included plasmolysis, starch accumulation, increased vacuolation and swollen chloroplasts with disarranged thylakoid membranes in cotyledons. Inductively coupled plasma-optical emission spectroscopy analyses of macro- and micro-nutrients revealed that the presence of copper sulfate in the growth medium of Petri-dish grown Prosopis pubescens seedlings resulted in dramatic decreases of magnesium, potassium and phosphorus. At 500-600 mg/L of copper sulfate, a substantial increase of sulfur was present in roots. PMID:24933900

  17. Effects of copper sulfate on seedlings of Prosopis pubescens (screwbean mesquite).

    PubMed

    Zappala, Marian N; Ellzey, Joanne T; Bader, Julia; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge

    2014-01-01

    Phytoextraction is an established method of removal of heavy metals from contaminated soils worldwide. Phytoextraction is most efficient if local plants are used in the contaminated site. We propose that Prosopis pubescens (Screw bean mesquite) would be a successful phytoextractor of copper in our local soils. In order to determine the feasibility of using Screw bean mesquite, we utilized inductively-coupled plasma-optical emission spectroscopy (ICP-OES) and elemental analysis to observe the uptake of copper and the effects on macro and micro nutrients within laboratory-grown seedlings. We have previously shown that P. pubescens is a hyperaccumulator of copper in soil-grown seedlings. Light and transmission electron microscopy demonstrated death of root cells and ultrastructural changes due to the presence of copper from 50 mg/L - 600 mg/L. Ultrastructural changes included plasmolysis, starch accumulation, increased vacuolation and swollen chloroplasts with disarranged thylakoid membranes in cotyledons. Inductively coupled plasma-optical emission spectroscopy analyses of macro- and micro-nutrients revealed that the presence of copper sulfate in the growth medium of Petri-dish grown Prosopis pubescens seedlings resulted in dramatic decreases of magnesium, potassium and phosphorus. At 500-600 mg/L of copper sulfate, a substantial increase of sulfur was present in roots.

  18. Pharmacokinetic study of copper (II) acetylsalicylate.

    PubMed

    Iqbal, Mohammad S; Sher, Muhammad; Pervez, Humayun; Saeed, Maryiam

    2008-09-01

    This study was aimed at determination of pharmacokinetic parameters of copper (II) acetylsalicylate (CAS). Ten volunteers received a 60-mg dose of CAS. Blood samples were collected just before and after 0.25, 0.5, 0.75, 1.0, 1.5, 2.5, 3.0, 3.5, 4.0, 4.5, 5.5, 7.0, 10, and 12.0 h of administration of the drug. The plasma samples were analyzed for CAS and its metabolites by a validated high-performance liquid chromatography method having a suitable lower limit of quantification. The dose of 60 mg was well tolerated without any adverse effect. The maximum plasma concentration of CAS was found to be 0.38 mg L(-1) with t (max) of 0.72 h. The plasma half-life, clearance, and volume of distribution of CAS were 8.67 h, 66.30 L h(-1) and 829 L kg(-1), respectively. The elimination of CAS, acetylsalicylic acid, copper salicylate, and salicylic acid follows the first order kinetics with r (2) 0.979, 0.880, 0.991, and 0.998, respectively. The study provided for the first time the pharmacokinetic data for CAS after oral administration of CAS. The data were found to be useful in understanding the claimed enhanced anti-inflammatory activity of the drug as compared with that of acetylsalicylic acid. PMID:18478192

  19. A copper sulfate and hydroxylysine treatment regimen for enhancing collagen cross-linking and biomechanical properties in engineered neocartilage

    PubMed Central

    Makris, Eleftherios A.; MacBarb, Regina F.; Responte, Donald J.; Hu, Jerry C.; Athanasiou, Kyriacos A.

    2013-01-01

    The objective of this study was to improve the biomechanical properties of engineered neotissues through promoting the development of collagen cross-links. It was hypothesized that supplementing medium with copper sulfate and the amino acid hydroxylysine would enhance the activity of lysyl oxidase enzyme to form collagen cross-links, increasing the strength and integrity of the neotissue. Neocartilage constructs were generated using a scaffoldless, self-assembling process and treated with copper sulfate and hydroxylysine, either alone or in combination, following a 2-factor, full-factorial study design. Following a 6-wk culture period, the biomechanical and biochemical properties of the constructs were measured. Results found copper sulfate to significantly increase pyridinoline (PYR) cross-links in all copper sulfate-containing groups over controls. When copper sulfate and hydroxylysine were combined, the result was synergistic, with a 10-fold increase in PYR content over controls. This increase in PYR cross-links manifested in a 3.3-fold significant increase in the tensile properties of the copper sulfate + hydroxylysine group. In addition, an 123% increase over control values was detected in the copper sulfate group in terms of the aggregate modulus. These data elucidate the role of copper sulfate and hydroxylysine toward improving the biomechanical properties of neotissues through collagen cross-linking enhancement.—Makris, E. A., MacBarb, R. F., Responte, D. J., Hu, J. C., Athanasiou, K. A. A copper sulfate and hydroxylysine treatment regimen for enhancing collagen cross-linking and biomechanical properties in engineered neocartilage. PMID:23457219

  20. Copper-Sulfate Pentahydrate as a Product of the Waste Sulfuric Acid Solution Treatment

    NASA Astrophysics Data System (ADS)

    Marković, Radmila; Stevanović, Jasmina; Avramović, Ljiljana; Nedeljković, Dragutin; Jugović, Branimir; Stajić-Trošić, Jasna; Gvozdenović, Milica

    2012-12-01

    The aim of this study is synthesis of copper-sulfate pentahydrate from the waste sulfuric acid solution-mother liquor generated during the regeneration process of copper bleed solution. Copper is removed from the mother liquor solution in the process of the electrolytic treatment using the insoluble lead anodes alloyed with 6 mass pct of antimony on the industrial-scale equipment. As the result of the decopperization process, copper is removed in the form of the cathode sludge and is precipitated at the bottom of the electrolytic cell. By this procedure, the content of copper could be reduced to the 20 mass pct of the initial value. Chemical characterization of the sludge has shown that it contains about 90 mass pct of copper. During the decopperization process, the very strong poison, arsine, can be formed, and the process is in that case terminated. The copper leaching degree of 82 mass pct is obtained using H2SO4 aqueous solution with the oxygen addition during the cathode sludge chemical treatment at 80 °C ± 5 °C. Obtained copper salt satisfies the requirements of the Serbian Standard for Pesticide, SRPS H.P1. 058. Therefore, the treatment of waste sulfuric acid solutions is of great economic and environmental interest.

  1. Crystal structures of copper(II) nitrate, copper(II) chloride, and copper(II) perchlorate complexes with 2-formylpyridine semicarbazone

    SciTech Connect

    Chumakov, Yu. M.; Tsapkov, V. I.; Antosyak, B. Ya.; Bairac, N. N.; Simonov, Yu. A.; Bocelli, G.; Pahontu, E.; Gulea, A. P.

    2009-05-15

    Compounds dinitrato(2-formylpyridinesemicarbazone)copper (I), dichloro(2-formylpyridinesemicarbazone) copper hemihydrate (II), and bis(2-formylpyridinesemicarbazone)copper(2+) perchlorate hydrate (III) are synthesized and their crystal structures are determined. In compounds I-III, the neutral 2-formylpyridine semicarbazone molecule (L) is tridentately attached to the copper atom via the N,N,O set of donor atoms. In compounds I and II, the Cu: L ratio is equal to 1: 1, whereas, in III, it is 1: 2. In complex I, the coordination sphere of the copper atom includes two nitrate ions with different structural functions in addition to the L ligand. The structure is built as a one-dimensional polymer in which the NO{sub 3} bidentate group fulfills a bridging function. The coordination polyhedron of the copper(2+) atom can be considered a distorted tetragonal bipyramid (4 + 1 + 1). Compound II has an ionic structure in which the main element is the [CuLCl{sub 2} . Cu(H{sub 2}O)LCl]{sup +} dimer. In the dimer, the copper atoms are linked via one of the {mu}{sub 2}-bridging chlorine atoms. The coordination polyhedra of the central atoms of the Cu(H{sub 2})LCl and CuLCl{sub 2} complex fragments are tetragonal bipyramid and tetragonal pyramid, respectively. In compound III, the copper atom is octahedrally surrounded by two L ligands in the mer configuration.

  2. Crystal structures of copper(II) nitrate, copper(II) chloride, and copper(II) perchlorate complexes with 2-formylpyridine semicarbazone

    NASA Astrophysics Data System (ADS)

    Chumakov, Yu. M.; Tsapkov, V. I.; Antosyak, B. Ya.; Bairac, N. N.; Simonov, Yu. A.; Bocelli, G.; Pahontu, E.; Gulea, A. P.

    2009-05-01

    Compounds dinitrato(2-formylpyridinesemicarbazone)copper ( I), dichloro(2-formylpyridinesemicarbazone) copper hemihydrate ( II), and bis(2-formylpyridinesemicarbazone)copper(2+) perchlorate hydrate ( III) are synthesized and their crystal structures are determined. In compounds I- III, the neutral 2-formylpyridine semicarbazone molecule ( L) is tridentately attached to the copper atom via the N,N,O set of donor atoms. In compounds I and II, the Cu: L ratio is equal to 1: 1, whereas, in III, it is 1: 2. In complex I, the coordination sphere of the copper atom includes two nitrate ions with different structural functions in addition to the L ligand. The structure is built as a one-dimensional polymer in which the NO3 bidentate group fulfills a bridging function. The coordination polyhedron of the copper(2+) atom can be considered a distorted tetragonal bipyramid (4 + 1 + 1). Compound II has an ionic structure in which the main element is the [Cu LCl2 · Cu(H2O) LCl]+ dimer. In the dimer, the copper atoms are linked via one of the μ2-bridging chlorine atoms. The coordination polyhedra of the central atoms of the Cu(H2) LCl and Cu LCl2 complex fragments are tetragonal bipyramid and tetragonal pyramid, respectively. In compound III, the copper atom is octahedrally surrounded by two L ligands in the mer configuration.

  3. Relative bioavailability of copper in tribasic copper chloride to copper in copper sulfate for laying hens based on egg yolk and feather copper concentrations.

    PubMed

    Kim, J W; Kim, J H; Shin, J E; Kil, D Y

    2016-07-01

    This experiment was conducted to determine the relative bioavailability (RBV) of Cu in tribasic copper chloride (TBCC) to Cu in copper sulfate (monohydrate form; CuSO4·H2O) for layer diets based on egg yolk and feather Cu concentrations. A total of 252, 72-wk-old Hy-Line Brown laying hens were allotted to 1 of 7 treatments with 6 replicates consisting of 6 hens per replicate in a completely randomized design. Hens were fed corn-soybean meal-based basal diets supplemented with 0 (basal), 100, 200, or 300 mg/kg Cu from CuSO4 or TBCC for 4 wk. Results indicated that egg production, egg weight, and egg mass were not affected by dietary treatments. However, increasing inclusion levels of Cu in diets from CuSO4 decreased (P < 0.05) feed conversion ratio (FCR), whereas increasing inclusion levels of Cu in diets from TBCC did not affect FCR, indicating significant interaction (P < 0.05). Increasing inclusion levels of Cu from TBCC or CuSO4 increased (P < 0.05) Cu concentrations of egg yolk and feathers. Feather Cu concentrations were greater (P < 0.01) for hens fed diets containing CuSO4 than for hens fed diets containing TBCC. The values for the RBV of Cu in TBCC to Cu in CuSO4 based on log10 transformed egg yolk and feather Cu concentrations were 107.4% and 69.5%, respectively. These values for the RBV of Cu in TBCC did not differ from Cu in CuSO4 (100%). The RBV measured in egg yolk did not differ from the RBV measured in feather. In conclusion, the RBV of Cu in TBCC to Cu in CuSO4 can be determined using Cu concentrations of egg yolk and feathers although the values depend largely on target tissues of laying hens. For a practical application, however, the RBV value of Cu in TBCC to Cu in CuSO4 could be 88.5% when the RBV values determined using egg yolk and feather Cu concentrations were averaged. PMID:26944968

  4. Relative bioavailability of copper in tribasic copper chloride to copper in copper sulfate for laying hens based on egg yolk and feather copper concentrations.

    PubMed

    Kim, J W; Kim, J H; Shin, J E; Kil, D Y

    2016-07-01

    This experiment was conducted to determine the relative bioavailability (RBV) of Cu in tribasic copper chloride (TBCC) to Cu in copper sulfate (monohydrate form; CuSO4·H2O) for layer diets based on egg yolk and feather Cu concentrations. A total of 252, 72-wk-old Hy-Line Brown laying hens were allotted to 1 of 7 treatments with 6 replicates consisting of 6 hens per replicate in a completely randomized design. Hens were fed corn-soybean meal-based basal diets supplemented with 0 (basal), 100, 200, or 300 mg/kg Cu from CuSO4 or TBCC for 4 wk. Results indicated that egg production, egg weight, and egg mass were not affected by dietary treatments. However, increasing inclusion levels of Cu in diets from CuSO4 decreased (P < 0.05) feed conversion ratio (FCR), whereas increasing inclusion levels of Cu in diets from TBCC did not affect FCR, indicating significant interaction (P < 0.05). Increasing inclusion levels of Cu from TBCC or CuSO4 increased (P < 0.05) Cu concentrations of egg yolk and feathers. Feather Cu concentrations were greater (P < 0.01) for hens fed diets containing CuSO4 than for hens fed diets containing TBCC. The values for the RBV of Cu in TBCC to Cu in CuSO4 based on log10 transformed egg yolk and feather Cu concentrations were 107.4% and 69.5%, respectively. These values for the RBV of Cu in TBCC did not differ from Cu in CuSO4 (100%). The RBV measured in egg yolk did not differ from the RBV measured in feather. In conclusion, the RBV of Cu in TBCC to Cu in CuSO4 can be determined using Cu concentrations of egg yolk and feathers although the values depend largely on target tissues of laying hens. For a practical application, however, the RBV value of Cu in TBCC to Cu in CuSO4 could be 88.5% when the RBV values determined using egg yolk and feather Cu concentrations were averaged.

  5. Uptake and distribution of copper sulfate and its effect on the respiration rate of the hemocyanin-producing freshwater snail Lymnaea natalensis

    SciTech Connect

    Wolmarans, C.T.; Yssel, E.

    1988-08-01

    Copper sulfate was one of the earliest compounds suggested as a molluscicide and although several new compounds have since been developed, copper sulfate is still widely used against freshwater snail intermediate hosts of trematode parasites causing bilharzia. However, the toxic effect that copper sulfate may have on these species has not yet been investigated adequately. This incomplete picture of the action of copper sulfate on freshwater snails is further complicated by the fact that some of these snail species have hemocyanin (a protein containing copper) as respiration pigment. Because of the existence of a copper metabolic pathway, these species may handle external copper differently from those species with hemoglobin as respiration pigment. In the present study, the uptake of external copper in the form of copper sulfate, as well as the effect of this ion on respiration rate, was investigated in Lymnaea natalensis, the intermediate host of Fasciola gigantica. This snail possesses hemocyanin as respiratory pigment.

  6. Copper(II)-Catalyzed Nitroaldol (Henry) Reactions: Recent Developments.

    PubMed

    Murugavel, Govindarasu; Sadhu, Pradeep; Punniyamurthy, Tharmalingam

    2016-08-01

    Self-assembled copper(II) complexes are described as effective catalysts for nitroaldol (Henry) reactions on water. The protocol involves a heterogeneous process and the catalysts can be recovered and recycled without loss of activity. Further, C2-symmetric N,N'-substituted chiral copper(II) salan complexes are found to be more effective catalysts than chiral copper(II) salen complexes for reactions in homogeneous catalysis, with high enantioselectivities. The reactions involve bifunctional catalysis, bearing the properties of a Brønsted base, as well as a Lewis acid, to effect the reaction in the absence of external additives.

  7. Stimulation of sulfated glycosaminoglycan synthesis by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+.

    PubMed

    Wegrowski, Y; Maquart, F X; Borel, J P

    1992-01-01

    Glycyl-L-histidyl-L-lysine-copper (II) complex (GHK-Cu) is a naturally occurring tripeptide with potential healing properties. We studied the effect of GHK-Cu on the synthesis of glycosaminoglycans (GAGs) by normal human fibroblasts in culture. Cells were incubated with 3H glucosamine and 35S sulfate and the radioactivity of isolated GAGs was determined. GHK-Cu induced a dose-dependent increase of the synthesis of total GAGs secreted into the culture medium and those associated with the cell layer. The effect of GHK-Cu was biphasic with a maximal stimulation at 10(-9) to 10(-8) M. At higher concentrations, the rate of synthesis returned progressively to that of control cultures. Electrophoretic analysis of the different GAG populations showed that GHK-Cu preferentially stimulated the synthesis of extracellular dermatan sulfate and cell layer associated heparan sulfate. No influence of GHK-Cu on the synthesis of hyaluronic acid was observed. GHK-Cu stimulation of GAG synthesis may be one of the phenomenons implicated in the wound healing properties of the peptide. PMID:1522753

  8. X-ray photoelectron spectroscopy of copper(II), copper(I), and mixed valence systems.

    PubMed

    Rupp, H; Weser, U

    1976-01-01

    X-ray photoelectron spectroscopy using copper(II), copper(I) and the mixed valence Cu(II)/Cu(I) compounds was employed as a means of studying electron transfer reactions in copper proteins. The X-ray photoelectron spectra of copper(II) compounds display characteristic satellites of both variable size and resolution. Some of these satellites could be assigned to specific ligand interactions. Unlike electron paramagnetic resonance spectroscopy, the X-ray photoelectron spectroscopic measurements of copper(I) compounds allowed the unequivocal assignment of this oxidation state. No satellites at all could be detected in the Cu(I) spectra. Furthermore, established mixed valence Cu(II)/Cu(I) complexes including Cu2SO3-CuSO3-2H2O and Cu4Cl5 (ethylenediamine)2 proved essentially a mixture of distinct portions of Cu(I) and Cu(II). This indicates that both oxidation states of copper survive in such complexes. In contrast, all Cu X-ray photoelectron signals of the more tentatively described mixed valence complexes Na2Cu3S3 and the mineral covellite, CuI4CuII2(S2)2S2, could be attributed exclusively to Cu(I). In view of the known binding of copper with sulfur in many copper proteins, it was of utmost importance to study the copper-sulfur interactions. We have demonstrated the absence of Cu(II) in CuS. This indicates strong metal-induced polarization of sulfur resulting in electron transfer to copper to yield Cu(I). PMID:953045

  9. Natural attenuation of inorganic pollutants (copper, sulfate) in the aquifer below an industrial site

    NASA Astrophysics Data System (ADS)

    Bourg, A. C. M.; Kedziorek, M. A. M.

    2003-05-01

    The contamination of soils and aquifers by inorganic pollutants is so widespread in industrial sites that it does not seem economically feasible to decontaminate the large areas or soil volumes involved. It is therefore interesting to investigate whether the local environment is capable to attenuate this contamination. Natural attenuation by degradation seems realistic for many organic pollutants. Here we show that it can take place also for inorganic pollutants. The phreatic fill aquifer underlying an industrial plant located on the river banks of the Garonne River is contaminated by acidic water (pH down to 1) and high concentrations of sulfate (up to 50 g/L) and copper (up to 30 g/L). As acid water, rich in Cu and sulfate. migrates away from the contamination source, pH increases due to buffering of aquifer solids, dissolved Cu concentrations decrease by 6 orders of magnitude, while sulfate concentrations decrease little.

  10. Investigation of copper(II) tetrafluoroborate catalysed epoxide opening

    PubMed Central

    Capes, Amy S.; Crossman, Arthur T.; Webster, Lauren A.; Ferguson, Michael A.J.; Gilbert, Ian H.

    2011-01-01

    We report the extension of the copper(II) tetrafluoroborate catalysed opening of epoxides with alcohols to include a wider variety of alcohols, a range of solvents and a method to purify the products from the reaction. PMID:22505782

  11. Removal of copper in an integrated sulfate reducing bioreactor-crystallization reactor system.

    PubMed

    Sierra-Alvarez, Reyes; Hollingsworth, Jeremy; Zhou, Michael S

    2007-02-15

    Removal of copper was investigated using an innovative water treatment system integrating a sulfidogenic bioreactor with a fluidized-bed crystallization reactor containing fine sand to facilitate the recovery of copper as a purified copper-sulfide mineral. The performance of the system was tested using a simulated semiconductor manufacturing wastewater containing high levels of Cu2+ (4-66 mg/L), sulfate, and a mixture of citrate, isopropanol, and polyethylene glycol (Mn 300). Soluble copper removal efficiencies exceeding 99% and effluent copper concentrations averaging 89 micog/L were demonstrated in the two-stage system, with near complete metal removal occurring in the crystallizer. Copper crystals deposited on sand grains were identified as covellite (CuS). The removal of organic constituents did not exceed 70% of the initial chemical oxygen demand due to incomplete degradation of isopropanol and its breakdown product (acetone). Taken as a whole, these results indicate the potential of this novel reactor configuration for the simultaneous removal of heavy metals and organic constituents. The ability of this process to recover heavy metals in a purified form makes it particularly attractive for the treatment of contaminated aqueous streams, including industrial wastewaters and acid mine drainage. PMID:17593752

  12. Copper sulfate affects Nile tilapia (Oreochromis niloticus) cardiomyocytes structure and contractile function.

    PubMed

    de Andrade Waldemarin, Kátia Cristina; Alves, Rosiane Nascimento; Beletti, Marcelo Emílio; Rantin, Francisco Tadeu; Kalinin, Ana Lúcia

    2012-04-01

    Copper sulfate (CuSO(4))is an inorganic chemical product worldwide used as an algaecide and a fungicide in aquaculture and agriculture and being discharged into freshwater environments where it can affect the freshwater fauna, especially fishes. The impact of copper on fish cardiac function was analyzed in two groups of Nile tilapias, Oreochromis niloticus (control group and group exposed to 1 mg l(-1) of CuSO(4) for 96 h). Structural and ultra-structural changes were studied and related to perturbations of the inotropic and chronotropic responses of ventricle strips. Fish of Cu exposed group did not show significant alterations in the medium diameter and in the percentage of collagen in the cardiac myocytes when evaluated through the light microscope. However, the ultrastructural analysis revealed cellular swelling followed by mitochondrial swelling. The myofibrils did not show significant variations among groups. Force contraction was significantly decreased, and rates of time to tension increase (contraction) and decrease (relaxation) were significantly augmented after copper exposure. The results suggest that the copper sulfate impairs the oxidative mitochondrial function and consequently alters the cardiac performance of this species.

  13. The performance of laying hens as affected by copper sulfate and methionine level.

    PubMed

    Christmas, R B; Harms, R H

    1983-02-01

    Two strains of White Leghorn hens were subjected to seven copper treatments that included a negative control for the first week of each of five 28-day periods. The hens were approximately 500 days of age when the experiment began. Copper treatments were assigned to simulate the different levels of copper intake that might result from differences in daily feed intake similar to the practice followed with commercial industry. In order to simulate daily dietary intake ranging from a low of 73 to a high of 136 g per bird, levels of 76, 91, 100, 114, 129, and 143 mg of copper sulfate per kilogram were added to each of the basal diets. Treatments were administered across two methionine levels in a corn-soy basal diet. Hen-day egg production, egg weight, daily feed intake, and feed efficiency values were not affected by dietary levels of copper or methionine. Hens fed diets containing low methionine laid eggs with significantly poorer specific gravity.

  14. Crystal structures of copper(II) chloride, copper(II) bromide, and copper(II) nitrate complexes with pyridine-2-carbaldehyde thiosemicarbazone

    SciTech Connect

    Chumakov, Yu. M.; Tsapkov, V. I.; Jeanneau, E.; Bairac, N. N.; Bocelli, G.; Poirier, D.; Roy, J.; Gulea, A. P.

    2008-09-15

    The crystal structures of chloro-(2-formylpyridinethiosemicarbazono)copper dimethyl sulfoxide solvate (I), bromo-(2-formylpyridinethiosemicarbazono)copper (II), and (2-formylpyridinethiosemicarbazono)copper(II) nitrate dimethyl sulfoxide solvate (III) are determined using X-ray diffraction. In the crystals, complexes I and II form centrosymmetric dimers in which the thiosemicarbazone sulfur atom serves as a bridge and occupies the fifth coordination site of the copper atom of the neighboring complex related to the initial complex through the center of symmetry. In both cases, the coordination polyhedron of the complexing ion is a distorted tetragonal bipyramid. Complex III in the crystal structure forms polymer chains in which the copper atom of one complex forms the coordination bond with the thicarbamide nitrogen atom of the neighboring complex. In this structure, the coordination polyhedron of the central atom is an elongated tetragonal bipyramid. It is established that complexes I-III at a concentration of 10{sup -5} mol/l selectively inhibit the growth of 60 to 90 percent of the cancer tumor cells of the human myeloid leukemia (HL-60).

  15. Mortality Effects of a Copper Smelter Strike and Reduced Ambient Sulfate Particulate Matter Air Pollution

    PubMed Central

    Pope, C. Arden; Rodermund, Douglas L.; Gee, Matthew M.

    2007-01-01

    Background Numerous studies have reported associations between fine particulate and sulfur oxide air pollution and human mortality. Yet there continues to be concern that public policy efforts to improve air quality may not produce actual improvement in human health. Objectives This study retrospectively explored a natural experiment associated with a copper smelter strike from 15 July 1967 through the beginning of April 1968. Methods In the 1960s, copper smelters accounted for approximately 90% of all sulfate emissions in the four Southwest states of New Mexico, Arizona, Utah, and Nevada. Over the 8.5-month strike period, a regional improvement in visibility accompanied an approximately 60% decrease in concentrations of suspended sulfate particles. We collected monthly mortality counts for 1960–1975 and analyzed them using Poisson regression models. Results The strike-related estimated percent decrease in mortality was 2.5% (95% confidence interval, 1.1–4.0%), based on a Poisson regression model that controlled for time trends, mortality counts in bordering states, and nationwide mortality counts for influenza/pneumonia, cardiovascular, and other respiratory deaths. Conclusions These results contribute to the growing body of evidence that ambient sulfate particulate matter and related air pollutants are adversely associated with human health and that the reduction in this pollution can result in reduced mortality. PMID:17520052

  16. The amyloid precursor protein of Alzheimer's disease in the reduction of copper(II) to copper(I)

    PubMed

    Multhaup, G; Schlicksupp, A; Hesse, L; Beher, D; Ruppert, T; Masters, C L; Beyreuther, K

    1996-03-01

    The transition metal ion copper(II) has a critical role in chronic neurologic diseases. The amyloid precursor protein (APP) of Alzheimer's disease or a synthetic peptide representing its copper-binding site reduced bound copper(II) to copper(I). This copper ion-mediated redox reaction led to disulfide bond formation in APP, which indicated that free sulfhydryl groups of APP were involved. Neither superoxide nor hydrogen peroxide had an effect on the kinetics of copper(II) reduction. The reduction of copper(II) to copper(I) by APP involves an electron-transfer reaction and could enhance the production of hydroxyl radicals, which could then attack nearby sites. Thus, copper-mediated toxicity may contribute to neurodegeneration in Alzheimer's disease. PMID:8596911

  17. The Amyloid Precursor Protein of Alzheimer's Disease in the Reduction of Copper(II) to Copper(I)

    NASA Astrophysics Data System (ADS)

    Multhaup, Gerd; Schlicksupp, Andrea; Hesse, Lars; Beher, Dirk; Ruppert, Thomas; Masters, Colin L.; Beyreuther, Konrad

    1996-03-01

    The transition metal ion copper(II) has a critical role in chronic neurologic diseases. The amyloid precursor protein (APP) of Alzheimer's disease or a synthetic peptide representing its copper-binding site reduced bound copper(II) to copper(I). This copper ion-mediated redox reaction led to disulfide bond formation in APP, which indicated that free sulfhydryl groups of APP were involved. Neither superoxide nor hydrogen peroxide had an effect on the kinetics of copper(II) reduction. The reduction of copper(II) to copper(I) by APP involves an electron-transfer reaction and could enhance the production of hydroxyl radicals, which could then attack nearby sites. Thus, copper-mediated toxicity may contribute to neurodegeneration in Alzheimer's disease.

  18. Effects of low molecular weight chondroitin sulfate on type II collagen-induced arthritis in DBA/1J mice.

    PubMed

    Cho, So Yean; Sim, Joon-Soo; Jeong, Choon Sik; Chang, Seung Yeup; Choi, Don Woong; Toida, Toshihiko; Kim, Yeong Shik

    2004-01-01

    In order to evaluate the improvement in the treatment of chronic arthritis, we investigated chondroitin sulfate depolymerization product (low molecular weight chondroitin sulfate, LMWCS) and intact chondroitin sulfate (CS) in vitro and in vivo. LMWCS was prepared by a chemical depolymerization process induced by hydrogen peroxide in the presence of copper salts. LMWCS (300 mg/kg) and CS (1200 mg/kg) were orally administered to DBA/1J mice once daily for 14 d prior to initial immunization with type II collagen. Their elastase activities and the production of cytokines in sera were examined on type II collagen-induced arthritis in DBA/1J mice. We also compared the paracellular transport of LMWCS and CS across Caco-2 cell monolayers and examined the inhibitory effects on elastase activities. LMWCS inhibited elastase activity slightly, but CS did not show inhibition. Hind paw edema was significantly decreased by LMWCS treatment. Levels of anti-type II collagen antibody and tumor necrosis factor-alpha (TNF-alpha) in sera were also reduced by LMWCS treatment but not in case of CS, although no significant difference was observed between LMWCS and CS on interleukin-6 (IL-6) induction. The LMWCS preparation showed preventive effects on the type II collagen-induced arthritis in DBA/1J mice and better permeability through Caco-2 cells. PMID:14709897

  19. Water soluble sodium sulfate nanorods as a versatile template for the designing of copper sulfide nanotubes.

    PubMed

    Das, Gautam; Kakati, Nitul; Lee, Seok Hee; Karak, Niranjan; Yoon, Young Soo

    2014-06-01

    The present study reports the use of water soluble sodium sulfate (Na2SO4) nanorods as a versatile template for generation of tubular copper sulfide (CuS) nanostructures. The Na2SO4 nanorods were synthesized from ammonium sulfate (NH4)2SO4 and sodium hydroxide (NaOH), under refluxing condition. The shape and morphology control of the Na2SO4 nanorods were studied with respect to nature of surfactant used and reactant mole ratio. While, PVP mole ratio was important to obtain homogeneous nanorods. Uniform and stable nanotubes of CuS were than obtained by the dissolution of the nanorods in water. The use of simple chemicals for synthesis of such nanotube templates opens the prospect for wide scale downstream applications. PMID:24738412

  20. Stick–slip behaviour on Au(111) with adsorption of copper and sulfate

    PubMed Central

    Podgaynyy, Nikolay; Wezisla, Sabine; Molls, Christoph; Iqbal, Shahid

    2015-01-01

    Summary Several transitions in the friction coefficient with increasing load are found on Au(111) in sulfuric acid electrolyte containing Cu ions when a monolayer (or submonolayer) of Cu is adsorbed. At the corresponding normal loads, a transition to double or multiple slips in stick–slip friction is observed. The stick length in this case corresponds to multiples of the lattice distance of the adsorbed sulfate, which is adsorbed in a √3 × √7 superstructure on the copper monolayer. Stick–slip behaviour for the copper monolayer as well as for 2/3 coverage can be observed at F N ≥ 15 nN. At this normal load, a change from a small to a large friction coefficient occurs. This leads to the interpretation that the tip penetrates the electrochemical double layer at this point. At the potential (or point) of zero charge (pzc), stick–slip resolution persists at all normal forces investigated. PMID:25977853

  1. Morphometric, structural, and ultrastructural studies of tench (Tinca tinca L. ) hepatocytes after copper sulfate administration

    SciTech Connect

    Roncero, V.; Duran, E.; Soler, F.; Masot, J.; Gomez, L. )

    1992-02-01

    A structural, ultrastructural, and morphometric study was made of the liver parenchyma of 12 adult tench (Tinca tinca, L.) subjected to acute experimental copper sulfate poisoning. The lesions observed were characterized by the accumulation in the cytoplasm of large amounts of hemoglobinemic pigment produced by intense hemolysis, initially in Kuppfer cells and by the last stage of the experiment in hepatocytes. This process became increasingly severe, and culminated in the massive necrosis of large areas of liver parenchyma, which led to the death of tench 12 days after the start of the experiment.

  2. A comparison of zooplankton sampling methods in evaluating copper sulfate toxicity in outdoor microcosms

    SciTech Connect

    Hellenbrandt, S.; La Point, T.W.; Shaw, J.L.; Marshall, S.J.; Ratte, H.T.

    1994-12-31

    Six outdoor microcosms (2m{sup 3}) were used to determine copper sulfate effects on epibenthic and planktonic zooplankton community structure. Microcosms were treated three times with CuSO{sub 4} at 0, 50, 100, 200, 350, 550 {mu}g Cu/L, respectively. Zooplankton was sampled biweekly from July through October 1993. Epibenthic zooplankton was collected with an inverted funnel trap, whereas planktonic zooplankton was sampled with an integrated water column sampler. Samples were sieved through a 35 {mu}m mesh and organisms preserved with 1% Lugol`s solution and later identified to genus or species level. Both communities initially decreased in total abundance at high copper rates. However, recovery started shortly after the final Cu application. Species richness was lowest at high copper concentrations, particularly in the epi-benthic community. Epibenthic zooplankton diversity decreased at high copper rates, whereas planktonic zooplankton diversity did not. Epi-benthic zooplankton may be a sensitive indicator of chemical stress and therefore be used to assess the bioavailability of sediment-bound xenobiotics.

  3. [Biosorption properties of extracellular polymeric substances produced by sulfate-reducing bacteria towards Cu(II) ion].

    PubMed

    Fang, Di; Zhang, Rui-Chang; Zhao, Yang-Guo

    2011-10-01

    The purpose of the present study was to investigate the Cu2+ biosorption properties of extracellular polymeric substances (EPS) produced by sulfate-reducing bacteria. The composition and physicochemical characteristics of EPS were determined. The adsorption characteristics of EPS towards Cu2+ were examined using thermodynamic equilibrium equations and determined by FTIR and SEM-EDS. The EPS was shown to have a strong copper-binding capacity and the biosorption data obtained were well described by the Freundlich isotherm model. The results of FTIR spectra and SEM-EDS confirmed the importance of the C-O-C group, -OH group and carbonyl group from polysaccharides and proteins in Cu2+ sorption by EPS. These findings suggest the potential of EPS produced by sulfate-reducing bacteria for the removal of Cu(II) ion from aqueous solution.

  4. Development of spherical iron(II) sulfate heptahydrate-containing solid particles with sustained drug release.

    PubMed

    Szabó-Révész, Piroska; Farkas, Béla; Gregor, Tamás; Nagy, Kálmán; Pallagi, Edina

    2007-05-01

    The aim of this work was to develop a simple, economic procedure for the manufacturing of coated iron(II) sulfate particles by using a crystallization technique for the development of round particles, followed by coating with a lipophilic material. Several batches of iron(II) sulfate heptahydrate were produced by a cooling crystallization, with variation of the crystallization parameters. The spherical crystals were coated with stearin. The products were characterized for particle size, roundness, bulk density and in vitro drug dissolution. Crystallization was performed from deionized water with no addition of seed crystals and by cooling by applying a linear cooling rate. The developed iron(II) sulfate crystals were round with average diameter of 729+/-165 microm. The best form for the sustained release of iron(II) sulfate was the sample HTP-2 which contained 11% of stearin relative to the iron(II) sulfate. The spherical crystallization of iron(II) sulfate is simple and fast, and does not require a dangerous, expensive solvent. The round particles can coat directly with lipophilic material which results in slow release of iron(II) sulfate and protects the iron(II) from oxidation and inhibits the loss of crystal water. The coated crystals can be filled into capsules to yield the final dosage form.

  5. The Thermal Decomposition of Basic Copper(II) Sulfate.

    ERIC Educational Resources Information Center

    Tanaka, Haruhiko; Koga, Nobuyoshi

    1990-01-01

    Discussed is the preparation of synthetic brochantite from solution and a thermogravimetric-differential thermal analysis study of the thermal decomposition of this compound. Other analyses included are chemical analysis and IR spectroscopy. Experimental procedures and results are presented. (CW)

  6. Spectrophotometric determination of copper(II) with o-bromophenylfluorone.

    PubMed

    Yamaguchi, Takako; Samma, Megumi; Kamino, Shinichiro; Matsushita, Momoka; Hashimoto, Tomoyuki; Fujita, Yoshikazu

    2009-12-01

    A simple, reliable and sensitive spectrophotometric method for the determination of copper(II) was established with o-bromophenylfluorone (OBPF), a novel chemical probe, in the presence of poly(N-vinylpyrrolidone). Beer's law was obeyed in the range of 8-160 ng ml(-1), with an apparent molar absorptivity at 570 nm, the relative standard deviation being 3.64 x 10(5) dm3 mol(-1) cm(-1) and 0.72% (n = 5). This method was applied to the recovery tests of copper(II) in human urine, bovine serum and tap water; the results were satisfactory.

  7. Development of a standardized sediment reference toxicant test using formulated sediment and copper sulfate

    SciTech Connect

    Suedel, B.C.; Hartzell, R.S.; Williams, C.W.; Connelly, R.A.

    1994-12-31

    The lack of suitable reference toxicant tests to assess the condition or health of populations of benthic test organisms is problematic because the precision and accuracy of definitive whole sediment tests cannot be assessed without this reference. To address this need, formulated sediment was prepared to provide a consistent substrate with respect to percent solids, particle size distribution, cation exchange capacity, organic carbon, organic matter, redox potential, and pH. Hyalella azteca and Chironomus tentans were exposed for 96-h to formulated sediment amended with serial dilutions of copper sulfate. Results indicate that (1) formulated sediments can be prepared consistently between batches with minimal variability with respect to sediment characteristics, providing a consistent test substrate; (2) when combined with formulated sediment, copper sulfate is a suitable sediment reference toxicant for assessing the condition and health of H. azteca and C tentans populations; and (3) formulated sediment provides a suitable substrate for H. azteca and C tentans (control survival > 80%). This method provides a means by which the health and sensitivity of benthic test organisms can be assessed and provides a measure of precision within and among laboratories through time.

  8. Histopathological and bacterial study of Persian sturgeon fry, Acipenser persicus (Borodin, 1897) exposed to copper sulfate and potassium permanganate.

    PubMed

    Moshtaghi, Batol; Khara, Hossein; Pazhan, Zabiyollah; Shenavar, Alireza

    2016-09-01

    Persian sturgeon frys were exposed to different concentrations of copper sulfate and potassium permanganate in order to the evaluation of their impacts on bacterial load of skin, gill and surrounding water and also the histopathological alternations of gill tissue. For this purpose, the sublethal doses were determined after a pre-test and then the experiment was done in 4 (for copper sulfate: 0.07, 0.14, 026 and 0.5 mg/l) and 5 (for potassium permanganate: 0.07, 0.14, 026, 0.5 and 1 mg/l) treatments with three replicates inside the glass aquaria. Also, one group without disinfecting drug was considered as control for each experiment. The microbial and histopathological investigations were done after 96 h exposure. According to our results, a range of histopathological alternations were observed in gills tissue including mucus coagulation and secretion, hyperplasia, lamellar necrosis, hyperplasia, lamellar adhesion, haemorrhage, thickening of secondary lamellae, hypertrophy of supporter cartilage, clubbing of gill lamellae and sliming of primary lamellae. The severity of these alternations increased with increasing of the doses of the copper sulfate and potassium permanganate. The bacterial load (CFU/g) of gill, skin and surrounding water was lower in 0.07 mg/l copper sulfate treatment and 1 mg/l potassium permanganate treatment (P < 0.05) than in other treatments. In conclusion, our results showed that the certain doses of the copper sulfate and potassium permanganate have disinfecting effects on bacterial load of gill, skin and surrounding water, although this is along with some histopathological alternations. Also, it seems that the copper sulfate has higher disinfecting power than potassium permanganate. PMID:27605784

  9. Determination of kjeldahl nitrogen in fertilizers by AOAC official methods 978.02: effect of copper sulfate as a catalyst.

    PubMed

    Abrams, Dean; Metcalf, David; Hojjatie, Michael

    2014-01-01

    In AOAC Official Method 955.04, Nitrogen (Total) in Fertilizers, Kjeldahl Method, fertilizer materials are analyzed using mercuric oxide or metallic mercury HgO or Hg) as a catalyst. AOAC Official Methods 970.02, Nitrogen (Total) in Fertilizers is a comprehensive total nitrogen (including nitrate nitrogen) method adding chromium metal. AOAC Official Method 978.02, Nitrogen (Total) in Fertilizers is a modified comprehensive nitrogen method used to measure total nitrogen in fertilizers with two types of catalysts. In this method, either copper sulfate or chromium metal is added to analyze for total Kjeldahl nitrogen. In this study, the part of AOAC Official Method 978.02 that is for nitrate-free fertilizer products was modified. The objective was to examine the necessity of copper sulfate as a catalyst for the nitrate-free fertilizer products. Copper salts are not environmentally friendly and are considered pollutants. Products such as ammonium sulfate, diammonium phosphate, monoammonium phosphate, urea-containing fertilizers such as isobutylene diurea (IBDU), and urea-triazone fertilizer solutions were examined. The first part of the study was to measure Kjeldahl nitrogen as recommended by AOAC Official Method 978.02. The second part of the study was to exclude the addition of copper sulfate from AOAC Official Method 978.02 to examine the necessity of copper sulfate as a catalyst in nitrate-free fertilizers, which was the primary objective. Our findings indicate that copper sulfate can be eliminated from the method with no significant difference in the results for the nitrogen content of the fertilizer products.

  10. Histopathological and bacterial study of Persian sturgeon fry, Acipenser persicus (Borodin, 1897) exposed to copper sulfate and potassium permanganate.

    PubMed

    Moshtaghi, Batol; Khara, Hossein; Pazhan, Zabiyollah; Shenavar, Alireza

    2016-09-01

    Persian sturgeon frys were exposed to different concentrations of copper sulfate and potassium permanganate in order to the evaluation of their impacts on bacterial load of skin, gill and surrounding water and also the histopathological alternations of gill tissue. For this purpose, the sublethal doses were determined after a pre-test and then the experiment was done in 4 (for copper sulfate: 0.07, 0.14, 026 and 0.5 mg/l) and 5 (for potassium permanganate: 0.07, 0.14, 026, 0.5 and 1 mg/l) treatments with three replicates inside the glass aquaria. Also, one group without disinfecting drug was considered as control for each experiment. The microbial and histopathological investigations were done after 96 h exposure. According to our results, a range of histopathological alternations were observed in gills tissue including mucus coagulation and secretion, hyperplasia, lamellar necrosis, hyperplasia, lamellar adhesion, haemorrhage, thickening of secondary lamellae, hypertrophy of supporter cartilage, clubbing of gill lamellae and sliming of primary lamellae. The severity of these alternations increased with increasing of the doses of the copper sulfate and potassium permanganate. The bacterial load (CFU/g) of gill, skin and surrounding water was lower in 0.07 mg/l copper sulfate treatment and 1 mg/l potassium permanganate treatment (P < 0.05) than in other treatments. In conclusion, our results showed that the certain doses of the copper sulfate and potassium permanganate have disinfecting effects on bacterial load of gill, skin and surrounding water, although this is along with some histopathological alternations. Also, it seems that the copper sulfate has higher disinfecting power than potassium permanganate.

  11. Rofecoxib prevents ctdsDNA against damage induced by copper sulfate and ultraviolet B radiation in vitro study

    PubMed Central

    Al-Nimer, Marwan S. M.; Al-Deen, Suad M.; Abdul Lateef, Zainab W.

    2010-01-01

    Rofecoxib is a selective cyclooxygenase COX-2 enzyme inhibitor with chemoprotective effect against cancer in experimental models. This study aimed to investigate the effect of rofecoxib against ctds DNA damage induced by copper ions or ultraviolet (UV)B radiation. Aliquot ctdsDNA samples were incubated with copper sulfate solution (50 nmol) and rofecoxib (0.8 mol) was added either before or after the admixing the ctdsDNA with copper sulfate. In another experimental series, aliquot of ctdsDNA were exposed to UVB radiation for 30 min in absence or presence of rofecoxib. Rofecoxib significantly attenuated the separation of double strands of DNA (detected by increase the absorbance of DNA at 260 nm) induced by Cu ions. Rofecoxib significantly offered protection against UVB-induced DNA damage. It is concluded that rofecoxib offered protection against copper ions or UVB induced-DNA damage via different mechanisms not related to the inhibition COX-2. PMID:24825998

  12. The Synthesis of Copper(II) Carboxylates Revisited

    ERIC Educational Resources Information Center

    Kushner, Kevin; Spangler, Robert E.; Salazar, Ralph A., Jr.; Lagowski, J. J.

    2006-01-01

    An electrochemical synthesis of copper(II) carboxylates has been developed and used in the general chemistry laboratory course for chemistry majors. This synthesis, using nonaqueous solutions, supplements the strategy of providing experiences in synthetic chemistry described by Yoder et al. ("J. Chem. Educ." 1995, 72, 267). (Contains 1 table.)

  13. Copper avoidance and mortality of juvenile brown trout (Salmo trutta) in tests with copper-sulfate-treated water from West Branch Reservoir, Putnam County, New York

    USGS Publications Warehouse

    Baldigo, Barry P.; Baudanza, T.P.

    2001-01-01

    Copper-avoidance tests and acute-toxicity (mortality) tests on hatchery-reared, young-of- the-year brown trout (salmo trutta) were conducted with water from West Branch Reservoir to assess the avoidance response to copper sulfate treatment, which is used occasionally by New York City Department of Environmental Protection to decrease phytoplankton populations in the reservoir. Avoidance-test results indicate that juvenile brown trout tend to avoid dissolved copper concentrations greater than about 55 ?g/L (micrograms per liter), which is the approximate avoidance-response threshold. The mean net avoidance response of brown trout to dissolved copper concentrations of 70 and 100 ?g/L, and possibly 80 ?g/L, was significantly different (at a = 0.1) from the mean net avoidance response of fish to control (untreated) water and to treated water at most other tested concentrations. Mortality-test results indicate that the 96-hr median lethal concentration (LC50) of dissolved copper was 61.5 ?g/L. All (100 percent) of the brown trout died at a dissolved copper concentration of 85 ?g/L, many died at concentrations of 62 ?g/L and 70 ?g/L, and none died in the control waters (7 ?g/L) or at concentrations of 10, 20, or 45 ?g/L. The estimated concentration of dissolved copper that caused fish mortality (threshold) was 53.5 ?g/L, virtually equivalent to the avoidance-response threshold. Additional factors that could affect the copper-avoidance and mortality response of individual brown trout and their populations in West Branch Reservoir include seasonal variations in certain water-quality parameters, copper-treatment regimes, natural fish distributions during treatment, and increased tolerance due to acclimation. These warrant additional study before the findings from this study can be used to predict the effects that copper sulfate treatments have on resident fish populations in New York City reservoirs.

  14. Thermal Decomposition of Copper (II) Calcium (II) Formate

    NASA Astrophysics Data System (ADS)

    Leyva, A. G.; Polla, G.; de Perazzo, P. K.; Lanza, H.; de Benyacar, M. A. R.

    1996-05-01

    The presence of different stages in the thermal decomposition process of CuCa(HCOO) 4has been established by means of TGA at different heating rates, X-ray powder diffraction of quenched samples, and DSC methods. During the first stage, decomposition of one of the two copper formate structural units contained in the unit cell takes place. The presence of CuCa 2(HCOO) 6has been detected. Calcium formate structural units break down at higher temperatures; the last decomposition peak corresponds to the appearance of different calcium-copper oxides.

  15. Copper(II) and nickel(II) binding sites of peptide containing adjacent histidyl residues.

    PubMed

    Grenács, Ágnes; Sanna, Daniele; Sóvágó, Imre

    2015-10-01

    Copper(II) and nickel(II) complexes of the terminally protected nonapeptide Ac-SGAEGHHQK-NH2 modeling the metal binding sites of the (8-16) domain of amyloid-β have been studied by potentiometric, UV-vis, CD and ESR spectroscopic methods. The studies on the mutants containing only one of the histidyl residues (Ac-SGAEGAHQK-NH2, Ac-SGAEGHAQK-NH2) have also been performed. The formation of imidazole and amide coordinated mononuclear complexes is characteristic of all systems with a preference of nickel(II) binding to the His14 site, while the involvement of both histidines in metal binding is suggested in the corresponding copper(II) complexes. The formation of bis(ligand) and dinuclear complexes has also been observed in the copper(II)-Ac-SGAEGHHQK-NH2 system. The results provide further support for the copper(II) binding ability of the (8-16) domain of amyloid-β and support the previous assumptions that via the bis(ligand) complex formation copper(II) ions may promote the formation of the oligomers of amyloid-β.

  16. Synthesis, structure and urease inhibition studies of Schiff base copper(II) complexes with planar four-coordinate copper(II) centers.

    PubMed

    Dong, Xiongwei; Guo, Taolian; Li, Yuguang; Cui, Yongming; Wang, Qiang

    2013-10-01

    Seven new Schiff base copper(II) complexes with planar four-coordinate copper(II) centers have been synthesized and structurally characterized. The solid state structures of complexes 1, 3, 4, 5, 6 and 7 present a square-planar coordination geometry at the metal centers while complex 2 shows a slightly distorted square-planar geometry. Density functional theory calculations have been performed to evaluate the electronic structure of copper(II) complex 7. Inhibition of jack bean urease by copper(II) complexes 1-7 have also been investigated, and potent inhibitory activities with IC50 range of 2.60-17.00μM have been observed for these mononuclear copper(II) complexes. A docking analysis using a DOCK program was conducted to explain the urease inhibitory activity of the copper(II) complexes and the structure-activity relationships were further discussed.

  17. Comparative effects of copper sulfate or potassium permanganate on channel catfish concurrently infected with Flavobacterium columnare and Ichthyobodo necator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An opportunistic study was conducted to determine the effects of two chemical therapeutants on channel catfish (CCF) Ictalurus punctatus concurrently infected Flavobacterium columnare and Ichthyobodo necator. Copper sulfate (CuSO4) and potassium permanganate (KMnO4) were investigated for their abil...

  18. Phosphate effects on copper(II) and lead(II) sorption to ferrihydrite

    NASA Astrophysics Data System (ADS)

    Tiberg, Charlotta; Sjöstedt, Carin; Persson, Ingmar; Gustafsson, Jon Petter

    2013-11-01

    Transport of lead(II) and copper(II) ions in soil is affected by the soil phosphorus status. Part of the explanation may be that phosphate increases the adsorption of copper(II) and lead(II) to iron (hydr)oxides in soil, but the details of these interactions are poorly known. Knowledge about such mechanisms is important, for example, in risk assessments of contaminated sites and development of remediation methods. We used a combination of batch experiments, extended X-ray absorption fine structure (EXAFS) spectroscopy and surface complexation modeling with the three-plane CD-MUSIC model to study the effect of phosphate on sorption of copper(II) and lead(II) to ferrihydrite. The aim was to identify the surface complexes formed and to derive constants for the surface complexation reactions. In the batch experiments phosphate greatly enhanced the adsorption of copper(II) and lead(II) to ferrihydrite at pH < 6. The largest effects were seen for lead(II).

  19. Determination of nitrogen content in milk by the Kjeldahl method using copper sulfate: interlaboratory study.

    PubMed

    Grappin, R; Horwitz, W

    1988-01-01

    Copper sulfate was substituted for mercury as the catalyst in the International Dairy Federation (IDF) Standard 20A:1986 method for the determination of nitrogen content in milk. The substitution was supported by results obtained in an interlaboratory study by 24 laboratories in 12 countries. Each laboratory analyzed 12 test samples of milk as blind duplicates in a double split level design with high, medium, and low nitrogen concentrations. The method protocol requires the concurrent analyses of an ammonium salt solution and a tryptophan solution as internal quality control standards with a minimum nitrogen recovery between 99 and 100% for the former and at least 98% for the latter. The repeatability and reproducibility relative standard deviations are 0.5 and 1%, respectively, for the range 0.35-0.70 g N/100 g. The performance of the laboratories that did not meet the required quality control specifications was clearly poorer than that of those that did meet the specifications.

  20. Determination of nitrogen content in milk by the Kjeldahl method using copper sulfate: interlaboratory study

    SciTech Connect

    Grappin, R.; Horwitz, W.

    1988-01-01

    Copper sulfate was substituted for mercury as the catalysts in the International Dairy Federation (IDF) Standard 20A:1986 method for the determination of nitrogen content in milk. The substitution was supported by results obtained in an interlaboratory study by 24 laboratories in 12 countries. Each laboratory analyzed 12 test samples of milk as blind duplicates in a double split level design with high, medium, and low nitrogen concentrations. The method protocol requires the concurrent analyses of an ammonium salt solution and a tryptophan solution as internal quality control standards with a minimum nitrogen recovery between 99 and 100% for the former and at least 98% for the latter. The repeatability and reproducibility relative standard deviations are 0.5 and 1%, respectively, for the range 0.35-0.70 N/100 g. The performance of the laboratories that did not meet the required quality control specifications was clearly poorer than that of those that did meet the specifications.

  1. Copper sulfate improves pullulan production by bioconversion using whole cells of Aureobasidium pullulans as the catalyst.

    PubMed

    Wang, Dahui; Ju, Xiaomin; Zhang, Gaochuan; Wang, Donghua; Wei, Gongyuan

    2016-10-01

    The effects of mineral salts on pullulan production by bioconversion using whole cells of Aureobasidium pullulans CCTCC M 2012259 as the catalyst were investigated. Copper sulfate (CuSO4) improved pullulan production by 36.2% and 42.3% when added at the optimum concentration of 0.2mg/L to the bioconversion broth or seed medium, respectively, as compared with controls without CuSO4 addition. Pullulan production was further enhanced when CuSO4 was added to both seed medium and bioconversion broth simultaneously. In order to probe the mechanism of CuSO4 improvement, cell viability, membrane integrity, intracellular adenosine triphosphate (ATP) levels and the activities of key enzymes involved in pullulan biosynthesis were determined. As a result, CuSO4 increased the activities of key biosynthetic enzymes, maintained intracellular ATP at a higher level, and accelerated the rate of pullulan secretion, all of which contributed to improved pullulan production by bioconversion.

  2. Redox properties of a mononuclear copper(II)-superoxide complex.

    PubMed

    Tano, Tetsuro; Okubo, Yuri; Kunishita, Atsushi; Kubo, Minoru; Sugimoto, Hideki; Fujieda, Nobutaka; Ogura, Takashi; Itoh, Shinobu

    2013-09-16

    Redox properties of a mononuclear copper(II) superoxide complex, (L)Cu(II)-OO(•), supported by a tridentate ligand (L = 1-(2-phenethyl)-5-[2-(2-pyridyl)ethyl]-1,5-diazacyclooctane) have been examined as a model compound of the putative reactive intermediate of peptidylglycine α-hydroxylating monooxygenase (PHM) and dopamine β-monooxygenase (DβM) (Kunishita et al. J. Am. Chem. Soc. 2009, 131, 2788-2789; Inorg. Chem. 2012, 51, 9465-9480). On the basis of the reactivity toward a series of one-electron reductants, the reduction potential of (L)Cu(II)-OO(•) was estimated to be 0.19 ± 0.07 V vs SCE in acetone at 298 K (cf. Tahsini et al. Chem.-Eur. J. 2012, 18, 1084-1093). In the reaction of TEMPO-H (2,2,6,6-tetramethylpiperidine-N-hydroxide), a simple HAT (hydrogen atom transfer) reaction took place to give the corresponding hydroperoxide complex LCu(II)-OOH, whereas the reaction with phenol derivatives ((X)ArOH) gave the corresponding phenolate adducts, LCu(II)-O(X)Ar, presumably via an acid-base reaction between the superoxide ligand and the phenols. The reaction of (L)Cu(II)-OO(•) with a series of triphenylphosphine derivatives gave the corresponding triphenylphosphine oxides via an electrophilic ionic substitution mechanism with a Hammett ρ value as -4.3, whereas the reaction with thioanisole (sulfide) only gave a copper(I) complex. These reactivities of (L)Cu(II)-OO(•) are different from those of a similar end-on superoxide copper(II) complex supported by a tetradentate TMG3tren ligand (1,1,1-Tris{2-[N(2)-(1,1,3,3-tetramethylguanidino)]ethyl}amine (Maiti et al. Angew. Chem., Int. Ed. 2008, 47, 82-85).

  3. Chemical speciation and bioavailability of Cu(II). Study of the ionic copper(II) and bis(glycinate)-copper(II) accumulation by Lemna species

    SciTech Connect

    Benda, F.; Kouba, J. )

    1991-03-01

    In this paper, the authors examined the accumulation of copper(II) in, and its toxic effect on, duckweed, a plant which exhibits extremely high concentration factors. The effect of copper(II) was investigated by adding it to the minimal medium in two forms: CuSO{sub 4} and (Cu(Gly){sub 2}). The neutral (2:1) tetracoordinated bis(glycinate)-copper(II) complex is constituted by two five-membered rings bonded to the central copper atom with the cis configuration. This complex was chosen to model the function of a neutral species (eliminating the charge effect) involving a nontoxic ligand, for which - in contrast to the hydrated Cu{sup 2+} species - direct permeation through the cell wall is conceivable.

  4. Determining the Amount of Copper(II) Ions in a Solution Using a Smartphone

    ERIC Educational Resources Information Center

    Montangero, Marc

    2015-01-01

    When dissolving copper in nitric acid, copper(II) ions produce a blue-colored solution. It is possible to determine the concentration of copper(II) ions, focusing on the hue of the color, using a smartphone camera. A free app can be used to measure the hue of the solution, and with the help of standard copper(II) solutions, one can graph a…

  5. Thermal Decomposition of Copper (II) Dicalcium (II) Formate

    NASA Astrophysics Data System (ADS)

    de Perazzo, P. K.; Leyva, A. G.; Polla, G.; Parisi, F.; de Benyacar, M. A. R.; Smichowski, P.; Lanza, H.

    1997-09-01

    The unit cell obtained through X-ray single crystal analysis of the synthetized CuCa 2(HCOO) 6crystals corresponds to a supercell of the basic structure described by M. Sanchis et al.( Inorg. Chem.31, 2915 (1992)). Thermal decomposition of this sample shows two stages up to 300°C; the first can be related to the superstructure, and the second corresponds to the breaking down of the remaining copper formate structural units and the simultaneous decomposition of the sample.

  6. Characterization of the Copper(II) Binding Sites in Human Carbonic Anhydrase II

    PubMed Central

    Nettles, Whitnee L.; Song, He; Farquhar, Erik R.; Fitzkee, Nicholas C.; Emerson, Joseph P.

    2015-01-01

    Human carbonic anhydrase (CA) is a well-studied, robust, mononuclear Zn-containing metalloprotein that serves as an excellent biological ligand system to study the thermodynamics associated with metal ion coordination chemistry in aqueous solution. The apo-form of human carbonic anhydrase II (CA) binds two equivalents of copper(II) with high affinity. The Cu2+ ions bind independently forming two non-coupled type-II copper centers in CA (CuA and CuB). However, the location and coordination mode of the CuA site in solution is unclear, compared to the CuB site that has been well characterized. Using paramagnetic NMR techniques and X-ray absorption spectroscopy we have identified an N-terminal Cu2+ binding location and collected information on the coordination mode of the CuA site in CA, which is consistent with a four to five coordinate N-terminal Cu2+ binding site reminiscent to a number of N-terminal copper(II) binding sites including the copper(II)-ATCUN and copper(II)-beta-amyloid complexes. Additionally, we report a more detailed analysis of the thermodynamics associated with copper(II) binding to CA. Although we are still unable to fully deconvolute Cu2+ binding data to the high-affinity CuA site, we have derived pH- and buffer-independent values for the thermodynamics parameters K and ΔH associated with Cu2+ binding to the CuB site of CA to be 2 × 109 and −17.4 kcal/mol, respectively. PMID:26010488

  7. Structure of catabolite activator protein with cobalt(II) and sulfate

    SciTech Connect

    Rao, Ramya R.; Lawson, Catherine L.

    2014-04-15

    The crystal structure of E. coli catabolite activator protein with bound cobalt(II) and sulfate ions at 1.97 Å resolution is reported. The crystal structure of cyclic AMP–catabolite activator protein (CAP) from Escherichia coli containing cobalt(II) chloride and ammonium sulfate is reported at 1.97 Å resolution. Each of the two CAP subunits in the asymmetric unit binds one cobalt(II) ion, in each case coordinated by N-terminal domain residues His19, His21 and Glu96 plus an additional acidic residue contributed via a crystal contact. The three identified N-terminal domain cobalt-binding residues are part of a region of CAP that is important for transcription activation at class II CAP-dependent promoters. Sulfate anions mediate additional crystal lattice contacts and occupy sites corresponding to DNA backbone phosphate positions in CAP–DNA complex structures.

  8. Reactions of copper(II)-phenol systems with O2: models for TPQ biosynthesis in copper amine oxidases.

    PubMed

    Tabuchi, Kae; Ertem, Mehmed Z; Sugimoto, Hideki; Kunishita, Atsushi; Tano, Tetsuro; Fujieda, Nobutaka; Cramer, Christopher J; Itoh, Shinobu

    2011-03-01

    Copper(II) complexes supported by a series of phenol-containing bis(pyridin-2-ylmethyl)amine N(3) ligands (denoted as L(o)H, L(m)H, and L(p)H) have been synthesized, and their O(2) reactivity has been examined in detail to gain mechanistic insights into the biosynthesis of the TPQ cofactor (2,4,5-trihydroxyphenylalaninequinone, TOPA quinone) in copper-containing amine oxidases. The copper(II) complex of L(o)H (ortho-phenol derivative) involves a direct phenolate to copper(II) coordination and exhibits almost no reactivity toward O(2) at 60 °C in CH(3)OH. On the other hand, the copper(II) complex of L(m)H (meta-phenol derivative), which does not involve direct coordinative interaction between the phenol moiety and the copper(II) ion, reacts with O(2) in the presence of triethylamine as a base to give a methoxy-substituted para-quinone derivative under the same conditions. The product structure has been established by detailed nuclear magnetic resonance (NMR), infrared (IR) spectroscopy, and electrospray ionization-mass spectroscopy (ESI-MS) (including (18)O-labeling experiment) analyses. Density functional theory predicts that the reaction involves (i) intramolecular electron transfer from the deprotonated phenol (phenolate) to copper(II) to generate a copper(I)-phenoxyl radical; (ii) the addition of O(2) to this intermediate, resulting in an end-on copper(II) superoxide; (iii) electrophilic substitution of the phenolic radical to give a copper(II)-alkylperoxo intermediate; (iv) O-O bond cleavage concomitant with a proton migration, giving a para-quinone derivative; and (v) Michael addition of methoxide from copper(II) to the para-quinone ring and subsequent O(2) oxidation. This reaction sequence is similar to that proposed for the biosynthetic pathway leading to the TPQ cofactor in the enzymatic system. The generated para-quinone derivative can act as a turnover catalyst for aerobic oxidation of benzylamine to N-benzylidene benzylamine. Another type of copper(II

  9. Complexation of copper(II) with chitosan nanogels: toward control of microbial growth.

    PubMed

    Brunel, Fabrice; El Gueddari, Nour Eddine; Moerschbacher, Bruno M

    2013-02-15

    Pure chitosan nanogels were produced, used to adsorb copper(II), and their antimicrobial activities were assessed. The complexation of copper(II) with chitosan solutions and dispersions was studied using UV-vis spectrometry. The adsorption capacity of chitosan nanogels was comparable to that of chitosan solutions, but copper(II)-loaded nanogels were more stable (i.e. no flocculation was observed while chitosan solutions showed macroscopic gelation at high copper concentration) and were easier to handle (i.e. no increase in viscosity). Adsorption isotherms of copper(II) onto chitosan were established and the impact of the pH on copper(II) release was investigated. The formation of a copper(II)-chitosan complex strongly depended on pH. Hence, release of copper(II) can be triggered by a decrease in pH (i.e. the protonation of chitosan amino groups). Furthermore, chitosan nanohydrogels were shown to be a suitable substrate for chitosan hydrolytic enzymes. Finally, a strong synergistic effect between chitosan and copper in inhibiting Fusarium graminearum growth was observed. The suitability of these copper(II)-chitosan colloids as a new generation of copper-based bio-pesticides, i.e. as a bio-compatible, bio-active and pH-sensitive delivery system, is discussed.

  10. Building reactive copper centers in human carbonic anhydrase II.

    PubMed

    Song, He; Weitz, Andrew C; Hendrich, Michael P; Lewis, Edwin A; Emerson, Joseph P

    2013-08-01

    Reengineering metalloproteins to generate new biologically relevant metal centers is an effective a way to test our understanding of the structural and mechanistic features that steer chemical transformations in biological systems. Here, we report thermodynamic data characterizing the formation of two type-2 copper sites in carbonic anhydrase and experimental evidence showing one of these new, copper centers has characteristics similar to a variety of well-characterized copper centers in synthetic models and enzymatic systems. Human carbonic anhydrase II is known to bind two Cu(2+) ions; these binding events were explored using modern isothermal titration calorimetry techniques that have become a proven method to accurately measure metal-binding thermodynamic parameters. The two Cu(2+)-binding events have different affinities (K a approximately 5 × 10(12) and 1 × 10(10)), and both are enthalpically driven processes. Reconstituting these Cu(2+) sites under a range of conditions has allowed us to assign the Cu(2+)-binding event to the three-histidine, native, metal-binding site. Our initial efforts to characterize these Cu(2+) sites have yielded data that show distinctive (and noncoupled) EPR signals associated with each copper-binding site and that this reconstituted enzyme can activate hydrogen peroxide to catalyze the oxidation of 2-aminophenol. PMID:23744511

  11. Responses of phtyoplankton photosynthesis and phosphorus kinetics to resuspended sediments in copper sulfate-treated ponds

    SciTech Connect

    Nalewajko, C.; Prepas, E.E.

    1996-01-01

    Six farm ponds (dugouts) and one lake that differ in the history of copper sulfate (CuSO{sub 4}) treatment were selected for studies of effects of sediments resuspension on phytoplankton. All sites are located within 50 km of Peace River, Alberta, and are shallow, hardwater, and eutrophic. Effects of sediment resuspension on phytoplankton photosynthesis were assessed by changes in the photosynthesis-irradiance P-D curve parameters, Pmax and {alpha}, after addition of sediment at 2% v/v to lakewater samples; the effects on phytoplankton P-state were assessed by changes in {sup 32}PO{sub 4} turnover time. Copper concentrations in sediments of Gour No. 4, the dugout that had received the largest dosage of CuSO{sub 4}, were 60-times greater than untreated sites but were only 1.5 to 3-times greater at the other treated sites. Changes of Pmax and {alpha} were not correlated with Cu concentrations in the sediments. Instead, the prevailing P-state in lakewater could better explain the observed trends in Pmax after sediment addition. Pmax values decreased at sites where phytoplankton were P-limited ({sup 32} P-PO{sub 4} turnover time <63 min) and increased at more P-sufficient sites ({sup 32}P-PO{sub 4} turnover time >63 min). Stimulation of Pmax and increase in {sup 32}P-PO{sub 4} turnover time were positively correlated. With the exception of Gour No. 4, values of a increased in all treatments. Similar changes in Pmax and a in response to sediment addition occurred in laboratory experiments with P-sufficient cultures of Anabaena flos-aquae. We suggest that, with the exception of grossly Cu-polluted sediments, resuspension of sediments in waters previously treated with CuSO{sub 4} will enhance phytoplankton photosynthesis by increasing P availability, and possibly by supplying Cu at trace metal levels. 25 refs., 4 figs., 6 tabs.

  12. Bis(triethano­lamine)nickel(II) sulfate

    PubMed Central

    Guo, Hong-Xu; Du, Zi-Xian; Li, Xi-Zhong

    2009-01-01

    The title compound, [Ni(C6H15NO3)2]SO4, contains two triethano­lamine (TEA) ligands bound to an Ni2+ metal centre, which lies on a crystallographic inversion centre, and one sulfate anion located on a twofold rotation axis such that the asymmetric unit contains one-half molecule of the cation and of the anion. The triethano­lamine ligands coordinate via each axial N atom and two of the three O atoms, while the third arm of the ligand has the hydroxyl group pointing away from the metal centre. The sulfate anions are hydrogen bonded to the coordinated hydroxyl groups and also to the free arm, forming a two-dimensional supra­molecular hydrogen-bonded network expanding parallel to (010). PMID:21582734

  13. Desorption measurements of copper and copper alloys for PEP-II

    SciTech Connect

    Foerster, C.L.; Halama, H.; Korn, G.; Calderon, M.; Barletta, W.

    1992-12-31

    PEP-II will be a meson factory circulating asymmetric beams of 9 GeV and 3.1 GeV having maximum currents of 3.0A. Copper beam chambers and absorbers will intercept resulting synchrotron radiation and it is critical that the dynamic gas load from photo stimulated desorption (PSD) and thermal outgassing is below 2 {times} 10{sup {minus}1} molecules per photon. An experiment was set up to measure PSD from 1m long bar samples and a chamber sample, fabricated from selected copper and copper alloys then exposed to white light with a critical energy of 500 eV, on beamline U10B at the VUV ring of the National Synchrotron Light Source (NSLS). Based on U10B results a prototype chamber was built and will be exposed to white light with higher critical energies of up to 5 KeV, on beamline X-28A at the X-ray Ring of the NSLS. This paper presents the measurements of H{sub 2}, CO, CO{sub 2} and CH{sub 4} desorption yields as function of accumulated photon flux, angle of incidence, sample material, and surface condition. The results are compared with that of previous work on similar materials and with that of others for copper.

  14. Copper sulfate improves pullulan production by bioconversion using whole cells of Aureobasidium pullulans as the catalyst.

    PubMed

    Wang, Dahui; Ju, Xiaomin; Zhang, Gaochuan; Wang, Donghua; Wei, Gongyuan

    2016-10-01

    The effects of mineral salts on pullulan production by bioconversion using whole cells of Aureobasidium pullulans CCTCC M 2012259 as the catalyst were investigated. Copper sulfate (CuSO4) improved pullulan production by 36.2% and 42.3% when added at the optimum concentration of 0.2mg/L to the bioconversion broth or seed medium, respectively, as compared with controls without CuSO4 addition. Pullulan production was further enhanced when CuSO4 was added to both seed medium and bioconversion broth simultaneously. In order to probe the mechanism of CuSO4 improvement, cell viability, membrane integrity, intracellular adenosine triphosphate (ATP) levels and the activities of key enzymes involved in pullulan biosynthesis were determined. As a result, CuSO4 increased the activities of key biosynthetic enzymes, maintained intracellular ATP at a higher level, and accelerated the rate of pullulan secretion, all of which contributed to improved pullulan production by bioconversion. PMID:27312631

  15. Effects of various polyoxyethylene sorbitan monooils (Tweens) and sodium dodecyl sulfate on reflux synthesis of copper nanoparticles

    SciTech Connect

    Zhang Xifeng; Yin Hengbo . E-mail: yin@ujs.edu.cn; Cheng Xiaonong; Hu Huifeng; Yu Qi; Wang Aili

    2006-11-09

    Size-controlled synthesis of phase pure Cu nanoparticles was carried out by using copper sulfate pentahydrate as a precursor, ascorbic acid as a reductant, Tweens and sodium dodecyl sulfate (SDS) as modifiers in an aqueous solution at 80 deg. C. The as-prepared Cu nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and Fourier transform infrared (FT-IR). The stabilizing effects of SDS and Tweens on the Cu nanoparticles should be through the coordination between Cu nanoparticles and the respective sulfate group and oxygen-containing bond. The synergic effect of the composite SDS and Tweens on Cu nanoparticles was different from those arising from the individuals.

  16. Anodonta imbecillis copper sulfate reference toxicant/food test, Clinch River - Environmental Restoration Program (CR-ERP)

    SciTech Connect

    Simbeck, D.J.

    1997-06-01

    Reference toxicant testing using juvenile freshwater mussels was conducted as part of the CR-ERP biomonitoring study of Clinch River sediments to assess the sensitivity of test organisms and the overall performance of the test. Tests were conducted using moderately hard synthetic water spiked with known concentrations of copper as copper sulfate. Two different foods, phytoplankton and YCT-Selenastrum (YCT-S), were tested in side by side tests to compare food quality. Toxicity testing of copper sulfate reference toxicant was conducted from July 6-15, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Results from this test showed LC{sub 50} values of 0.97 and 0.84 mg Cu/L for phytoplankton and YCT-S, respectively. Previously obtained values for phytoplankton tests are 2.02 and 1.12 mg Cu/L. Too few tests have been conducted with copper as the toxicant to determine a normal range of values. Although significant reduction in growth, compared to the phytoplankton control, was seen in all treatments, including the YCT-S Control, the consequence of this observation has not been established. Ninety-day testing of juvenile mussels exhibited large variations in growth within treatment and replicate groups.

  17. Genome sequence of Desulfovibrio sp. A2, a highly copper resistant, sulfate-reducing bacterium isolated from effluents of a zinc smelter at the Urals.

    PubMed

    Mancini, Stefano; Abicht, Helge K; Karnachuk, Olga V; Solioz, Marc

    2011-12-01

    Desulfovibrio sp. A2 is an anaerobic gram-negative sulfate-reducing bacterium with remarkable tolerance to copper. It was isolated from wastewater effluents of a zinc smelter at the Urals. Here, we report the 4.2-Mb draft genome sequence of Desulfovibrio sp. A2 and identify potential copper resistance mechanisms.

  18. EXAFS study of mercury(II) sorption to Fe- and Al-(hydr)oxides. II. Effects of chloride and sulfate.

    PubMed

    Kim, Christopher S; Rytuba, James J; Brown, Gordon E

    2004-02-01

    Common complexing ligands such as chloride and sulfate can significantly impact the sorption of Hg(II) to particle surfaces in aqueous environmental systems. To examine the effects of these ligands on Hg(II) sorption to mineral sorbents, macroscopic Hg(II) uptake measurements were conducted at pH 6 and [Hg](i)=0.5 mM on goethite (alpha-FeOOH), gamma-alumina (gamma-Al(2)O(3)), and bayerite (beta-Al(OH)(3)) in the presence of chloride or sulfate, and the sorption products were characterized by extended X-ray absorption fine structure (EXAFS) spectroscopy. The presence of chloride resulted in reduced uptake of Hg(II) on all three substrates over the Cl(-) concentration ([Cl(-)]) range 10(-5) to 10(-2) M, lowering Hg surface coverages on goethite, gamma-alumina, and bayerite from 0.42 to 0.07 micromol/m(2), 0.06 to 0.006 micromol/m(2), and 0.55 to 0.39 micromol/m(2) ([Cl(-)]=10(-5) to 10(-3) M only), respectively. This reduction in Hg(II) uptake is primarily a result of the formation of stable, nonsorbing aqueous HgCl(2) complexes in solution, limiting the amount of free Hg(II) available to sorb. At higher [Cl(-)] beam reduction of Hg(II) to Hg(I) was observed, resulting in the possible formation of aqueous Hg(2)Cl(2) species and the precipitation of calomel, Hg(2)Cl(2(s)). The presence of sulfate caused enhanced Hg(II) uptake over the sulfate concentration ([SO(4)(2-)]) range 10(-5) to 0.9 M, increasing Hg surface coverages on goethite, gamma-alumina, and bayerite from 0.39 to 0.45 micromol/m(2), 0.11 to 0.38 micromol/m(2), and 0.36 to 3.33 micromol/m(2), respectively. This effect is likely due to the direct sorption or accumulation of sulfate ions at the substrate interface, effectively reducing the positive surface charge that electrostatically inhibits Hg(II) sorption. Spectroscopic evidence for ternary surface complexation was observed in isolated cases, specifically in the Hg-goethite-sulfate system at high [SO(4)(2-)] and in the Hg-goethite-chloride system.

  19. EXAFS study of mercury(II) sorption to Fe- and Al-(hydr)oxides - II. Effects of chloride and sulfate

    USGS Publications Warehouse

    Kim, C.S.; Rytuba, J.J.; Brown, Gordon E.

    2004-01-01

    Common complexing ligands such as chloride and sulfate can significantly impact the sorption of Hg(II) to particle surfaces in aqueous environmental systems. To examine the effects of these ligands on Hg(II) sorption to mineral sorbents, macroscopic Hg(II) uptake measurements were conducted at pH 6 and [Hg]i=0.5 mM on goethite (??-FeOOH), ??-alumina (??-Al2O3), and bayerite (??-Al(OH)3) in the presence of chloride or sulfate, and the sorption products were characterized by extended X-ray absorption fine structure (EXAFS) spectroscopy. The presence of chloride resulted in reduced uptake of Hg(II) on all three substrates over the Cl- concentration ([Cl-]) range 10-5 to 10-2 M, lowering Hg surface coverages on goethite, ??-alumina, and bayerite from 0.42 to 0.07 ??mol/m2, 0.06 to 0.006 ??mol/m2, and 0.55 to 0.39 ??mol/m2 ([Cl -]=10-5 to 10-3 M only), respectively. This reduction in Hg(II) uptake is primarily a result of the formation of stable, nonsorbing aqueous HgCl2 complexes in solution, limiting the amount of free Hg(II) available to sorb. At higher [Cl-] beam reduction of Hg(II) to Hg(I) was observed, resulting in the possible formation of aqueous Hg2Cl2 species and the precipitation of calomel, Hg 2Cl2(s). The presence of sulfate caused enhanced Hg(II) uptake over the sulfate concentration ([SO42-]) range 10-5 to 0.9 M, increasing Hg surface coverages on goethite, ??-alumina, and bayerite from 0.39 to 0.45 ??mol/m2, 0.11 to 0.38 ??mol/m2, and 0.36 to 3.33 ??mol/m2, respectively. This effect is likely due to the direct sorption or accumulation of sulfate ions at the substrate interface, effectively reducing the positive surface charge that electrostatically inhibits Hg(II) sorption. Spectroscopic evidence for ternary surface complexation was observed in isolated cases, specifically in the Hg-goethite-sulfate system at high [SO42-] and in the Hg-goethite-chloride system. ?? 2003 Elsevier Inc. All rights reserved.

  20. Homeopathic Preparations of Quartz, Sulfur and Copper Sulfate Assessed by UV-Spectroscopy

    PubMed Central

    Wolf, Ursula; Wolf, Martin; Heusser, Peter; Thurneysen, André; Baumgartner, Stephan

    2011-01-01

    Homeopathic preparations are used in homeopathy and anthroposophic medicine. Although there is evidence of effectiveness in several clinical studies, including double-blinded randomized controlled trials, their nature and mode of action could not be explained with current scientific approaches yet. Several physical methods have already been applied to investigate homeopathic preparations but it is yet unclear which methods are best suited to identify characteristic physicochemical properties of homeopathic preparations. The aim of this study was to investigate homeopathic preparations with UV-spectroscopy. In a blinded, randomized, controlled experiment homeopathic preparations of copper sulfate (CuSO4; 11c–30c), quartz (SiO2; 10c–30c, i.e., centesimal dilution steps) and sulfur (S; 11×–30×, i.e., decimal dilution steps) and controls (one-time succussed diluent) were investigated using UV-spectroscopy and tested for contamination by inductively coupled plasma mass spectrometry (ICP-MS). The UV transmission for homeopathic preparations of CuSO4 preparations was significantly lower than in controls. The transmission seemed to be also lower for both SiO2 and S, but not significant. The mean effect size (95% confidence interval) was similar for the homeopathic preparations: CuSO4 (pooled data) 0.0544% (0.0260–0.0827%), SiO2 0.0323% (–0.0064% to 0.0710%) and S 0.0281% (–0.0520% to 0.1082%). UV transmission values of homeopathic preparations had a significantly higher variability compared to controls. In none of the samples the concentration of any element analyzed by ICP-MS exceeded 100 ppb. Lower transmission of UV light may indicate that homeopathic preparations are less structured or more dynamic than their succussed pure solvent. PMID:19474239

  1. Efficient electron-induced removal of oxalate ions and formation of copper nanoparticles from copper(II) oxalate precursor layers

    PubMed Central

    Rückriem, Kai; Grotheer, Sarah; Vieker, Henning; Penner, Paul; Beyer, André; Gölzhäuser, Armin

    2016-01-01

    Summary Copper(II) oxalate grown on carboxy-terminated self-assembled monolayers (SAM) using a step-by-step approach was used as precursor for the electron-induced synthesis of surface-supported copper nanoparticles. The precursor material was deposited by dipping the surfaces alternately in ethanolic solutions of copper(II) acetate and oxalic acid with intermediate thorough rinsing steps. The deposition of copper(II) oxalate and the efficient electron-induced removal of the oxalate ions was monitored by reflection absorption infrared spectroscopy (RAIRS). Helium ion microscopy (HIM) reveals the formation of spherical nanoparticles with well-defined size and X-ray photoelectron spectroscopy (XPS) confirms their metallic nature. Continued irradiation after depletion of oxalate does not lead to further particle growth giving evidence that nanoparticle formation is primarily controlled by the available amount of precursor. PMID:27547602

  2. Efficient electron-induced removal of oxalate ions and formation of copper nanoparticles from copper(II) oxalate precursor layers.

    PubMed

    Rückriem, Kai; Grotheer, Sarah; Vieker, Henning; Penner, Paul; Beyer, André; Gölzhäuser, Armin; Swiderek, Petra

    2016-01-01

    Copper(II) oxalate grown on carboxy-terminated self-assembled monolayers (SAM) using a step-by-step approach was used as precursor for the electron-induced synthesis of surface-supported copper nanoparticles. The precursor material was deposited by dipping the surfaces alternately in ethanolic solutions of copper(II) acetate and oxalic acid with intermediate thorough rinsing steps. The deposition of copper(II) oxalate and the efficient electron-induced removal of the oxalate ions was monitored by reflection absorption infrared spectroscopy (RAIRS). Helium ion microscopy (HIM) reveals the formation of spherical nanoparticles with well-defined size and X-ray photoelectron spectroscopy (XPS) confirms their metallic nature. Continued irradiation after depletion of oxalate does not lead to further particle growth giving evidence that nanoparticle formation is primarily controlled by the available amount of precursor. PMID:27547602

  3. Evolution of copper(II) as a new alkene amination promoter and catalyst

    PubMed Central

    Chemler, Sherry R.

    2010-01-01

    Copper(II) carboxylates and chiral copper(II) triflate·bis(oxazoline) complexes promote and catalyze intramolecular alkene carboamination, diamination and aminooxygenation reactions, creating an array of nitrogen heterocycles. High diastereoselectivity and enantioselectivity can be achieved in these transformations. This account reviews the discovery and development of these useful and interesting reactions. PMID:21379363

  4. Persistent endosulfan sulfate is found with highest abundance among endosulfan I, II, and sulfate in German forest soils.

    PubMed

    Bussian, Bernd M; Pandelova, Marchela; Lehnik-Habrink, Petra; Aichner, Bernhard; Henkelmann, Bernhard; Schramm, Karl-Werner

    2015-11-01

    Endosulfan - an agricultural insecticide and banned by Stockholm Convention - is produced as a 2:1 to 7:3 mixture of isomers endosulfan I (ESI) and endosulfan II (ESII). Endosulfan is transformed under aerobic conditions into endosulfan sulfate (ESS). The study shows for 76 sampling locations in German forests that endosulfan is abundant in all samples with an opposite ratio between the ESI and ESII than the technical product, where the main metabolite ESS is found with even higher abundance. The ratio between ESI/ESII and ESS show clear dependence on the type of stands (coniferous vs. deciduous) and humus type and increases from deciduous via mixed to coniferous forest stands. The study argues for a systematic monitoring of ESI, ESII, and ESS and underlines the need for further research, specifically on the fate of endosulfan including biomagnifications and bioaccumulation in soil.

  5. Electrochemistry of copper(II) induced complexes in mycorrhizal maize plant tissues.

    PubMed

    Zitka, Ondrej; Merlos, Miguel-Angel; Adam, Vojtech; Ferrol, Nuria; Pohanka, Miroslav; Hubalek, Jaromir; Zehnalek, Josef; Trnkova, Libuse; Kizek, Rene

    2012-02-15

    Aim of the present paper was to study the electrochemical behavior of copper(II) induced complexes in extracts obtained from mycorrhizal and non-mycorrhizal maize (Zea mays L.) plants grown at two concentrations of copper(II): physiological (31.7 ng/mL) and toxic (317 μg/mL). Protein content was determined in the plant extracts and, after dilution to proper concentration, various concentrations of copper(II) ions (0, 100, 200 and 400 μg/mL) were added and incubated for 1h at 37°C. Further, the extracts were analyzed using flow injection analysis with electrochemical detection. The hydrodynamic voltammogram (HDV), which was obtained for each sample, indicated the complex creation. Steepness of measured dependencies was as follows: control 317 μg/mL of coppercoppercoppercopper. Based on these results it can be concluded that mycorrhizal fungus actively blocks transport copper(II) ions to upper parts of a plant by means of adsorbing of copper(II) in roots. Rapid complex formation was determined under applied potentials 300, 500 and 600 mV during the measuring HDVs. It was also verified that mycorrhizal colonization reduced root to shoot translocation of Cu(II) ions.

  6. Static renewal tests using Anodonta imbecillus (freshwater mussels). Anodonta imbecillis copper sulfate reference toxicant test, Clinch River-Environmental Restoration Program (CR-ERP)

    SciTech Connect

    Simbeck, D.J.

    1993-12-31

    Reference toxicant testing using juvenile freshwater mussels was conducted as part of the CR-ERP biomonitoring study of Clinch River sediments to assess the sensitivity of test organisms and the overall performance of the test. Tests were conducted using moderately hard synthetic water spiked with known concentrations of copper as copper sulfate. Toxicity testing of copper sulfate reference toxicant was conducted from May 12--21, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Results from this test showed an LC{sub 50} value of 1.12 mg Cu/L which is lower than the value of 2.02 mg Cu/L obtained in a previous test. Too few tests have been conducted with copper as the toxicant to determine a normal range of values. Attachments to this report include: Toxicity test bench sheets and statistical analyses; Copper analysis request and results; and Personnel training documentation.

  7. Multiple Sulfate Isotopic Evidence on the Formation of Oxide Copper Ore at Spence, Atacama Desert, Northern Chile

    NASA Astrophysics Data System (ADS)

    Sun, T.; Bao, H.; Reich, M.; Palacios, C.

    2007-12-01

    In the Atacama Desert of northern Chile, one of the world's richest metallogenic provinces, porphyry copper deposits are characterized by the unique occurrence of atacamite in their oxidized zones. The origin and formation of the oxide zone of these copper deposits is, however, controversial. It was proposed that Cl-rich deep formation water pumping-up events along faults by earthquakes, after onset of the hyperaridity, were required (Cameron et al., 2007). Their model would imply that supplies of saline deep formation water from fractures to the surface should have left behind a homogeneous or fracture-controlled salt profile from surface down to the oxide zone. While no excluding the deep formation water model in other deposit, here we propose that, in our sampling region, the alternative saline source, which is critical for atacamite formation, could be locally evaporated groundwater, Cl-rich salts leached from arid surface by meteoric water, or brines from eastern salar basins at a time when the climate in northern Chile was changing from arid to hyperarid. At this climate transition, arid- requiring minerals such as atacamite in the oxide zone were formed and, more importantly, preserved upon evaporation beneath the surface alluvial deposits. Since salt accumulation at the surface remain active during hyperarid condition, our model would predict that water-soluble salt profile from surface to the oxide zone should have a characteristic pattern: salts with an atmospheric component on the surface gradually transitioning to salts of the oxide ore zone on the bottom and a mixing zone in between. To test these two alternative models, we focus on sulfate salts, one of the common water-soluble salts in arid environments. An added advantage is that sulfate accumulated on desert surface has a secondary atmospheric component that bears a unique triple oxygen isotope signature, easily distinguishable from sulfate formed by the oxidation of sulfide minerals at the oxide

  8. Spectral studies on cobalt(II), nickel(II) and copper(II) complexes of naphthaldehyde substituted aroylhydrazones.

    PubMed

    Singh, Pramod Kumar; Kumar, Deo Nandan

    2006-07-01

    A series of new coordination complexes of cobalt(II), nickel(II) and copper(II) with two new aroylhydrazones, 2-hydroxy-1-naphthaldehyde isonicotinoylhydrazone (H(2)L(1)) and 2-hydroxy-1-naphthaldehyde-2-thenoyl-hydrazone (H(2)L(2)) have been synthesized and characterized by elemental analysis, conductance measurements, magnetic susceptibility measurements, (1)H NMR spectroscopy, IR spectroscopy, electronic spectroscopy, EPR spectroscopy and thermal analysis. IR spectra suggests ligands acts as a tridentate dibasic donor coordinating through the deprotonated naphtholic oxygen atom, azomethine nitrogen atom and enolic oxygen atom. EPR and ligand field spectra suggests octahedral geometry for Co(II) and Ni(II) complexes and a square planar geometry for Cu(II) complexes. PMID:16529995

  9. Spectral studies on cobalt(II), nickel(II) and copper(II) complexes of naphthaldehyde substituted aroylhydrazones

    NASA Astrophysics Data System (ADS)

    Singh, Pramod Kumar; Kumar, Deo Nandan

    2006-07-01

    A series of new coordination complexes of cobalt(II), nickel(II) and copper(II) with two new aroylhydrazones, 2-hydroxy-1-naphthaldehyde isonicotinoylhydrazone (H 2L 1) and 2-hydroxy-1-naphthaldehyde-2-thenoyl-hydrazone (H 2L 2) have been synthesized and characterized by elemental analysis, conductance measurements, magnetic susceptibility measurements, 1H NMR spectroscopy, IR spectroscopy, electronic spectroscopy, EPR spectroscopy and thermal analysis. IR spectra suggests ligands acts as a tridentate dibasic donor coordinating through the deprotonated naphtholic oxygen atom, azomethine nitrogen atom and enolic oxygen atom. EPR and ligand field spectra suggests octahedral geometry for Co(II) and Ni(II) complexes and a square planar geometry for Cu(II) complexes.

  10. Proteomic analysis of acute responses to copper sulfate stress in larvae of the brine shrimp, Artemia sinica

    NASA Astrophysics Data System (ADS)

    Zhou, Qian; Wu, Changgong; Dong, Bo; Li, Fuhua; Liu, Fengqi; Xiang, Jianhai

    2010-03-01

    Proteomics was used to reveal the differential protein expression profiles of acute responses to copper sulfate exposure in larvae of Artemia sinica. Fourteen differentially displayed protein spots were detected and seven of them were identified. Three spots were up-expressed and identified: actin, heat shock protein 70, and chaperone subunit 1; three down-regulated proteins were identified: arginine kinase, elongation factor-2, and glycine-rich protein; and a newly expressed protein was identified as peroxiredoxin. The study indicates the involvement of all the differentially expressed proteins in the early responses of protein expression, and in the survival of A. sinica in the presence of copper and other heavy metals; the findings improve understanding of the organism’s adaptive responses and resistance.

  11. Biosorption characteristics of copper (II), chromium (III), nickel (II), and lead (II) from aqueous solutions by Chara sp. and Cladophora sp.

    PubMed

    Elmaci, Ayşe; Yonar, Taner; Ozengin, Nihan

    2007-09-01

    The aim of this research was to expose individual removals of copper, chromium, nickel, and lead from aqueous solutions via biosorption using nonliving algae species, Chara sp. and Cladophora sp. Optimum pH values for biosorption of copper (II), chromium (III), nickel (II), and lead (II) from aqueous solutions were determined to be 6, 7, 7, and 3 for Cladophora sp. and 5, 3, 5, and 4 for Chara sp. respectively. Maximum adsorption capacities of Chara sp. [10.54 for chromium (III) and 61.72 for lead (II)] and Cladophora sp. [6.59 for chromium (III) and 16.75 and 23.25 for lead (II)] for chromium (III) and lead (II) are similar. On the other hand, copper (II) and nickel (II) biosorption capacity of Cladophora sp. [14.28 for copper (II) and 16.75 for nickel (II)] is greater than Chara sp. [6.506 for copper (II) and 11.76 for nickel (II)]. Significantly high correlation coefficients indicated for the Langmuir adsorption isotherm models can be used to describe the equilibrium behavior of copper, chromium, nickel, and lead adsorption onto Cladophora sp. and Chara sp.

  12. Synthesis, superoxide dismutase, nuclease, and anticancer activities of copper(II) complexes incorporating bis(2-picolyl)amine with different counter anions

    NASA Astrophysics Data System (ADS)

    Ibrahim, Mohamed M.; Ramadan, Abdel-Motaleb M.; Mersal, Gaber A. M.; El-Shazly, Samir A.

    2011-07-01

    Interaction of the tridentate ligand bis(2-picolyl)amine L with copper(II) salts gave a series of copper(II) complexes with the formula types: [ LCu(X) 2] (X = Cl -1, = Br -2), [( LCu (H 2O)(μ-SO 4)( LCu(H 2O)]SO 43, [ LCu(OAc)](OAc )H 2O 4, [ LCu(H 2O) 2](Y) 2 (Y = NO3-5, = ClO4-6). Their structures and properties were characterized by elemental analysis, thermal analysis (TGA), IR, UV-vis and ESR spectroscopy, electrochemical measurements including cyclic voltammetry and electrical molar conductivity, and magnetic moment measurements. A square pyramidal geometry is proposed for the halogeno complexes 1 and 2 in monomeric structures. For sulfate complex, the sulfate group bridged two copper(II) ions of the two [N 3O] donor units to give the dimeric complex molecule 3 in square pyramidal environment around the copper(II) ions. In the case of complexes 4- 6, square planar stereochemistries in monomeric structures are suggested. The SOD biomimetic catalytic activity of the obtained complexes was assessed for their ability to inhibit the reduction of nitroblue tetrazolium (NBT). The catalytic efficiency of O2- scavenging by complexes depends on the nature of the particular acidic anion radical incorporated in the complex molecule and follows the order: NO3- > ClO4- > Br - ⩾ Cl - > SO4- > AcO -. A probable mechanistic implications for the catalytic dismutation of O2- by copper(II) complexes are proposed. Furthermore, complex 1 exhibits significant hydrolytic cleavage of the genomic DNA in the absence of any external additives. In addition, the in vitro study of cytotoxicity of complex 1 on colon cancer cell line (Caco-2) indicates that the complex has the potential to act as an effective anticancer drug with IC 50 value of 156 ± 0.35 μM.

  13. Differences in Median Ultraviolet Light Transmissions of Serial Homeopathic Dilutions of Copper Sulfate, Hypericum perforatum, and Sulfur.

    PubMed

    Klein, Sabine D; Sandig, Annegret; Baumgartner, Stephan; Wolf, Ursula

    2013-01-01

    Homeopathic remedies are produced by potentising, that is, the serial logarithmic dilution and succussion of a mother tincture. Techniques like ultraviolet spectroscopy, nuclear magnetic resonance, calorimetry, or thermoluminescence have been used to investigate their physical properties. In this study, homeopathic centesimal (c) potencies (6c to 30c) of copper sulfate, Hypericum perforatum, and sulfur as well as succussed water controls were prepared. Samples of these preparations were exposed to external physical factors like heat, pressure, ultraviolet radiation, or electromagnetic fields to mimic possible everyday storage conditions. The median transmissions from 190 nm to 340 nm and 220 nm to 340 nm were determined by ultraviolet light spectroscopy on five measurement days distributed over several months. Transmissions of controls and potencies of sulfur differed significantly on two of five measurement days and after exposure to physical factors. Transmissions of potencies exposed to ultraviolet light and unexposed potencies of copper sulfate and Hypericum perforatum differed significantly. Potency levels 6c to 30c were also compared, and wavelike patterns of higher and lower transmissions were found. The Kruskal-Wallis test yielded significant differences for the potency levels of all three substances. Aiming at understanding the physical properties of homeopathic preparations, this study confirmed and expanded the findings of previous studies.

  14. Differences in Median Ultraviolet Light Transmissions of Serial Homeopathic Dilutions of Copper Sulfate, Hypericum perforatum, and Sulfur

    PubMed Central

    Klein, Sabine D.; Sandig, Annegret; Baumgartner, Stephan; Wolf, Ursula

    2013-01-01

    Homeopathic remedies are produced by potentising, that is, the serial logarithmic dilution and succussion of a mother tincture. Techniques like ultraviolet spectroscopy, nuclear magnetic resonance, calorimetry, or thermoluminescence have been used to investigate their physical properties. In this study, homeopathic centesimal (c) potencies (6c to 30c) of copper sulfate, Hypericum perforatum, and sulfur as well as succussed water controls were prepared. Samples of these preparations were exposed to external physical factors like heat, pressure, ultraviolet radiation, or electromagnetic fields to mimic possible everyday storage conditions. The median transmissions from 190 nm to 340 nm and 220 nm to 340 nm were determined by ultraviolet light spectroscopy on five measurement days distributed over several months. Transmissions of controls and potencies of sulfur differed significantly on two of five measurement days and after exposure to physical factors. Transmissions of potencies exposed to ultraviolet light and unexposed potencies of copper sulfate and Hypericum perforatum differed significantly. Potency levels 6c to 30c were also compared, and wavelike patterns of higher and lower transmissions were found. The Kruskal-Wallis test yielded significant differences for the potency levels of all three substances. Aiming at understanding the physical properties of homeopathic preparations, this study confirmed and expanded the findings of previous studies. PMID:23401712

  15. Enhanced bioremediation of heavy metal from effluent by sulfate-reducing bacteria with copper-iron bimetallic particles support.

    PubMed

    Zhou, Qin; Chen, Yongzhe; Yang, Ming; Li, Wenkai; Deng, Le

    2013-05-01

    The purpose of this study was to investigate the potential of copper-iron bimetallic particles supported sulfate-reducing bacteria (SRB) in enhancing the reduction of Cu(2+) and Zn(2+) in effluent. The results showed that the copper-iron bimetallic particles can enhance Cu(2+) and Zn(2+) removal and the resistance of the sulfate-reducing bacteria towards metals toxicity, the inhibiting concentration of Cu(2+) and Zn(2+) for SRB was significantly increased (from 100 to 200 mg/L for Cu(2+) and 300 to 400 mg/L for Zn(2+)). The removal efficiencies of Cu(2+) and Zn(2+) (initial concentration 100 mg/L) were 98.17% and 99.67% in SRB-Cu/Fe system after 48 h, while only 29.83% Cu(2+), 90.88% Zn(2+) and 63.81% Cu(2+), 72.63% Zn(2+) were removed in the SRB and Cu/Fe system at the same condition.

  16. Solvent effects on the stability of nifuroxazide complexes with cobalt(II), nickel(II) and copper(II) in alcohols.

    PubMed

    Khan, Mustayeen A; Ali, S Kauser; Bouet, Gilles M

    2002-05-21

    A spectrophotometric study of the complexation of nifuroxazide with cobalt(II), nickel(II) and copper(II) was carried out in different alcohols. The formation of a complex in each case is reported and their stability constants have been calculated. For a given solvent, the stability of the complexes increases from cobalt to copper. In the case of copper(II), the stability varies as an inverse function of the dielectric constant of the solvent. A possible structure of the complex is proposed. PMID:12009257

  17. Electrochemistry of Ferrous Sulfate-Sodium Thiosulphate and Copper Sulfate-Sodium Thiosulphate Systems for Template-Assisted Nanowire Synthesis

    NASA Astrophysics Data System (ADS)

    Brogan, Lee Jeffery

    Two related series of investigations are presented in this dissertation. First, two candidate systems for electrochemical deposition of metal sulfides for photovoltaic applications have been characterized. Secondly, a general electrochemical synthesis method allowing countable numbers of wires embedded in porous anodic alumina arrays to be measured using macroscopic contacts was developed. Electrochemical studies of the FeSO4-Na2S 2O3 system and the CuSO4-Na2S 2O3 system were undertaken to evaluate their suitability as electrodeposition baths for FeS2 and CuxS, respectively. Each solution system was studied extensively using cyclic voltammetry to characterize electrochemical processes at various concentrations. The iron sulfide / thiosulfate system was found to be unsuitable for the synthesis of FeS2 due to the preferential formation of FeS. The copper sulfide / thiosulfate system was found to be suitable for the synthesis of Cu2S, with thiosulfate concentration being the most important parameter due to the high complexation of Cu(I) by thiosulfate. Investigations into the electrochemical synthesis of metal wires in porous anodic alumina templates revealed an interesting synthesis mechanism wherein sparse, isolated wires are created in a very small fraction of the available pores. These wires are nucleated through the reduction of metal from the deposition bath by aluminum at the base of the alumina pores. This reduction causes a localized increase in acidity, accelerating the dissolution of the alumina barrier layer and allowing more typical wire deposition to occur. The sparse nucleation is exaggerated by the increasing rate of wire deposition as the wires lengthen and the swift rate of overgrowth formation at the surface of the template, resulting in domes of overgrowth attached to countable numbers of nanowires. This geometry has been exploited to obtain in situ measurements of known numbers of nanowires.

  18. Highly cytotoxic DNA-interacting copper(II) coordination compounds.

    PubMed

    Brissos, Rosa F; Torrents, Ester; dos Santos Mello, Francyelli Mariana; Carvalho Pires, Wanessa; Silveira-Lacerda, Elisângela de Paula; Caballero, Ana B; Caubet, Amparo; Massera, Chiara; Roubeau, Olivier; Teat, Simon J; Gamez, Patrick

    2014-10-01

    Four new Schiff-base ligands have been designed and prepared by condensation reaction between hydrazine derivatives (i.e. 2-hydrazinopyridine or 2-hydrazinoquinoline) and mono- or dialdehyde (3-tert-butyl-2-hydroxybenzaldehyde and 5-tert-butyl-2-hydroxyisophthalaldehyde, respectively). Six copper(II) coordination compounds of various nuclearities have been obtained from these ligands, which are formulated as [Cu(L1)Cl](CH3OH) (1), [Cu(L2)NO3] (2), [Cu2(L3)(ClO4)2(CH3O)(CH3OH)](CH3OH) (3), [Cu2(L4)(ClO4)(OH)(CH3OH)](ClO4) (4), [Cu8(L3)4(NO3)4(OH)5](NO3)3(CH3OH)5(H2O)8 (5) and [Cu3(HL2')4Cl6](CH3OH)6 (6), as revealed by single-crystal X-ray studies. Their DNA-interacting abilities have been investigated using different characterization techniques, which suggest that the metal complexes act as efficient DNA binders. Moreover, cytotoxicity assays with several cancer cell lines show that some of them are very active, as evidenced by the sub-micromolar IC50 values achieved in some cases. PMID:25096758

  19. Highly cytotoxic DNA-interacting copper(II) coordination compounds.

    PubMed

    Brissos, Rosa F; Torrents, Ester; dos Santos Mello, Francyelli Mariana; Carvalho Pires, Wanessa; Silveira-Lacerda, Elisângela de Paula; Caballero, Ana B; Caubet, Amparo; Massera, Chiara; Roubeau, Olivier; Teat, Simon J; Gamez, Patrick

    2014-10-01

    Four new Schiff-base ligands have been designed and prepared by condensation reaction between hydrazine derivatives (i.e. 2-hydrazinopyridine or 2-hydrazinoquinoline) and mono- or dialdehyde (3-tert-butyl-2-hydroxybenzaldehyde and 5-tert-butyl-2-hydroxyisophthalaldehyde, respectively). Six copper(II) coordination compounds of various nuclearities have been obtained from these ligands, which are formulated as [Cu(L1)Cl](CH3OH) (1), [Cu(L2)NO3] (2), [Cu2(L3)(ClO4)2(CH3O)(CH3OH)](CH3OH) (3), [Cu2(L4)(ClO4)(OH)(CH3OH)](ClO4) (4), [Cu8(L3)4(NO3)4(OH)5](NO3)3(CH3OH)5(H2O)8 (5) and [Cu3(HL2')4Cl6](CH3OH)6 (6), as revealed by single-crystal X-ray studies. Their DNA-interacting abilities have been investigated using different characterization techniques, which suggest that the metal complexes act as efficient DNA binders. Moreover, cytotoxicity assays with several cancer cell lines show that some of them are very active, as evidenced by the sub-micromolar IC50 values achieved in some cases.

  20. Spectral studies of copper(II) complexes of 6-(3-thienyl) pyridine-2-thiosemicarbazone

    SciTech Connect

    Mahjoub, Omima Abdalla; Farina, Yang

    2014-09-03

    Two novel copper(II) complexes [Cu(HL)Cl]Cl.H{sub 2}O (1) and [Cu(L)NO{sub 3}]Ðœ‡H{sub 2}O (2) of the three NNS donor thiosemicarbazone ligand 6-(3-thienyl) pyridine-2-thiosemicarbazone have been synthesized. The ligand and its copper(II) complexes were characterized by elemental analysis (C, H, N, and S), FT-IR, UV-visible, magnetic susceptibility and molar conductance. The thiosemicarbazone is present either as the thione form in complex 1 or as thiol form in complex 2 and is coordinated to copper(II) atom via the pyridine nitrogen atom, the azomethine nitrogen atom and the sulfur atom. The physicochemical and spectral data suggest square planar geometry for copper(II) atoms.

  1. Growth and characterization of Cu (II) doped negatively soluble lithium sulfate monohydrate crystals

    NASA Astrophysics Data System (ADS)

    Boopathi, K.; Ramasamy, P.; Bhagavannarayana, G.

    2014-01-01

    Single crystals of pure and Cu (II) doped negatively soluble lithium sulfate monohydrate have been grown by slow evaporation solution technique. In the present work, to improve the crystalline quality of lithium sulfate monohydrate crystal, metal dopant was incorporated into the pure crystals. The as grown crystals are clear, transparent and the sizes of the crystals were up to 18×12×3 mm3 and 50×15×5 mm3. The presence of metal dopant has been confirmed by energy dispersive spectroscopy, atomic absorption spectroscopy analysis. Single crystal and powder X-ray diffraction studies were carried out to ascertain lattice parameters and identify different phase nature. Optical transmission spectrum of the grown crystals was recorded. FT-IR and thermal analysis were carried out to investigate the functional group and thermal behavior of the grown crystals respectively. The grown crystal was subjected to Vickers micro hardness, HRXRD, piezoelectric, laser damage threshold measurements and second harmonic generation efficiency studies.

  2. Effectiveness of copper sulfate, potassium permanganate, and peracetic acid to reduce mortality and infestation of Ichthyobodo nector in channel catfish Ictalurus punctatus (Rafinesque 1818)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ichthyobodo necator is a single celled bi-flagellate parasite, and in high density can causes significant mortality in young fish. Copper sulfate (CuSO4), potassium permanganate (KMnO4) and peracetic acid (PAA) were evaluated for effectiveness against ichthyobodosis. Treatments were: untreated con...

  3. The effectiveness of repeated tank treatments of copper sulfate and formalin on gill flukes and Ich in naturally infested white bass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ectoparasites infesting the gills of juvenile fish reared in tanks can cause serious fish losses. Multiple treatments of formalin and copper sulfate (CuSO4) were evaluated for effectiveness against a natural infestation of gill flukes Onchocleidus mimus (Monogenoidea: Ancyrocephalidae) and Ichthyop...

  4. The effectiveness of flow-through and/or static copper sulfate treatments on the survival of Golden Shiners and Fathead Minnows infected with Flavobacterium columare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four studies were done comparing various treatments of copper sulfate (CuSO4) on the survival of golden shiner and fathead minnow (both economically important baitfish) that had columnaris disease. The treatments were observed for their ability to reduce mortality in well water. In experiment 1 and ...

  5. The effectiveness of flow-through and/or static copper sulfate treatments on the survival of Golden Shiners and Fathead Minnows infected with Flavobacterium columare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four studies were done comparing various treatments of copper sulfate (CuSO4) on the survival of golden shiner and fathead minnow (both economically important baitfish) that had columnaris disease. The treatments were observed for their ability to reduce mortality in well water. In experiment 1 an...

  6. Comparison of percent hatch and fungal infestation in channel catfish eggs after copper sulfate, diquat bromide, formalin, and hydrogen peroxide treatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reduced survival is often a result of fungal (Saprolegnia spp.) infestation of fish eggs. However, timely chemical treatments often limit these infestations and increase survival. The effect of copper sulfate pentahydrate (CSP - 10 mg/L), diquat bromide (25 mg/L diquat cation), formalin (433 mg/L)...

  7. Comparing the efficacy of four immersion flush and static hydorgen peroxide and copper sulfate treatments on channel catfish eggs infected with water molds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water mold infestations on channel catfish eggs lower the hatch rate (egg survival) and ultimately the number of catfish fry available for stocking in production ponds. This study compared the potential of two hydrogen peroxide (HP) and two copper sulfate pentahydrate (CSP) treatments to increase c...

  8. Synthesis, spectroscopic and thermal studies of the copper(II) aspartame chloride complex

    NASA Astrophysics Data System (ADS)

    Çakır, S.; Coşkun, E.; Naumov, P.; Biçer, E.; Bulut, İ.; İçbudak, H.; Çakır, O.

    2002-08-01

    Aspartame adduct of copper(II) chloride Cu(Asp) 2Cl 2·2H 2O (Asp=aspartame) is synthesized and characterized by elemental analysis, FT IR, UV/vis, ESR spectroscopies, TG, DTG, DTA measurements and molecular mechanics calculations. Aqueous solution of the green solid absorbs strongly at 774 and 367 nm. According to the FT IR spectra, the aspartame moiety coordinates to the copper(II) ion via its carboxylate ends, whereas the ammonium terminal groups give rise to hydrogen bonding network with the water, the chloride ions or neighboring carboxylate groups. The results suggest tetragonally distorted octahedral environment of the copper ions.

  9. Modeling of copper(II) sites in proteins based on histidyl and glycyl residues.

    PubMed

    Orfei, Marco; Alcaro, Maria Claudia; Marcon, Giordana; Chelli, Mario; Ginanneschi, Mauro; Kozlowski, Henryk; Brasuń, Justyna; Messori, Luigi

    2003-11-01

    The complexes between copper(II) and four synthetic tetrapeptides bearing a single histidine residue within the sequence (AcHGGG, AcGHGG, AcGGHG and AcGGGH, respectively), have been investigated by potentiometric and spectroscopic methods (UV-Vis, circular dichroism and electron paramagnetic resonance). Potentiometric studies in the pH range 4-12 allowed identification and quantitative determination of the species present in solution for each copper-peptide complex. In all cases, upon raising pH, copper(II) coordination starts from the imidazole nitrogen of the His; afterwards three deprotonated amide nitrogens are progressively involved in copper coordination, except in the case of AcGHGG. Based on the potentiometric and spectroscopic results, detailed molecular structures are proposed for the dominant copper(II) tetrapeptide species existing in solution, either at neutral or alkaline pH. The structural consequences of the presence and of the location of a unique histidine residue within the tetrameric sequence are specifically analyzed. Results are discussed in relation to the modeling of copper(II) binding sites in proteins, particular emphasis being devoted to the copper complexes of the prion protein. PMID:14511892

  10. Diffusion behavior of copper atoms under Cu(II) reduction in Cucurbit[8]uril cavity at elevated temperatures

    SciTech Connect

    Bakovets, Vladimir V.; Nadolinnii, Vladimir A.; Kovalenko, Ekaterina A.; Plyusnin, Pavel E.; Dolgovesova, Irina P.; Zaikovskii, Vladimir I.

    2015-01-15

    In this paper we describe copper clusters and nanoparticles formation by the reduction of copper (II) ions inside cavities of macrocycle molecules using supramolecular compound [Cu(Cyclen)(H{sub 2}O)@CB[8

  11. Iron versus Copper II. Principles and Applications in Bioinorganic Chemistry.

    ERIC Educational Resources Information Center

    Ochiai, Ei-Ichiro

    1986-01-01

    Discusses the differences between iron and copper. Describes various aspects of the behaviors of these two elements, including those of biological and environmental significance. Addresses the evolution of the atmosphere and sedimentary ore formation, the phylogeny of iron and copper, and some anthropological notes regarding the use of the metals.…

  12. Structural Diversity of Copper(II) Complexes with 9-Deazahypoxanthine and Their in Vitro SOD-Like Activity

    PubMed Central

    Gáliková, Jana; Trávníček, Zdeněk

    2015-01-01

    Two structurally different copper(II) complexes of the compositions [{Cu(9dhx)(H2O)3}2(µ-SO4)2] (1) and [Cu(9dhx)2(H2O)2(NO3)2]·H2O (2), involving 9-deazahypoxanthine (9dhx; 6-oxo-9-deazapurine; 9-deazahypoxanthine), have been prepared and characterized by elemental analysis, infrared and electronic spectroscopy, electrospray ionisation (ESI) mass spectrometry, thermogravimetric (TG) and differential thermal (DTA) analyses, and cyclic voltammetry. The X-ray structures of complexes 1 and [Cu(9dhx)2(H2O)2(NO3)2] (2a) revealed the distorted octahedral geometry in the vicinity of the copper(II) atoms, with the NO5 and N2O4 donor set, respectively. In the dimeric compound 1, the {Cu(9dhx)(H2O)3}2 units are bridged by sulfate groups with the Cu···Cu separation being 5.3446(2) Å. In both structures the 9dhx ligands are coordinated through the N3 atoms of the pyrimidine moieties. The SOD-like activity of complexes 1 and 2 was evaluated in vitro showing moderate effect, with the IC50 values equal to 18.20, and 53.33 μM, respectively. PMID:26184182

  13. Structural Diversity of Copper(II) Complexes with 9-Deazahypoxanthine and Their in Vitro SOD-Like Activity.

    PubMed

    Gáliková, Jana; Trávníček, Zdeněk

    2015-01-01

    Two structurally different copper(II) complexes of the compositions [{Cu(9dhx)(H2O)3}2(µ-SO4)2] (1) and [Cu(9dhx)2(H2O)2(NO3)2]·H2O (2), involving 9-deazahypoxanthine (9dhx; 6-oxo-9-deazapurine; 9-deazahypoxanthine), have been prepared and characterized by elemental analysis, infrared and electronic spectroscopy, electrospray ionisation (ESI) mass spectrometry, thermogravimetric (TG) and differential thermal (DTA) analyses, and cyclic voltammetry. The X-ray structures of complexes 1 and [Cu(9dhx)2(H2O)2(NO3)2] (2a) revealed the distorted octahedral geometry in the vicinity of the copper(II) atoms, with the NO5 and N2O4 donor set, respectively. In the dimeric compound 1, the {Cu(9dhx)(H2O)3}2 units are bridged by sulfate groups with the Cu···Cu separation being 5.3446(2) Å. In both structures the 9dhx ligands are coordinated through the N3 atoms of the pyrimidine moieties. The SOD-like activity of complexes 1 and 2 was evaluated in vitro showing moderate effect, with the IC50 values equal to 18.20, and 53.33 μM, respectively.

  14. Structural Diversity of Copper(II) Complexes with 9-Deazahypoxanthine and Their in Vitro SOD-Like Activity.

    PubMed

    Gáliková, Jana; Trávníček, Zdeněk

    2015-01-01

    Two structurally different copper(II) complexes of the compositions [{Cu(9dhx)(H2O)3}2(µ-SO4)2] (1) and [Cu(9dhx)2(H2O)2(NO3)2]·H2O (2), involving 9-deazahypoxanthine (9dhx; 6-oxo-9-deazapurine; 9-deazahypoxanthine), have been prepared and characterized by elemental analysis, infrared and electronic spectroscopy, electrospray ionisation (ESI) mass spectrometry, thermogravimetric (TG) and differential thermal (DTA) analyses, and cyclic voltammetry. The X-ray structures of complexes 1 and [Cu(9dhx)2(H2O)2(NO3)2] (2a) revealed the distorted octahedral geometry in the vicinity of the copper(II) atoms, with the NO5 and N2O4 donor set, respectively. In the dimeric compound 1, the {Cu(9dhx)(H2O)3}2 units are bridged by sulfate groups with the Cu···Cu separation being 5.3446(2) Å. In both structures the 9dhx ligands are coordinated through the N3 atoms of the pyrimidine moieties. The SOD-like activity of complexes 1 and 2 was evaluated in vitro showing moderate effect, with the IC50 values equal to 18.20, and 53.33 μM, respectively. PMID:26184182

  15. Histopathological and bacterial study of skin and gill of grass carp, Ceteopharyngodon idella, (Valenciennes 1844) exposed to copper sulfate and potassium permanganate.

    PubMed

    Jooyandeh, Fatemeh; Sadeghpour, Ali; Khara, Hossein; Pajand, Zabihollah

    2016-09-01

    The gill histology and bacterial load of skin of the grass carp juveniles were investigated in relation to various concentrations of copper sulfate and potassium permanganate. For this purpose, the sublethal doses were determined after a pre-test and then the experiment was done in five treatments (for copper sulfate: 1, 1.94, 3.71, 7.07 and 15 mg/l and for potassium permanganate: 0.25, 0.52, 1.91, 2.27 and 5 mg/l) with three replicates inside the glass aquaria. Also, one group without disinfecting product was considered as control for each experiment. The microbial and histopathological investigations were done after 96 h exposure. According to results, the lowest bacterial load (CFU/g) of skin was observed in 15 mg/l copper sulfate treatment and 0.25 mg/l potassium permanganate treatment (P < 0.05). Also, the histological investigation showed a range of histopathological alternations in gills tissue including lamellar necrosis, hyperplasia, lamellar adhesion, haemorrhage, clubbing of gill lamellae. The severity of these alternations increased with increasing of the doses of the copper sulfate and potassium permanganate. In this regard, the highest histological damages were observed in 15 mg/l copper sulfate and 5 mg/l potassium permanganate respectively. Our results showed that low dosage of potassium permanganate has best effect on reducing of bacterial load of skin with lowest adverse effects on gill tissue. PMID:27605829

  16. Synthesis and crystal structure of thiosemicarbazide complexes of nickel(II) and copper(II)

    NASA Astrophysics Data System (ADS)

    Sadikov, G. G.; Antsyshkina, A. S.; Koksharova, T. V.; Sergienko, V. S.; Kurando, S. V.; Gritsenko, I. S.

    2012-07-01

    Thiosemicarbazide complexes of nickel(II) [Ni( TSC)2](H Sal)2 ( I) and copper(II) [Cu( TSC)2](H Sal)2 ( Ia) ( TSC is thiosemicarbazide and H Sal is a salycilate anion), as well as complexes [Ni( TSC)2](SO4) · 2H2O ( II) and [Ni( TSC)3]Cl2 · H2O ( III), are synthesized and characterized by IR spectroscopy and X-ray diffraction. Monoclinic crystals I and Ia are isostructural; space group P21/ n, Z = 2. Crystals II are monoclinic, space group P21/ m, Z = 2. Crystals III are orthorhombic, space group Pbca, Z = 8. In I and Ia, two planar salycilate anions sandwich a planar centrosymmetric [Ni( TSC)2]2+ cation to form a supermolecule. The cation and anions are additionally bound by hydrogen bonds. Other hydrogen bonds connect supermolecules into planar layers. In structure II, centrosymmetric [Ni( TSC)2]2+ cations are connected by π-stacking interactions into supramolecular ensembles of a specific type. The ensembles, water molecules, and (SO4)2- anions are bound in the crystal via hydrogen bonds. In the [Ni( TSC)3]2+ cation of structure III, ligands coordinate the Ni atom by the bidentate chelate pattern with the formation of five-membered metallocycles. These metallocycles have an envelope conformation unlike those in I and II, which are planar. In III (unlike in analogous complexes), a meridional isomer of the coordination octahedron of the Ni atom is formed. Together with Cl1- and Cl2- anions, cations form supermolecules, which are packed into planar layers with a square-cellular structure. The layers are linked by hydrogen bonds formed by crystallization water molecules that are located between the layers.

  17. 78 FR 78727 - Copper Sulfate Pentahydrate; Exemption From the Requirement of a Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ..., 2013 (78 FR 43115) (FRL-9392- 9), EPA issued a document pursuant to FFDCA section 408, 21 U.S.C. 346a... final rule published in the Federal Register of August 11, 2006 (71 FR 46106) (FRL-8085-3). Copper is... review under Executive Order 12866, entitled ``Regulatory Planning and Review'' (58 FR 51735, October...

  18. Pyrrolidine dithiocarbamate-zinc(II) and -copper(II) complexes induce apoptosis in tumor cells by inhibiting the proteasomal activity☆

    PubMed Central

    Milacic, Vesna; Chen, Di; Giovagnini, Lorena; Diez, Alejandro; Fregona, Dolores; Dou, Q. Ping

    2013-01-01

    Zinc and copper are trace elements essential for proper folding, stabilization and catalytic activity of many metalloenzymes in living organisms. However, disturbed zinc and copper homeostasis is reported in many types of cancer. We have previously demonstrated that copper complexes induced proteasome inhibition and apoptosis in cultured human cancer cells. In the current study we hypothesized that zinc complexes could also inhibit the proteasomal chymotrypsin-like activity responsible for subsequent apoptosis induction. We first showed that zinc(II) chloride was able to inhibit the chymotrypsin-like activity of a purified 20S proteasome with an IC50 value of 13.8 μM, which was less potent than copper(II) chloride (IC50 5.3 μM). We then compared the potencies of a pyrrolidine dithiocarbamate (PyDT)-zinc(II) complex and a PyDT-copper(II) complex to inhibit cellular proteasomal activity, suppress proliferation and induce apoptosis in various human breast and prostate cancer cell lines. Consistently, zinc complex was less potent than copper complex in inhibiting the proteasome and inducing apoptosis. Additionally, zinc and copper complexes appear to use somewhat different mechanisms to kill tumor cells. Zinc complexes were able to activate calpain-, but not caspase-3-dependent pathway, while copper complexes were able to induce activation of both proteases. Furthermore, the potencies of these PyDT-metal complexes depend on the nature of metals and also on the ratio of PyDT to the metal ion within the complex, which probably affects their stability and availability for interacting with and inhibiting the proteasome in tumor cells. PMID:18501397

  19. Pyrrolidine dithiocarbamate-zinc(II) and -copper(II) complexes induce apoptosis in tumor cells by inhibiting the proteasomal activity

    SciTech Connect

    Milacic, Vesna; Chen Di; Giovagnini, Lorena; Diez, Alejandro; Fregona, Dolores; Dou, Q. Ping

    2008-08-15

    Zinc and copper are trace elements essential for proper folding, stabilization and catalytic activity of many metalloenzymes in living organisms. However, disturbed zinc and copper homeostasis is reported in many types of cancer. We have previously demonstrated that copper complexes induced proteasome inhibition and apoptosis in cultured human cancer cells. In the current study we hypothesized that zinc complexes could also inhibit the proteasomal chymotrypsin-like activity responsible for subsequent apoptosis induction. We first showed that zinc(II) chloride was able to inhibit the chymotrypsin-like activity of a purified 20S proteasome with an IC{sub 50} value of 13.8 {mu}M, which was less potent than copper(II) chloride (IC{sub 50} 5.3 {mu}M). We then compared the potencies of a pyrrolidine dithiocarbamate (PyDT)-zinc(II) complex and a PyDT-copper(II) complex to inhibit cellular proteasomal activity, suppress proliferation and induce apoptosis in various human breast and prostate cancer cell lines. Consistently, zinc complex was less potent than copper complex in inhibiting the proteasome and inducing apoptosis. Additionally, zinc and copper complexes appear to use somewhat different mechanisms to kill tumor cells. Zinc complexes were able to activate calpain-, but not caspase-3-dependent pathway, while copper complexes were able to induce activation of both proteases. Furthermore, the potencies of these PyDT-metal complexes depend on the nature of metals and also on the ratio of PyDT to the metal ion within the complex, which probably affects their stability and availability for interacting with and inhibiting the proteasome in tumor cells.

  20. Pyrrolidine dithiocarbamate-zinc(II) and -copper(II) complexes induce apoptosis in tumor cells by inhibiting the proteasomal activity.

    PubMed

    Milacic, Vesna; Chen, Di; Giovagnini, Lorena; Diez, Alejandro; Fregona, Dolores; Dou, Q Ping

    2008-08-15

    Zinc and copper are trace elements essential for proper folding, stabilization and catalytic activity of many metalloenzymes in living organisms. However, disturbed zinc and copper homeostasis is reported in many types of cancer. We have previously demonstrated that copper complexes induced proteasome inhibition and apoptosis in cultured human cancer cells. In the current study we hypothesized that zinc complexes could also inhibit the proteasomal chymotrypsin-like activity responsible for subsequent apoptosis induction. We first showed that zinc(II) chloride was able to inhibit the chymotrypsin-like activity of a purified 20S proteasome with an IC(50) value of 13.8 microM, which was less potent than copper(II) chloride (IC(50) 5.3 microM). We then compared the potencies of a pyrrolidine dithiocarbamate (PyDT)-zinc(II) complex and a PyDT-copper(II) complex to inhibit cellular proteasomal activity, suppress proliferation and induce apoptosis in various human breast and prostate cancer cell lines. Consistently, zinc complex was less potent than copper complex in inhibiting the proteasome and inducing apoptosis. Additionally, zinc and copper complexes appear to use somewhat different mechanisms to kill tumor cells. Zinc complexes were able to activate calpain-, but not caspase-3-dependent pathway, while copper complexes were able to induce activation of both proteases. Furthermore, the potencies of these PyDT-metal complexes depend on the nature of metals and also on the ratio of PyDT to the metal ion within the complex, which probably affects their stability and availability for interacting with and inhibiting the proteasome in tumor cells. PMID:18501397

  1. Mercury bioaccumulation and bioaccumulation factors for Everglades mosquitofish as related to sulfate: a re-analysis of Julian II (2013).

    PubMed

    Pollman, Curtis D; Axelrad, Donald M

    2014-11-01

    The Everglades, an ecosystem of international significance, has elevated biota mercury levels representing risk to human and wildlife consumers of fish. Given the critical role of sulfate in the methylation of mercury, and because there is a significant agricultural contribution, one potential means of reducing these mercury levels is reducing Everglades sulfate inputs. Julian II (Bull Environ Contam Toxicol 90:329-332, 2013) conducted regression modeling of the relationship between surface water sulfate concentrations and Gambusia spp. mercury bioconcentration factors across the major hydrologic subunits of the Everglades, and used those results to draw conclusions about the role of sulfate in the cycling of mercury in the Everglades. We however demonstrate a number of fundamental problems with the analysis, interpretation and conclusions. As a result, we strongly caution against using the results of Julian II (Bull Environ Contam Toxicol 90:329-332, 2013) to formulate management decisions regarding mitigation of the Everglades mercury problem. PMID:25260994

  2. Iron(II) sulfate release from drop-formed lipophilic matrices developed by special hot-melt technology.

    PubMed

    Pallagi, E; Vass, K; Pintye-Hódi, K; Kása, P; Falkay, G; Eros, I; Szabó-Révész, P

    2004-03-01

    Iron(II) sulfate-containing lipophilic matrices were developed by a special hot-melt technology (melt solidification in drops), using stearin, white wax and their mixture as conventional bed materials. The special technology resulted in spherical particles which can be filled directly into capsules; these store iron as a depot and ensure a slow and uniform release, whereby the irritation of the gastric mucosa by the iron can be decreased. The rates of dissolution of the iron(II) sulfate from the various lipophilic matrices were different, but fundamentally low. Kinetic calculations demonstrated that the rate of dissolution of the iron(II) sulfate was of approximately zero kinetic order. The results of in vivo experiments on rabbits correlated well with the in vitro data. The plasma curves for the animals treated with the iron(II) sulfate preparations varied with the excipients in the depot products. The properties and ratio of the bed materials influenced the release of the iron(II) sulfate. In all probability, the release of the active agent can be regulated through the use of a melt of stearin and white wax in different ratios. The development products functioned as a sustained-release system and ensured elimination of the irritation of the gastric mucosa. At the same time, the results justified the applicability of the special hot-melt technology in the development of the solid dosage form. PMID:15018986

  3. Highly enantioselective Henry reactions of aromatic aldehydes catalyzed by an amino alcohol-copper(II) complex.

    PubMed

    Qin, Dan-Dan; Lai, Wen-Han; Hu, Di; Chen, Zheng; Wu, An-An; Ruan, Yuan-Ping; Zhou, Zhao-Hui; Chen, Hong-Bin

    2012-08-20

    Amino alcohol-Cu(II) catalyst: Highly enantioselective Henry reactions between aromatic aldehydes and nitromethane have been developed. The reactions were catalyzed by an easily available and operationally simple amino alcohol-copper(II) catalyst. In total, 38 substrates were tested and the R-configured products were obtained in good yields with excellent enantioselectivities. PMID:22791567

  4. Effect of phosphate and sulfate on Ni repartitioning during Fe(II)-catalyzed Fe(III) oxide mineral recrystallization

    NASA Astrophysics Data System (ADS)

    Hinkle, Margaret A. G.; Catalano, Jeffrey G.

    2015-09-01

    Dissolved Fe(II) activates coupled oxidative growth and reductive dissolution of Fe(III) oxide minerals, causing recrystallization and the repartitioning of structurally-compatible trace metals. Phosphate and sulfate, two ligands common to natural aquatic systems, alter Fe(II) adsorption onto Fe(III) oxides and affect Fe(III) oxide dissolution and precipitation. However, the effect of these oxoanions on trace metal repartitioning during Fe(II)-catalyzed Fe(III) oxide recrystallization is unclear. The effects of phosphate and sulfate on Ni adsorption and Ni repartitioning during Fe(II)-catalyzed Fe(III) oxide recrystallization were investigated as such repartitioning may be affected by both Fe(II)-oxoanion and metal-oxoanion interactions. In most systems examined, phosphate alters Ni repartitioning during Fe(II)-catalyzed recrystallization to a larger extent than sulfate. Phosphate substantially enhances Ni adsorption onto hematite but decreases (nearly inhibiting) Fe(II)-catalyzed Ni incorporation into and release from this mineral. In the goethite system, however, phosphate suppresses Ni release but enhances Ni incorporation in the presence of aqueous Fe(II). In contrast, sulfate has little effect on macroscopic Ni adsorption and release of Ni from Fe(III) oxides, but substantially enhances Ni incorporation into goethite. This demonstrates that phosphate and sulfate have unique, mineral-specific interactions with Ni during Fe(II)-catalyzed Fe(III) oxide recrystallization. This research suggests that micronutrient bioavailability at redox interfaces in hematite-dominated systems may be especially suppressed by phosphate, while both oxoanions likely have limited effects in goethite-rich soils or sediments. Phosphate may also exert a large control on contaminant fate at redox interfaces, increasing Ni retention on iron oxide surfaces. These results further indicate that trace metal retention by iron oxides during lithification and later repartitioning during

  5. Filtration by a novel nanofiber membrane and alumina adsorption to remove copper(II) from groundwater.

    PubMed

    Sang, Yimin; Gu, Qingbao; Sun, Tichang; Li, Fasheng; Liang, Cunzhen

    2008-05-01

    The elevated level of heavy metals in groundwater poses a substantial risk potentially to local resource users and the natural environment. Micellar-enhanced filtration (MEF) and alumina adsorption are considered from the viewpoint of copper(II) removal in groundwater, by taking copper(II) as an example. In MEF, copper(II) cations are collected electrostatically on micelles of sodium dodecyl benzene sulfonate (SDBS) and separated from the mother liquor by filtration using a novel nanofiber membrane prepared from chloridized polyvinyl chloride by high-voltage electrospinning process. After MEF with 10-layer filtration and SDBS concentration of 5 mmol/L, the removal of copper(II) in groundwater is above 70%. However, the final solution contains a large amount of surfactant causing serious second contamination in groundwater. This problem is overcome by alumina adsorption, where negatively charged surfactants are adsorbed on positively charged alumina particles and then recovered by conventional filtration. The hybrid process of MEF and alumina adsorption is successfully applied to removing almost 100% of copper(II) from groundwater. Finally, the characterization of the membrane and filtration mechanism are presented here. PMID:17945414

  6. Filtration by a novel nanofiber membrane and alumina adsorption to remove copper(II) from groundwater.

    PubMed

    Sang, Yimin; Gu, Qingbao; Sun, Tichang; Li, Fasheng; Liang, Cunzhen

    2008-05-01

    The elevated level of heavy metals in groundwater poses a substantial risk potentially to local resource users and the natural environment. Micellar-enhanced filtration (MEF) and alumina adsorption are considered from the viewpoint of copper(II) removal in groundwater, by taking copper(II) as an example. In MEF, copper(II) cations are collected electrostatically on micelles of sodium dodecyl benzene sulfonate (SDBS) and separated from the mother liquor by filtration using a novel nanofiber membrane prepared from chloridized polyvinyl chloride by high-voltage electrospinning process. After MEF with 10-layer filtration and SDBS concentration of 5 mmol/L, the removal of copper(II) in groundwater is above 70%. However, the final solution contains a large amount of surfactant causing serious second contamination in groundwater. This problem is overcome by alumina adsorption, where negatively charged surfactants are adsorbed on positively charged alumina particles and then recovered by conventional filtration. The hybrid process of MEF and alumina adsorption is successfully applied to removing almost 100% of copper(II) from groundwater. Finally, the characterization of the membrane and filtration mechanism are presented here.

  7. Interactions of copper (II) chloride with sucrose, glucose, and fructose in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Ribeiro, A. C. F.; Esteso, M. A.; Lobo, V. M. M.; Valente, A. J. M.; Simões, S. M. N.; Sobral, A. J. F. N.; Burrows, H. D.

    2007-01-01

    The interaction between copper (II) chloride and the carbohydrates sucrose, glucose, and fructose has been studied in aqueous solutions at 298.15 and 310.15 K, using measurements of diffusion coefficients and electrical conductivity. Significant effects on the electrical conductivity were observed in the presence of these carbohydrates, suggesting interactions between them and copper chloride. Support for this came from diffusion coefficient measurements. These studies have been complemented by molecular mechanics calculations.

  8. Toxic effects of copper on photosystem II of spinach chloroplasts

    SciTech Connect

    Hsu, Bandar; Lee, Jeeyau )

    1988-05-01

    The room temperature fluorescence induction of chloroplasts was utilized as a probe to locate the site of inhibition on PSII by copper. It was found that, while the initial fluorescence yield was hardly affected, the variable fluorescence yield was lowered without significant change in its kinetics. Addition of DCMU, or abolishing oxygen evolution capability by Tris treatment, did not alter this basic inhibition pattern. Copper was also found to lower the fluorescence yield of chloroplasts treated with linolenic acid which inhibited the secondary electron transport on both oxidizing and reducing sides of PSII. The data indicate that copper adversely affects the primary change separation at the PSII reaction center. We suggest that the inhibition is due to creation of a lesion close to the reaction center, leading to increased dissipation of incoming excitation energy to heat.

  9. Sodium lauryl sulfate-ruthenium(II) interactions: Photogalvanic and photophysical behavior of Ru(II)-diimine complexes

    SciTech Connect

    Akasheh, T.S.; Al-Rawashdeh, N.A.F. )

    1990-11-15

    The photogalvanic and photophysical behavior of a number of mixed-ligand ruthenium(II) complexes of 2,2{prime}-bipyridine (bpy), 3,3{prime}-bipyradzine (bpd), 2-(2{prime}-pyridyl)quinoline (pyrq), 4,4{prime}-dimethyl-2,2{prime}-bipyridine (dmbpy), and 2,3-bis(2{prime}-pyridyl)pyrazine (dpp) is reported both in water and in sodium lauryl sulfate (SDS) solutions. The effect of SDS on the photogalvanic experiment is predominantly an enhancement and/or modification of the photochemical and electrochemical processes. Luminescence, lifetime measurements, and photochemical behavior are affected by SDS and are used to predict possible modes of micelle-complex interactions.

  10. Efficient degradation of atrazine by magnetic porous copper ferrite catalyzed peroxymonosulfate oxidation via the formation of hydroxyl and sulfate radicals.

    PubMed

    Guan, Ying-Hong; Ma, Jun; Ren, Yue-Ming; Liu, Yu-Lei; Xiao, Jia-Yue; Lin, Ling-qiang; Zhang, Chen

    2013-09-15

    Magnetic porous copper ferrite (CuFe2O4) showed a notable catalytic activity to peroxymonosulfate (PMS). More than 98% of atrazine was degraded within 15 min at 1 mM PMS and 0.1 g/L CuFe2O4. In contrast, CuFe2O4 exhibited no obvious catalytic activity to peroxodisulfate or H2O2. Several factors affecting the catalytic performance of PMS/CuFe2O4 were investigated. Results showed that the catalytic degradation efficiency of atrazine increased with PMS and CuFe2O4 doses, but decreased with the increase of natural organic matters concentration. The catalytic oxidation also showed a dependence on initial pH. The presence of bicarbonate stimulated atrazine degradation by PMS/CuFe2O4 at low concentrations but inhibited the degradation at high concentrations. Furthermore, the reactive species for atrazine degradation in PMS/CuFe2O4 system were identified as hydroxyl radical (HO) and sulfate radical (SO4(·-)) through competition reactions of atrazine and nitrobenzene, instead of commonly used alcohol scavenging, which was not a reliable method in metal oxide catalyzed oxidation. Surface hydroxyl groups of CuFe2O4 were a critical part in radical generation and the copper on CuFe2O4 surface was an active site to catalyze PMS. The catalytic degradation of atrazine by PMS/CuFe2O4 was also effective under the background of actual waters.

  11. Selenium isotope fractionation during reduction by Fe(II)-Fe(III) hydroxide-sulfate (green rust)

    USGS Publications Warehouse

    Johnson, T.M.; Bullen, T.D.

    2003-01-01

    We have determined the extent of Se isotope fractionation induced by reduction of selenate by sulfate interlayered green rust (GRSO4), a Fe(II)-Fe(III) hydroxide-sulfate. This compound is known to reduce selenate to Se(0), and it is the only naturally relevant abiotic selenate reduction pathway documented to date. Se reduction reactions, when they occur in nature, greatly reduce Se mobility and bioavailability. Se stable isotope analysis shows promise as an indicator of Se reduction, and Se isotope fractionation by various Se reactions must be known in order to refine this tool. We measured the increase in the 80Se/76Se ratio of dissolved selenate as lighter isotopes were preferentially consumed during reduction by GRSO4. Six different experiments that used GRSO4 made by two methods, with varying solution compositions and pH, yielded identical isotopic fractionations. Regression of all the data yielded an instantaneous isotope fractionation of 7.36 ?? 0.24???. Selenate reduction by GRSO4 induces much greater isotopic fractionation than does bacterial selenate reduction. If selenate reduction by GRSO4 occurs in nature, it may be identifiable on the basis of its relatively large isotopic fractionation. ?? 2003 Elsevier Science Ltd.

  12. COPPER TOLERANCE IN FATHEAD MINNOWS: II. MATERNAL TRANSFER

    PubMed Central

    Peake, Elizabeth B.; Locke, Jessica C.; Tierney, Laura L.; Kolok, Alan S.

    2009-01-01

    Female fathead minnows (Pimephales promelas) exposed to copper (Cu) maternally transfer Cu tolerance to their larval offspring. Larvae produced after female parents received a sublethal 5-d, 100 µg/L Cu exposure had significantly greater survivorship in potentially lethal Cu solutions than larvae produced before those females were exposed to Cu. PMID:14768887

  13. Bis[2-(cyclo-pentyl-imino-meth-yl)-5-meth-oxy-phenolato]copper(II).

    PubMed

    Ji, Xiao-Hui; Lu, Jiu-Fu

    2010-01-01

    The title compound, [Cu(C(13)H(16)NO(2))(2)], is a mononuclear copper(II) complex derived from the Schiff base ligand 2-(cyclo-pentyl-imino-meth-yl)-5-meth-oxy-phenol and copper acetate. The Cu(II) atom is four-coordinated by the phenolate O atoms and imine N atoms from two Schiff base ligands, in a highly distorted square-planar geometry. The O- and N-donor atoms are mutually trans and the dihedral angle between the two benzene rings is 55.8 (3)°. PMID:21588128

  14. Assessment of the Polychlorinated Biphenyl (PCB) Occurrence in Copper Sulfates and the Influential Role of PCB Levels on Grapes

    PubMed Central

    Li, Xiaomin; Su, Xiaoou

    2015-01-01

    Copper sulfates (CuSO4) are widely used as the primary component of fungicides in the grape industry. The agricultural-grade CuSO4 that we collected from Chinese nationwide markets were found to be contaminated by polychlorinated dibenzo-p-dioxins and dibenzofurans and high levels of polychlorinated biphenyls (Σ19PCBs: 0.32~9.51 ng/g). In the following research, we studied the impact of CuSO4 application on PCB levels in grape products through a field experiment, and conducted a national survey to speculate the role that CuSO4 played on the occurrence of PCB in grapes. In the field experiment, an obvious increase of PCBs in grape leaves (from 174 to 250 pg/g fw) was observed after Bordeaux mixture (the main component of which is CuSO4) application. As to the main PCB congener in CuSO4, the most toxic CB 126 (toxic equivalency factor = 0.1) also increased in grape peels (from 1.66 to 2.93 pg/g fw) after pesticide spray. Both the correlation study and the principal component analysis indicated that environmental factors were dominant PCB contributors to grapes, and grapes from e-waste dismantling area containing the highest PCBs also proved the notion. It is worth noting that this report describes the first research examining PCBs in CuSO4 and its influence on agricultural products to date. PMID:26658158

  15. Effectiveness of 5-Pyrrolidone-2-carboxylic Acid and Copper Sulfate Pentahydrate Association against Drug Resistant Staphylococcus Strains.

    PubMed

    Governa, Paolo; Miraldi, Elisabetta; De Fina, Gianna; Biagi, Marco

    2016-04-01

    Bacterial resistance is an ongoing challenge for pharmacotherapy and pharmaceutical chemistry. Staphylococcus aureus is the bacterial species which makes it most difficult to treat skin and soft tissue infections and it is seen in thousands of hospitalization cases each year. Severe but often underrated infectious diseases, such as complicated nasal infections, are primarily caused by MRSA and S. epidermidis too. With the aim of studying new drugs with antimicrobial activity and effectiveness on drug resistant Staphylococcus strains, our attention in this study was drawn on the activity of a new association between two natural products: 5-pyrrolidone-2-carboxylic acid (PCA), naturally produced by certain Lactobacillus species, and copper sulfate pentahydrate (CS). The antimicrobial susceptibility test was conducted taking into account 12 different Staphylococcus strains, comprising 6 clinical isolates and 6 resistant strains. PCA 4%, w/w, and CS 0.002%, w/w, association in distilled water solution was found to have bactericidal activity against all tested strains. Antimicrobial kinetics highlighted that PCA 4%, w/w, and CS 0.002% association could reduce by 5 log10 viable bacterial counts of MRSA and oxacillin resistant S. epidennidis in less than 5 and 3 minutes respectively. Microscopic investigations suggest a cell wall targeting mechanism of action. Being very safe and highly tolerated, the natural product PCA and CS association proved to be a promising antimicrobial agent to treat Staphylococcus related infections. PMID:27396191

  16. Effectiveness of 5-Pyrrolidone-2-carboxylic Acid and Copper Sulfate Pentahydrate Association against Drug Resistant Staphylococcus Strains.

    PubMed

    Governa, Paolo; Miraldi, Elisabetta; De Fina, Gianna; Biagi, Marco

    2016-04-01

    Bacterial resistance is an ongoing challenge for pharmacotherapy and pharmaceutical chemistry. Staphylococcus aureus is the bacterial species which makes it most difficult to treat skin and soft tissue infections and it is seen in thousands of hospitalization cases each year. Severe but often underrated infectious diseases, such as complicated nasal infections, are primarily caused by MRSA and S. epidermidis too. With the aim of studying new drugs with antimicrobial activity and effectiveness on drug resistant Staphylococcus strains, our attention in this study was drawn on the activity of a new association between two natural products: 5-pyrrolidone-2-carboxylic acid (PCA), naturally produced by certain Lactobacillus species, and copper sulfate pentahydrate (CS). The antimicrobial susceptibility test was conducted taking into account 12 different Staphylococcus strains, comprising 6 clinical isolates and 6 resistant strains. PCA 4%, w/w, and CS 0.002%, w/w, association in distilled water solution was found to have bactericidal activity against all tested strains. Antimicrobial kinetics highlighted that PCA 4%, w/w, and CS 0.002% association could reduce by 5 log10 viable bacterial counts of MRSA and oxacillin resistant S. epidennidis in less than 5 and 3 minutes respectively. Microscopic investigations suggest a cell wall targeting mechanism of action. Being very safe and highly tolerated, the natural product PCA and CS association proved to be a promising antimicrobial agent to treat Staphylococcus related infections.

  17. Real-time cell analysis: sensitivity of different vertebrate cell cultures to copper sulfate measured by xCELLigence(®).

    PubMed

    Rakers, S; Imse, F; Gebert, M

    2014-10-01

    In this study, we report the use of a real-time cell analysis (RTCA) test system, the xCELLigence(®) RTCA, as efficient tool for a fast cytotoxicity analysis and comparison of four different vertebrate cell cultures. This new dynamic real-time monitoring and impedance-based assay allows for a combined measurement of cell adhesion, spreading and proliferation. Cell cultures were obtained from mouse, rat, human and fish, all displaying a fibroblast-like phenotype. The measured impedance values could be correlated to characteristic cell culture behaviours. In parallel, relative cytotoxicity of a commonly used but due to its very good water solubility highly hazardous pesticide, copper sulfate, was evaluated under in vitro conditions through measurements of cell viability by classical end-point based assays MTT and PrestoBlue(®). Cell line responses in terms of viability as measured by these three methods were variable between the fish skin cells and cells from higher vertebrates and also between the three methods. The advantage of impedance-based measurements is mainly based on the continuous monitoring of cell responses for a broad range of different cells, including fish cells. PMID:25001081

  18. Assessment of the Polychlorinated Biphenyl (PCB) Occurrence in Copper Sulfates and the Influential Role of PCB Levels on Grapes.

    PubMed

    Li, Xiaomin; Su, Xiaoou

    2015-01-01

    Copper sulfates (CuSO4) are widely used as the primary component of fungicides in the grape industry. The agricultural-grade CuSO4 that we collected from Chinese nationwide markets were found to be contaminated by polychlorinated dibenzo-p-dioxins and dibenzofurans and high levels of polychlorinated biphenyls (Σ19PCBs: 0.32~9.51 ng/g). In the following research, we studied the impact of CuSO4 application on PCB levels in grape products through a field experiment, and conducted a national survey to speculate the role that CuSO4 played on the occurrence of PCB in grapes. In the field experiment, an obvious increase of PCBs in grape leaves (from 174 to 250 pg/g fw) was observed after Bordeaux mixture (the main component of which is CuSO4) application. As to the main PCB congener in CuSO4, the most toxic CB 126 (toxic equivalency factor = 0.1) also increased in grape peels (from 1.66 to 2.93 pg/g fw) after pesticide spray. Both the correlation study and the principal component analysis indicated that environmental factors were dominant PCB contributors to grapes, and grapes from e-waste dismantling area containing the highest PCBs also proved the notion. It is worth noting that this report describes the first research examining PCBs in CuSO4 and its influence on agricultural products to date. PMID:26658158

  19. Structural specifics of light-induced metastable states in copper(II)-nitroxide molecular magnets.

    PubMed

    Barskaya, I Yu; Veber, S L; Fokin, S V; Tretyakov, E V; Bagryanskaya, E G; Ovcharenko, V I; Fedin, M V

    2015-12-28

    Although light-induced magnetostructural switching in copper(II)-nitroxide molecular magnets Cu(hfac)2L(R) has been known for several years, structural characterization of metastable photoinduced states has not yet been accomplished due to significant technical demands. In this work we apply, for the first time, variable-temperature FTIR spectroscopy with photoexcitation to investigate the structural specifics of light-induced states in the Cu(hfac)2L(R) family represented by (i) Cu(hfac)2L(Me) comprising two-spin copper(II)-nitroxide clusters, and (ii) Cu(hfac)2L(Pr) comprising three-spin nitroxide-copper(II)-nitroxide clusters. The light-induced state of Cu(hfac)2L(Me) manifests the same set of vibrational bands as the corresponding thermally-induced state, implying their similar structures. For the second compound Cu(hfac)2L(Pr), the coordination environment of copper(II) is similar in light- and thermally-induced states, but distinct differences are found for packing of the peripheral n-propyl substituent of nitroxide. Thus, generally the structures of the corresponding thermally- and light-induced states in molecular magnets Cu(hfac)2L(R) might differ, and FTIR spectroscopy provides a useful approach for revealing and elucidating such differences.

  20. Effect of Dioxygen on Copper(II) Binding to α-Synuclein

    PubMed Central

    Lucas, Heather R.; Lee, Jennifer C.

    2010-01-01

    Using the fluorescent amino acid tryptophan (Trp), we have characterized the copper(II) binding of F4W α-synuclein in the presence and absence of dioxygen at neutral pH. Variations in Trp fluorescence indicate that copper(II) binding is enhanced by the presence of dioxygen, with the apparent dissociation constant (Kd(app)) changing from 100 nM (anaerobic) to 10 nM (aerobic). To investigate the possible role of methionine oxidation, complementary work focused on synthetic peptide models of the N-terminal Cu(II)-α-syn site, MDV(F/W) and M*DV(F/W), where M*= methionine sulfoxide. Furthermore, we employed circular dichroism (CD) spectroscopy to demonstrate that the phenyl-to-indole (F→W) substitution does not alter copper(II) binding properties and to confirm the 1:1 metal-peptide binding stoichiometry. CD comparisons also revealed that Met1 oxidation does not affect the copper-peptide conformation and further suggested the possible existence of a CuII-Trp/Phe (cation-π) interaction. PMID:20064662

  1. Effect of dioxygen on copper(II) binding to alpha-synuclein.

    PubMed

    Lucas, Heather R; Lee, Jennifer C

    2010-03-01

    Using the fluorescent amino acid tryptophan (Trp), we have characterized the copper(II) binding of F4W alpha-synuclein in the presence and absence of dioxygen at neutral pH. Variations in Trp fluorescence indicate that copper(II) binding is enhanced by the presence of dioxygen, with the apparent dissociation constant (K(d(app))) changing from 100nM (anaerobic) to 10nM (aerobic). To investigate the possible role of methionine oxidation, complementary work focused on synthetic peptide models of the N-terminal Cu(II)-alpha-syn site, MDV(F/W) and M( *)DV(F/W), where M( *)=methionine sulfoxide. Furthermore, we employed circular dichroism (CD) spectroscopy to demonstrate that the phenyl-to-indole (F-->W) substitution does not alter copper(II) binding properties and to confirm the 1:1 metal-peptide binding stoichiometry. CD comparisons also revealed that Met1 oxidation does not affect the copper-peptide conformation and further suggested the possible existence of a Cu(II)-Trp/Phe (cation-pi) interaction. PMID:20064662

  2. Static renewal tests using Anodonta imbecillis (freshwater mussels). Anodonta imbecillis copper sulfate reference toxicant/food test, Clinch River-Environmental Restoration Program (CR-ERP)

    SciTech Connect

    Simbeck, D.J.

    1993-12-31

    Reference toxicant testing using juvenile freshwater mussels was conducted as part of the CR-ERP biomonitoring study of Clinch River sediments to assess the sensitivity of test organisms and the overall performance of the test. Tests were conducted using moderately hard synthetic water spiked with known concentrations of copper as copper sulfate. Two different foods, phytoplankton and YCT-Selenastrum (YCT-S), were tested in side by side tests to compare food quality. Toxicity testing of copper sulfate reference toxicant was conducted from July 6--15, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Although significant reduction in growth, compared to the phytoplankton control, was seen in all treatments, including the YCT-S Control, the consequence of this observation has not been established. Ninety-day testing of juvenile mussels exhibited large variations in growth within treatment and replicate groups. Attachments to this report include: Toxicity test bench sheets and statistical analyses; and Copper analysis request and results.

  3. A computational study of the copper(II)-catalyzed enantioselective intramolecular aminooxygenation of alkenes.

    PubMed

    Belding, Lee; Chemler, Sherry R; Dudding, Travis

    2013-10-18

    The origin of the enantioselectivity in the [Cu(R,R)-Ph-box](OTf)2-catalyzed intramolecular aminooxygenation of N-sulfonyl-2-allylanilines and 4-pentenylsulfonamides to afford chiral indolines and pyrrolidines, respectively, was investigated using density functional theory (DFT) calculations. The pyrrolidine-forming transition-state model for the major enantiomer involves a chairlike seven-membered cyclization transition state with a distorted square-planar copper center, while the transition-state model for the minor enantiomer was found to have a boatlike cyclization geometry having a distorted tetrahedral geometry about the copper center. Similar copper-geometry trends were observed in the chiral indoline-forming reactions. These models were found to be qualitatively consistent with experimental results and allow for rationalization of how substitution on the substrate backbone and N-sulfonyl substituent affect the level of enantioselectivity in these and related copper(II)-catalyzed enantioselective reactions. PMID:24032369

  4. Magnetic Interactions in the Copper Complex (L-Aspartato)(1,10-phenanthroline)copper(II) Hydrate. An Exchange-Coupled Extended System with Two Dissimilar Copper Ions.

    PubMed

    Brondino, Carlos D.; Calvo, Rafael; Atria, Ana María; Spodine, Evgenia; Nascimento, Otaciro R.; Peña, Octavio

    1997-07-01

    We report EPR measurements in single-crystal samples at the microwave frequencies 9.8 and 34.3 GHz and magnetic susceptibility measurements in polycrystalline samples for the ternary complex of copper with aspartic acid and phenanthroline, (L-aspartato)(1,10-phenanthroline)copper(II) hydrate. The crystal lattice of this compound is composed of two dissimilar copper ions identified as Cu(A) and Cu(B), which are in two types of copper chains called A and B, respectively, running parallel to the b crystal axis. The copper ions in the A chains are connected by the aspartic acid molecule, and those in the B chains by a chemical path that involves a carboxylate bridge and a hydrogen bond. Both chains are held together by a complex network of hydrogen bonds and by hydrophobic interactions between aromatic amines. Magnetic susceptibility data indicate a Curie-Weiss behavior in the studied temperature range (2-300 K). The EPR spectra at 9.8 GHz display a single exchange collapsed resonance for any magnetic field orientation, in the so-called strong exchange regime. Those at 34.3 GHz are within the so-called weak exchange regime and display two resonances which belong to each type of copper ion chain. The decoupling of the spectra at 34.3 GHz using a theory based on Anderson's model for the case of two weakly exchange coupled spins S = (1)/(2) allows one to obtain the angular variation of the squares of the g-factor and the peak-to-peak line width of each resonance. This model also allows one to evaluate the exchange parameter |J(AB)/k| = 2.7(6) mK associated with the chemical path connecting dissimilar copper ions. The line width data obtained for each component of the spectra at 34.3 GHz are analyzed in terms of a model based on Kubo and Tomita's theory, to obtain the exchange parameters |J(A)/k| = 0.77(2) K and |J(B)/k| = 1.44(2) K associated with the chemical paths connecting the similar copper ions of types A and B, respectively.

  5. Bis[4-bromo-2-(cyclo-pentyl-imino-meth-yl)phenolato]copper(II).

    PubMed

    Cai, Bang-Hong

    2009-01-01

    The title compound, [Cu(C(12)H(13)BrNO)(2)], was prepared by the reaction of 5-bromo-salicylaldehyde, cyclo-pentyl-amine and copper(II) acetate in an ethanol solution. The Cu(II) atom lies on an inversion center and is four-coordinated in a square-planar geometry by two N and two O atoms from two 4-bromo-2-(cyclo-pentyl-imino-meth-yl)phenolate Schiff base ligands. PMID:21582106

  6. Heparan Sulfate Proteoglycans Promote Telomerase Internalization and MHC Class II Presentation on Dendritic Cells.

    PubMed

    Galaine, Jeanne; Kellermann, Guillaume; Guillaume, Yves; Boidot, Romain; Picard, Emilie; Loyon, Romain; Queiroz, Lise; Boullerot, Laura; Beziaud, Laurent; Jary, Marine; Mansi, Laura; André, Claire; Lethier, Lydie; Ségal-Bendirdjian, Evelyne; Borg, Christophe; Godet, Yann; Adotévi, Olivier

    2016-09-01

    Telomerase is a prototype-shared tumor Ag and represents an attractive target for anticancer immunotherapy. We have previously described promiscuous and immunogenic HLA-DR-restricted peptides derived from human telomerase reverse transcriptase (hTERT) and referred as universal cancer peptide (UCP). In nonsmall cell lung cancer, the presence of spontaneous UCP-specific CD4 T cell responses increases the survival of chemotherapy-responding patients. However, the precise mechanisms of hTERT's uptake, processing, and presentation on MHC-II molecules to stimulate CD4 T cells are poorly understood. In this work, by using well-characterized UCP-specific CD4 T cell clones, we showed that hTERT processing and presentation on MHC-II involve both classical endolysosomal and nonclassical cytosolic pathways. Furthermore, to our knowledge, we demonstrated for the first time that hTERT's internalization by dendritic cells requires its interaction with surface heparan sulfate proteoglycans. Altogether, our findings provide a novel mechanism of tumor-specific CD4 T cell activation and will be useful for the development of novel cancer immunotherapies that harness CD4 T cells. PMID:27481844

  7. Copper(II) Carboxylate Promoted Intramolecular Carboamination of Alkenes for the Synthesis of Polycyclic Lactams

    PubMed Central

    Fuller, Peter H.; Chemler, Sherry R.

    2008-01-01

    The copper(II) carboxylate promoted intramolecular carboamination reactions of variously substituted γ-alkenyl amides have been investigated. These oxidative cyclization reactions efficiently provide polycyclic lactams, useful intermediates in nitrogen heterocycle synthesis, in good to excellent yields. The efficiency of the carboamination process is dependent upon the structure of the amide backbone as well as the nitrogen substituent. PMID:18044907

  8. Reversible DNA i-motif to hairpin switching induced by copper(II) cations.

    PubMed

    Day, Henry Albert; Wright, Elisé Patricia; MacDonald, Colin John; Gates, Andrew James; Waller, Zoë Ann Ella

    2015-09-25

    i-Motif DNA structures have previously been utilised for many different nanotechnological applications, but all have used changes in pH to fold the DNA. Herein we describe how copper(II) cations can alter the conformation of i-motif DNA into an alternative hairpin structure which is reversible by chelation with EDTA.

  9. Surface confined heteroleptic copper(II)-polypyridyl complexes for photonuclease activity.

    PubMed

    Singh, Vikram; Mondal, Prakash C; Kumar, Anup; Jeyachandran, Yekkoni L; Awasthi, Satish K; Gupta, Rinkoo D; Zharnikov, Michael

    2014-10-01

    Heteroleptic copper(II)-polypyridyl complexes with extended π-conjugated, aromatic terminal units were immobilized on glass/Si substrates to intercalate DNA and cleave it upon photoexposure. Photonuclease activity is shown to be high, well reproducible and non-destructible towards the assembled complexes.

  10. Fe(III)EDTA and Fe(II)EDTA-NO reduction by a sulfate reducing bacterium in NO and SO₂ scrubbing liquor.

    PubMed

    Chen, Mingxiang; Zhou, Jiti; Zhang, Yu; Wang, Xiaojun; Shi, Zhuang; Wang, Xiaowei

    2015-03-01

    A viable process concept, based on NO and SO2 absorption into an alkaline Fe(II)EDTA (EDTA: ethylenediaminetetraacetic acid) solution in a scrubber combined with biological reduction of the absorbed SO2 utilizing sulfate reducing bacteria (SRB) and regeneration of the scrubbing liquor in a single bioreactor, was developed. The SRB, Desulfovibrio sp. CMX, was used and its sulfate reduction performances in FeEDTA solutions and Fe(II)EDTA-NO had been investigated. In this study, the detailed regeneration process of Fe(II)EDTA solution, which contained Fe(III)EDTA and Fe(II)EDTA-NO reduction processes in presence of D. sp. CMX and sulfate, was evaluated. Fe(III)EDTA and Fe(II)EDTA-NO reduction processes were primarily biological, even if Fe(III)EDTA and Fe(II)EDTA-NO could also be chemically convert to Fe(II)EDTA by biogenic sulfide. Regardless presence or absence of sulfate, more than 87 % Fe(III)EDTA and 98 % Fe(II)EDTA-NO were reduced in 46 h, respectively. Sulfate and Fe(III)EDTA had no affection on Fe(II)EDTA-NO reduction. Sulfate enhanced final Fe(III)EDTA reduction. Effect of Fe(III)EDTA on Fe(II)EDTA-NO reduction rate was more obvious than effect of sulfate on Fe(II)EDTA-NO reduction rate before 8 h. To overcome toxicity of Fe(II)EDTA-NO on SRB, Fe(II)EDTA-NO was reduced first and the reduction of Fe(III)EDTA and sulfate occurred after 2 h. First-order Fe(II)EDTA-NO reduction rate and zero-order Fe(III)EDTA reduction rate were detected respectively before 8 h.

  11. The Unusual Colour of Copper Deposited on a Graphite Electrode in an Aqueous Solution of CuSO[subscript 4

    ERIC Educational Resources Information Center

    Petrusevski, Vladimir M.; Stojanovska, Marina

    2010-01-01

    The colour of the copper layer deposited on a graphite electrode during electrolysis of an aqueous solution of copper(II) sulfate looks whitish-grey when inspected in situ. Taking the electrode out of the solution reveals the familiar orange-red colour of deposited copper. The explanation is found in terms of the almost ideal complementary colours…

  12. Binary adsorption of copper(II) and cadmium(II) from aqueous solutions by biomass of marine alga Durvillaea potatorum

    SciTech Connect

    Yu, Q.; Kaewsarn, P.

    1999-06-01

    Much work on the biosorption of heavy metals by low-cost, natural biomass has been on the uptake of single metals. In practice, wastewaters often contain multiple heavy metal ions. In this paper the binary adsorption of copper(II) and cadmium(II) by a pretreated biomass of the marine alga Durvillaea potatorum from aqueous solutions was studied. The results showed that the uptake capacities for each heavy metal of the binary system were lower when compared with the single metal biosorption for copper and cadmium, respectively, but the total capacities for the binary system were similar to those obtained for single metal biosorption. The uptake capacities for copper and cadmium increased as the equilibrium pH increased and reached a plateau at a pH around 5.0. The uptake process was relatively fast, with 90% of the adsorption completed within 10 minutes for copper and 30 minutes for cadmium, and equilibrium reached after about 60 minutes of stirring. The biosorption isotherms of binary systems were not significantly affected by equilibrium temperature. The presence of light metal ions in solution also did not affect adsorption significantly. The binary adsorption was successfully predicted by the extended Langmuir model, using parameters and capacities obtained from single component systems.

  13. Synthesis of the native copper(II)-transport site of human serum albumin and its copper(II)-binding properties.

    PubMed Central

    Iyer, K S; Lau, S J; Laurie, S H; Sarkar, B

    1978-01-01

    A derivative of the native-sequence tripeptide of the specific Cu(II)-transport site of human serum albumin, L-aspartyl-L-alanyl-L-histidine N-methylamide, was synthesized, and its binding to Cu(II) was examined to determine the influence of the side-chain groups on the Cu(II) binding. The equilibria involved in the Cu(II)-L-aspartyl-L-alanyl-L-histidine N-methylamide system were investigated by analytical potentiometry. Three complex species were found in the pH range 4-10. The same species were identified in both the visible and circular-dichroism spectra. The main species present in the physiological pH range is shown to have the same ligands around the square-planar Cu(II) ion as those reported for albumin and tripeptides diglycyl-L-histidine and its N-methylamide derivative. The results obtained from competition experiments showed that this tripeptide has a higher affinity towards Cu(II) than has albumin itself. The overall findings are compared with those from albumin. At neutral pH the side chains do not play any important role in the Cu(II) binding, but at low pH the beta-carboxyl group of the N-terminal aspartic residue becomes important. A possible competition site on albumin for Cu(II) at low pH is discussed. PMID:24440

  14. Redox Activity of Copper(II) Complexes with NSFRY Pentapeptide and Its Analogues

    PubMed Central

    Wiloch, Magdalena Zofia; Wawrzyniak, Urszula Elżbieta; Ufnalska, Iwona; Piotrowski, Grzegorz; Bonna, Arkadiusz; Wróblewski, Wojciech

    2016-01-01

    The influence of cation-π interactions on the electrochemical properties of copper(II) complexes with synthesized pentapeptide C-terminal fragment of Atrial Natriuretic Factor (ANF) hormone was studied in this work. Molecular modeling performed for Cu(II)-NSFRY-NH2 complex indicated that the cation-π interactions between Tyr and Cu(II), and also between Phe-Arg led to specific conformation defined as peptide box, in which the metal cation is isolated from the solvent by peptide ligand. Voltammetry experiments enabled to compare the redox properties and stability of copper(II) complexes with NSFRY-NH2 and its analogues (namely: NSFRA-NH2, NSFRF-NH2, NSAAY-NH2, NSAAA-NH2, AAAAA-NH2) as well as to evaluate the contribution of individual amino acid residues to these properties. The obtained results led to the conclusion, that cation-π interactions play a crucial role in the effective stabilization of copper(II) complexes with the fragments of ANF peptide hormone and therefore could control the redox processes in other metalloproteins. PMID:27517864

  15. Redox Activity of Copper(II) Complexes with NSFRY Pentapeptide and Its Analogues.

    PubMed

    Wiloch, Magdalena Zofia; Wawrzyniak, Urszula Elżbieta; Ufnalska, Iwona; Piotrowski, Grzegorz; Bonna, Arkadiusz; Wróblewski, Wojciech

    2016-01-01

    The influence of cation-π interactions on the electrochemical properties of copper(II) complexes with synthesized pentapeptide C-terminal fragment of Atrial Natriuretic Factor (ANF) hormone was studied in this work. Molecular modeling performed for Cu(II)-NSFRY-NH2 complex indicated that the cation-π interactions between Tyr and Cu(II), and also between Phe-Arg led to specific conformation defined as peptide box, in which the metal cation is isolated from the solvent by peptide ligand. Voltammetry experiments enabled to compare the redox properties and stability of copper(II) complexes with NSFRY-NH2 and its analogues (namely: NSFRA-NH2, NSFRF-NH2, NSAAY-NH2, NSAAA-NH2, AAAAA-NH2) as well as to evaluate the contribution of individual amino acid residues to these properties. The obtained results led to the conclusion, that cation-π interactions play a crucial role in the effective stabilization of copper(II) complexes with the fragments of ANF peptide hormone and therefore could control the redox processes in other metalloproteins. PMID:27517864

  16. Isolation, Characterization and Antitumour Propirties of the 1,2-Popylenediaminetetraacetate trans-Diaqua-Copper (II)

    PubMed Central

    Kamah, S.; Vilaplana, R.; Moreno, J.; Akdi, K.; García-Herdugo, G.

    2000-01-01

    A trans-diaquacomplex formed by copper(II) sulphate and the sequestering polyamminopolycarboxylic ligand 1,2-propylenediaminetetraacetic acid (PDTA) has been isolated and characterized by chemical analysis, titrimetry, FT-IR and electronic spectroscopy, Potentiometric and electronic measurements identified the ligand as tetradentate, two nitrogen and two oxygen atoms being bonded to the Cu(II) in planar positions. This octahedral monomeric soluble compound, is an unusual example of a copper (II) substance showing significant in vitro antitumour activity against the human ovarian tumour cells TG (ID50 = 2.29 μM at 48 h) and important in vivo antitumour activity against solid Sarcoma 180 with complete regression of the tumour at a dose of 12.5 mg/Kg body weight. PMID:18475948

  17. Control of size in losartan/copper(II) coordination complex hydrophobic precipitate.

    PubMed

    Denadai, Ângelo M L; Da Silva, Jeferson G; Guimarães, Pedro P G; Gomes, Leonardo Bertolini S; Mangrich, Antonio S; de Rezende, Edivaltrys I P; Daniel, Izabela M P; Beraldo, Heloísa; Sinisterra, Rubén D

    2013-10-01

    Reaction of highly soluble orally active, non-peptide antihypertensive drug losartan with copper(II) leads to the spontaneous formation of a very insoluble 2:1 covalent complex, which self assembles in a hydrophobic supramolecular structure of nanometric dimensions. Thermal analysis showed that Los/Cu(II) complex presents intermediate stability in comparison with its precursors KLos and Cu(OAc)2·H2O. Isothermal titration calorimetry indicated complexation to be a stepwise process, driven by enthalpy and entropy. Zeta potential and DLS measurements showed that it is possible to control the size and charge of nanoprecipitates by adjusting the relative concentration of Los(-) and Cu(II).

  18. Antitubercular and fluorescence studies of copper(II) complexes with quinolone family member, ciprofloxacin

    NASA Astrophysics Data System (ADS)

    Kharadi, G. J.

    2011-09-01

    Four new mixed-ligand complexes of Cu(II) with ciprofloxacin (Cip) and uninegative bidentate ligands have been synthesized and characterized. The structure of mixed-ligand complexes was investigated using spectroscopic method, physicochemical and elemental analyses. The fluorescence spectra of complexes show red shift, which may be due to the chelation by the ligands to the metal ion. It enhances ligand ability to accept electrons and decreases the electron transition energy. Antimycobacterial screening of ligand and its copper compound against Mycobacterium tuberculosis shows clear enhancement in the antitubercular activity upon copper complexation.

  19. Copper(II) ions and the Alzheimer's amyloid-β peptide: Affinity and stoichiometry of binding

    NASA Astrophysics Data System (ADS)

    Tõugu, Vello; Friedemann, Merlin; Tiiman, Ann; Palumaa, Peep

    2014-10-01

    Deposition of amyloid beta (Aβ) peptides into amyloid plaques is the hallmark of Alzheimer's disease. According to the amyloid cascade hypothesis this deposition is an early event and primary cause of the disease, however, the mechanisms that cause this deposition remain elusive. An increasing amount of evidence shows that the interactions of biometals can contribute to the fibrillization and amyloid formation by amyloidogenic peptides. From different anions the copper ions deserve the most attention since it can contribute not only toamyloid formation but also to its toxicity due to the generation of ROS. In this thesis we focus on the affinity and stoichiometry of copper(II) binding to the Aβ molecule.

  20. Polynuclear and mixed-ligand complexes of copper(II) and nickel(II) with (1-hydroxyethylidene)bisphosphonic acid

    SciTech Connect

    Amirov, R.R.; Saprykova, Z.A.

    1987-12-20

    The compositions and stabilities of heteronuclear and mixed-ligand copper(II) and nickel(II) (1-hydroxyethylidene)bisphosphonates were determined. Parameters of the compatibility of the ligands and central ions in the complexes were calculated. It was shown that the monoprotonated anion of (1-hydroxyethylidene)bisphosphonic acid is capable of terdentate coordination with the participation of the alcoholic hydroxy group. The acidities of the solutions were determined on a pH-673 meter. The spin-lattice relaxation time was measured on a pulse NMR spectrometer.

  1. Experimental investigation on the mechanism of chelation-assisted, copper(II) acetate-accelerated azide-alkyne cycloaddition.

    PubMed

    Kuang, Gui-Chao; Guha, Pampa M; Brotherton, Wendy S; Simmons, J Tyler; Stankee, Lisa A; Nguyen, Brian T; Clark, Ronald J; Zhu, Lei

    2011-09-01

    A mechanistic model is formulated to account for the high reactivity of chelating azides (organic azides capable of chelation-assisted metal coordination at the alkylated azido nitrogen position) and copper(II) acetate (Cu(OAc)(2)) in copper(II)-mediated azide-alkyne cycloaddition (AAC) reactions. Fluorescence and (1)H NMR assays are developed for monitoring the reaction progress in two different solvents, methanol and acetonitrile. Solvent kinetic isotopic effect and premixing experiments give credence to the proposed different induction reactions for converting copper(II) to catalytic copper(I) species in methanol (methanol oxidation) and acetonitrile (alkyne oxidative homocoupling), respectively. The kinetic orders of individual components in a chelation-assisted, copper(II)-accelerated AAC reaction are determined in both methanol and acetonitrile. Key conclusions resulting from the kinetic studies include (1) the interaction between copper ion (either in +1 or +2 oxidation state) and a chelating azide occurs in a fast, pre-equilibrium step prior to the formation of the in-cycle copper(I)-acetylide, (2) alkyne deprotonation is involved in several kinetically significant steps, and (3) consistent with prior experimental and computational results by other groups, two copper centers are involved in the catalysis. The X-ray crystal structures of chelating azides with Cu(OAc)(2) suggest a mechanistic synergy between alkyne oxidative homocoupling and copper(II)-accelerated AAC reactions, in which both a bimetallic catalytic pathway and a base are involved. The different roles of the two copper centers (a Lewis acid to enhance the electrophilicity of the azido group and a two-electron reducing agent in oxidative metallacycle formation, respectively) in the proposed catalytic cycle suggest that a mixed valency (+2 and +1) dinuclear copper species be a highly efficient catalyst. This proposition is supported by the higher activity of the partially reduced Cu(OAc)(2) in

  2. Immobilization of Hg(II) by Coprecipitation in Sulfate-Cement Systems

    PubMed Central

    2012-01-01

    Uptake and molecular speciation of dissolved Hg during formation of Al- or Fe-ettringite-type and high-pH phases were investigated in coprecipitation and sorption experiments of sulfate-cement treatments used for soil and sediment remediation. Ettringite and minor gypsum were identified by XRD as primary phases in Al systems, whereas gypsum and ferrihydrite were the main products in Hg–Fe precipitates. Characterization of Hg–Al solids by bulk Hg EXAFS, electron microprobe, and microfocused-XRF mapping indicated coordination of Hg by Cl ligands, multiple Hg and Cl backscattering atoms, and concentration of Hg as small particles. Thermodynamic predictions agreed with experimental observations for bulk phases, but Hg speciation indicated lack of equilibration with the final solution. Results suggest physical encapsulation of Hg as a polynuclear chloromercury(II) salt in ettringite as the primary immobilization mechanism. In Hg–Fe solids, structural characterization indicated Hg coordination by O atoms only and Fe backscattering atoms that is consistent with inner-sphere complexation of Hg(OH)20 coprecipitated with ferrihydrite. Precipitation of ferrihydrite removed Hg from solution, but the resulting solid was sufficiently hydrated to allow equilibration of sorbed Hg species with the aqueous solution. Electron microprobe XRF characterization of sorption samples with low Hg concentration reacted with cement and FeSO4 amendment indicated correlation of Hg and Fe, supporting the interpretation of Hg removal by precipitation of an Fe(III) oxide phase. PMID:22594782

  3. Reconstitution of Formylglycine-generating Enzyme with Copper(II) for Aldehyde Tag Conversion

    PubMed Central

    Holder, Patrick G.; Jones, Lesley C.; Drake, Penelope M.; Barfield, Robyn M.; Bañas, Stefanie; de Hart, Gregory W.; Baker, Jeanne; Rabuka, David

    2015-01-01

    To further our aim of synthesizing aldehyde-tagged proteins for research and biotechnology applications, we developed methods for recombinant production of aerobic formylglycine-generating enzyme (FGE) in good yield. We then optimized the FGE biocatalytic reaction conditions for conversion of cysteine to formylglycine in aldehyde tags on intact monoclonal antibodies. During the development of these conditions, we discovered that pretreating FGE with copper(II) is required for high turnover rates and yields. After further investigation, we confirmed that both aerobic prokaryotic (Streptomyces coelicolor) and eukaryotic (Homo sapiens) FGEs contain a copper cofactor. The complete kinetic parameters for both forms of FGE are described, along with a proposed mechanism for FGE catalysis that accounts for the copper-dependent activity. PMID:25931126

  4. Catalytic wet oxidation of thiocyanate with homogeneous copper(II) sulphate catalyst.

    PubMed

    Collado, Sergio; Laca, Adriana; Díaz, Mario

    2010-05-15

    The wet oxidation of thiocyanate has been investigated in a semi-batch reactor at temperatures between 423 and 473 K and pressures between 6.1 x 10(3) and 1.0 x 10(4)kPa in the presence of copper(II) sulphate as catalyst. The effects of copper concentration, initial thiocyanate concentration, pressure and temperature on the reaction rate were analyzed and the main products of reaction were identified. A kinetic model for the Cu-catalyzed reaction is here proposed, including temperature, oxygen concentration, and the reduction of Cu(2+) to Cu(+) that gives an accurate prediction of the oxidation process under the assayed conditions. A mechanistic model based on the formation of a transition complex between a copper cation and two thiocyanate anions has been proposed for the catalytic wet oxidation.

  5. Biosorption of copper(II) and zinc(II) from aqueous solution by Pseudomonas putida CZ1.

    PubMed

    Chen, Xin Cai; Wang, Yuan Peng; Lin, Qi; Shi, Ji Yan; Wu, Wei Xiang; Chen, Ying Xu

    2005-12-10

    To study Pseudomonas putida CZ1, having high tolerance to copper and zinc on the removal of toxic metals from aqueous solutions, the biosorption of Cu(II) and Zn(II) by living and nonliving P. putida CZ1 were studied as functions of reaction time, initial pH of the solution and metal concentration. It was found that the optimum pH for Zn(II) removal by living and nonliving cells was 5.0, while it was 5.0 and 4.5, respectively, for Cu(II) removal. At the optimal conditions, metal ion biosorption was increased as the initial metal concentration increased. The adsorption data with respect to both metals provide an excellent fit to the Langmuir isotherm. The binding capacity of living cells is significantly higher than that of nonliving cells at tested conditions. It demonstrated that about 40-50% of the metals were actively taken up by P. putida CZ1, with the remainder being passively bound to the bacterium. Moreover, desorption efficiency of Cu(II) and Zn(II) by living cells was 72.5 and 45.6% under 0.1M HCl and it was 95.3 and 83.8% by nonliving cells, respectively. It may be due to Cu(II) and Zn(II) uptake by the living cells enhanced by intracellular accumulation. PMID:16289732

  6. Determination of the equilibrium, kinetic and thermodynamic parameters of adsorption of copper(II) ions onto seeds of Capsicum annuum.

    PubMed

    Ozcan, Adnan; Ozcan, A Safa; Tunali, Sibel; Akar, Tamer; Kiran, Ismail

    2005-09-30

    Adsorption of copper ions onto Capsicum annuum (red pepper) seeds was investigated with the variation in the parameters of pH, contact time, adsorbent and copper(II) concentrations and temperature. The nature of the possible adsorbent and metal ion interactions was examined by the FTIR technique. The copper(II) adsorption equilibrium was attained within 60 min. Adsorption of copper(II) ions onto C. annuum seeds followed by the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. Maximum adsorption capacity (q(max)) of copper(II) ions onto red pepper seeds was 4.47x10(-4) molg(-1) at 50 degrees C. Three kinetic models including the pseudo-first-order, pseudo-second-order and intraparticle diffusion equations were selected to follow the adsorption process. Kinetic parameters such as rate constants, equilibrium adsorption capacities and related correlation coefficients, for each kinetic model were calculated and discussed. It was indicated that the adsorption of copper(II) ions onto C. annuum seeds could be described by the pseudo-second-order kinetic model and also followed the intraparticle diffusion model up to 60 min, but diffusion is not only the rate controlling step. Thermodynamics parameters such as the change of free energy, enthalpy and entropy were also evaluated for the adsorption of copper(II) ions onto C. annuum seeds.

  7. Intercalation of organic molecules in 2D copper (II) nitroprusside: Intermolecular interactions and magnetic properties

    SciTech Connect

    Osiry, H.; Cano, A.; Lemus-Santana, A.A.; Rodríguez, A.; Carbonio, R.E.; Reguera, E.

    2015-10-15

    This contribution discusses the intercalation of imidazole and its 2-ethyl derivative, and pyridine in 2D copper nitroprusside. In the interlayer region, neighboring molecules remain interacting throu gh their dipole and quadrupole moments, which supports the solid 3D crystal structure. The crystal structure of this series of intercalation compounds was solved and refined from powder X-ray diffraction patterns complemented with spectroscopic information. The intermolecular interactions were studied from the refined crystal structures and low temperature magnetic measurements. Due to strong attractive forces between neighboring molecules, the resulting π–π cloud overlapping enables the ferromagnetic coupling between metal centers on neighboring layers, which was actually observed for the solids containing imidazole and pyridine as intercalated molecules. For these two solids, the magnetic data were properly described with a model of six neighbors. For the solid containing 2-ethylimidazole and for 2D copper nitroprusside, a model of four neighbors in a plane is sufficient to obtain a reliable data fitting. - Highlights: • Intercalation of organic molecules in 2D copper (II) nitroprusside. • Molecular properties of intercalation compounds of 2D copper (II) nitroprusside. • Magnetic properties of hybrid inorganic–organic solids. • Hybrid inorganic–organic 3D framework.

  8. The structure of amorphous bulk and silica-supported copper(II) hydroxides

    SciTech Connect

    Kriventsov, V.V.; Kochubey, D.I.; Elizarova, G.L.; Matvienko, L.G.; Parmon, V.N.

    1999-07-01

    Determination of the structure of surface hydroxocompounds is one of the most delicate areas of environmental chemistry, geochemistry, and catalysis. In nature, these compounds are formed everywhere, mostly by absorption of multicharged metal cations on different soil constitutents from water solutions. The data obtained show that at pH 7 copper(II) ions are adsorbed on a SiO{sub 2} surface as polymeric species of hydroxide nature. The structure of these species is similar to that of the bulk amorphous copper hydroxide. The amorphous state of supported Cu(OH){sub 2} is caused by a small (ca. 11 {angstrom}) size of the surface particles. In contrast, the overstoichiometric water molecules seem to act as ``amorphizers`` of the bulk copper hydroxide. The structures of the bulk and dispersed amorphous copper(II) hydroxide were determined. The amorphous Cu(OH){sub 2} has a layered structure close to the structure of the crystalline hydroxide, but the layers in the amorphous hydroxide are shifted toward one another approximately for {1/4} of the c period of the lattice.

  9. Electron-nuclear double resonance on copper (II) tetraimidazole

    NASA Astrophysics Data System (ADS)

    Van Camp, Harlan L.; Sands, Richard H.; Fee, James A.

    1981-09-01

    We have investigated the electron-nuclear double resonance (ENDOR) from frozen aqueous solutions of 65Cu++(imidazole)4, 65Cu++ (imidazole-15N)4, and 65Cu++(imidazole-Dn)4, where n = 1, 2, 3, and 4 for selectively deuterated imidazole. We have observed ENDOR associated with the imidazole protons and the two imidazole nitrogens. The selective deuteration has allowed us to attempt identification of the weakly coupled protons responsible for the ENDOR spectrum, and a comparison of the overall line shape of that spectrum taken at two extreme points of the EPR spectrum suggests that some of the imidazole planes are tilted with respect to the plane of the complex. The ENDOR arising from the nitrogen nearest the copper is primarily isotropic with A(g⊥) = 41.6±1.5 MHz and A(g∥) = 39.8±1.5 MHz. The resonance shows little structure and seems consistent with a picture that requires some inequivalence among the various imidazoles. The remote nitrogen ENDOR reveals both hyperfine and quadrupole effects with approximately isotropic A(14N) = 1.79 MHz, Qz'z'?0.360 MHz, and Qx'x'y'x'?0.349 MHz. These values are in agreement with the results of the nuclear modulation effect [J. Chem. Phys. 69, 4921 (1978)]. The values for the quadrupole constants are thought to be accurate within 10% and are the same as are found in free imidazole. It is also demonstrated that, in this instance, ENDOR and the nuclear modulation effect are complementary in that they have each provided different parts of the same hyperfine spectrum.

  10. The Tachykinin Peptide Neurokinin B Binds Copper Forming an Unusual [CuII(NKB)2] Complex and Inhibits Copper Uptake into 1321N1 Astrocytoma Cells

    PubMed Central

    2013-01-01

    Neurokinin B (NKB) is a member of the tachykinin family of neuropeptides that have neuroinflammatory, neuroimmunological, and neuroprotective functions. In a neuroprotective role, tachykinins can help protect cells against the neurotoxic processes observed in Alzheimer’s disease. A change in copper homeostasis is a clear feature of Alzheimer’s disease, and the dysregulation may be a contributory factor in toxicity. Copper has recently been shown to interact with neurokinin A and neuropeptide γ and can lead to generation of reactive oxygen species and peptide degradation, which suggests that copper may have a place in tachykinin function and potentially misfunction. To explore this, we have utilized a range of spectroscopic techniques to show that NKB, but not substance P, can bind CuII in an unusual [CuII(NKB)2] neutral complex that utilizes two N-terminal amine and two imidazole nitrogen ligands (from each molecule of NKB) and the binding substantially alters the structure of the peptide. Using 1321N1 astrocytoma cells, we show that copper can enter the cells and subsequently open plasma membrane calcium channels but when bound to neurokinin B copper ion uptake is inhibited. This data suggests a novel role for neurokinin B in protecting cells against copper-induced calcium changes and implicates the peptide in synaptic copper homeostasis. PMID:23875773

  11. Breast Cancer Stem Cell Potent Copper(II)-Non-Steroidal Anti-Inflammatory Drug Complexes.

    PubMed

    Boodram, Janine N; Mcgregor, Iain J; Bruno, Peter M; Cressey, Paul B; Hemann, Michael T; Suntharalingam, Kogularamanan

    2016-02-18

    The breast cancer stem cell (CSC) potency of a series of copper(II)-phenanthroline complexes containing the nonsteroidal anti-inflammatory drug (NSAID), indomethacin, is reported. The most effective copper(II) complex in this series, 4, selectivity kills breast CSC-enriched HMLER-shEcad cells over breast CSC-depleted HMLER cells. Furthermore, 4 reduces the formation, size, and viability of mammospheres, to a greater extent than salinomycin, a potassium ionophore known to selectively inhibit CSCs. Mechanistic studies revealed that the CSC-specificity observed for 4 arises from its ability to generate intracellular reactive oxygen species (ROS) and inhibit cyclooxygenase-2 (COX-2), an enzyme that is overexpressed in breast CSCs. The former induces DNA damage, activates JNK and p38 pathways, and leads to apoptosis.

  12. Processing of O.F.E. copper beam chambers for PEP-II high energy ring

    SciTech Connect

    Hoyt, E.; Hoyt, M.; Kirby, R.; Perkins, C.; Wright, D.; Farvid, A.

    1995-08-01

    Using laboratory scale and full size PEP-II vacuum chambers, chemical cleaning, glow discharge and thermal process effects were evaluated using surface analysis by x-ray photoelectron spectroscopy (XPS). These processes were optimized to reduce surface carbon and thereby minimize photodesorption gas loads. The relation of surface carbon to ion dose was investigated and compared for pure argon, 5% oxygen in argon, and pure hydrogen plasmas. Argon incorporation was noted only when the copper was oxidized in the mixed gas. Surfaces, stable in ambient atmosphere, were obtained having surface carbon values less than 10%. These optimized recipes will be used in processing copper vacuum chambers for the PEP-II B-Factory.

  13. Chitosan-Copper (II) complex as antibacterial agent: synthesis, characterization and coordinating bond- activity correlation study

    NASA Astrophysics Data System (ADS)

    Mekahlia, S.; Bouzid, B.

    2009-11-01

    The antimicrobial activity of chitosan is unstable and sensitive to many factors such as molecular weight. Recent investigations showed that low molecular weight chitosan exhibited strong bactericidal activities compared to chitosan with high molecular weight. Since chitosan degradation can be caused by the coordinating bond, we attempt to synthesize and characterize the chitosan-Cu (II) complex, and thereafter study the coordinating bond effect on its antibacterial activity against Salmonella enteritidis. Seven chitosan-copper complexes with different copper contents were prepared and characterized by FT-IR, UV-vis, XRD and atomic absorption spectrophotometry (AAS). Results indicated that for chitosan-Cu (II) complexes with molar ratio close to 1:1, the inhibition rate reached 100%.

  14. Antiangiogenic activity of mononuclear copper(II) polypyridyl complexes for the treatment of cancers.

    PubMed

    Nagababu, Penumaka; Barui, Ayan Kumar; Thulasiram, Bathini; Devi, C Shobha; Satyanarayana, S; Patra, Chitta Ranjan; Sreedhar, Bojja

    2015-07-01

    A series of four new mononuclear copper(II) polypyridyl complexes (1-4) have been designed, developed, and thoroughly characterized by several physicochemical techniques. The CT-DNA binding properties of 1-4 have been investigated by absorption, emission spectroscopy, and viscosity measurements. All the complexes especially 1 and 4 exhibit cytotoxicity toward several cancer cell lines, suggesting their anticancer properties as observed by several in vitro assays. Additionally, the complexes show inhibition of endothelial cell (HUVECs) proliferation, indicating their antiangiogenic nature. In vivo chick embryo angiogenesis assay again confirms the antiangiogenic properties of 1 and 4. The formation of excessive intracellular ROS (H2O2 and O2(•-)) and upregulation of BAX induced by copper(II) complexes may be the plausible mechanisms behind their anticancer activities. The present study may offer a basis for the development of new transition metal complexes through suitable choice of ligands for cancer therapeutics by controlling tumor angiogenesis.

  15. Potential complex of rhodamine B and copper (II) for dye sensitizer on solar cell

    NASA Astrophysics Data System (ADS)

    Setyawati, Harsasi; Purwaningsih, Aning; Darmokoesoemo, Handoko; Hamami, Rochman, Faidur; Permana, Ahmadi Jaya

    2016-03-01

    A complex from copper(II) and rhodamine B as ligand was synthesized, characterized and applied as potential dye sensitizer on solar cell. A complex was synthesized from the reaction of copper(II) salts and rhodamine B with mole ratio 1:3. A complex showing Metal Ligand Charge Transfer (MLCT) phenomenon at 260 nm. Metal-ligand bonding through carbonyl (CO) groups at 617.22 cm-1 and methoxy (CH3O) groups at 339.47 cm-1. Electrical conductivity analysis confirms that the complex was ionic compound. The complex was applied as potential dye sensitizer with open circuit voltage 0.48775 V, short circuit current 0.01025 mA/cm2 and efficiency 0.0039 %.

  16. Para-Selective Halogenation of Nitrosoarenes with Copper(II) Halides.

    PubMed

    van der Werf, Angela; Selander, Nicklas

    2015-12-18

    The para-selective direct bromination and chlorination of nitrosoarenes with copper(II) bromide and chloride is reported. Under mild reaction conditions, a range of halogenated arylnitroso compounds are obtained in moderate to good yields with high regioselectivity. Additionally, the versatility of the method is demonstrated by the development of a one-pot procedure to obtain the corresponding para-halogenated aniline- and nitrobenzene derivatives. PMID:26606695

  17. Copper(II) binding by free and kaolinite-sorbed humic substances

    NASA Astrophysics Data System (ADS)

    Kholodov, V. A.; Kiryushin, A. V.; Yaroslavtseva, N. V.; Frid, A. S.

    2014-07-01

    Humic preparations isolated from different sources—soils (a soddy-podzolic soil and a typical chernozem), high-moor peat, and brown coal—have been used. To analyze the binding of copper ions by humic substances (HSs), the preparations were obtained in two forms: solutions and humic-clay complexes (HSs irreversibly sorbed on kaolinite). With this approach, the binding of copper(II) ions by HSs has been studied in different systems: (1) Cu(II)-HSs irreversibly sorbed on kaolinite, (2) Cu(II)-dissolved HSs, and (3) Cu(II)-dissolved HSs-HSs irreversibly sorbed on kaolinite. In the systems containing both dissolved HSs and humic-clay complexes, HSs of similar structure isolated from the same source were used. The quantitative estimation of the copper binding was based on the constant of sorption ( K) for HSs in humic-kaolinite complexes and the stability constant (β) of complexes for free (dissolved) substances. Both parameters were expressed in similar units: L/kg. The values of log K = 3.31—3.33 are independent of the quantity and quality of the HSs in the sorption complexes but reliably exceed the K value for pure kaolinite (2.92). The value of β is not affected by the presence of insoluble HSs together with their soluble forms, but it depends on the source of HSs. The value of logβ varies in the range from 5.62 to 6.93, which significantly exceeds K and indicates a significantly higher affinity of dissolved HSs for copper ions than that of irreversibly sorbed HSs. The revealed regularities have shown that the content of HSs in the soil solution can significantly affect the mobility of a heavy metal bound to the soil organic matter.

  18. Complexes of sulfur-containing ligands. I. Factors influencing complex formation between D-penicillamine and copper (II) ion.

    PubMed

    Gergely, A; Sóvágó, I

    1978-07-01

    Complex formation and redox reactions between copper (II) ion and D-penicillamine were studied in detail as functions of the metal/-ligand ratio and the concentration of halide ions. It was established that a copper (I)- D-penicillamine polymeric complex of amphoteric character is formed when excess D-penicillamine is present. When the D-penicillamine/copper (II) ratio = 1.45 in the starting reaction mixture, a mixed valence complex with an intense red-violet color is formed. The formation of this compound, which contains 44% copper (II) ion, is greatly influenced by the experimental conditions, primarily by the concentration of halide ions. The main chemical and physical characteristics of the mixed valence complex were determined via magnetic and spectroscopic measurements. It was further established that a very intense blue complex is formed when the D-penicillamine/copper (II) ratio = 2 and halide ions are present. On the basis of the nature of the products formed under various conditions it was concluded that the copper (II)-D-penicillamine system may serve as a good model for studying the binding sites of copper-containing proteins. PMID:210846

  19. The effect of chain length on the thermal stability of 2-alkylimidazoles on copper and 2-alkylimidazolato copper(II) complexes

    NASA Astrophysics Data System (ADS)

    Yoshida, Shuji; Ishida, Hatsuo

    1985-02-01

    The molecular structure and thermal stability of imidazole, 2-methylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-undecylimidazole, and 2-heptadecylimidazole on copper are studied using FT-IR reflection—absorption spectroscopy. As model compounds of these complexes formed on copper, corresponding imidazole copper(II) complexes are synthesized in solution. The complexes appear to be the semicrystalline or crystalline structure. The series of imidazoles employed on copper indicates the same oxidation and degradation process at high temperatures even though imidazole, 2-methylimidazole and 2-ethylimidazole possess better thermal stability below 150°C. The synthesized complexes indicate poor thermal stability as the chain length of the alkyl substituent increases and the enhanced oxidation by the addition of copper powder. The difference in oxidation between imidazoles on copper and synthesized imidazole complexes are due to the presence of copper ion migrating from the copper substrate to catalyze oxidation and different morphological structure. The difference in oxidation among the imidazole derivatives depend on the melting points and the fraction of the imidazole ring which occupies the molecule.

  20. Electroanalytical study of the interaction between dsDNA and curcumin in the presence of copper(II).

    PubMed

    Serpi, C; Stanić, Z; Girousi, S

    2010-06-15

    As a result of the reaction between curcumin (CC) and copper(II) the characteristic peak of curcumin at -1.0V significantly increased, and the peak at -1.6V disappeared. Curcumin forms complex with copper(II). The interaction between double stranded (ds) calf-thymus DNA and curcumin in the presence of Cu(II) was studied in solution, by differential pulse adsorptive transfer voltammetry using carbon paste electrode (CPE) and hanging mercury drop electrode (HMDE). Cu(II)-CC complex generated changes in calf-thymus DNA. The characteristic peak of dsDNA, due to the oxidation of guanine residues, decreased. The increased DNA damage by Cu(II)-CC complex was observed in the presence of various concentrations of the transition metal ions, copper(II).

  1. Guanine-containing copper(II) complexes: synthesis, X-ray structures and magnetic properties.

    PubMed

    Mastropietro, Teresa F; Armentano, Donatella; Grisolia, Ettore; Zanchini, Claudia; Lloret, Francesc; Julve, Miguel; De Munno, Giovanni

    2008-01-28

    Three new compounds of formula {[Cu(gua)(H(2)O)(3)](BF(4))(SiF(6))(1/2)}(n) (1), {[Cu(gua)(H(2)O)(3)](CF(3)SO(3))(2).H(2)O}(n) (2) and [Cu(gua)(2)(H(2)O)(HCOO)]ClO(4).H(2)O.1/2HCOOH] (3) [gua = 2-amino-1H-purin-6(9H)-one] showing the unprecedented coordination of neutral guanine, have been synthesised and structurally characterized. The structures of the compounds 1 and 2 contain uniform copper(II) chains of formula [Cu(gua)(H(2)O)(3)](n)(2n+), where the copper atoms are bridged by guanine ligands coordinated via N(3) and N(7). The electroneutrality is achieved by uncoordinated tetrafluoroborate and hexafluorosilicate (1) and triflate (2). Each copper atom in 1 and 2 is five-coordinated in a distorted square pyramidal environment: two water molecules in trans positions and the N(3) and N(7a) nitrogen atoms of two guanine ligands build the basal plane whereas a water molecule fills the axial position. The values of the copper-copper separation across the bridging guanine ligand are 7.183(1) (1) and 7.123(1) A (2). is an ionic salt whose structure is made up of mononuclear [Cu(gua)(2)(H(2)O)(HCOO)](+) cations and perchlorate anions plus water and formic acid as crystallization molecules. The two guanine ligands in the cation are coordinated to the copper centre through the N(9) atom. The copper atom in 3 is four-coordinated with two monodentate guanine molecules in the trans position, a water molecule and a monodenate formate ligand building a quasi square planar surrounding. Magnetic susceptibility measurements for 1 and 2 in the temperature range 1.9-300 K show the occurrence of significant intrachain antiferromagnetic interactions between the copper(ii) ions across the guanine bridge [J = -9.6(1) (1) and -10.3(1) cm(-1) (2) with H = -J summation operator(i)S(i).S(i+1)].

  2. STUDIES ON BIOSORPTION OF ZINC(II) AND COPPER(II) ON DESULFOVIBRIO DESULFURICANS

    EPA Science Inventory

    The objectives of thes studies are to determine the equilibrium concentration and kinetics of metal sorption on sulfate-reducing bacteria (SRB) isolates. Adsorption establishes the net reversible cellular metal uptake and is related to SRB metal toxicity and the effects of enviro...

  3. Copper (II) - HisAibGly complex and its superoxide dismutase activity.

    PubMed

    Singh, Raj K; Prasad, Sudhanand; Singh, Udai P

    2010-02-01

    The superoxide anion radical is a highly reactive toxic species produced during metabolic processes. Several copper (II) complexes with peptides are known to show superoxide dismutase (SOD) activity but those having a peptide with a non-natural amino acid are limited. The synthesis of HisAibGly peptide and its complexation with copper (II) ions has been reported. The interaction of the synthetic peptide with Cu(II) was studied by electron spray ionization-mass (ESI-MS), circular dichroism (CD), absorption (UV-Vis) and electron paramagnetic resonance (EPR) spectroscopic methods. The solution studies and species distribution were performed by both spectrophotometric and potentiometric methods. The studies were performed at 25 + 0.1 degrees C with constant ionic strength (micro = 0.1 M NaNO(3)) in aqueous solution using Bjerrum-Calvin's pH-titration technique as adopted by Irving and Rossotti for binary systems. The species distribution stidies indicated that the complexation occurred from 3-11 pH and a three nitrogen coordinated species predominates at 8-9 whereas a four nitrogen coordinated species was formed between pH 9-11. The copper-peptide complex was tested for SOD activity using xanthine-xanthine oxidase - nitroblue tetrazolium (NBT) methods. PMID:20214649

  4. An unusual 3D interdigitated architecture assembled from Keggin polyoxometalates and dinuclear copper(II) complexes

    SciTech Connect

    Pang, Haijun; Yang, Ming; Kang, Lu; Ma, Huiyuan; Liu, Bo; Li, Shaobin; Liu, Heng

    2013-02-15

    A novel organic-inorganic hybrid compound, [Cu{sub 2}(bipy){sub 3}({mu}{sub 1}-H{sub 2}O){sub 2}({mu}{sub 2}-H{sub 2}O)({mu}{sub 2}-OH)(H{sub 2}BW{sub 12}O{sub 40})]{center_dot}4 H{sub 2}O (1) (bipy=4,4 Prime -bipy), has been synthesized in hydrothermal condition and characterized by elemental analysis, IR spectrum, TG analysis and single-crystal X-ray diffraction. Compound 1 possesses poly-pendant layered motifs composed of 12-tungstoborates and dinuclear copper(II) complexes, in which the mono-coordinated bipy molecules are orderly appended to both sides of the layer, respectively. Adjacent layers mutually engage in a zipper-like pattern to result in a novel 3D interdigitated architecture. The variable-temperature magnetic susceptibility of 1 showed that there existed weak antiferromagnetic interaction in 1. Toward the reduction of hydrogen peroxide, 1 has good electrocatalytic activity and remarkable stability. - A new compound has been obtained, which represents the first interdigitated architecture assembled by POMs and dinuclear copper(II) complexes. Highlights: Black-Right-Pointing-Pointer The first example of interdigitated architecture assembled by POMs and dinuclear copper(II) complexes is observed. Black-Right-Pointing-Pointer A zipper-like pattern is observed in the structure. Black-Right-Pointing-Pointer The IR, TG, XRPD, magnetism and electrochemical property of the title compound were studied.

  5. Kinetic and Spectroscopic Studies of Aerobic Copper(II)-Catalyzed Methoxylation of Arylboronic Esters and Insights into Aryl Transmetalation to Copper(II).

    PubMed

    King, Amanda E; Ryland, Bradford L; Brunold, Thomas C; Stahl, Shannon S

    2012-11-26

    We previously reported a preliminary mechanistic study of aerobic Cu(OAc)(2)-catalyzed methoxylation of 4-tolylboronic ester (King, et al. J. Am. Chem. Soc., 2009, 131, 5044-5045), which revealed that aryl transmetalation from the boronic ester to Cu(II) is the turnover-limiting step. In the present study, more-thorough kinetic and spectroscopic studies provide additional insights into transmetalation pathway and the identity of the Cu(II) catalyst resting state(s). EPR spectroscopic studies show that at least two copper(II) species are present under catalytic conditions and their relative populations vary as a function of reaction time and acidity of the arylboronic ester, and are influenced by addition of acetic acid or acetate to the reaction mixture. Analysis of kinetic data and (11)B NMR and EPR spectra under diverse reaction conditions suggests that aryl transmetalation occurs from a tetracoordinate, anionic boronate to a cationic Cu(II) species, mediated by a methoxide-bridge. PMID:23204631

  6. Copper(I) and copper(II) complexes possessing cross-linked imidazole-phenol ligands: structures and dioxygen reactivity.

    PubMed

    Kamaraj, Kaliappan; Kim, Eunsuk; Galliker, Benedikt; Zakharov, Lev N; Rheingold, Arnold L; Zuberbühler, Andreas D; Karlin, Kenneth D

    2003-05-21

    Catalytic reduction of O2 to H2O, and coupling to membrane proton translocation, occurs at the heterobinuclear heme a3-CuB active site of cytochrome c oxidase. One of the CuB ligated histidines is cross-linked to a neighboring tyrosine (C-N bond; tyrosine C6 and histidine epsilon-nitrogen), and the protic residue of this cross-linked His-Tyr moiety is proposed to participate as both an electron and a proton donor in the catalytic dioxygen reduction event. To provide insight into the chemistry of such a moiety, we have synthesized and characterized tetra- and tridentate pyridylalkylamine chelate ligands {LN4OR and LN3OR (R = H or Me)}, which include an imidazole-phenol (or anisole) cross-link and their copper(I/II) complexes. [CuI(LN4OH)]B(C6F5)4 (1) reacts with dioxygen at -80 degrees C in THF, forming an unstable trans-mu-1,2-peroxodicopper(II)complex, which subsequently converts to a dimeric copper(II)-phenolate complex [{Cu(LN4O-)}2](B(C6F5)4)2 (5a). The close analogue [CuI(LN4OMe)]B(C6F5)4 (3) binds dioxygen reversibly at -80 degrees C in tetrahydrofuran. Stopped-flow kinetics of the reaction [CuI(LN3OH)]ClO4 (2) with O2 in CH2Cl2 indicate a steady formation of the purple dimeric product [{Cu(LN3O-)}2](ClO4)2 (5b), which has been analyzed in the temperature range from -40 to +20 degrees C, DeltaH = -9.6 (6) kJ mol-1, DeltaS = -168 (2) J mol-1 K-1 (k(-40 degrees C) = 1.05(4) x 106 and k(+20 degrees C) = 4.6(2) x 105 M-2 s-1). The X-ray crystal structures of 1, [CuII(LN3OH)(MeOH)(OClO3-)](ClO4) (4), 5a, and 5b are reported. PMID:12785812

  7. EPR, mass, IR, electronic, and magnetic studies on copper(II) complexes of semicarbazones and thiosemicarbazones

    NASA Astrophysics Data System (ADS)

    Chandra, Sulekh; Gupta, Lokesh Kumar

    2005-01-01

    Copper(II) complexes having the general composition Cu(L) 2X 2 [where L = isopropyl methyl ketone semicarbazone (LLA), isopropyl methyl ketone thiosemicarbazone (LLB), 4-aminoacetophenone semicarbazone (LLC), and 4-aminoacetophenone thiosemicarbazone (LLD) and X = Cl -, 1/2SO 42-] have been synthesized. All the Cu(II) complexes reported here have been characterized by elemental analyses, molar conductance, magnetic moment susceptibility, EI mass, 1H NMR, IR, EPR, and electronic spectral studies. All the complexes were found to have magnetic moments corresponding to one unpaired electrons. The possible geometries of the complexes were assigned on the basis of EPR, electronic, and infrared spectral studies.

  8. Enhancing the copper(II) complexes cytotoxicity to cancer cells through bound to human serum albumin.

    PubMed

    Gou, Yi; Zhang, Yao; Qi, Jinxu; Zhou, Zuping; Yang, Feng; Liang, Hong

    2015-03-01

    We use Schiff-base salicylaldehyde benzoylhydrazone (HL) as the ligand for copper(II), resulting in the complexes [CuCl(L)]·H2O (C1), [CuNO3(L)]·H2O (C2) and [CuBr(L)]2 (C3). We characterize the Cu(II) compounds' interactions with human serum albumin (HSA) using fluorescence spectroscopy and molecular docking. These studies revealed that Cu(II) compounds propensity bound to IIA subdomain of HSA possible by hydrophobic interactions and hydrogen bond. Cu(II) compounds produce intracellular reactive oxygen species (ROS) in cancer cells. Complexes of HSA and copper(II) compounds enhance about 2-fold cytotoxicity in cancer cells but do not raise cytotoxicity levels in normal cells in vitro. Compared with C3 alone, HSA-C3 complex promotes HepG2 cell apoptosis and has a stronger capacity to promote cell cycle arrest at the G2/M phase of HepG2.

  9. Dispersion of chitosan on perlite for enhancement of copper(II) adsorption capacity.

    PubMed

    Hasan, Shameem; Ghosh, Tushar K; Viswanath, Dabir S; Boddu, Veera M

    2008-04-01

    Chitosan coated perlite beads were prepared by drop-wise addition of slurry, made of chitosan dissolved in oxalic acid and perlite, to an alkaline bath (0.7 M NaOH). The beads that contained 32% chitosan enhanced the accessibility of OH and amine groups present in chitosan for adsorption of copper ions. The experiments using Cu(II) ions were carried out in the concentration range of 50-4100 mg/L (0.78-64.1 mmol/L). Adsorption capacity for Cu(II) was pH dependent and a maximum uptake of 104 mg/g of beads (325 mg/g of chitosan) was obtained at pH 4.5 when its equilibrium concentration in the solution was 812.5 mg/L at 298 K. The XPS and TEM data suggested that copper was mainly adsorbed as Cu(II) and was attached to amine groups. The adsorption data could be fitted to one-site Langmuir adsorption model. Anions in the solution had minimal effect on Cu(II) adsorption by chitosan coated perlite beads. EDTA was used effectively for the regeneration of the bed. The diffusion coefficient of Cu(II) onto chitosan coated beads was calculated from the breakthrough curve and was found to be 2.02 x 10(-8) cm(2)/s.

  10. Di- versus Trinuclear Copper(II) Cryptate for the Uptake of Dicarboxylate Anions.

    PubMed

    Esteves, Catarina V; Mateus, Pedro; André, Vânia; Bandeira, Nuno A G; Calhorda, Maria José; Ferreira, Liliana P; Delgado, Rita

    2016-07-18

    Searching for receptors selective for the binding of dicarboxylate anions, the copper(II) complexes of the known ditopic octaazacryptand (t2pN8), derived from bistren [tren = tris(2-aminoethyl)amine] linked by p-xylyl spacers, were re-examined, with the expectation of observing a selective binding of oxalate or malonate by bridging the two copper centers of the [Cu2(t2pN8)(H2O)2](4+) receptor. Solution studies involving the supramolecular species formed by the receptor and oxalate (oxa(2-)), malonate (mal(2-)), and succinate (suc(2-)) anions are reported. The determined association constants revealed the unexpected formation of a 3:1:1 Cu/t2pN8/anion stoichiometry for the cascade species with oxa(2-) and mal(2-), and the single crystal X-ray structural characterization confirmed the presence of tricopper(II) complexes, with an unusual binding mode for the dicarboxylate anions. Each of the two copper atoms binds four nitrogen donor atoms of the t2pN8 cryptand and one additional hydroxide group, which bridges to the third copper. The square planar environment of this one is complete with two oxygen atoms from the oxalate (or the malonate). The two copper centers bound to the tren heads are ∼6.5 Å apart, each one at about 3.5 Å from the third Cu center. These studies were complemented by SQUID magnetization measurements and DFT calculations. The magnetic susceptibility measurements of the oxalate cascade complex showed a strong magnetic coupling (J = - 210 cm(-1)) between the Cu centers at a short distance (3.5 Å), while the coupling between the two equivalent Cu atoms (∼6.5 Å) was only -70 cm(-1). This result was well reproduced by DFT calculations. PMID:27355987

  11. Joint toxicity of tetracycline with copper(II) and cadmium(II) to Vibrio fischeri: effect of complexation reaction.

    PubMed

    Tong, Fei; Zhao, Yanping; Gu, Xueyuan; Gu, Cheng; Lee, Charles C C

    2015-03-01

    Co-contamination of antibiotic and heavy metals commonly occurs in the environment. Tetracycline (TC), a common antibiotic, can behave as an efficient organic ligand to complex with cations. In this paper, the joint toxicity of TC with two commonly existing metals, copper(II) and cadmium(II), towards a luminescent bacteria, Vibrio fischeri, are investigated. Results showed that coexistence of TC and Cu(II) showed a significant antagonistic effect, while TC and Cd(II) showed a synergistic effect. The aqueous speciation of TC with two metal cations was calculated using a chemical equilibrium software Visual MINTEQ and results indicated that a strong complexation exist between TC and Cu(II), while much weaker interaction between TC and Cd(II). Traditional joint toxicity prediction model based on independent action failed to predict the combined toxicity of TC with metals. A new method based on speciation calculation was used to evaluate the joint toxicity of ligands and cations. It is assumed that the metal-ligand complexes are non-toxic to V. fischeri and the joint toxicity is determined by the sum of toxic unit of free metal-ions and free organic ligands. It explained the joint toxicity of the mixed systems reasonably well. Meanwhile, citric acid (CA) and fulvic acid (FA) were also introduced in this study to provide a benchmark comparison with TC. Results showed it is also valid for mixed systems of CA and FA with metals except for the Cd-CA mixture.

  12. DNA breakage induced by piceatannol and copper(II): Mechanism and anticancer properties

    PubMed Central

    LI, ZHENSHENG; YANG, XIAOZHAN; DONG, SHIWU; LI, XIAOHUI

    2012-01-01

    Piceatannol (3,3′,4,5′-tetrahydroxy-trans-stilbene; Pice), found in a variety of plant sources including grapes, red wine, peanuts and rhubarb, is known as a metabolite and analog of Resveratrol (3,5,4′-trihydroxy-trans-stilbene; Res) and has higher bioactivity than Res. To explore the mechanism of DNA damage induced by Pice in the presence of copper (Cu)(II), gel electrophoresis, UV-visible spectroscopy, fluorescence spectroscopy and Fourier transform infrared spectroscopy were used. The results of gel electrophoresis demonstrated that the hydroxyl radical played a critical role in DNA cleavage. Spectroscopy confirmed that the mechanism of DNA cleavage induced by Pice-Cu(II) involves the Haber Weiss and Fenton reactions. Pice chelates with Cu(II) as a bidentate ligand, and the Pice-Cu(II) complex undergoes intramolecular electron transfer to form the semiquinone radical anion and Cu(I), which may be reoxidated by O2 to form Cu(II) with hydroxyl radical generation. In brief, the formation of the hydroxyl radical and the Cu(II)/Cu(I) redox cycle play a key role in inducing DNA damage. In this process, Pice demonstrated pro-oxidant properties. Oxidative product(s) of Pice, semiquinone, was formed and Cu(I) was reoxidized to Cu(II). The redox cycling of copper generated reactive oxygen species, which induced DNA cleavage, the hallmark of cell apoptosis. The mechanism of DNA breakage induced by Pice-Cu(II) may be a significant pathway through which cancer cells are killed. PMID:22783397

  13. The structures of the crystalline phase and columnar mesophase of rhodium (II) heptanoate and of its binary mixture with copper (II) heptanoate probed by EXAFS

    NASA Astrophysics Data System (ADS)

    Inb-Elhaj, M.; Guillon, D.; Skoulios, A.; Maldivi, P.; Giroud-Godquin, A. M.; Marchon, J.-C.

    1992-12-01

    EXAFS was used to investigate the local structure of the polar spines of rhodium (II) soaps in the columnar liquid crystalline state. It was also used to ascertain the degree of blending of the cores in binary mixtures of rhodium (II) and copper (II) soaps. For the pure rhodium soaps, the columns are shown to result from the stacking of binuclear metal-metal bonded dirhodium tetracarboxylate units bonded to one another by apical ligation of the metal atom of each complex with one of the oxygen atoms of the adjacent molecule. Mixtures of rhodium (II) and copper (II) soaps give a hexagonal columnar mesophase in which pure rhodium and pure copper columns are randomly distributed.

  14. Application of copper sulfate pentahydrate as an ammonia removal reagent for the determination of trace impurities in ammonia by gas chromatography.

    PubMed

    Aomura, Yoko; Kobayashi, Yoshihiko; Miyazawa, Yuzuru; Shimizu, Hideharu

    2010-03-12

    Rapid analysis of trace permanent gas impurities in high purity ammonia gas for the microelectronics industry is described, using a gas chromatograph equipped with a phtoionization detector. Our system incorporates a reactive precolumn in combination with the analytical column to remove the ammonia matrix peak that otherwise would complicate the measurements due to baseline fluctuations and loss of analytes. The performance of 21 precolumn candidate materials was evaluated. Copper sulfate pentahydrate (CuSO(4).5H(2)O) was shown to selectively react with ammonia at room temperature and atmospheric column pressures, without affecting the hydrogen, oxygen, nitrogen, methane or carbon monoxide peak areas. To prevent loss of trace carbon dioxide, an additional boron trioxide reactant layer was inserted above the copper sulfate pentahydrate bed in the reactive precolumn. Using the combined materials, calibration curves for carbon dioxide proved to be equivalent in both ammonia and helium matrix gases. These curves were equivalent in both matrix gases. The quantitative performance of the system was also evaluated. Peak repeatabilities, based on eight injections, were in the range of 4.1-8.2% relative standard deviation; and detection limits were 6.9 ppb for H(2), 1.8 ppb for O(2), 1.6 ppb for N(2), 6.4 ppb for CH(4), 13 ppb for CO, and 5.4 ppb for CO(2).

  15. Copper deposition on TiO{sub 2} from copper(II)hexafluoroacetylacetonate

    SciTech Connect

    Rayner, David G.; Mulley, James S.; Bennett, Roger A.

    2013-01-15

    The authors have studied the adsorption of Cu{sup II}(hfac){sub 2} on the surface of a model oxide system, TiO{sub 2}(110), and probed the molecular stability with respect to thermal cycling, using atomic scale imaging by scanning tunneling microscopy supported by x-ray photoemission spectroscopy. They find that at 473 K, the adsorbed metal-organic molecules begin to dissociate and release Cu atoms which aggregate and form Cu nanoparticles. These Cu nanoparticles ripen over time and the size (height) distribution develops into a bimodal distribution. Unlike other organometallic systems, which show a bimodal distribution due to enhanced nucleation or growth at surface step edges, the nanoparticles do not preferentially form at steps. The reduced mobility of the Cu islands may be related to the co-adsorbed ligands that remain in very small clusters on the surface.

  16. Near infrared fluorescence quenching properties of copper (II) ions for potential applications in biological imaging

    NASA Astrophysics Data System (ADS)

    Maji, Dolonchampa; Zhou, Mingzhou; Sarder, Pinaki; Achilefu, Samuel

    2014-03-01

    Fluorescence quenching properties of copper(II) ions have been used for designing Cu(II) sensitive fluorescent molecular probes. In this paper, we demonstrate that static quenching plays a key role in free Cu(II)-mediated fluorescence quenching of a near infrared (NIR) fluorescent dye cypate. The Stern-Volmer quenching constant was calculated to be KSV = 970,000 M-1 in 25 mM MES buffer, pH 6.5 at room temperature. We synthesized LS835, a compound containing cypate attached covalently to chelated Cu(II) to study fluorescence quenching by chelated Cu(II). The fluorescence quenching mechanism of chelated Cu(II) is predominantly dynamic or collisional quenching. The quenching efficiency of chelated Cu(II) was calculated to be 58% ± 6% in dimethylsulfoxide at room temperature. Future work will involve further characterization of the mechanism of NIR fluorescence quenching by Cu(II) and testing its reversibility for potential applications in designing fluorophore-quencher based molecular probes for biological imaging.

  17. Extraction of copper(II) from acid chloride solutions by N-dodecyl- and N,N-dihexylpyridinecarboxamides

    SciTech Connect

    Borowiak-Resterna, A.

    1999-01-01

    N-dodecyl- and N,N-dihexylpyridinecarboxamides with amide group at 2, 3 or 4 position were synthesized. Model individual amides were used to recover copper(II) from chloride solutions at constant water activity and constant total concentration of dissolved species in aqueous solution. It was found, that pyridine-2-carboxamide forms with copper complexes (CuCl{sub 2}){sub x}(Ext){sub 2}. Remaining amides form with copper complexes CuCl{sub 2}(Ext){sub 2}. Monoalkylamides are not suitable for extraction because they and their complexes are slightly soluble in the hydrocarbon diluents. N,N-dialkylpyridinecarboxamides and their copper complexes are sufficiently soluble in the hydrocarbon phase to carry out extraction. However, they are strong extractants and extract efficiently copper already from dilute chloride solutions ([Cl{sup {minus}}] = 0.1 M). They extract also significant amounts of copper from concentrated (3--4 M) nitrate solutions.

  18. Bis{N-[5-(4-methoxy-phen-yl)-1,3,4-oxa-diazol-2-yl]ethanimidamidato}copper(II).

    PubMed

    Djebli, Yacine; Mosbah, Salima; Boufas, Sihem; Bencharif, Leila; Roisnel, Thierry

    2010-01-01

    The title compound, [Cu(C(11)H(11)N(4)O(2))(2)], was prepared by solvothermal synthesis using 2-amino-5-(4-methoxy-phen-yl)-1,3,4-oxadiazole and copper sulfate penta-hydrate in an acetonitrile solution. The Cu(II) atom lies on an inversion center and is four-coordinated in a slightly distorted square-planar geometry by four N atoms of the ligands obtained from the formation of a bond between the amine N atom of the oxadiazole mol-ecule and the nitrile C atom of the solvent. In the crystal structure an inter-molecular N-H⋯N hydrogen bond links inversion-related mol-ecules. PMID:21580509

  19. Effect of copper(II) on natural organic matter removal during drinking water coagulation using aluminum-based coagulants.

    PubMed

    Liu, Guojing; Zhang, Xiangru; Talley, Jeffrey W

    2007-06-01

    Coagulation has been proposed as a best available technology for controlling natural organic matter (NOM) during drinking water treatment. The presence of heavy metals such as copper(II) in source water, which may form copper-NOM complexes and/or interact with a coagulant, may pose a potential challenge on the coagulation of NOM. In this work, the effect of copper(II) on NOM removal by coagulation using alum or PAX-18 (a commercial polymerized aluminum chloride from Kemiron Inc., Bartow, Florida) was examined. The results show that the presence of 1 to 10 mg/L of copper(H) in the simulated waters improved the total organic carbon (TOC) removal by up to 25% for alum coagulation and by up to 22% for PAX-18 coagulation. The increased NOM removal with the presence of copper(II) in the waters can most likely be ascribed to the formation copper-NOM complexes that may be more adsorbable on aluminum precipitates and to the formation of copper(II) co-precipitates that may also adsorb NOM. The presence of 1 to 5 mg/L of copper(I) in the waters containing 3 mg/L NOM as carbon was reduced below the maximum contaminant level goal (1.3 mg/L as copper) using either coagulant. The results suggest that the presence of copper(H) in source water may not adversely affect the NOM removal by coagulation. A good linear correlation was observed between the TOC removal efficiency and the log-total moles of the precipitated metals, which include the metal ion from a coagulant and the divalent metal ion(s) in source water. PMID:17605328

  20. Paintings on copper by the Flemish artist Frans Francken II: PIXE characterization by external microbeam

    NASA Astrophysics Data System (ADS)

    Corregidor, V.; Oliveira, A. R.; Rodrigues, P. A.; Alves, L. C.

    2015-04-01

    Resorting to an external proton microbeam, PIXE analyses of three oil paintings on copper support dated from the XVII century and attributed to the Flemish artist Frans Francken II, were undertaken. The present work aims to contribute to the compositional study of the painting materials employed by XVII century artists that exploited copper as a support for oil painting, and specifically the materials used by Francken's workshop, particularly copper plates. Because of the low thickness of the pictorial layers of this type of paintings and its non-destructive character, PIXE is the ideal technique to study the elemental composition of the paintings. Several spots in each painting were chosen for analysis in order to cover almost all the pigments used in the colour palette. Lead and calcium were detected in practically every analysed regions, probably related to the presence of lead white and chalk, usually used as ground layer on copper paintings. Small quantities of gold were also detected, which is present in many of this artist's works to embellish some details of the representations. Also this work reports the first application of the external proton microbeam set-up available at CTN/IST in Portugal for the characterization of oil paintings.

  1. Building reactive copper center(s) in human carbonic anhydrase II

    PubMed Central

    Song, He; Weitz, Andrew C.; Hendrich, Michael P.; Lewis, Edwin A.; Emerson, Joseph P.

    2014-01-01

    Re-engineering metalloproteins to generate new biologically relevant metal centers is an effective a way to test our understanding of the structural and mechanistic features that steer chemical transformations in biological systems. Here we report thermodynamic data characterizing the formation of two type-2 (T2) copper sites in carbonic anhydrase and experimental evidence showing one of these new copper centers has characteristics similar to a variety of well-characterized copper centers in synthetic models and in enzymatic systems. Human CA II is known to bind two Cu2+ ions; herein, these binding events are explored using modern isothermal titration calorimetry (ITC) techniques that have become a proven method to accurately measure metal-binding thermodynamic parameters. The two Cu2+-binding events have different affinities (Ka ∼ 5 × 1012 and 1 × 1010) and both are enthalpically driven processes. Reconstituting these Cu2+ sites under a range of conditions has allowed us to assign the Cu2+-binding event to the three-histidine, native, metal binding site. Our initial efforts to characterize these Cu2+ sites have yielded data that show distinctive (and noncoupled) EPR signals associated with each copper-binding site, and that this reconstituted enzyme can activate hydrogen peroxide to catalyze the oxidation of 2-aminophenol. PMID:23744511

  2. Structural and magnetic characterization of a tetranuclear copper(II) cubane stabilized by intramolecular metal cation-π interactions.

    PubMed

    Papadakis, Raffaello; Rivière, Eric; Giorgi, Michel; Jamet, Hélène; Rousselot-Pailley, Pierre; Réglier, Marius; Simaan, A Jalila; Tron, Thierry

    2013-05-20

    A novel tetranuclear copper(II) complex (1) was synthesized from the self-assembly of copper(II) perchlorate and the ligand N-benzyl-1-(2-pyridyl)methaneimine (L(1)). Single-crystal X-ray diffraction studies revealed that complex 1 consists of a Cu4(OH)4 cubane core, where the four copper(II) centers are linked by μ3-hydroxo bridges. Each copper(II) ion is in a distorted square-pyramidal geometry. X-ray analysis also evidenced an unusual metal cation-π interaction between the copper ions and phenyl substituents of the ligand. Calculations based on the density functional theory method were used to quantify the strength of this metal-π interaction, which appears as an important stabilizing parameter of the cubane core, possibly acting as a driving parameter in the self-aggregation process. In contrast, using the ligand N-phenethyl-1-(2-pyridyl)methaneimine (L(2)), which only differs from L(1) by one methylene group, the same synthetic procedure led to a binuclear bis(μ-hydroxo)copper(II) complex (2) displaying intermolecular π-π interactions or, by a slight variation of the experimental conditions, to a mononuclear complex (3). These complexes were studied by X-ray diffraction techniques. The magnetic properties of complexes 1 and 2 are reported and discussed.

  3. Structure and Dynamics of Solvation Shells of Copper(II) Complexes with N,O-Containing Ligands.

    PubMed

    Bukharov, Mikhail S; Shtyrlin, Valery G; Mamin, Georgy V; Stapf, Siegfried; Mattea, Carlos; Mukhtarov, Anvar Sh; Serov, Nikita Yu; Gilyazetdinov, Edward M

    2015-10-19

    EPR, NMR relaxation methods, and DFT calculations were jointly used to investigate the structural and dynamical characteristics of solvation shells of copper(II) complexes with iminodiacetic acid, glycylglycine, and glycyglycylglycine in comparison with the copper(II) bis-glycinate studied previously. A strong trans influence of deprotonated peptide nitrogen was revealed in EPR spectra parameters of copper(II) complexes with oligopeptides. With models of the experimental NMRD data and literature X-ray structural information, it was suggested that only one water molecule coordinates in axial position of copper(II) complexes with glycine and di- and triglycine (Cu(Gly)2, Cu(GGH(-1)), and Cu(GGGH(-2))(-)), and the copper ion in these complexes is pentacoordinated, while in the iminodiacetate complex, Cu(IDA), both apical positions can be occupied by solute molecules. The obtained structural results were confirmed by DFT calculations of structures of studied compounds using different functionals and basis sets. It was shown that the donor ability of equatorial ligands and trans influence have an effect on the characteristics of the axial water bond. With increasing donor strength of equatorial ligands, pentacoordination of copper(II) complexes in water solutions becomes more preferable. PMID:26440723

  4. Subneurotoxic copper(II)-induced NF-κB-dependent microglial activation is associated with mitochondrial ROS

    SciTech Connect

    Hu, Zhuqin; Yu, Fengxiang; Gong, Ping; Qiu, Yu; Zhou, Wei; Cui, Yongyao; Li, Juan Chen, Hongzhuan

    2014-04-15

    Microglia-mediated neuroinflammation and the associated neuronal damage play critical roles in the pathogenesis of neurodegenerative disorders. Evidence shows an elevated concentration of extracellular copper(II) in the brains of these disorders, which may contribute to neuronal death through direct neurotoxicity. Here we explored whether extracellular copper(II) triggers microglial activation. Primary rat microglia and murine microglial cell line BV-2 cells were cultured and treated with copper(II). The content of tumor necrosis factor-α (TNF-α) and nitric oxide in the medium was determined. Extracellular hydrogen peroxide was quantified by a fluorometric assay with Amplex Red. Mitochondrial superoxide was measured by MitoSOX oxidation. At subneurotoxic concentrations, copper(II) treatment induced a dose- and time-dependent release of TNF-α and nitric oxide from microglial cells, and caused an indirect, microglia-mediated neurotoxicity that was blocked by inhibition of TNF-α and nitric oxide production. Copper(II)-initiated microglial activation was accompanied with reduced IkB-α expression as well as phosphorylation and translocation of nuclear factor-κB (NF-κB) p65 and was blocked by NF-κB inhibitors (BAY11-7082 and SC-514). Moreover, copper(II) treatment evoked a rapid release of hydrogen peroxide from microglial cells, an effect that was not affected by NADPH oxidase inhibitors. N-acetyl-cysteine, a scavenger of reactive oxygen species (ROS), abrogated copper(II)-elicited microglial release of TNF-α and nitric oxide and subsequent neurotoxicity. Importantly, mitochondrial production of superoxide, paralleled to extracellular release of hydrogen peroxide, was induced after copper(II) stimulation. Our findings suggest that extracellular copper(II) at subneurotoxic concentrations could trigger NF-κB-dependent microglial activation and subsequent neurotoxicity. NADPH oxidase-independent, mitochondria-derived ROS may be involved in this activation

  5. Synthesis and spectroscopic studies of copper(II) and nickel(II) complexes containing hydrazonic ligands and heterocyclic coligand

    NASA Astrophysics Data System (ADS)

    Gup, Ramazan; Kırkan, Bülent

    2005-12-01

    Two types of copper(II) and nickel(II) complexes derived from benzophenone anthranoylhydrazone (L 1), 2-acetonaftanone anthranoylhydrazone (L 2), 4-phenylacetonaftonone anthranoylhydrazone (L 3), benzophenone salicyoylhydrazone (L 4), 2-acetonaftanon salicyoylhydrazone (L 5), 4-phenylacetonaftanon salicyoylhydrazone (L 6) and bidentate heterocyclic base [1,10-phenanthroline (phen)] with general stoichiometry [ML 2] and [ML(phen)]Cl have been synthesized and characterized by elemental analysis, infrared spectra, UV-vis electronic absorption spectra and magnetic susceptibility measurements. The effect of varying pH and solvent on the absorption behavior of both ligands and complexes have been investigated. According to the IR spectra, the ligands act as monobasic bidentate and coordination takes place in the enol tautomeric form.

  6. Anisotropic behavior of layer-by-layer films using highly disordered copper hexacyanoferrate(II) nanoparticles

    NASA Astrophysics Data System (ADS)

    Soek, Rafael N.; Schmidt, Ariane; Winnischofer, Herbert; Vidotti, Marcio

    2016-08-01

    Copper hexacyanoferrate(II) (Cuhcf(II)) nanoparticles (NPs) were synthesized by using a simple and straightforward methodology using aqueous solution without the need of any further passivating agent. The 15 nm NPs (obtained by TEM) were fully characterized by XRD, FTIR and Raman spectroscopy that revealed a high number of structural defects. These structural defects are responsible to produce a strong internal dipole moment. This leads to an anisotropic growth onto the electrode surface by using the layer-by-layer technique. Specular Reflectance FTIR corroborates with our assumption. The defects are also responsible for the high electroactivity of the Cuhcf(II)NPs modified electrodes in sodium based electrolytes. Our results contrast with others in which the authors attributed the cell distortion as the main phenomenon.

  7. Four copper(II) compounds synthesized by anion regulation: Structure, anticancer function and anticancer mechanism.

    PubMed

    Zhang, Zhenlei; Gou, Yi; Wang, Jun; Yang, Kun; Qi, Jinxu; Zhou, Zuping; Liang, Shichu; Liang, Hong; Yang, Feng

    2016-10-01

    Copper (Cu) compounds are a promising candidate for next generation metal anticancer drugs. Therefore, we regulated anions to synthesize four mononuclear and binuclear Cu(II) compounds derived from thiosemicarbazone Schiff base ligands and characterized them. Four of these compounds showed very high cytotoxicity to cancer cell lines in vitro. These Cu(II) compounds strongly promoted the apoptosis of BEL-7404 cells and had a capacity to arrest the cell cycle at S phase of those cells. Furthermore, reactive oxygen species (ROS), mitochondrial membrane potential and Western blot analyses revealed that these Cu(II) compounds exert their cytotoxicity through an ROS-mediated intrinsic mitochondrial pathway accompanied by the regulation of Bcl-2 family proteins. PMID:27309677

  8. (Bis(terpyridine))copper(II) Tetraphenylborate: A Complex Example for the Jahn-Teller Effect.

    PubMed

    Meyer, Andreas; Schnakenburg, Gregor; Glaum, Robert; Schiemann, Olav

    2015-09-01

    The surprisingly complicated crystal structure of (bis(terpyridine))copper(II) tetraphenylborate [Cu(tpy)2](BPh4)2 (tpy = 2,2':6',2″-terpyridine) consists of six crystallographically independent [Cu(tpy)2](2+) complexes. At ambient temperature, five out of six [Cu(II)N6] chromophores appear to be compressed octahedra, while at 100 K, four exhibit elongated and only two compressed octahedral geometry. Temperature dependent single crystal UV/vis (100, 298 K) and EPR measurements (20, 100, 298 K) as well as AOM calculations suggest that the octahedra which show apparently compressed octahedral geometry (XRD) result from dynamic Jahn-Teller behavior of elongated octahedra [Cu(II)N6]. The detailed correlation of structural and spectroscopic data allows an understanding of the strongly solvent-dependent structures of the [Cu(tpy)2](2+) complex in solution. PMID:26275138

  9. Spectrochemical study and effect of high energatic gamma ray on copper (II) complexes

    NASA Astrophysics Data System (ADS)

    Abou Sekkina, Morsy M.; Kashar, Tahani I.; Aly, Samar A.

    2011-12-01

    Series of copper (II) complexes of 2- phenylaminoacetyl-N-phenylhydrazine carbthioamide (H 2L) has been prepared and characterized by elemental and analyses, IR, electronic spectra, magnetic moment, molar conductance measurements, thermogravimetric analyses and X-ray diffraction pattern. The IR data before and after γ- irradiation reveal that the ligand behaves as neutral, monobasic bidentate coordination of copper ion via the carbonyl group or enolic oxygen group, NH group and thiol sulphr atom group in complex B 2. The molar conductance data reveal that the chelates are non-electrolytes. From the electronic spectra and magnetic moment data, the complexes were found to have octahedral and square planar geometrical structures. The thermal behavior of these chelates before and after γ-irradiation induced more thermal stability after radiation. The X-ray diffraction patterns before and after γ- irradiation suffer partial damage after irradiation.

  10. Electrical conductivity of solutions of copper(II) nitrate crystalohydrate in dimethyl sulfoxide

    NASA Astrophysics Data System (ADS)

    Mamyrbekova, Aigul K.; Mamitova, A. D.; Mamyrbekova, Aizhan K.

    2016-06-01

    Conductometry is used to investigate the electric conductivity of Cu(NO3)2 ṡ 3H2O solutions in dimethyl sulfoxide in the 0.01-2.82 M range of concentrations and at temperatures of 288-318 K. The limiting molar conductivity of the electrolyte and the mobility of Cu2+ and NO 3 - ions, the effective coefficients of diffusion of copper(II) ions and nitrate ions, and the degree and constant of electrolytic dissociation are calculated for different temperatures from the experimental results. It is established that solutions containing 0.1-0.6 M copper nitrate trihydrate in DMSO having low viscosity and high electrical conductivity can be used in electrochemical deposition.

  11. Synthesis, characterization and catalytic activities towards epoxidation of olefins of dinuclear copper(II) complexes

    NASA Astrophysics Data System (ADS)

    Halder, Shibashis; Mukherjee, Aparajita; Ghosh, Koushik; Dey, Sudipto; Nandi, Mahasweta; Roy, Partha

    2015-12-01

    Two copper(II) complexes, [Cu2(L1)Cl3].2H2O (1) and [Cu2(L2)(N3)Cl2] (2) where HL1 = 4-methyl-2,6-bis((2-morpholinoethylimino)methyl)phenol and HL2 = 4-methyl-2,6-bis((3-morpholinopropylimino)methyl)phenol have been synthesized and characterized by elemental analysis, various spectroscopic methods, TGA and single crystal X-ray diffraction analysis. Single crystal X-ray diffraction analysis reveals that in both the complexes, two copper atoms are linked by phenoxo oxygen atom and a bridging ligand, namely chloride and azide, respectively. These complexes have been used as catalyst for the epoxidation of cyclohexene, styrene, α-methyl styrene, trans-stilbene and norbornene using tert-butyl hydroperoxide as the oxidant in acetonitrile under mild conditions. All of the substrates undergo conversion to produce respective epoxide as the major product.

  12. Isotope effects in far-infrared spectra of bis(theophyllinato)copper(II)-complexes

    NASA Astrophysics Data System (ADS)

    Drożdżewski, Piotr; Kordon, Ewa

    1998-07-01

    Far-infrared spectra have been measured for 63Cu and 65Cu isotope substituted theophylline (Tp)-metal ion complexes: Cu(Tp) 2(NH 3) 2 · 2H 2O, Cu(Tp) 2(NH 3) 2, Cu(Tp) 2 · 2H 2O and Cu(Tp) 2. In addition, spectrum of Cu(Tp) 2(ND 3) 2 · 2D 2O has been recorded. Metal-theophylline, metal-ammine and water librational and translational modes have been assigned based on observed isotope shifts and complex dehydration effects. The copper-ammine vibrations have been found at 453 and 224 cm -1, whereas the bis(theophyllinato)copper(II) modes have been detected at 192 cm -1 for Cu(Tp) 2(NH 3) 2 and presumably at about 170 cm -1 for Cu(Tp) 2.

  13. Copper

    Integrated Risk Information System (IRIS)

    Copper ; CASRN 7440 - 50 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

  14. Nickel(II) and copper(II) complexes with humic acid anions and their derivatives

    SciTech Connect

    Ryabova, I.N.

    2008-01-15

    Complexation of Ni(II) and Cu(II) in aqueous solutions with anions of humic acids, extracted from naturally oxidized coal, and with their hydroxymethyl derivatives is studied spectrophotometrically and potentiometrically. The complexation stoichiometry and the stability constants of the complexes are determined.

  15. Comparison of availability of copper(II) complexes with organic ligands to bacterial cells and to chitin

    SciTech Connect

    Vasconcelos, M.T.S.D.; Azenha, M.A.O.; Cabral, J.P.S.

    1997-10-01

    Bacterial cells or chitin were exposed to solutions with 100 {micro}M total but only 5 {micro}M free copper, due to the presence of a proper concentration of proline, lysine, cysteine, or ethylenediamine tetraacetate (EDTA). The influence of the nature and concentration of the particles and soluble ligands, on the sorption and on the desorption of the copper, at pH 6.50 and 25.0 C, was investigated. The metal sorbed by the particles and that left in the solution were measured by atomic absorption spectrometry, after different periods of contact between particles and solution. The interpretation of the results was based on the copper(II) speciation calculated through equilibrium approaches applied to homogeneous or heterogeneous systems. A significant fraction of copper bound to the organic ligands was displaced to the bacteria or chitin, and the extent of chemical reaction depended on the nature of both the soluble (or leaving) ligands and sites on the particle surface (or entering ligands), as expected by the equilibrium theory. But with chitin, the uptake of copper in the presence of cysteine or EDTA was higher than expected, which may be due to the adsorption of the soluble copper complexes on the particle surface. In consequence of a competition between soluble and particulate ligands (cells or chitin), the free copper(II) concentration decreased in the solution, even in the presence of very strong chelators. The results indicate that copper availability is not a simple function of the initial free copper concentration in the solution. Desorption of the previously fixed copper, originated by free soluble ligands indicated that the sorption of copper was quasireversible for both particles, though a larger dismissal of the equilibrium position occurred for the cells, probably due to their biological activity.

  16. Synthesis and structural characterisation of iron(II) and copper(II) diphosphates containing flattened metal oxotetrahedra

    SciTech Connect

    Keates, Adam C.; Wang, Qianlong; Weller, Mark T.

    2014-02-15

    Single crystal and bulk polycrystalline forms of K{sub 2}MP{sub 2}O{sub 7} (M=Fe(II), Cu(II)) have been synthesised and their structures determined from single crystal X-ray diffraction data. Both compounds crystallize in the tetragonal system, space group P-42{sub 1}m. Their structures are formed from infinite sheets of linked oxopolyhedra of the stoichiometry [MP{sub 2}O{sub 7}]{sup 2−} with potassium cations situated between the layers. The MO{sub 4} tetrahedra share oxygen atoms with [P{sub 2}O{sub 7}]{sup 4−} diphosphate groups and the potassium ions have KO{sub 8} square prismatic geometry. In both compounds the M(II) centre has an unusual strongly flattened, tetrahedral coordination to oxygen, as a result of the Jahn–Teller (JT) effect for the high spin d{sup 6} Fe(II) and p-orbital mixing or a second order JT effect for d{sup 9} Cu(II) centres in four fold coordination. The uncommon transition metal ion environments found in these materials are reflected in their optical absorption spectra and magnetism data. - Graphical abstract: The structures of the tetragonal polymorphs of K{sub 2}MP{sub 2}O{sub 7}, M=Cu(II), Fe(II), consist of infinite sheets of stoichiometry [MP{sub 2}O{sub 7}]{sup 2−}, formed from linked pyrophosphate groups and MO{sub 4} tetrahedra, separated by potassium ions. In both compounds the unusual tetrahedral coordination of the M(II) centre is strongly flattened as a result of Jahn–Teller (JT) effects for high spin, d{sup 6} Fe(II) and p-orbital mixing and second-order JT effects for d{sup 9} Cu(II). Display Omitted - Highlights: • Tetrahedral copper and iron(II) coordinated by oxygen. • New layered phosphate structure. • Jahn–Teller and d{sup 10} distorted coordinations.

  17. Coagulation of quartz particles in aqueous solutions of copper(II)

    SciTech Connect

    Larson, I.; Pugh, R.J.

    1998-12-15

    The colloidal stability of quartz suspension was determined over a wide range of pH in aqueous copper nitrate where the state of Cu(II) is changed from mainly aqua ions and monohydroxyl complexes in the acid and neutral pH to polynuclear hydroxo complexes and colloidal precipitated copper hydroxide at higher pH. Two regions of instability were observed and in both cases the particles were shown to have low electrophoretic mobility. In the neutral pH region, the uptake of Cu(II) was sufficient to reduce the mobility of the particles to zero, while in the high-pH region evidence suggested coagulation between precipitated Cu(OH){sub 2} and the quartz particles. It was shown that in all cases the coagulation was reversible and that the uptake of Cu(II) was dependent on the uncharged surface hydroxyl density. Studies of the coagulation kinetics showed that extended time scales were involved (several minutes in the neutral pH region to tens of minutes at high pH).

  18. 21 CFR 184.1307 - Ferric sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by treating ferric oxide...

  19. Redox noninnocence of the bridge in copper(II) salophen and bis(oxamato) complexes.

    PubMed

    de Bellefeuille, David; Orio, Maylis; Barra, Anne-Laure; Aukauloo, Ally; Journaux, Yves; Philouze, Christian; Ottenwaelder, Xavier; Thomas, Fabrice

    2015-09-21

    Two square-planar copper(II) complexes of 1,2-bis(2-hydroxy-3,5-di-tert-butylbenzimino)-4,5-bis(dimethylamino)benzene (1) and N-[4,5-bis(dimethylamino)-2-(oxalylamino)benzene]oxamate (2(2-)) were prepared. The crystal structures of the proligands H2L(1) and Et2H2L(2), as well as the corresponding complexes, are reported. The proligands each display a one-electron-oxidation wave, which is assigned to oxidation of the bis(dimethylamino)benzene moiety into a π radical. Complexes 1 and 2(2-) exhibit reversible one-electron-oxidation waves in their cyclic voltammograms (E1/2(1) = 0.14 and E1/2(2) = 0.31 V for 1 and E1/2(1) = -0.47 V vs Fc(+)/Fc for 2(2-)). The first process corresponds to oxidation of the bis(dimethylamino)benzene central ring into a π radical, while the second process for 1 is ascribed to oxidation of the π radical into an α-diiminoquinone. The one-electron-oxidized species 1(+) and 2(-) exhibit intense visible-near-IR absorptions, which are diagnostic of π radicals. They display a triplet signal in their electron paramagnetic resonance spectra, which stem from magnetic coupling between the ligand-radical spin and the copper(II) spin. The zero-field-splitting parameters are larger for 2(-) than 1(+) because of greater delocalization of the spin density onto the coordinated amidato N atoms. Density functional theory calculations support a π-radical nature of the one-electron-oxidized complexes, as well as S = 1 ground spin states. The electrogenerated 1(2+) comprises a closed-shell diiminoquinone ligand coordinated to a copper(II) metal center. Both 1 and 2 catalyze the aerobic oxidation of benzyl alcohol, albeit with different yields. PMID:26340100

  20. Analytical use of copper(II)-neocuproine in the spectrophotometric determination of hydrazines

    SciTech Connect

    Besada, A.

    1988-10-01

    This work characterizes a newly developed, sensitive and convenient spectrophotometric procedure for determination of sub-ppm concentrations of hydrazine and its organic derivatives. The method is based on formation of the cuprous neocuproine chelate after reaction of hydrazines with a prepared aqueous solution of the copper (II)--neocuproine complex. The cuprous chelate is then directly measured in aqueous solution at 458 nm. The effect of several experimental conditions influencing the reaction are presented and the method was employed for the analysis of 5 different hydrazine compounds. The standard deviation did not exceed /+/-/ 0.47%.

  1. The cytotoxic mechanisms of disulfiram and copper(ii) in cancer cells

    PubMed Central

    Tawari, Patricia Erebi; Wang, Zhipeng; Najlah, Mohammad; Tsang, Chi Wai; Kannappan, Vinodh; Liu, Peng; McConville, Christopher; He, Bin; Armesilla, Angel L.

    2015-01-01

    The anticancer activity of disulfiram (DS) is copper(ii) (Cu)-dependent. This study investigated the anticancer mechanisms of DS/Cu using in vitro cytotoxicity and metabolic kinetic analysis. Our study indicates that DS/Cu targets cancer cells by the combination of two types of actions: (1) instant killing executed by DS/Cu reaction generated reactive oxygen species; (2) delayed cytotoxicity introduced by the end product, DDC-Cu. Nanoencapsulation of DS might shed light on repositioning of DS into cancer treatment.

  2. Colossal internal barrier layer capacitance effect in polycrystalline copper (II) oxide

    NASA Astrophysics Data System (ADS)

    Sarkar, Sudipta; Jana, Pradip Kumar; Chaudhuri, B. K.

    2008-01-01

    Dielectric spectroscopy analysis of the high permittivity (κ˜104) copper (II) oxide (CuO) ceramic shows that the grain contribution plays a major role for the giant-κ value at low temperature, whereas grain boundary (GB) contribution dominates around room temperature and above. Moreover, impedance spectroscopy analysis reveals electrically heterogeneous microstructure in CuO consisting of semiconducting grains and insulating GBs. Finally, the giant dielectric phenomenon exhibited by CuO is attributed to the internal barrier layer (due to GB) capacitance mechanism.

  3. The toxicity of copper(II) species to marine algae, with particular reference to macroalgae

    SciTech Connect

    Gledhill, M.; Nimmo, M.; Hill, S.J.; Brown, M.T.

    1997-02-01

    Ambient concentrations of dissolved copper(II) in seawater are very low. However, levels can increase as a result of natural and anthropogenic sources. Such increase can have profound effects on organisms in the vicinity resulting in inhibition of growth, reduced fecundity, and even death. This paper highlights the importance of pecieation when considering the toxic effects of cooper, with particular reference to macroalgae in a marine environment, and to encourage more biologists to take account of this in their studies of metal pollution. 104 refs., 2 figs., 4 tabs.

  4. METHANOGENESIS AND SULFATE REDUCTION IN CHEMOSTATS: II. MODEL DEVELOPMENT AND VERIFICATION

    EPA Science Inventory

    A comprehensive dynamic model is presented that simulates methanogenesis and sulfate reduction in a continuously stirred tank reactor (CSTR). This model incorporates the complex chemistry of anaerobic systems. A salient feature of the model is its ability to predict the effluent ...

  5. Cytotoxic origin of copper(II) oxide nanoparticles: comparative studies with micron-sized particles, leachate, and metal salts.

    PubMed

    Gunawan, Cindy; Teoh, Wey Yang; Marquis, Christopher P; Amal, Rose

    2011-09-27

    The work investigates the source of toxicity of copper oxide nanoparticles (CuO NPs) with respect to its leaching characteristic and speciation. Complexation-mediated leaching of CuO NPs by amino acids was identified as the source of toxicity toward Escherichia coli, the model microorganism used in the current study. The leached copper-peptide complex induces a multiple-fold increase in intracellular reactive oxygen species generation and reduces the fractions of viable cells, resulting in the overall inhibition of biomass growth. The cytotoxicity of the complex leachate is however different from that of equivalent soluble copper salts (nitrates and sulfates). A pH-dependent copper speciation during the addition of copper salts gives rise to uncoordinated copper ions, which in turn result in greater toxicity and cell lysis, the latter of which was not observed for CuO NPs even at comparable pH. Since leaching did not occur with micrometer-sized CuO, no cytotoxicty effect was observed, thus highlighting the prominence of materials toxicity at the nanoscale. PMID:21812479

  6. Spectrophotometric determination of vitamin E (alpha-tocopherol) using copper(II)-neocuproine reagent.

    PubMed

    Tütem, E; Apak, R; Günaydı, E; Sözgen, K

    1997-02-01

    The possibility of the utilization of the copper(II)-neocuproine spectrophotometric method, which has previously been shown to permit the determination of various reducing agents, to the determination of vitamin E was investigated. The molar absorptivity for vitamin E was found to be (2.1 +/- 0.1) x 10(4)l mol(-1)cm(-1) and Beer's law was obeyed between 2.4 x 10(-6) and 9.0 x 10(-5)M concentrations of alpha-tocopherol. The relative standard deviation of the slope of the absorbance vs. concentration plot was 2.1%. The results obtained by the copper(II)-neocuproine method were compared with those achieved by both the standard HPLC and the widely used iron(III)-bathophenanthroline method by means of a t-test which showed that the precision of the developed method was not essentially different from those of the others. The developed method was successfully applied to three commercial samples, two in dragée and one in ampoule form. The alpha-tocopheryl acetate contained in the samples, which did not respond directly to the Cu(II)-neocuproine reagent, was subjected to alkaline hydrolysis prior to the analysis of the hydrolysis product, i.e., alpha-tocopherol. The molar absorptivity due to Cu(I)-neocuproine at 450 nm against a reagent blank indicated a two-electron oxidation of vitamin E by Cu(II)-neocuproine, which may be slightly enhanced by solvent effects. Copper(II)-neocuproine is an oxidant of strength comparable to that of Fe(III)-bathophenanthroline. The developed method, although less sensitive, is easy to use in conventional laboratories, unlike the Fe(III)-bathophenanthroline method, which requires specially prepared reagents and solvents. The method is free from interferences from such common reductants as ascorbic acid and Fe(II) salts, found in pharmaceutical formulations, after washing the formulation with water and collecting vitamin E in the ether extract for subsequent analysis.

  7. Ultraviolet spectrophotometric characterization of copper(II) complexes with imidazole N-methyl derivatives of ?-histidine in aqueous solution

    NASA Astrophysics Data System (ADS)

    Prenesti, Enrico; Berto, Silvia; Daniele, Pier Giuseppe

    2003-01-01

    In this study we considered π-methyl- L-histidine (π-methis) and τ-methyl- L-histidine (τ-methis) as ligands for copper(II) ion, in order to clarify, by means of ultraviolet (UV) spectroscopy in aqueous solution ( T=25 °C, I=0.1 M), some aspects of the co-ordination mode with respect to other ligands of a previous study in which copper(II) complexes of L-histidine, N-acetyl- L-histidine, histamine, L-histidine methyl ester or carnosine were investigated. Particularly, UV spectra (300-400 nm) were recorded on solutions at various pH values, containing each binary system Cu-L; afterwards, an UV absorption spectrum for single complexes was calculated, taking into account the chemical model previously assessed, in order to fulfil a correct spectrum-structure correlation. The problem related to the eventual superimposition of the CT shoulder (≈330 nm) to copper(II) of OH - and imidazole pyridine nitrogen groups were now solved by means of a comparison of the UV spectra of dimer species formed by both π-methis or τ-methis. Finally, copper(II) complex formation with 2,2'-bipyridine was taken into account to compare the behaviour of pyridine (from 2,2'-bipyridine) and pyridine imidazole nitrogens (from π-methis or τ-methis) with respect to the UV charge transfer process to copper(II) ion.

  8. Synthesis, structure, and magnetic properties of regular alternating μ-bpm/di-μ-X copper(II) chains (bpm = 2,2'-bipyrimidine; X = OH, F).

    PubMed

    Marino, Nadia; Armentano, Donatella; De Munno, Giovanni; Cano, Joan; Lloret, Francesc; Julve, Miguel

    2012-04-01

    The preparation and X-ray crystal structure of four 2,2'-bipyrimidine (bpm)-containing copper(II) complexes of formula {[Cu(2)(μ-bpm)(H(2)O)(4)(μ-OH)(2)][Mn(H(2)O)(6)](SO(4))(2)}(n) (1), {[Cu(2)(μ-bpm)(H(2)O)(4)(μ-OH)(2)]SiF(6)}(n) (2), {Cu(2)(μ-bpm)(H(2)O)(2)(μ-F)(2)F(2)}(n) (3), and [Cu(bpm)(H(2)O)(2)F(NO(3))][Cu(bpm)(H(2)O)(3)F]NO(3)·2H(2)O (4) are reported. The structures of 1-3 consist of chains of copper(II) ions with regular alternation of bis-bidentate bpm and di-μ-hydroxo (1 and 2) or di-μ-fluoro (3) groups, the electroneutrality being achieved by either hexaaqua manganese(II) cations plus uncoordinated sulfate anions (1), uncoordinated hexafluorosilicate anions (2), or terminally bound fluoride ligands (3). Each copper(II) ion in 1-4 is six-coordinated in elongated octahedral surroundings. 1 and 2 show identical, linear chain motifs with two bpm-nitrogen atoms and two hydroxo groups building the equatorial plane at each copper(II) ion and the axial position being filled by water molecules. In the case of 3, the axial sites at the copper atom are occupied by a bpm-nitrogen atom and a bis-monodentate fluoride anion, producing a "step-like" chain motif. The values of the angle at the hydroxo and fluoro bridges are 94.11(6) (1), 94.75(4) (2), and 101.43(4)° (3). In each case, the copper-copper separation through the bis-bidentate bpm [5.428(1) (1), 5.449(1) (2), and 5.9250(4) Å (3)] is considerably longer than that through the di-μ-hydroxo [2.8320(4) (1) and 2.824(1) Å (2)] or di-μ-fluoro [3.3027(4) Å (3)] bridges. Compound 4 is a mononuclear species whose structure is made up of neutral [Cu(bpm)(H(2)O)(2)F(NO(3))] units, [Cu(bpm)(H(2)O)(3)F](+) cations, uncoordinated nitrate anions, and crystallization water molecules, giving rise to a pseudo-helical, one-dimensional (1D) supramolecular motif. The magnetic properties of 1-3 have been investigated in the temperature range 1.9-300 K. Relatively large, alternating antiferro- [J = -149 (1) and

  9. Synthesis and crystal structure of catena-bis(nicotinamide)aqua({mu}-phthalato)copper(II) hemihydrate

    SciTech Connect

    Sadikov, G. G.; Koksharova, T. V.; Antsyshkina, A. S.; Gritsenko, I. S.; Sergienko, V. S.

    2008-07-15

    The copper(II) phthalate complex with nicotinamide [CuL{sub 2}({mu}-Pht)(H{sub 2}O)] . 0.5H{sub 2}O(I) (where L is nicotinamide and Pht{sup 2-} is an anion of phthalic acid) is synthesized and investigated using IR spectroscopy and X-ray diffraction. The crystals of compound I are monoclinic, a = 13.368(2) A, b = 7.891(3) A, c = 20.480(2) A, {beta} = 108.69(2){sup o}, Z = 4, and space group P2{sub 1}/c. The structural units of crystal I are linear chains formed by bridging phthalate anions and crystallization water molecules. The copper atom is coordinated by two pyridine nitrogen atoms of two nicotinamide ligands (Cu-N, 2.001 and 2.045 A), two oxygen atoms of different phthalate anions (Cu-O, 1.964 and 2.235 A), and the oxygen atom of the H{sub 2} O molecule (Cu-O, 2.014 A). The coordination polyhedron of the copper atom is completed to an elongated (4 + 1 + 1) tetragonal bipyramid by the second (chelating) oxygen atom of the carboxyl group (Cu-O, 2.587 A), which is one of the anions of phthalic acid. The linear polymer molecules are joined into complex macromolecular dimers with the closest internal contacts of the specific type. The macromolecular dimers are the main supramolecular ensembles of the crystal structure.

  10. The structures and thermodynamic stability of copper(II) chloride surfaces.

    PubMed

    Altarawneh, Mohammednoor; Jiang, Zhong-Tao; Dlugogorski, Bogdan Z

    2014-11-28

    Using density functional theory calculations of periodic slabs, within the generalised gradient approximation, this study provides optimised structures for all plausible terminations of copper(II) chloride surfaces along the three low-index orientations. The ab initio atomistic thermodynamic approach serves to construct a thermodynamic stability diagram for CuCl2 configurations as a function of the chemical potential of chlorine (ΔμCl(T,P)). We observe a shift in thermodynamic stability ordering at around ΔμCl(T,P) = -1.0 eV between a copper-chlorine terminated (001) surface (i.e., (001)CuCl) and a (001) chlorine-covered surface (i.e., (001)Cl). This conclusion accords with experimental observations that report CuCl-bulk like structures, acting as a prerequisite for the formation of CuCl2-bulk like arrangements in the course of copper chlorination. Profound stabilities and optimised structures of (001)CuCl and (001)Cl configurations are discussed within the context of the functionality of CuCl2 as the chief chlorination and condensation catalyst of aromatic pollutants under conditions relevant to their formation in thermal systems, i.e. 400-1000 K, a total operating pressure of 1.0 atm and PCl2 = 10(-6)-10(-4) atm (1.0-100.0 ppm). PMID:25294121

  11. USING RESPIROMETRY TO MEASURE HYDROGEN UTILIZATION IN SULFATE REDUCING BACTERIA IN THE PRESENCE OF COPPER AND ZINC

    EPA Science Inventory

    A respirometric method has been developed to measure hydrogen utilization by sulfate reducing bacteria (SRB). One application of this method has been to test inhibitory metals effects on the SRB culture used in a novel acid mine drainage treatment technology. As a control param...

  12. Atelosteogenesis type II is caused by mutations in the diastrophic dysplasia sulfate-transporter gene (DTDST): evidence for a phenotypic series involving three chondrodysplasias.

    PubMed

    Hästbacka, J; Superti-Furga, A; Wilcox, W R; Rimoin, D L; Cohn, D H; Lander, E S

    1996-02-01

    Atelosteogenesis type II (AO II) is a neonatally lethal chondrodysplasia whose clinical and histological characteristics resemble those of another chondrodysplasia, the much less severe diastrophic dysplasia (DTD). The similarity suggests a shared pathogenesis involving lesions in the same biochemical pathway and perhaps the same gene. DTD is caused by mutations in the recently identified diastrophic dysplasia sulfate-transporter gene (DTDST). Here, we report that AOII patients also have DTDST mutations, which lead to defective uptake of inorganic sulfate and insufficient sulfation of macromolecules by patient mesenchymal cells in vitro. Together with our recent observation that a third even more severe chondrodysplasia, achondrogenesis type IB, is also caused by mutations in DTDST, these results demonstrate a phenotypic series of three chondrodysplasias of increasing severity caused by lesions in a single sulfate-transporter gene. The severity of the phenotype appears to be correlated with the predicted effect of the mutations on the residual activity of the DTDST protein. PMID:8571951

  13. Impact of DIC, Sulfate and Chloride on Pb(II) Solubility

    EPA Science Inventory

    Corrosion of lead and the subsequent release of lead into drinking water distribution systems pose a concern to public health. Consequently, the U.S. Environmental Protection Agency’s (U.S. EPA) Lead and Copper rule established an action level for lead at the consumer’s tap of 0....

  14. Spectrophotometric determination of copper(II) in pharmaceutical, biological and water samples by 4-(2'-benzothiazolylazo)-salicylic acid

    NASA Astrophysics Data System (ADS)

    Hashem, E. Y.; Seleim, M. M.; El-Zohry, A. M.

    2011-09-01

    A highly sensitive method is proposed to determine copper(II) ions by forming a stable complex through their interaction with 4-(2'-benzothiazolylazo)-salicylic acid (BTAS) at room temperature and pH of about 5.0. The complex gave a maximum absorption at λ = 485 nm with a molar absorptivity coefficient of 2.35·104 l/(mol·cm). The linear range for the copper determination is 0.63-5.04 mg/l. The method can be applied to determine copper ions in different biological specimens like some drugs and water samples.

  15. Characterization and biological activities of two copper(II) complexes with dipropylenetriamine and diamine as ligands

    NASA Astrophysics Data System (ADS)

    AL-Noaimi, Mousa; Choudhary, Mohammad I.; Awwadi, Firas F.; Talib, Wamidh H.; Hadda, Taibi Ben; Yousuf, Sammer; Sawafta, Ashraf; Warad, Ismail

    2014-06-01

    Two new mixed-ligand copper(II) complexes, [Cu(dipn)(Nsbnd N)]Br2(1-2) [dipn = dipropylenetriamine, Nsbnd N = ethylenediamine (en) (1) and propylenediamine (pn) (2)], have been synthesized. These complexes were characterized by spectroscopic and thermal techniques. Crystal structure for 2 shows a distorted trigonal-bipyramidal geometry around Cu(II) ion with one solvate water molecule. Antimicrobial and antiproliferative assays were conducted to evaluate the biological activities of these complexes. The complexes exhibit a promising antimicrobial effect against an array of microbes at 200 μg/mL concentration. The antiproliferative assay shows a high potential of these complexes to target Human keratinocyte cell line with IC50 values of 155 and 152 μM. The absorption spectrum of 2 in water was modeled by time-dependent density functional theory (TD-DFT).

  16. Quantum transport effects in copper(II) phthalocyanine sandwiched between gold nanoelectrodes.

    PubMed

    Tada, Tomofumi; Hamayama, Shinya; Kondo, Masakazu; Yoshizawa, Kazunari

    2005-06-30

    The electrical transmission of copper(II) phthalocyanine (CuPc) sandwiched between gold nanoelectrodes is studied on the basis of the Green function formalism coupled with the Gaussian-broadening technique. In the Au-CuPc-Au junction, broadened density of states (DOS) of the Au chains is defined as continuous DOS of electrodes to calculate the Green function of the electrodes. Two peaks of the transmission function found in the vicinity of the Fermi level are analyzed in terms of molecular orbitals (MOs). A convenient procedure to analyze MO contribution to a transmission peak is proposed. It is found that (I) symmetry-matched interactions between CuPc and the gold nanoelectrodes are important to the enhancement of the transmission function and (II) the nanoelectrodes have almost no effect on the electronic states of CuPc.

  17. Spectroscopic, structural and theoretical studies of copper(II) complexes of tridentate NOS Schiff bases

    NASA Astrophysics Data System (ADS)

    Olalekan, Temitope E.; Ogunlaja, Adeniyi S.; VanBrecht, Bernardus; Watkins, Gareth M.

    2016-10-01

    Two newly synthesized Schiff bases (L4 and L5) were derived from the condensation reaction of 2-(methylthiomethyl)anilines and 4-methoxysalicylaldehyde. Coordination complexes of these and four previously reported NOS Schiff bases, Cu(L1)2-Cu(L6)2, were synthesized via the reflux reaction of the various Schiff base ligands with CuCl2·2H2O. The compounds were characterized by means of elemental analysis, FTIR and UV-Vis. The crystal structures of Cu(L1)2 and Cu(L2)2 were obtained by X-ray diffraction. The Schiff bases were coordinated to copper ion as monobasic tridentate ligands through the phenolic oxygen, azomethine nitrogen and thioether sulfur. The microanalyses of the coordination complexes were agreeable with bimolar binding of the ligands to the copper metal ion. The crystal structures of the copper complexes confirmed an octahedral geometry around the metal centre and showed they are mononuclear. The magnetic moment values indicated the presence of a lone electron in each copper(II) orbital and confirmed the mononuclearity of the complexes. The electronic spectra of the coordination compounds consist of the intraligand, charge transfer and d→d bands. Molecular modeling studies on the complexes (Cu(L1)2-Cu(L6)2) by employing DFT revealed that complex Cu(L5)2 possessed the smallest optimization energy as well as a small HOMO-LUMO energy gap which may best explain its higher polarizability as well as reactivity in comparison to the other complexes.

  18. Electron-Nuclear Double Resonance of a Protein That Contains Copper: Evidence for Nitrogen Coordination to Cu(II) in Stellacyanin

    PubMed Central

    Rist, Günther H.; Hyde, James S.; Vänngård, Tore

    1970-01-01

    Electron-nuclear double resonance has been used to study ligand hyperfine interactions of the copper (II) complex in a frozen solution of the blue protein stellacyanin. It is shown that the copper ion coordinates with at least one nitrogen ligand, and probably more than one, and that the copper ion is in a hydrophobic environment. PMID:16591867

  19. Use of anodic stripping voltammetry to determine zinc(II), lead(II), and copper(II) in foods

    SciTech Connect

    Maksimkina, L.M.; Gus'kova, V.P.

    1988-01-20

    The existing standard procedure for the polarographic determination of Zn, Pb, and Cu, based on the cathodic polarization of a dropping mercury electrode, is laborious and time-consuming and allows one to determine the above-mentioned trace elements only when they are separated beforehand. We consider the possibility of using anodic stripping voltammetry with a mercury film electrode for the simultaneous determination of Zn(II), Pb(II), and Cu(II) in foods.

  20. Oxidation of substituted phenols using copper(II) metallatriangles formed through ligand sharing

    NASA Astrophysics Data System (ADS)

    Mahiya, Kuldeep; Kumar, Ravinder; Lloret, Francisco; Mathur, Pavan

    2014-12-01

    Reaction of N2,N2";-bis-[(1-butyl-benzimidazol-2yl)methyl]biphenyl-2,2";-dicarboxamide (L) with CuX2ṡnH2O in methanol leads to the assembly of four trinuclear Cu(II) complexes with the general formula [Cu3(L)3X3]ṡ3XṡnH2OṡmMeCN, where X = Cl-, Br-, NO3- and C6H5COO- and n = 0-5, m = 0-8 (compounds 1-4, respectively). The structure of one of the complex contains three Cu(II) metal ions at the corners of an equilateral triangle. Each of the copper(II) are coordinated through two benzimidazolyl imine N-atoms and two amide carbonyl O-atoms and the apical position is occupied by an anionic nitrate ion, leading to a distorted square pyramidal environment. The magnetic susceptibility data were analyzed through Hamiltonian H = -J (S1S2 + S2S3 + S1S3) obtaining -J = 0.16, 0.12, 0.15 and 0.14 cm-1 for 1-4, respectively. X-Band EPR spectra typically show a broad single line at 120 K with g ∼ 2.11. Oxidation of phenols was studied homogeneously using copper(II) metallatriangles (1-3) as catalyst in acetonitrile. The oxidation of 2,4,6-tri-tert-butyl phenol yields the corresponding quinone after oxidative dealkylation. The oxidation of 2-amino-5-methyl phenol yields the corresponding phenoxazinone while the oxidation of 2-amino-4-tert-butyl phenol yields the phenoxazine instead of phenoxazinone. The products so obtained were analyzed by NMR and X-ray single crystallography.

  1. Uranyl-copper(II) heterometallic oxalate complexes: coordination polymers and frameworks.

    PubMed

    Thuéry, Pierre; Rivière, Eric

    2013-08-01

    Five oxalate complexes containing both uranyl and copper(II) ions and 2,2′-bipyridine (bipy), 2,2′-bipyrimidine (bipym) or 1,10-phenanthroline (phen) as co-ligands have been synthesized under hydrothermal conditions and their crystal structures were determined. [UO2Cu(C2O4)(NO3)2(bipy)(H2O)] (1) is a molecular complex in which the two cations are connected by the bis-chelating oxalate. A one-dimensional uranyl oxalate ribbon is formed in [UO2Cu(C2O4)2(bipym)(H2O)] (2), with uranyl ions bound to two chelating anions and to a third, monodentate oxalate which holds the decorating [Cu(bipym)(H2O)]2+ groups. Complex [(UO2)2Cu2(C2O4)2(bipym)3(OH)2]·2NO3 (3) is a two-dimensional assembly in which uranyl oxalate chains are linked to one another by [Cu2(bipym)3]4+ dinuclear units through bridging hydroxide ions. Finally, [UO2Cu(C2O4)2(bipy)] (4) and [UO2Cu(C2O4)2(phen)] (5) display identical three-dimensional arrangements containing uranyl oxalate sheets connected to one another by copper oxalate dinuclear units. The magnetic properties of compounds 2 and 4 have been investigated. Weak inter-chain antiferromagnetic interactions between copper(II) atoms are present in 2, while 4 displays strong oxalate-mediated antiferromagnetic exchange (J = -335 cm(-1)). These complexes are the first uranyl-d block metal oxalate complexes to be reported. PMID:23760346

  2. Benthic sulfate reduction along the Chesapeake Bay central channel. II. Temporal controls

    USGS Publications Warehouse

    Marvin-DiPasquale, M. C.; Boynton, W.R.; Capone, D.G.

    2003-01-01

    Seasonal and interannual controls of benthic sulfate reduction (SR) were examined at 3 sites (upper [UB], mid- [MB] and lower [LB] bay) along the Chesapeake Bay central channel, from early spring through fall, for 6 yr (1989 to 1994). The combined influences of temperature, sulfate, organic loading and bioturbation affected seasonal SR rates differently in the 3 regions. Consistently low SR rates at UB resulted from low overlying-water sulfate concentrations and the dominance of refractory organic terrestrial material. Combined seasonal variation in temperature and sulfate accounted for 50% of the annual variability in 0 to 2 cm depth interval SR rates, while sediment organic content had no significant seasonal influence. In contrast, MB and LB sites had high rates of SR fostered by high levels of overlying water SO42- and organic input dominated by labile phytoplankton detritus. New organic loading (measured as chl a) stimulated 0 to 2 cm SR during spring at both sites. Combined organic quantity (as particulate C and/or N) and temperature accounted for > 75% of the variability in 0 to 2 cm SR at MB during spring and fall. Molecular diffusion supplied 25 to 45% of the SO 42- needed to fuel 0 to 12 cm depth interval SR at MB, with the balance presumably supplied by S-recycling. Interannual differences in summertime SR rates were linked to the extent of freshwater flow during spring, with high-flow years associated with high SR rates at UB and MB, and low rates at LB. The negative trend between benthic SR and river flow at LB may result from the up-estuary transport of senescing organic matter in bottom water, which increases in the lower reach of the estuary with increasing freshwater inflow.

  3. Highly efficient visual detection of trace copper(II) and protein by the quantum photoelectric effect.

    PubMed

    Wang, Peng; Lei, Jianping; Su, Mengqi; Liu, Yueting; Hao, Qing; Ju, Huangxian

    2013-09-17

    This work presented a photocurrent response mechanism of quantum dots (QDs) under illumination with the concept of a quantum photoelectric effect. Upon irradiation, the photoelectron could directly escape from QDs. By using nitro blue tetrazolium (NBT) to capture the photoelectron, a new visual system was proposed due to the formation of an insoluble reduction product, purple formazan, which could be used to visualize the quantum photoelectric effect. The interaction of copper(II) with QDs could form trapping sites to interfere with the quantum confinement and thus blocked the escape of photoelectron, leading to a "signal off" visual method for sensitive copper(II) detection. Meanwhile, by using QDs as a signal tag to label antibody, a "signal on" visual method was also proposed for immunoassay of corresponding protein. With meso-2,3-dimercaptosuccinic-capped CdTe QDs and carcino-embryonic antigen as models, the proposed visual detection methods showed high sensitivity, low detection limit, and wide detectable concentration ranges. The visualization of quantum photoelectric effect could be simply extended for the detection of other targets. This work opens a new visual detection way and provides a highly efficient tool for bioanalysis.

  4. Pure and Sr(II)-added copper aluminate nanocomposites: structural, electrical and alcohol sensing studies.

    PubMed

    Kumar, R Thinesh; Vijaya, J Judith; Kennedy, L John

    2013-08-01

    The effect of ethylenediamine addition in the sol-gel method for the preparation of pure and Sr(II)-added nano copper aluminate (CuAl2O4) composites for the enhancement in their structural, electrical, and alcohol sensing properties were investigated. The effect of addition of Sr(II) to pure CuAl2O4 in both the methods were also discussed. X-ray diffraction, scanning electron microscopy, nitrogen adsorption/desorption isotherms, temperature dependant conductance measurements and thermoelectric power measurements were used to characterize the composites prepared. Among the composites, 0.8 molar ratio strontium added copper aluminate composite prepared by modified sol-gel method showed the highest sensitivity towards alcohols. The stability, response and recovery of MS-CuSA5 were also discussed. The response and recovery characteristics showed that the order of sensing alcohols by the composites was butanol > isopropanol > ethanol > methanol, which could be explained on the basis of oxidation of alcohols.

  5. Structural characterization and EPR spectral studies on mononuclear copper(II) complex of saccharin with ethylnicotinate

    NASA Astrophysics Data System (ADS)

    Uçar, İbrahim; Bozkurt, Esat; Kazak, Canan; Bulut, Ahmet

    2009-02-01

    Mononuclear copper(II) saccharinate (sac) complex containing ethylnicotinate (enc), [Cu(enc) 2(sac) 2(H 2O)]·1.4H 2O has been synthesized and characterized by spectroscopic (IR, UV-vis, EPR), X-ray diffraction technique and electrochemical methods. It crystallizes in the tetragonal crystal systems with space group I4 1cd and Z = 8. The copper(II) ion presents a CuN 4O distorted square pyramidal coordination. Based on EPR and optical absorption studies, spin-Hamiltonian and bonding parameters have been calculated. The g-values, calculated for title complex in polycrystalline state at 298 K and in frozen DMF (110 K), indicate the presence of the unpaired electron in the d orbital. The evaluated metal-ligand bonding parameters showed strong in-plane σ and in-plane π-bonding. Some comparisons with related structures are made and the most important features of its IR spectrum were also discussed. The cyclic voltammogram of the title complex investigated in DMF (dimethylformamide) solution exhibits only metal centred electroactivity in the potential range ±1.25 V vs. Ag/AgCl reference electrode.

  6. Ligand effects on the structures and magnetic properties of tricyanomethanide-containing copper(II) complexes.

    PubMed

    Yuste, Consuelo; Bentama, Abdeslem; Stiriba, Salah-Eddine; Armentano, Donatella; De Munno, Giovanni; Lloret, Francesc; Julve, Miguel

    2007-11-28

    The preparation, crystal structure and magnetic properties of four heteroleptic copper(II) complexes with the tricyanomethanide (tcm(-)) and the heterocyclic nitrogen donors 3,6-bis(2-pyridyl)pyridazine (dppn), 2,5-bis(2-pyridyl)pyrazine (2,5-dpp), 2,3-bis(2-pyridyl)pyrazine (2,3-dpp) and 2,3-bis(2-pyridyl)quinoxaline (2,3-dpq) are reported, {[Cu(2)(dppn)(OH)(tcm)(2)] x tcm}(n) (1), {[Cu(2,5-dpp)(tcm)] x tcm}(n) (2), {[Cu(2)(2,3-dpp)(2)(tcm)(3)(H(2)O)(0.5)] x tcm x 0.5H(2)O}(n) (3) and [Cu(2,3-dpq)(tcm)(2)](n) (4). 1 has a ladder-like structure with single mu-1,5-tcm ligands forming the sides and a bis-bidentate dppn and a single mu-hydroxo providing the rung. Each copper atom in 1 exhibits a distorted square pyramidal CuN(4)O surrounding: the basal plane is built by the hydroxo-oxygen, a nitrile-nitrogen atom from a tcm group and one pyrazine and a pyridyl nitrogen atoms from the dppn whereas the apical position is filled by a nitrile-nitrogen atom from a symmetry-related tcm ligand. The structures of 2-4 consists of zig-zag (2 and 3)/linear (4) chains of copper(II) ions which are bridged by either bis-bidentate 2,5-dpp (2) and 2,3-dpp (3) molecules or single mu-1,5-tcm (4) groups. The copper atoms in 2 and 4 are five coordinated with distorted trigonal bipyramidal (2) and square pyramidal (4) CuN(5) surroundings. The axial positions in 2 are occupied by two pyridyl-nitrogen atoms from two 2,5-dpp ligands whereas the trigonal plane is built by a nitrile-nitrogen from a terminally bound tcm group and two pyrazine nitrogen atoms from two 2,5-dpp molecules. The basal plane in 4 is defined by a pyridyl and a pyrazine nitrogen atoms from the bidentate 2,3-dpq ligand and two nitrile nitrogen atoms from two tcm groups (one terminal and the other bridging) whereas the apical position is filled by a nitrile nitrogen from another tcm ligand. The crystallographically independent copper atoms in 3 [Cu(1) and Cu(2)] exhibit elongated octahedral geometries being defined by four

  7. Geometrical and optical benchmarking of copper(II) guanidine-quinoline complexes: insights from TD-DFT and many-body perturbation theory (part II).

    PubMed

    Hoffmann, Alexander; Rohrmüller, Martin; Jesser, Anton; dos Santos Vieira, Ines; Schmidt, Wolf Gero; Herres-Pawlis, Sonja

    2014-11-01

    Ground- and excited-state properties of copper(II) charge-transfer systems have been investigated starting from density-functional calculations with particular emphasis on the role of (i) the exchange and correlation functional, (ii) the basis set, (iii) solvent effects, and (iv) the treatment of dispersive interactions. Furthermore (v), the applicability of TD-DFT to excitations of copper(II) bis(chelate) charge-transfer systems is explored by performing many-body perturbation theory (GW + BSE), independent-particle approximation and ΔSCF calculations for a small model system that contains simple guanidine and imine groups. These results show that DFT and TD-DFT in particular in combination with hybrid functionals are well suited for the description of the structural and optical properties, respectively, of copper(II) bis(chelate) complexes. Furthermore, it is found an accurate theoretical geometrical description requires the use of dispersion correction with Becke-Johnson damping and triple-zeta basis sets while solvent effects are small. The hybrid functionals B3LYP and TPSSh yielded best performance. The optical description is best with B3LYP, whereby heavily mixed molecular transitions of MLCT and LLCT character are obtained which can be more easily understood using natural transition orbitals. An natural bond orbital analysis sheds light on the donor properties of the different donor functions and the intraguanidine stabilization during coordination to copper(I) and (II).

  8. Copper(I) nitrosyls from reaction of copper(II) thiolates with S-nitrosothiols: mechanism of NO release from RSNOs at Cu.

    PubMed

    Zhang, Shiyu; Çelebi-Ölçüm, Nihan; Melzer, Marie M; Houk, K N; Warren, Timothy H

    2013-11-13

    S-nitrosothiols (RSNOs) serve as ready sources of biological nitric oxide activity, especially in conjunction with copper centers. We report a novel pathway for the generation of NO within the coordination sphere of copper model complexes from reaction of copper(II) thiolates with S-nitrosothiols. Reaction of tris(pyrazolyl)borate copper(II) thiolates (iPr2)TpCu-SR (R = C6F5 or CPh3) with (t)BuSNO leads to formation of (iPr2)TpCu(NO) and the unsymmetrical disulfide RS-S(t)Bu. Quantum mechanical investigations with B3LYP-D3/6-311G(d) suggest formation of a κ(1)-N-RSNO adduct (iPr2)TpCu(SR)(R'SNO) that precedes release of RSSR' to deliver (iPr2)TpCu(NO). This process is reversible; reaction of (iPr2)TpCu(NO) (but not (iPr2)TpCu(NCMe)) with C6F5S-SC6F5 forms (iPr2)TpCu-SC6F5. Coupled with the facile, reversible reaction between (iPr2)TpCu(NO) and C6F5SNO to give (iPr2)TpCu-SC6F5 and 2 equiv NO, we outline a new, detailed catalytic cycle for NO generation from RSNOs at Cu.

  9. Far-red resonance Raman study of copper A in subunit II of cytochrome c oxidase

    SciTech Connect

    Wallace-Williams, S.E.; James, C.A.; Woodruff, W.H.; Vries, S. de; Saraste, M.; Lappalainen, P.; Oost, J. van der; Fabian, M.; Palmer, G.

    1996-04-24

    The present work employs far-red resonance Raman spectroscopy (RR) to investigate whether a Cu-Cu bonding interaction exists in Cu{sub A}. The electronic transition of Cu{sub A} near 830 nm provides the opportunity for specific RR observation of the vibrations of this chromophore. We have employed RR with Cu isotopic substitution on genetically modified, solubilized forms of CcO subunit II from Bacillus subtilis and Paracoccus denitrificans. We have also probed the Cu{sub A} site of native beef heart CcO for comparison. The similarity of the CcO and Cu{sub A} fragment (subunit II) spectra suggests that Cu{sub A} in the isolated subunit II has essentially the same structure as that of Cu{sub A} in intact CcO. Thus, the suggested Cu-Cu bonding in Cu{sub A}, if correct, applies both to the isolated subunit II and native CcO. The functional reasons why nature may choose such a structure, or in fact why a two-copper center of any sort is constructed to perform a function which is commonly believed to be simple one-electron transfer, are unclear. 34 refs., 1 fig., 1 tab.

  10. Copper(I)/S(8) reversible reactions leading to an end-on bound dicopper(II) disulfide complex: nucleophilic reactivity and analogies to copper-dioxygen chemistry.

    PubMed

    Maiti, Debabrata; Woertink, Julia S; Vance, Michael A; Milligan, Ashley E; Sarjeant, Amy A Narducci; Solomon, Edward I; Karlin, Kenneth D

    2007-07-18

    Elemental sulfur (S8) reacts reversibly with the copper(I) complex [(TMPA')CuI](+) (1), where TMPA' is a TMPA (tris(2-pyridylmethyl)amine) analogue with a 6-CH2OCH3 substituent on one pyridyl ligand arm, affording a spectroscopically pure end-on bound disulfido-dicopper(II) complex [{(TMPA')Cu(II)}2(mu-1,2-S2(2-))](2+) (2) {nu(S-S) = 492 cm(-1); nu(Cu-S)sym = 309 cm(-1)}; by contrast, [(TMPA)Cu(I)(CH3CN)](+) (3)/S8 chemistry produces an equilibrium mixture of at least three complexes. The reaction of excess PPh3 with 2 leads to formal "release" of zerovalent sulfur and reduction of copper ion to give the corresponding complex [(TMPA')Cu(I)(PPh3)](+) (11) along with S=PPh3 as products. Dioxygen displaces the disulfur moiety from 2 to produce the end-on Cu2O2 complex, [{(TMPA')Cu(II)}2(mu-1,2-O2(2-)](2+) (9). Addition of the tetradentate ligand TMPA to 2 generates the apparently more thermodynamically stable [{(TMPA)Cu(II)}2(mu-1,2-S2(2-))](2+) (4) and expected mixture of other species. Bubbling 2 with CO leads to the formation of the carbonyl adduct [(TMPA')CuI(CO)](+) (8). Carbonylation/sulfur-release/CO-removal cycles can be repeated several times. Sulfur atom transfer from 2 also occurs in a near quantitative manner when it is treated with 2,6-dimethylphenyl isocyanide (ArNC), leading to the corresponding isothiocyanate (ArNCS) and [(TMPA')Cu(I)(CNAr)](+) (12). Complex 2 readily reacts with PhCH2Br: [{(TMPA')Cu(II)}2(mu-1,2-S(2)(2-)](2+) (2) + 2 PhCH2Br --> [{(TMPA')Cu(II)(Br)}2](2+) (6) + PhCH2SSCH2Ph. The unprecedented substrate reactivity studies reveal that end-on bound mu-1,2-disulfide-dicopper(II) complex 2 provides a nucleophilic S2(2-) moiety, in striking contrast to the electrophilic behavior of a recently described side-on bound mu-eta(2):eta(2)-disulfido-dicopper(II) complex, [{(N3)Cu(II)}(2)(mu-eta(2):eta(2)-S2(2-))](2+) (5) with tridentate N3 ligand. The investigation thus reveals striking analogies of copper/sulfur and copper/dioxygen chemistries

  11. Crystal structures of copper(II) and nickel(II) nitrate and chloride complexes with 4-bromo-2-[(2-hydroxyethylimino)-methyl]phenol

    SciTech Connect

    Chumakov, Yu. M.; Tsapkov, V. I.; Filippova, I. G.; Bocelli, G.; Gulea, A. P.

    2008-07-15

    The crystal structures of {l_brace}4-bromo-2-[(2-hydroxyethylimino)-methyl]phenolo{r_brace}aquacopper(II) nitrate hemihydrate (I), chloro-{l_brace}4-bromo-2-[(2-hydroxyethylimino)-methyl]phenolo{r_brace}copper hemihydrate (II), and chloro-{l_brace}4-bromo-2-[(2-hydroxyethylimino)-methyl]phenolo{r_brace}aquanickel (III) are determined using X-ray diffraction. Crystals of compound I are formed by cationic complexes, nitrate ions, and solvate water molecules. In the cation, the copper atom coordinates the singly deprotonated molecule of tridentate azomethine and the water molecule. The copper complexes are joined into centrosymmetric dimers by the O{sub w}-H...O hydrogen bonds. The crystal structure of compound II is composed of binuclear copper complexes and solvate water molecules. The copper atom coordinates the O,N,O ligand molecule and the chlorine ion, which fulfills a bridging function. The coordination polyhedron of the metal atom is a distorted tetragonal bipyramid in which the vertex is occupied by the chlorine atom of the neighboring complex in the dimer. Compound III is a centrosymmetric dimer complex. The coordination polyhedra of two nickel atoms related via the inversion center are distorted octahedra shared by the edge.

  12. Selective transport of copper(I, II), cadmium(II), and zinc(II) ions through a supported liquid membrane containing bathocuproine, neocuproine, or bathophenanthroline

    SciTech Connect

    Saito, Takashi )

    1994-06-01

    Some selective transport systems for heavy metallic ions through a supported liquid membrane (SLM) containing a 2,2[prime]-dipyridyl derivative ligand, 4,7-diphenyl-2,9-dimethyl-1, 10-phenanthroline (bathocuproine), 2,9-dimethyl-1,10-phenanthroline (neocuproine), or 4,7-diphenyl-1,10-phenanthroline (bathophenanthroline), were investigated. The transport of copper(I, II), cadmium(II), zinc(II), lead(II), and cobalt(II) ions was accomplished with a halogen ion such as chloride, bromide, or iodide ion as a pairing ion species for any SLM. The ranking of the permeability of the metallic ions was Cu[sup +,2+], Zn[sup 2+], Cd[sup 2+] [much gt] Pb[sup 2+], Co[sup 2+]. When the oxidation-reduction potential gradient was used as a driving force for metallic ions, the transport of Cu[sup +] ions was higher than those of Cd[sup 2+] and Zn[sup 2+] ions for any SLM containing bathocuproine, neocuproine, or bathophenanthroline. On the other hand, in the transport system which used the concentration gradient of pairing ion species, the permeability of the Cu[sup 2+] ion decreased whereas that of the Cd[sup 2+] ion increased. Moreover, it was found that the different selectivity for the transport of metallic ions is produced by using various pairing ion species. 18 refs., 9 figs.

  13. Aluminum potassium sulfate and tannic acid sclerotherapy for Goligher Grades II and III hemorrhoids: Results from a multicenter study

    PubMed Central

    Miyamoto, Hidenori; Hada, Takenori; Ishiyama, Gentaro; Ono, Yoshito; Watanabe, Hideo

    2016-01-01

    AIM: To show that aluminum potassium sulfate and tannic acid (ALTA) sclerotherapy has a high success rate for Grade II and III hemorrhoids. METHODS: This study was based on the clinical data of 604 patients with hemorrhoids who underwent ALTA sclerotherapy between January 2009 and February 2015. The objective of this study was to assess the efficacy of this treatment for Grades II and III hemorrhoids. Preoperative and postoperative symptoms, complications and success rate were all assessed retrospectively. Follow-up consisted of a simple questionnaire, physical examination and an anoscopy. Patients were followed-up at one day, one week, two weeks, one month, one year, two years, three years, four years and five years after the ALTA sclerotherapy. RESULTS: One hundred and sixty-nine patients were diagnosed with Grade II hemorrhoids and 435 patients were diagnosed with Grade III hemorrhoids. The one year, three year and five year cumulative success rates of ALTA sclerotherapy for Grades II and III hemorrhoids were 95.9% and 93.1%; 89.3% and 83.7%; and 89.3% and 78.2%, respectively. No significant differences were observed in the cumulative success rates after ALTA sclerotherapy between Grades II and III hemorrhoids (P = 0.09). There were forty-seven post-operative complications (low grade fever; anal pain; urinary retention; rectal ulcer; and others). No serious or life-threatening complications occurred and all cases improved through conservative treatment. At univariate analysis there were no predictive factors of failure. CONCLUSION: ALTA sclerotherapy has had a high success rate for Grade II and III hemorrhoids during five years of post-operative treatment. However, additional studies are needed to evaluate the efficacy of this ALTA sclerotherapy in the management of hemorrhoidal disease. PMID:27458504

  14. Rare configuration of tautomeric benzimidazolecarboxylate ligands in cadmium(II) and copper(II) coordination polymers

    SciTech Connect

    Wu, Jing-Yun; Yang, Ciao-Wei; Chen, Hui-Fang; Jao, Yu-Chen; Huang, Sheng-Ming; Tsai, Chiitang; Tseng, Tien-Wen; Lee, Gene-Hsiang; Peng, Shie-Ming; Lu, Kuang-Lieh

    2011-07-15

    Two Cd(HBimc)-based isomers, [Cd(HBimc{sup N})(HBimc{sup T})(H{sub 2}O)].3.5H{sub 2}O.EtOH (1a.3.5H{sub 2}O.EtOH, H{sub 2}Bimc=1H-benzimidazole-5-carboxylic acid) and [Cd(HBimc{sup N})(HBimc{sup T})(H{sub 2}O)] (1b), and two Cu(HMBimc)-based coordination polymers, [Cu(HMBimc{sup N}){sub 2}(H{sub 2}O)].1/2H{sub 2}O (2.1/2H{sub 2}O, H{sub 2}MBimc=2-methyl-1H-benzimidazole-5-carboxylic acid) and [Cu(HMBimc{sup T}){sub 2}].2THF.H{sub 2}O (3.2THF.H{sub 2}O), were self-assembled from Cd(ClO{sub 4}){sub 2}.6H{sub 2}O/H{sub 2}Bimc and Cu(ClO{sub 4}){sub 2}.6H{sub 2}O/H{sub 2}MBimc systems, respectively. Compound 1a adopts a ladder-like chain structure, comprised of a hydrogen-bond-stabilized Cd{sub 2}(HBimc{sup N}){sub 2}-metallocyclic stair and a 1D straight -(Cd-HBimc{sup T}){sub n}- edge, whereas compound 1b exhibits a 2D (4,4)-rhombus layered structure, intercrossed by 1D -(Cd-HBimc{sup N}){sub n}- chains and -(Cd-HBimc{sup T}){sub n}- chains. Compound 2 shows a 1D double-stranded wave-like chain from two single-stranded wave-like -(Cu-HMBimc{sup N}){sub n}- chains and compound 3 adopts a 2D (4,4)-topological layer structure, intercrossed by subunits of 1D -(Cu-HMBimc{sup T}){sub n}- chains. Interestingly, a pair of tautomeric HBimc building blocks-normal (N or HBimc{sup N}) and tautomer (T or HBimc{sup T})-is simultaneously included in the structures of 1a and 1b, whilst the N- and T-configured HMBimc building blocks are present as separate entities in Cu species, 2 and 3, respectively. The existence of only a tautomer (T) mode of the benzimidazolecarboxylate-based ligand in a Cu(II) network is observed for the first time. - Graphical abstract: A pair of tautomeric HBimc building blocks (normal (N) and tautomer (T)) is found simultaneously in two Cd(II) networks, whereas, the normal and tautomer modes of HMBimc are present as separate entities in two Cu(II) frameworks. The isolation of a Cu(II) network with only a tautomer (T) mode of the benzimidazolecarboxylate

  15. Can copper(II) mediate Hoogsteen base-pairing in a left-handed DNA duplex? A pulse EPR study.

    PubMed

    Santangelo, Maria Grazia; Antoni, Philipp M; Spingler, Bernhard; Jeschke, Gunnar

    2010-02-22

    Pulse EPR spectroscopy is used to investigate possible structural features of the copper(II) ion coordinated to poly(dG-dC).poly(dG-dC) in a frozen aqueous solution, and the structural changes of the polynucleotide induced by the presence of the metal ion. Two different copper species were identified and their geometry explained by a molecular model. According to this model, one species is exclusively coordinated to a single guanine with the N7 nitrogen atom forming a coordinative bond with the copper. In the other species, a guanine and a cytosine form a ternary complex together with the copper ion. A copper crosslink between the N7 of guanine and N3 of cytosine is proposed as the most probable coordination site. Moreover, no evidence was found for an interaction of either copper species with a phosphate group or equatorial water molecules. In addition, circular dichroism (CD) spectroscopy showed that the DNA of the Cu(II)-poly(dG-dC).poly(dG-dC) adducts resembles the left-handed Z-form. These results suggest that metal-mediated Hoogsteen base pairing, as previously proposed for a right-handed DNA duplex, can also occur in a double-stranded left-handed DNA.

  16. 2,6-Bis(2,6-diethylphenyliminomethyl)pyridine coordination compounds with cobalt(II), nickel(II), copper(II), and zinc(II): synthesis, spectroscopic characterization, X-ray study and in vitro cytotoxicity.

    PubMed

    Martinez-Bulit, Pablo; Garza-Ortíz, Ariadna; Mijangos, Edgar; Barrón-Sosa, Lidia; Sánchez-Bartéz, Francisco; Gracia-Mora, Isabel; Flores-Parra, Angelina; Contreras, Rosalinda; Reedijk, Jan; Barba-Behrens, Norah

    2015-01-01

    Coordination compounds with cobalt(II), nickel(II), copper(II) and zinc(II) and the ligand 2,6-bis(2,6-diethylphenyliminomethyl)pyridine (L) were synthesized and fully characterized by IR and UV-Vis-NIR spectroscopy, elemental analysis, magnetic susceptibility and X-ray diffraction for two representative cases. These novel compounds were designed to study their activity as anti-proliferative drugs against different human cancer cell lines. The tridentate ligand forms heptacoordinated compounds from nitrate metallic salts, where the nitrate acts in a chelating form to complete the seven coordination positions. In vitro cell growth inhibition was measured for Co(II), Cu(II) and Zn(II) complexes, as well as for the free ligand. Upon coordination, the IC50 value of the transition-metal compounds is improved compared to the free ligand. The copper(II) and zinc(II) compounds are the most promising candidates for further in vitro and in vivo studies. The activity against colon and prostate cell lines merits further research, in views of the limited therapeutic options for such cancer types.

  17. Stability of bromine, iodine monochloride, copper (II) chloride, and nickel (II) chloride intercalated pitch-based graphite fibers

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Slabe, Melissa E.; Shaffer, Nanette

    1987-01-01

    Four different grades of pitch-based graphite fibers (Amoco P-55, P-75, P-100. and P-120) were intercalated with each of four different intercalates: bromine (Br2), iodine monochloride (ICl), copper (II) chloride (CuCl2), and nickel (II) chloride (NiCl2). The P-55 fibers did not react with Br2 or NiCl2, and the P-75 did not react with NiCl2. The stability of the electrical resistance of the intercalated fibers was monitored over long periods of time in ambient, high humidity (100 percent at 60 C), vacuum (10 to the -6 torr), and high temperature (up to 400 C) conditions. Fibers with lower graphitization form graphite intercalation compounds (GIC's) which are more stable than those with higher graphitization (i.e., P-55 (most stable) greater than P-75 greater than P-100 greater than P-120 (least stable). Br2 formed the most stable GIC's followed in order of decreasing stability by ICl, CuCl2, and NiCl2. While Br2 GIC's had the most stability, ICl had the advantages of forming GIC's with slightly greater reduction in resistance (by about 10%) than Br2, and the ability to intercalate P-55 fiber. Transition metal chlorides are susceptible to water vapor and high temperature. The stability of fibers in composites differs.

  18. 2,4-Dinitrophenylhydrazine functionalized sodium dodecyl sulfate-coated magnetite nanoparticles for effective removal of Cd(II) and Ni(II) ions from water samples.

    PubMed

    Sobhanardakani, Soheil; Zandipak, Raziyeh

    2015-07-01

    2,4-Dinitrophenylhydrazine immobilized on sodium dodecyl sulfate (SDS)-coated magnetite and was used for removal of Cd(II) and Ni(II) ions from aqueous solution. The prepared product was characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The size of the nanoparticles according to SEM was obtained around 20-35 nm. In batch tests, the effects of pH, contact time, initial metal concentration, and temperature were studied. The kinetic and equilibrium data were modeled with recently developed models. The adsorption kinetics and isotherms were well fitted by the fractal-like pseudo-second-order model and Langmuir-Freundlich model, respectively. Maximum adsorption capacity by this adsorbent is 255.1 mg g(-1) for Cd(II) ion and 319.6 mg g(-1) for Ni(II) ion at pH 7.0 and 25 °C. The method was successfully applied to the removal of metal cations in real samples (tap water, river water, and petrochemical wastewater).

  19. Ternary complexes of copper(II) and cobalt(II) involving nitrite/pyrazole and tetradentate N4-coordinate ligand: Synthesis, characterization, structures and antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Solanki, Ankita; Sadhu, Mehul H.; Kumar, Sujit Baran

    2015-12-01

    Five new mononuclear mixed ligand complexes of the type [Cu(NCCH3)(dbdmp)](ClO4)2, [M(ONO)(dbdmp)]ClO4, [M(pz) (dbdmp)](ClO4)2 where M = Cu(II) and Co(II), pz = 3,5-dimethylpyrazole and dbdmp = N,N-diethyl-N‧,N‧-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)ethane-1,2-diamine have been synthesized and characterized by physico-chemical and spectroscopy studies. The crystal structures of three copper(II) complexes [Cu(NCCH3)(dbdmp)](ClO4)2, [Cu(ONO)(dbdmp)]ClO4 and [Cu(pz)(dbdmp)](ClO4)2 have been determined by single crystal X-ray diffraction studies. Structural analyses reveal the geometry of [Cu(pz)(dbdmp)](ClO4)2 is distorted square pyramidal and other two copper(II) complexes have distorted trigonal bipyramidal geometry. Molecular composition of cobalt(II) complexes have been determined by mass spectral data. The EPR spectra of copper(II) complexes in frozen acetonitrile solution exhibit axial spectra, characteristic of dx2-y2 ground state. Electrochemical studies of copper(II) complexes using glassy carbon as working electrode in acetonitrile solution show Cu(II)/Cu(I) couple with quasi reversible electron transfer versus Ag/Ag+ reference electrode. Antimicrobial activity of all the synthesized complexes were investigated against two Gram positive and two Gram negative bacterial strains.

  20. Hexadentate bispidine derivatives as versatile bifunctional chelate agents for copper(II) radioisotopes.

    PubMed

    Juran, Stefanie; Walther, Martin; Stephan, Holger; Bergmann, Ralf; Steinbach, Jörg; Kraus, Werner; Emmerling, Franziska; Comba, Peter

    2009-02-01

    The preparation and use of bispidine derivatives (3,7-diazabicyclo[3.3.1]nonane) as chelate ligands for radioactive copper isotopes for diagnosis (64Cu) or therapy (67Cu) are reported. Starting from the hexadentate bispidine-based bis(amine)tetrakis(pyridine) ligand 1 with a keto and two ester substituents, the corresponding mono-ol 2 and two dicarboxylic acid derivatives 3 and 5 have been synthesized. A range of techniques, including single-crystal X-ray structure analysis, UV/vis spectroscopy, cyclic voltammetry, thin-layer- (TLC), and high-performance liquid chromatography (HPLC), have been used to characterize the structure and stability of the copper(II)-bispidine complexes. A rapid formation (within 1 min) of stable copper(II)-bispidine complexes under mild conditions (ambient temperature, aqueous solution) has been observed. Challenge experiments of these complexes in the presence of a high excess of competing ligands, such as glutathione, cyclam, or superoxide dismutase (SOD), as well as in rat plasma, gave no evidence of demetalation or transchelation. The bifunctional bispidine derivative 5 can be readily functionalized with biologically active molecules at the pendant carboxylate groups. The coupling of a bombesin analogue betahomo-Glu-betaAla-betaAla-[Cha(13),Nle(14)]BBN(7-14), by condensation of a carboxylate of the bispidine backbone with the N-terminus of the peptide produced the bifunctional ligand 6. The radiocopper(II) complex of this bombesin-bispidine conjugate has a considerable hydrophilicity (log D(o/w) < -2.4), and this leads to a very fast blood clearance (blood: 0.28 +/- 0.02 SUV, 1 h p.i.), low liver tissue accumulation (liver: 1.20 +/- 0.27 SUV, 1 h p.i.), and rapid renal-urinary excretion (kidneys: 6.06 +/- 2.96 SUV, 1 h p.i.) as shown by biodistribution studies of 64Cu-6 in Wistar rats. Preliminary in vivo studies of 64Cu-6 in NMRI nu/nu mice, bearing the human prostate tumor PC-3 showed an accumulation of the conjugate in the tumor (2

  1. Aqua-{2-(pyridin-2-yl)-N-[(pyridin-2-yl)methyl-idene]ethanamine-κ(3) N,N',N''}(sulfato-κ(2) O,O')copper(II) tetra-hydrate.

    PubMed

    Tinguiano, Daniel; Sow, Mouhamadou Moustapha; Tamboura, Farba Bouyagui; Barry, Aliou Hamady; Gaye, Mohamed

    2013-01-01

    The title complex, [Cu(SO4)(C13H13N3)(H2O)]·4H2O, was obtained by mixing copper sulfate penta-hydrate and 2-(pyridin-2-yl)-N-(pyridin-2-yl-methyl-idene)ethanamine in eth-anol under reflux conditions. The Cu(II) ion shows a Jahn-Teller-distorted octa-hedral geometry, with equatorial positions occupied by three N atoms from the tridentate ligand (average Cu-N = 2.004 Å) and one O atom from a bidentate sulfate anion [Cu-O = 1.963 (2) Å]. The axial positions are occupied by one O atom from a coordinating water mol-ecule [Cu-O = 2.230 (3) Å] and one weakly bonded O atom [Cu-O = 2.750 (2) Å] from the bidentate sulfate ion. The complex mol-ecules are connected through O-H⋯O hydrogen bonds between the coordinating water mol-ecules and sulfate ions from neighboring complexes, forming a double chain parallel to the c axis. The chains are stabilized through additional hydrogen bonds by one of the non-coordinating water mol-ecules bridging between neighboring strands of the double chains. The remaining three water mol-ecules fill the inter-stitial space between the double chains and are involved in an intricate hydrogen-bonding network that consolidates the structure. PMID:23476324

  2. Polymeric networks of copper(II) phenylmalonate with heteroaromatic n-donor ligands: synthesis, crystal structure, and magnetic properties.

    PubMed

    Pasán, Jorge; Sanchiz, Joaquín; Ruiz-Pérez, Catalina; Lloret, Francesc; Julve, Miguel

    2005-10-31

    Two new phenylmalonate-bridged copper(II) complexes with the formulas [Cu(4,4'-bpy)(Phmal)](n).2nH(2)O (1) and [Cu(2,4'-bpy)(Phmal)(H(2)O)](n)() (2) (Phmal = phenylmalonate dianion, 4,4'-bpy = 4,4'-bipyridine, 2,4'-bpy = 2,4'-bipyridine) have been synthesized and characterized by X-ray diffraction. Complex 1 crystallizes in monoclinic space group P2(1), Z = 4, with unit cell parameters of a = 9.0837(6) Angstroms, b = 9.3514(4) Angstroms, c = 11.0831(8) Angstroms, and beta = 107.807(6) degrees , whereas complex 2 crystallizes in orthorhombic space group C2cb, Z = 8, with unit cell parameters of a = 10.1579(7) Angstroms, b = 10.3640(8) Angstroms, and c = 33.313(4) Angstroms. The structures of 1 and 2 consist of layers of copper(II) ions with bridging bis-monodentate phenylmalonate (1 and 2) and 4,4'-bpy (1) ligands and terminal monodentate 2,4'-bpy (2) groups. Each layer in 1 contains rectangles with dimensions of 11.08 x 4.99 Angstroms(2), the edges being defined by the Phmal and 4,4'-bpy ligands. The intralayer copper-copper separations in 1 through the anti-syn equatorial-apical carboxylate-bridge and the 4,4'-bpy molecule are 4.9922(4) and 11.083(1) Angstroms, respectively. The anti-syn equatorial-equatorial carboxylate bridge links the copper(II) atoms in complex 2 within each layer with a mean copper-copper separation of 5.3709(8) Angstroms. The presence of 2,4'-bpy as a terminal ligand accounts for the large interlayer separation of 15.22 Angstroms. The copper(II) environment presents a static pseudo-Jahn-Teller disorder which has been studied by EPR and low-temperature X-ray diffraction. Magnetic susceptibility measurements of both compounds in the temperature range 2-290 K show the occurrence of weak antiferromagnetic [J = -0.59(1) cm(-1) (1)] and ferromagnetic [J = +0.77(1) cm(-1) (2)] interactions between the copper(II) ions. The conformation of the phenylmalonate-carboxylate bridge and other structural factors, such as the planarity of the exchange

  3. Electronic Structure of a CuII-Alkoxide Complex Modeling Intermediates in Copper-Catalyzed Alcohol Oxidations

    PubMed Central

    Hayes, Ellen C.; Porter, Thomas R.; Barrows, Charles J.; Kaminsky, Werner; Mayer, James M.; Stoll, Stefan

    2016-01-01

    In the copper-catalyzed oxidation of alcohols to aldehydes, a CuII-alkoxide (CuII-OR) intermediate is believed to modulate the αC-H bond strength of the deprotonated substrate to facilitate the oxidation. As a structural model for these intermediates, we characterized the electronic structure of the stable compound TptBuCuII(OCH2CF3) (TptBu = (hydro-tris (3-tert-butyl-pyrazolyl) borate) and investigated the influence of the trifluoroethoxide ligand on the electronic structure of the complex. The compound exhibits an electron paramagnetic resonance (EPR) spectrum with an unusually large gzz value of 2.44 and a small copper hyperfine coupling Azz of 40·10−4 cm−1 (120 MHz). Single-crystal electron nuclear double resonance (ENDOR) spectra show that the unpaired spin population is highly localized on the copper ion (≈ 68 %), with no more than 15 % on the ethoxide oxygen. Electronic absorption and magnetic circular dichroism (MCD) spectra show weak ligand-field transitions between 5000 and 12000 cm−1 and an intense ethoxide-to-copper charge transfer (LMCT) transition at 24000 cm−1, resulting in the red color of this complex. Resonance Raman (rR) spectroscopy reveals a Cu-O stretch mode at 592 cm−1. Quantum chemical calculations support the interpretation and assignment of the experimental data. Compared to known CuII-thiolate and CuII-alkylperoxo complexes from the literature, we found an increased σ interaction in the CuII-OR bond that results in the spectroscopic features. These insights lay the basis for further elucidating the mechanism of copper-catalyzed alcohol oxidations. PMID:26907976

  4. Electronic Structure of a Cu(II)-Alkoxide Complex Modeling Intermediates in Copper-Catalyzed Alcohol Oxidations.

    PubMed

    Hayes, Ellen C; Porter, Thomas R; Barrows, Charles J; Kaminsky, Werner; Mayer, James M; Stoll, Stefan

    2016-03-30

    In the copper-catalyzed oxidation of alcohols to aldehydes, a Cu(II)-alkoxide (Cu(II)-OR) intermediate is believed to modulate the αC-H bond strength of the deprotonated substrate to facilitate the oxidation. As a structural model for these intermediates, we characterized the electronic structure of the stable compound Tp(tBu)Cu(II)(OCH2CF3) (Tp(tBu) = hydro-tris(3-tert-butyl-pyrazolyl)borate) and investigated the influence of the trifluoroethoxide ligand on the electronic structure of the complex. The compound exhibits an electron paramagnetic resonance (EPR) spectrum with an unusually large gzz value of 2.44 and a small copper hyperfine coupling Azz of 40 × 10(-4) cm(-1) (120 MHz). Single-crystal electron nuclear double resonance (ENDOR) spectra show that the unpaired spin population is highly localized on the copper ion (≈68%), with no more than 15% on the ethoxide oxygen. Electronic absorption and magnetic circular dichroism (MCD) spectra show weak ligand-field transitions between 5000 and 12,000 cm(-1) and an intense ethoxide-to-copper charge transfer (LMCT) transition at 24,000 cm(-1), resulting in the red color of this complex. Resonance Raman (rR) spectroscopy reveals a Cu-O stretch mode at 592 cm(-1). Quantum chemical calculations support the interpretation and assignment of the experimental data. Compared to known Cu(II)-thiolate and Cu(II)-alkylperoxo complexes from the literature, we found an increased σ interaction in the Cu(II)-OR bond that results in the spectroscopic features. These insights lay the basis for further elucidating the mechanism of copper-catalyzed alcohol oxidations. PMID:26907976

  5. Role of Fe(II), phosphate, silicate, sulfate, and carbonate in arsenic uptake by coprecipitation in synthetic and natural groundwater.

    PubMed

    Ciardelli, Mark C; Xu, Huifang; Sahai, Nita

    2008-02-01

    Competitive effects of phosphate, silicate, sulfate, and carbonate on As(III) and As(V) removal at pH approximately 7.2 have been investigated to test the feasibility of Fe(II)(aq) and hydroxylapatite crystals as inexpensive and potentially efficient agents for remediation of contaminated well-water, using Bangladesh as a type study. Arsenic(III) removal approximately 50-55% is achieved, when Fe(II)(aq) oxidizes to Fe(III) and precipitates as Fe(OH)3 at 25 degrees C and 3h reaction time, in the presence of all the oxyanion. Similar results were obtained for well-water samples from two sites in Bangladesh. Heating at 95 degrees C for 24h results in 70% As(III) uptake due to precipitation of magnesian calcite. A two-step process, Fe(II) oxidation and Fe(OH)3 precipitation at 25 degrees C for 2h, followed by magnesian calcite precipitation at 95 degrees C for 3h, yields approximately 65% arsenic removal while reducing the expensive heating period. In the absence of silicate, up to 70% As(III) uptake occurs at 25 degrees C. In all cases, As(III) was oxidized to As(V) in solution by dissolved oxygen and the reaction rate was probably promoted by intermediates formed during Fe(II) oxidation. Iron-catalyzed oxidation of As(III) by oxygen and hydrogen peroxide is pH-dependent with formation of oxidants in the Fenton reaction. Buffering pH at near-neutral values by dissolved carbonate and hydroxylapatite seeds is important for faster Fe(II) oxidation kinetics ensuring rapid coprecipitation of As as As(V) in the ferric phases.

  6. Synthesis, characterization, DNA-binding and cleavage studies of polypyridyl copper(II) complexes

    NASA Astrophysics Data System (ADS)

    Gubendran, Ammavasi; Rajesh, Jegathalaprathaban; Anitha, Kandasamy; Athappan, Periyakaruppan

    2014-10-01

    Six new mixed-ligand copper(II) complexes were synthesized namely [Cu(phen)2OAc]ClO4ṡH2O(1), [Cu(bpy)2OAc]ClO4ṡH2O(2), [Cu(o-ampacac)(phen)]ClO4(3), [Cu(o-ampbzac)(phen)]ClO4(4), [Cu(o-ampacac)(bpy)]ClO4(5), and [Cu(o-ampbzac)(bpy)]ClO4(6) (phen = 1,10-phenanthroline, bpy = 2, 2‧-bipyridine, o-ampacac = (Z)-4-(2-hydroxylamino)pent-3-ene-2-one,o-ampbzac = (Z)-4-(2-hydroxylamino)-4-phenylbut-3-ene-2-one)and characterized by UV-Vis, IR, EPR and cyclic voltammetry. Ligands were characterized by NMR spectra. Single crystal X-ray studies of the complex 1 shows Cu(II) ions are located in a highly distorted octahedral environment. Absorption spectral studies reveal that the complexes 1-6 exhibit hypochromicity during the interaction with DNA and binding constant values derived from spectral and electrochemical studies indicate that complexes 1, 2 and 3 bind strongly with DNA possibly by an intercalative mode. Electrochemical studies reveal that the complexes 1-4 prefer to bind with DNA in Cu(I) rather than Cu(II) form. The shift in the formal potentials E1/2 and CD spectral studies suggest groove or electrostatic binding mode for the complexes 4-6. Complex 1 can cleave supercoiled (SC) pUC18 DNA efficiently into nicked form II under photolytic conditions and into an open circular form (form II) and linear form (form III) in the presence of H2O2 at pH 8.0 and 37 °C, while the complex 2 does not cleave DNA under similar conditions.

  7. Interaction of a copper (II) complex containing an artificial sweetener (aspartame) with calf thymus DNA.

    PubMed

    Shahabadi, Nahid; Khodaei, Mohammad Mehdi; Kashanian, Soheila; Kheirdoosh, Fahimeh

    2014-01-01

    A copper (II) complex containing aspartame (APM) as ligand, Cu(APM)2Cl2⋅2H2O, was synthesized and characterized. In vitro binding interaction of this complex with native calf thymus DNA (CT-DNA) was studied at physiological pH. The interaction was studied using different methods: spectrophotometric, spectrofluorometric, competition experiment, circular dichroism (CD) and viscosimetric techniques. Hyperchromicity was observed in UV absorption band of Cu(APM)2Cl2⋅2H2O. A strong fluorescence quenching reaction of DNA to Cu(APM)2Cl2⋅2H2O was observed and the binding constants (Kf) and corresponding numbers of binding sites (n) were calculated at different temperatures. Thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) were calculated to be+89.3 kJ mol(-1) and+379.3 J mol(-1) K(-1) according to Van't Hoff equation which indicated that reaction is predominantly entropically driven. Experimental results from spectroscopic methods were comparable and further supported by viscosity measurements. We suggest that Cu(APM)2Cl2⋅2H2O interacts with calf thymus DNA via a groove interaction mode with an intrinsic binding constant of 8×10+4 M(-1). Binding of this copper complex to DNA was found to be stronger compared to aspartame which was studied recently.

  8. [Study on color reaction of copper(II)-neocuprine-glutathione-alcohol system].

    PubMed

    Guo, L; Liu, G; Zhang, Z; Liu, S; Wang, L

    2000-06-01

    The colour reaction of glutathione with copper(II)-neocuproine-alcohol was investigated in the present paper. The absorbance increased distinctly by about 13.8% when alcohol was added to the system. The maximum absorption wavelength lambda max of [Cu (neocuproine)2]+ was at 456 nm and the apparent molar absorptivity was 1.2 x 10(4) L.mol-1.cm-1 in the selected system. Linear dynamic relationship was obtained in the concentration range of 2-24 micrograms.mL-1 for glutathione. The regression equation was as following: A = 0.0104 + 0.0385c. The correlation coefficients was 0.9998. The recoveries obtained were between 98.5% and 99.9%. The relative standard deviations were less than 0.9% for all analyses. This method was used to determine glutathione in soybean extracts by the electromagnetic field technique and satisfactory results were obtained.

  9. EXAFS Studies of Some Copper(II) Mixed-Ligand Complexes

    SciTech Connect

    Joshi, S. K.; Katare, R. K.; Shrivastava, B. D.

    2007-02-02

    X-ray K-absorption spectroscopic studies have been carried out on copper (II) mixed-ligand complexes with glutamic acid and aspartic acid as the primary ligands, where as water, pyridine, imidazole and benz-imidazole have been used as secondary ligands. Chemical shifts obtained from the X-ray absorption data have indicated that the glutamic acid complexes are more ionic as compared to their corresponding aspartic acid complexes having similar secondary ligands. Further, we have estimated the average metal-ligand bond distances from the from structure data. For the different complexes studied under the present investigation, the studies reveal that the bonding parameter {alpha}1 decreases with the increase in the percentage covalency of the metal-ligand bond. Thus, the bonding parameter {alpha}1 may be used for the estimation of percentage covalency of the metal-ligand bond in other similar complexes.

  10. Antimalarial, antimicrobial, cytotoxic, DNA interaction and SOD like activities of tetrahedral copper(II) complexes

    NASA Astrophysics Data System (ADS)

    Mehta, Jugal V.; Gajera, Sanjay B.; Patel, Mohan N.

    2015-02-01

    The mononuclear copper(II) complexes with P, O-donor ligand and different fluoroquinolones have been synthesized and characterized by elemental analysis, electronic spectra, TGA, EPR, FT-IR and LC-MS spectroscopy. An antimicrobial efficiency of the complexes has been tested against five different microorganisms in terms of minimum inhibitory concentration (MIC) and displays very good antimicrobial activity. The binding strength and binding mode of the complexes with Herring Sperm DNA (HS DNA) have been investigated by absorption titration and viscosity measurement studies. The studies suggest the classical intercalative mode of DNA binding. Gel electrophoresis assay determines the ability of the complexes to cleave the supercoiled form of pUC19 DNA. Synthesized complexes have been tested for their SOD mimic activity using nonenzymatic NBT/NADH/PMS system and found to have good antioxidant activity. All the complexes show good cytotoxic and in vitro antimalarial activities.

  11. Spatial distribution of phases during gradual magnetostructural transitions in copper(II)-nitroxide based molecular magnets.

    PubMed

    Fedin, Matvey V; Veber, Sergey L; Bagryanskaya, Elena G; Romanenko, Galina V; Ovcharenko, Victor I

    2015-11-21

    Copper(ii)-nitroxide based molecular magnets Cu(hfac)2L(R) exhibit thermally-induced transitions between high- and low-temperature (HT/LT) magnetostructural states. In this work we report the first study on the spatial distribution of HT/LT phases during gradual transitions in these compounds. We explore the possibility of domain formation at intermediate temperatures, which has never been addressed before. For this purpose, we reexamine the available electron paramagnetic resonance (EPR) and X-ray diffraction data, and perform numerical calculations of EPR spectra for different models of exchange-coupled networks. A thorough analysis shows that during gradual transitions, molecular magnets Cu(hfac)2L(R) represent solid solutions of disordered HT and LT phases, and the formation of single-phase domains larger than a few nanometers in size is unlikely.

  12. Zero thermal expansion in a flexible, stable framework : tetramethylammonium copper(I) zinc(II) cyanide.

    SciTech Connect

    Phillips, A. E.; Halder, G. J.; Chapman, K. W.; Goodwin, A. L.; Kepert, C. J.; Univ. Sydney; Univ. Cambridge

    2010-01-13

    Tetramethylammonium copper(I) zinc(II) cyanide, which consists of N(CH{sub 3}){sub 4}{sup +} ions trapped within a cristobalite-like metal cyanide framework, has been studied by variable-temperature powder and single-crystal X-ray diffraction. Its coefficient of thermal expansion is approximately zero over the temperature range 200-400 K and comparable with the best commercial zero thermal expansion materials. The atomic displacement parameters, apparent bond lengths, and structure of a low-temperature, low-symmetry phase reveal that the low-energy vibrational modes responsible for this behavior maintain approximately rigid Zn coordination tetrahedra but involve significant distortion of their Cu counterparts.

  13. Coordination chemistry, thermodynamics and DFT calculations of copper(II) NNOS Schiff base complexes.

    PubMed

    Esmaielzadeh, Sheida; Azimian, Leila; Shekoohi, Khadijeh; Mohammadi, Khosro

    2014-12-10

    Synthesis, magnetic and spectroscopy techniques are described for five copper(II) containing tetradentate Schiff bases are synthesized from methyl-2-(N-2'-aminoethane), (1-methyl-2'-aminoethane), (3-aminopropylamino)cyclopentenedithiocarboxylate. Molar conductance and infrared spectral evidences indicate that the complexes are four-coordinate in which the Schiff bases are coordinated as NNOS ligands. Room temperature μeff values for the complexes are 1.71-1.80B.M. corresponding to one unpaired electron respectively. The formation constants and free energies were measured spectrophotometrically, at constant ionic strength 0.1M (NaClO4), at 25˚C in DMF solvent. Also, the DFT calculations were carried out to determine the structural and the geometrical properties of the complexes. The DFT results are further supported by the experimental formation constants of these complexes.

  14. Magnetic properties of copper(II) complexes containing peptides. Crystal structure of [Cu(phe-leu)

    NASA Astrophysics Data System (ADS)

    Sanchiz, J.; Kremer, C.; Torre, M. H.; Facchin, G.; Kremer, E.; Castellano, E. E.; Ellena, J.

    2006-09-01

    A novel copper(II) complex containing the peptide phe-leu has been prepared and characterized. The crystal structure of [Cu(phe-leu)] ( 1) was determined by X-ray diffraction. The presence of carboxylate and amido bridges allows the formation of an extended 2D arrangement. This structure is similar to those found in [Cu(gly-val)] · 1/2H 2O ( 2), [Cu(val-gly)] ( 3), [Cu(val-phe)] ( 4), and [Cu(phe-phe)] ( 5). The magnetic properties of compounds 1- 5 were studied and analyzed comparatively. The experimental data show that the magnetic interactions are mainly transmitted through μ 2-COO - bridges, being ferromagnetic for 1 and 3, and antiferromagnetic for 2, 4 and 5.

  15. Femtomole level photoelectrochemical aptasensing for mercury ions using quercetin-copper(II) complex as the DNA intercalator.

    PubMed

    Li, Hongbo; Xue, Yan; Wang, Wei

    2014-04-15

    An ultrasensitive and selective photoelectrochemical (PEC) aptasensor for mercury ions was first fabricated based on perylene-3, 4, 9, 10-tetracarboxylic acid/graphene oxide (PTCA/GO) heterojunction using quercetin-copper(II) complex intercalated into the poly(dT)-poly(dA) duplexes. Both the PTCA/GO heterojunction and the quercetin-copper(II) complex are in favor of the sensitivity for the fabricated PEC aptasensor due to band alignment and strong reduction capability, respectively. And they efficiently promote the separation of photoexcited carriers and enhance the photocurrent. The formation of thymine-Hg(2+)-thymine coordination chemistry resulted in the dehybridization of poly(dT)-poly(dA) duplexes and then the intercalator quercetin-copper(II) complex broke away from the surface of the PEC aptasensor. As the concentration of mercury ions increased, the photocurrent gradually decreased. The electrode response for mercury ions detection was in the linear range from 0.01 pmol L(-1) to 1.00 pmol L(-1) with the detection limit of 3.33 fmol L(-1). The label-free PEC aptasensor has excellent performances with ultrasensitivity and good selectivity besides the advantage of economic and facile fabrication. The strategy of quercetin-copper(II) complex as a novel DNA intercalator paves a new way to improve the performances for PEC sensors. PMID:24291750

  16. Silver(I)- or copper(II)-mediated dearomatization of aromatic ynones: direct access to spirocyclic scaffolds.

    PubMed

    James, Michael J; Cuthbertson, James D; O'Brien, Peter; Taylor, Richard J K; Unsworth, William P

    2015-06-22

    A high-yielding silver(I)- or copper(II)-catalyzed dearomatizing spirocyclization strategy allows the conversion of simple aromatic compounds that contain ynone substituents, including indole, anisole, pyrrole, and benzofuran derivatives, into functionalized spirocyclic scaffolds. A high-yielding asymmetric variant furnishes spirocyclic indolenines in up to 89:11 e.r. PMID:25960013

  17. Copper(II) as an efficient scavenger of singlet molecular oxygen.

    PubMed

    Joshi, P C

    1998-08-01

    Reactive oxygen species (ROS) are considered to play an important role in tissue injury that damages DNA, proteins, carbohydrates and lipids. Increased production of ROS and/or decreased efficiency of antioxidant defense system has been shown to contribute to a number of degenerative processes including cancer and AIDS. Among the various forms of ROS, singlet oxygen (1O2), which is generated predominantly in photosensitization reactions, is of particular physiologic significance because of its selectively long life in aqueous solution, its ability to cross the cell membrane barrier and high reactivity towards biomolecules. In the present study, the 1O2 scavenging potential of Cu(II) has been evaluated by (i) generating 1O2 by photosensitization of rose bengal (RB), (ii) establishing 1O2 quenching with recognized 1O2 scavengers like sodium azide, DABCO and (iii) examining the effect of Cu(II) in scavenging of 1O2. The results revealed that Cu(II) inhibited the rate of 1O2 production by 88%, 68%, 40%, 21% and 10% at a concentration of 10(-2) M, 5 x 10(-3) M, 10(-3) M; 5 x 10(-4) M, and 10(-4) M, respectively. Under similar experimental condition, sodium azide or DABCO at 10(-2) M inhibited the 1O2 production by 86% and 88%, respectively. Other 1O2 generating photosensitizer like hematoporphyrin, riboflavin and methylene blue also produced identical results with Cu(II) but Fe(II), Fe(III), Zn(II) or As(III) did not produce any quenching of 1O2. Presence of a copper binding peptide (Gly-Gly-His) in the reaction system reduced the 1O2 scavenging capacity of Cu(II) by 52-66% depending upon the UV dose. The 1O2 scavenging property of metal ion appears to have an advantage to reduce the oxidative damage of photodynamic reactions in order to prevent ROS-induced toxicity reactions. PMID:9854900

  18. Copper(II) complexation of tacrine hybrids with potential anti-neurodegenerative roles.

    PubMed

    Quintanova, Catarina; Keri, Rangappa S; Chaves, Sílvia; Santos, M Amélia

    2015-10-01

    The complexity and multifactorial nature of neurodegenerative diseases turn quite difficult the development of adequate drugs for their treatment. Multi-target analogues, in conjugation with natural moieties, have been developed in order to combine acetylcholinesterase (AChE) inhibition with antioxidant properties, metal-binding capacity and inhibition of amyloid-β (Aβ) aggregation. Due to the recent interest on natural-based drugs and also the importance of studying the role of transition metal ions in the disease process, we herein evaluate the copper chelating capacity and inhibitory ability for self- and Cu-induced Aβ1-42 aggregation of two nature-base hybrid model compounds obtained from conjugation of a tacrine moiety with a S-allylcystein (1) or S-propargylcystein (2) moiety. Both compounds show a moderate chelating power towards Cu(II) (pCu 7.13-7.51, CL/CCu=10, CCu=10(-6)M, pH7.4), with predominant formation of 1:1 complex species (CuL, CuH-1L) for which the coordination sphere involves the N-amide and the NH2 amine of the cysteine derivative as well as the NH of tacrine. The compounds are able to improve the inhibition of Aβ aggregation in the presence of Cu(II) and this is slightly more relevant for the allyl derivative (1), a stronger copper chelator, than for the propargyl (2). Moreover, the presence of a chloro atom in the tacrine moiety and the size of the chain length between the two NH groups appeared also to improve the inhibition capacity for Aβ aggregation.

  19. Supramolecular control of a mononuclear biomimetic copper(II) center: bowl complexes vs funnel complexes.

    PubMed

    Gout, Jérôme; Višnjevac, Aleksandar; Rat, Stéphanie; Parrot, Arnaud; Hessani, Assia; Bistri, Olivia; Le Poul, Nicolas; Le Mest, Yves; Reinaud, Olivia

    2014-06-16

    Modeling the mononuclear site of copper enzymes is important for a better understanding of the factors controlling the reactivity of the metal center. A major difficulty stems from the difficult control of the nuclearity while maintaining free sites open to coordination of exogenous ligands. A supramolecular approach consists in associating a hydrophobic cavity to a tripodal ligand that will define the coordination spheres as well as access to the metal ion. Here, we describe the synthesis of a bowl Cu(II) complex based on the resorcinarene scaffold. This study supplements a previous work on Cu(I) coordination. It provides a complete picture of the cavity-copper system in its two oxidation states. The first XRD structure of such a bowl complex was obtained, evidencing a 5-coordinate Cu(II) ion with the three imidazole donors bound to the metal (two in the base of the pyramid, one in the apical position) and with an acetate anion, completing the base of the pyramid, and deeply included in the bowl. Solution studies conducted by EPR and UV-vis absorption spectroscopies as well as cyclic voltammetry highlighted interaction with coordinating solvents, various carboxylates that can sit either in the endo or in the exo position depending on their size as well as possible stabilization of hydroxo species in a mononuclear state. A comparison of the binding and redox properties of the bowl complex with funnel complexes based on the calix[6]arene core further highlights the importance of supramolecular features defining the first, second, and third coordination sphere for control of the metal ion. PMID:24901070

  20. Effect of copper sulfate on the immune response and susceptibility to Vibrio alginolyticus in the white shrimp Litopenaeus vannamei.

    PubMed

    Yeh, Su-Tuen; Liu, Chun-Hung; Chen, Jiann-Chu

    2004-11-01

    White shrimp Litopenaeus vannamei (Boone) held in 35 per thousand seawater were challenged with Vibrio alginolyticus at a dose of 3 x 10(5) colony-forming units (cfu) shrimp(-1), and then placed in water containing concentrations of Cu2+ at 0 (control), 1, 5, 10 and 20 mg l(-1). Mortality of shrimp in 5, 10 and 20 mg l(-1) Cu2+ was significantly higher than those in 1 mg l(-1) Cu2+ and the control solution after 24-96 h. In another experiment, L. vannamei which had been exposed to control, 1, 5, 10 and 20 mg l(-1) Cu2+ for 24, 48 and 96 h were examined for THC (total haemocyte count), phenoloxidase activity, respiratory burst (release of superoxide anion), phagocytic activity and clearance efficiency to V. alginolyticus. Copper concentrations at 1 mg l(-1) or greater for 24h resulted in decreased THC, phenoloxidase activity, phagocytic activity and clearance efficiency, whereas copper concentration at 20 mg l(-1) caused significant increase in respiratory burst of L. vannamei. In conclusion, concentration of Cu2+ at 1 mg l(-1) or greater increased the susceptibility of L. vannamei to V. alginolyticus infection by a depression in immune ability. The release of superoxide anion by L. vannamei exposed to 20 mg l(-1) Cu2+ was considered to be cytotoxic to the host. PMID:15313510

  1. Characterization of sodium dodecyl sulfate modified iron pillared montmorillonite and its application for the removal of aqueous Cu(II) and Co(II).

    PubMed

    Li, Shu-Zhen; Wu, Ping-Xiao

    2010-01-15

    Anionic surfactant modified Fe-pillared montmorillonites were prepared by Fe-hydrate solution and sodium dodecyl sulfate (SDS) solution. These organo-inorgano complex montmorillonites were divided into three types (CM1, CM2 and CM3) depending on different intercalation processes. X-ray diffraction spectra, the Fourier transform infrared (FTIR) spectra were used to analyze the structure of the raw and modified montmorillonites. X-ray photoelectron spectra of the samples have been studied to determine spectral characteristics to allow the identification of Fe(III) hydroxide. The specific surface area of the host montmorillonite (M0) is 73.2m(2)/g, while for the modified montmorillonites it is 114.0m(2)/g, 117.2m(2)/g, and 115.8m(2)/g, respectively. The mesopore volumes of the montmorillonites decrease after modification. Ions of copper and cobalt were selected as adsorbates to evaluate the adsorption performance of each montmorillonite. The adsorption data was analyzed by both Freundlich and Langmuir isotherm models and the data was well fit by the Langmuir isotherm model. The adsorption was efficient and significantly influenced by metal speciation, metal concentration, contact time, and pH. Higher adsorption capacity of the modified montmorillonites were obtained at pH 5-6. The results of desorption indicated that the metal ions were covalently bound to the modified montmorillonites. PMID:19748730

  2. Norfloxacin and N-Donor Mixed-Ligand Copper(II) Complexes: Synthesis, Albumin Interaction, and Anti-Trypanosoma cruzi Activity

    PubMed Central

    Martins, Darliane A.; Gouvea, Ligiane R.; Muniz, Gabriel S. Vignoli; Louro, Sonia R. W.; Batista, Denise da Gama Jaen; Soeiro, Maria de Nazaré C.; Teixeira, Letícia R.

    2016-01-01

    Copper(II) complexes with the first-generation quinolone antibacterial agent norfloxacin containing a nitrogen donor heterocyclic ligand 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen) were prepared and characterized by IR, EPR spectra, molar conductivity, and elemental analyses. The experimental data suggest that norfloxacin was coordinated to copper(II) through the carboxylato and ketone oxygen atoms. The interaction of the copper(II) complexes with bovine serum albumin (BSA) and human serum albumin (HSA) was investigated using fluorescence quenching of the tryptophan residues and copper(II) EPR spectroscopy. The results of fluorescence titration revealed that copper(II) complexes have a moderate ability to quench the intrinsic fluorescence of the albumins through a static quenching mechanism. EPR experiments showed that BSA and HSA Cu(II) sites compete with NOR for Cu(II)-bipy and Cu(II)-phen to form protein mixed-ligand complexes. Copper(II) complexes, together with the corresponding ligands, were evaluated for their trypanocidal activity in vitro against Trypanosoma cruzi, the causative agent of Chagas disease. The tests performed using bloodstream trypomastigotes showed that the Cu(II)-N-donor precursors and the metal complexes were more active than the free fluoroquinolone. PMID:26924953

  3. In vitro DNA binding studies of the sweetening agent saccharin and its copper(II) and zinc(II) complexes.

    PubMed

    Icsel, Ceyda; Yilmaz, Veysel T

    2014-01-01

    The interactions of fish sperm DNA (FS-DNA) with the sodium salt of sweetener saccharin (sacH) and its copper and zinc complexes, namely [M(sac)2(H2O)4]·2H2O (M=Cu(II) or Zn(II)) were studied by using UV-Vis titration, fluorometric competition, thermal denaturation, viscosity and gel electrophoresis measurements. The intrinsic binding constants (Kb) obtained from absorption titrations were estimated to be 2.86 (±0.06)×10(4)M(-1) for Na(sac), 6.67 (±0.12)×10(4)M(-1) for Cu-sac and 4.01 (±0.08)×10(4)M(-1) for Zn-sac. The Cu-sac complex binds to FS-DNA via intercalation with a KA value of 50.12 (±0.22)×10(4)M(-1) as evidenced by competitive binding studies with ethidium bromide. Moreover, competition experiments with Hoechst 33258 are indicative of a groove binding mode of Na(sac) and Zn-sac with binding constants of 3.13 (±0.16)×10(4)M(-1) and 5.25 (±0.22)×10(4)M(-1), respectively. The spectroscopic measurements indicate a moderate DNA binding affinity of Na(sac) and its metal complexes. The suggested binding modes are further confirmed by the thermal denaturation and viscosity measurements. In addition, Cu-sac and Zn-sac show weak ability to damage to pBR322 supercoiled plasmid DNA.

  4. Zinc(II)-Thiosemicarbazone Complexes Are Localized to the Lysosomal Compartment Where They Transmetallate with Copper Ions to Induce Cytotoxicity.

    PubMed

    Stacy, Alexandra E; Palanimuthu, Duraippandi; Bernhardt, Paul V; Kalinowski, Danuta S; Jansson, Patric J; Richardson, Des R

    2016-05-26

    As the di-2-pyridylketone thiosemicarbazone (DpT) and 2-acetylpyridine thiosemicarbazone (ApT) series show potent antitumor activity in vitro and in vivo, we synthesized their fluorescent zinc(II) complexes to assess their intracellular distribution. The Zn(II) complexes generally showed significantly greater cytotoxicity than the thiosemicarbazones alone in several tumor cell-types. Notably, specific structure-activity relationships demonstrated the importance of the di-2-pyridyl pharmacophore in their activity. Confocal fluorescence imaging and live cell microscopy showed that the Zn(II) complex of our lead compound, di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), which is scheduled to enter clinical trials, was localized to lysosomes. Under lysosomal conditions, the Zn(II) complexes were shown to transmetallate with copper ions, leading to redox-active copper complexes that induced lysosomal membrane permeabilization (LMP) and cytotoxicity. This is the first study to demonstrate direct lysosomal targeting of our novel Zn(II)-thiosemicarbazone complexes that mediate their activity via transmetalation with copper ions and LMP. PMID:27023111

  5. Determination of copper(II) in the dairy product by an electrochemical sensor based on click chemistry.

    PubMed

    Qiu, Suyan; Xie, Lidan; Gao, Sen; Liu, Qida; Lin, Zhenyu; Qiu, Bin; Chen, Guonan

    2011-11-30

    Herein, a novel sensitive electrochemical sensor for copper(II) based on Cu(I) catalyzed alkyne-azide cycloaddition reaction (CuAAC) is described. The catalyst of Cu(I) species is derived from electrochemical reduction of Cu(II) through bulk electrolysis (BE) with coulometry technique. The propargyl-functionalized ferrocene (propargyl-functionalized Fc) is covalently coupled onto the electrode surface via CuAAC reaction and forms propargyl-functionalized Fc modified gold electrode, which allows a good and stable electrochemical signal. The change of current at peak (dI), detected by differential pulse voltammetry (DPV), exhibits a linear response to the logarithm of Cu(II) concentration in the range of 1.0×10(-14)-1.0×10(-9) mol L(-1). It is also found that the proposed sensor has a good selectivity for copper(II) assay even in the presence of other common metal ions. Additionally, the proposed method has been applied to determine copper(II) in the dairy product (yoghurt) with satisfactory results.

  6. Copper(II) ions affect the gating dynamics of the 20S proteasome: a molecular and in cell study.

    PubMed

    Santoro, Anna Maria; Monaco, Irene; Attanasio, Francesco; Lanza, Valeria; Pappalardo, Giuseppe; Tomasello, Marianna Flora; Cunsolo, Alessandra; Rizzarelli, Enrico; De Luigi, Ada; Salmona, Mario; Milardi, Danilo

    2016-01-01

    Due to their altered metabolism cancer cells are more sensitive to proteasome inhibition or changes of copper levels than normal cells. Thus, the development of copper complexes endowed with proteasome inhibition features has emerged as a promising anticancer strategy. However, limited information is available about the exact mechanism by which copper inhibits proteasome. Here we show that Cu(II) ions simultaneously inhibit the three peptidase activities of isolated 20S proteasomes with potencies (IC50) in the micromolar range. Cu(II) ions, in cell-free conditions, neither catalyze red-ox reactions nor disrupt the assembly of the 20S proteasome but, rather, promote conformational changes associated to impaired channel gating. Notably, HeLa cells grown in a Cu(II)-supplemented medium exhibit decreased proteasome activity. This effect, however, was attenuated in the presence of an antioxidant. Our results suggest that if, on one hand, Cu(II)-inhibited 20S activities may be associated to conformational changes that favor the closed state of the core particle, on the other hand the complex effect induced by Cu(II) ions in cancer cells is the result of several concurring events including ROS-mediated proteasome flooding, and disassembly of the 26S proteasome into its 20S and 19S components. PMID:27633879

  7. Copper(II) ions affect the gating dynamics of the 20S proteasome: a molecular and in cell study

    PubMed Central

    Santoro, Anna Maria; Monaco, Irene; Attanasio, Francesco; Lanza, Valeria; Pappalardo, Giuseppe; Tomasello, Marianna Flora; Cunsolo, Alessandra; Rizzarelli, Enrico; De Luigi, Ada; Salmona, Mario; Milardi, Danilo

    2016-01-01

    Due to their altered metabolism cancer cells are more sensitive to proteasome inhibition or changes of copper levels than normal cells. Thus, the development of copper complexes endowed with proteasome inhibition features has emerged as a promising anticancer strategy. However, limited information is available about the exact mechanism by which copper inhibits proteasome. Here we show that Cu(II) ions simultaneously inhibit the three peptidase activities of isolated 20S proteasomes with potencies (IC50) in the micromolar range. Cu(II) ions, in cell-free conditions, neither catalyze red-ox reactions nor disrupt the assembly of the 20S proteasome but, rather, promote conformational changes associated to impaired channel gating. Notably, HeLa cells grown in a Cu(II)-supplemented medium exhibit decreased proteasome activity. This effect, however, was attenuated in the presence of an antioxidant. Our results suggest that if, on one hand, Cu(II)-inhibited 20S activities may be associated to conformational changes that favor the closed state of the core particle, on the other hand the complex effect induced by Cu(II) ions in cancer cells is the result of several concurring events including ROS-mediated proteasome flooding, and disassembly of the 26S proteasome into its 20S and 19S components. PMID:27633879

  8. Determination of copper(II) in the dairy product by an electrochemical sensor based on click chemistry.

    PubMed

    Qiu, Suyan; Xie, Lidan; Gao, Sen; Liu, Qida; Lin, Zhenyu; Qiu, Bin; Chen, Guonan

    2011-11-30

    Herein, a novel sensitive electrochemical sensor for copper(II) based on Cu(I) catalyzed alkyne-azide cycloaddition reaction (CuAAC) is described. The catalyst of Cu(I) species is derived from electrochemical reduction of Cu(II) through bulk electrolysis (BE) with coulometry technique. The propargyl-functionalized ferrocene (propargyl-functionalized Fc) is covalently coupled onto the electrode surface via CuAAC reaction and forms propargyl-functionalized Fc modified gold electrode, which allows a good and stable electrochemical signal. The change of current at peak (dI), detected by differential pulse voltammetry (DPV), exhibits a linear response to the logarithm of Cu(II) concentration in the range of 1.0×10(-14)-1.0×10(-9) mol L(-1). It is also found that the proposed sensor has a good selectivity for copper(II) assay even in the presence of other common metal ions. Additionally, the proposed method has been applied to determine copper(II) in the dairy product (yoghurt) with satisfactory results. PMID:22027119

  9. Copper(II)-Specific Fluorogenic Task-Specific Ionic Liquids as Selective Fluorescence Probes and Recyclable Extractants.

    PubMed

    Chatterjee, Sobhan; Gohil, Hardipsinh; Suresh, E; Paital, Alok Ranjan

    2015-09-28

    The designed synthesis of a series of copper(II) specific fluorogenic hydrophobic task-specific ionic liquids (TSILs) from a new naphthalene-based tetradentate ligand is reported. Absorption and fluorescence spectral studies reveal both the ligand and its derivative TSILs show exclusive selectivity towards copper(II) ions. The Stern-Volmer method for calculation of the detection limit for ligand and TSIL1-3 shows values of 0.12, 20, 17, and 15 μM, respectively. Extraction and striping studies by doping these TSILs in [bmim][NTf2] demonstrated that these TSILs are recyclable extractants for the selective recovery of Cu(II) ions from a mixture of 14 relevant metal chloride aqueous solutions in biphasic liquid-liquid extraction with approximately 95% recovery. PMID:26285155

  10. Manganese (II) Chelate Functionalized Copper Sulfide Nanoparticles for Efficient Magnetic Resonance/Photoacoustic Dual-Modal Imaging Guided Photothermal Therapy.

    PubMed

    Liu, Renfa; Jing, Lijia; Peng, Dong; Li, Yong; Tian, Jie; Dai, Zhifei

    2015-01-01

    The integration of diagnostic and therapeutic functionalities into one nanoplatform shows great promise in cancer therapy. In this research, manganese (II) chelate functionalized copper sulfide nanoparticles were successfully prepared using a facile hydrothermal method. The obtained ultrasmall nanoparticles exhibit excellent photothermal effect and photoaoustic activity. Besides, the high loading content of Mn(II) chelates makes the nanoparticles attractive T1 contrast agent in magnetic resonance imaging (MRI). In vivo photoacoustic imaging (PAI) results showed that the nanoparticles could be efficiently accumulated in tumor site in 24 h after systematic administration, which was further validated by MRI tests. The subsequent photothermal therapy of cancer in vivo was achieved without inducing any observed side effects. Therefore, the copper sulfide nanoparticles functionalized with Mn(II) chelate hold great promise as a theranostic nanomedicine for MR/PA dual-modal imaging guided photothermal therapy of cancer.

  11. Manganese (II) Chelate Functionalized Copper Sulfide Nanoparticles for Efficient Magnetic Resonance/Photoacoustic Dual-Modal Imaging Guided Photothermal Therapy

    PubMed Central

    Liu, Renfa; Jing, Lijia; Peng, Dong; Li, Yong; Tian, Jie; Dai, Zhifei

    2015-01-01

    The integration of diagnostic and therapeutic functionalities into one nanoplatform shows great promise in cancer therapy. In this research, manganese (II) chelate functionalized copper sulfide nanoparticles were successfully prepared using a facile hydrothermal method. The obtained ultrasmall nanoparticles exhibit excellent photothermal effect and photoaoustic activity. Besides, the high loading content of Mn(II) chelates makes the nanoparticles attractive T1 contrast agent in magnetic resonance imaging (MRI). In vivo photoacoustic imaging (PAI) results showed that the nanoparticles could be efficiently accumulated in tumor site in 24 h after systematic administration, which was further validated by MRI tests. The subsequent photothermal therapy of cancer in vivo was achieved without inducing any observed side effects. Therefore, the copper sulfide nanoparticles functionalized with Mn(II) chelate hold great promise as a theranostic nanomedicine for MR/PA dual-modal imaging guided photothermal therapy of cancer. PMID:26284144

  12. Effects of ammonium sulfate aerosols on vegetation—II. Mode of entry and responses of vegetation

    NASA Astrophysics Data System (ADS)

    Gmur, Nicholas F.; Evans, Lance S.; Cunningham, Elizabeth A.

    These experiments were designed to provide information on the rates of aerosol deposition, mode of entry, and effects of deposition of submicrometer ammonium sulfate aerosols on foliage of Phaseolus vulgaris L. A deposition velocity of 3.2 × 10 3cms-1 was constant during 3-week exposures of plants to aerosol concentrations of 26mg m -3 (i.e. about two orders of magnitude above ambient episode concentrations). Mean deposition rate on foliage was 4.1 × 10 -11 μg cm -2s -1. Visible injury symptoms included leaf chlorosis, necrosis and loss of turgor. Chlorosis was most frequent near leaf margins causing epinasty and near major veins. Internal injury occurred initially in spongy mesophyll cells. Eventually abaxial epidermal and palisade parenchyma cells were injured. These results suggest that submicrometer aerosols enter abaxial stomata and affect more internal cells before affecting leaf surface cells. Exposure to aerosols decreased both abaxial and adaxial leaf resistances markedly. Although visible injury to foliage occurred, no changes in dry mass of roots and shoots or leaf area occurred. These results suggest that for the plant developmental stage studied, while leaf resistances decreased and cellular injury occurred in foliage, these factors were not significantly related to plant growth and development.

  13. Synthesis, characterization, spectroscopic and theoretical studies of new zinc(II), copper(II) and nickel(II) complexes based on imine ligand containing 2-aminothiophenol moiety

    NASA Astrophysics Data System (ADS)

    Shafaatian, Bita; Mousavi, S. Sedighe; Afshari, Sadegh

    2016-11-01

    New dimer complexes of zinc(II), copper(II) and nickel(II) were synthesized using the Schiff base ligand which was formed by the condensation of 2-aminothiophenol and 2-hydroxy-5-methyl benzaldehyde. This tridentate Schiff base ligand was coordinated to the metal ions through the NSO donor atoms. In order to prevent the oxidation of the thiole group during the formation of Schiff base and its complexes, all of the reactions were carried out under an inert atmosphere of argon. The X-ray structure of the Schiff base ligand showed that in the crystalline form the SH groups were oxidized to produce a disulfide Schiff base as a new double Schiff base ligand. The molar conductivity values of the complexes in dichloromethane implied the presence of non-electrolyte species. The fluorescence properties of the Schiff base ligand and its complexes were also studied in dichloromethane. The products were characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis, and conductometry. The crystal structure of the double Schiff base was determined by single crystal X-ray diffraction. Furthermore, the density functional theory (DFT) calculations were performed at the B3LYP/6-31G(d,p) level of theory for the determination of the optimized structures of Schiff base complexes.

  14. Synthesis, structural characterization, cytotoxic properties and DNA binding of a dinuclear copper(II) complex.

    PubMed

    Ferreira, B J M Leite; Brandão, P; Meireles, M; Martel, Fátima; Correia-Branco, Ana; Fernandes, Diana M; Santos, T M; Félix, V

    2016-08-01

    In this study a novel dinuclear copper(II) complex with adenine and phenanthroline has been synthesized and its structure determined by single crystal X-ray diffraction. In the dinuclear complex [Cu₂(μ-adenine)₂(phen)₂(H2O)2](NO3)4·0.5H2O (phen=1,10-phenanthroline) (1) the two Cu(II) centres exhibit a distorted square pyramidal coordination geometry linked by two nitrogen donors from adenine bridges leading to a Cu-Cu distance of 3.242(3)Å. Intramolecular and intermolecular π⋯π interactions as well as an H-bonding network were observed. The antitumor capacity of the complex has been tested in vitro against human cancer cell lines, cervical carcinoma (HeLa) and colorectal adenocarcinoma (Caco-2), by metabolic tests, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide as reagent. The complex 1 has remarkable low IC50 values of 0.87±0.06μM (HeLa) and 0.44±0.06μM (Caco-2), when compared with values for cisplatin against the same cell lines. The interaction of complex 1 with calf thymus DNA (CT DNA) was further investigated by absorption and fluorescence spectroscopic methods. A binding constant of 5.09×10(5)M(-1) was obtained from UV-vis absorption studies. PMID:27157979

  15. Electroactive copper(II) bimetallic self-assembled multilayers on Si(100)

    NASA Astrophysics Data System (ADS)

    Sánchez, Alejandra; Urcuyo, Roberto; González-Flores, Diego; Montalberth-Smith, Ricardo; León-Rojas, Carlos; Pineda, Leslie W.; Montero, Mavis L.

    2012-02-01

    Silicon (100) surfaces were modified by reacting 4-aminopyridine and Si-Cl bond. These surfaces were further used for tethering copper bimetallic complexes and growing monolayers and multilayers by changing the axial position via Lewis acid-base reactions. In this way, coordination chemistry approach can be used as building blocks for controlling the design of functional surfaces. Furthermore, the outcomes of the several characterization techniques indicate that the complex is spatially oriented suggesting that this simple strategy allows the preparation of three dimensional molecular structures exhibiting spatial order. The structures on surface show interesting electroactive behaviors leading two cathodic signals, that can be related to Cu(II)/Cu(I) and Cu(I)/Cu(0) electro-reduction species (signals at - 0.15 V and - 0.50 V) and one peak in the anodic region (- 0.15 V) ascribed to the Cu(0)/Cu(II) electro-oxidation reaction, using an Ag/AgCl saturated electrode and platinum wire as reference and counter electrodes, respectively.

  16. Glycosidase- and β-lactamase-like activity of dinuclear copper(II) patellamide complexes.

    PubMed

    Comba, Peter; Eisenschmidt, Annika; Kipper, Nora; Schießl, Jasmin

    2016-06-01

    Prochloron, a blue-green algae belonging to ancient prokaryotes, produces, like other cyanobacteria, cyclic pseudo-peptides, which are also found in its obligate symbiont ascidiae (Lissoclinum patellum). Although research has focused for some time on the putative metabolic function of these cyclic peptides, to date it is still not understood. Their role might be connected to the increased concentrations of divalent metal ions, especially Cu(II), found in ascidiae. Dinuclear copper(II) complexes of cyclic pseudo-peptides revealed a broad hydrolytic capacity, including carboanhydrase and phosphatase activity. This study reports their β-lactamase as well as α- and β-glycosidase activity with kcat=(11.34±0.91)ˑ10(-4)s(-1) for β-lactamase, kcat=(1.55±0.13)ˑ10(-4)s(-1) for α-glycosidase and kcat=(1.22±0.09)ˑ10(-4)s(-1) for β-glycosidase activity. PMID:26921720

  17. Structural characterization of a metal-based perfusion tracer: copper(II) pyruvaldehyde bis(N4-methylthiosemicarbazone).

    PubMed

    John, E; Fanwick, P E; McKenzie, A T; Stowell, J G; Green, M A

    1989-01-01

    Copper(II) pyruvaldehyde bis(N4-methylthiosemicarbazone), Cu(PTSM), has been obtained as a dark red crystalline solid from EtOH-DMSO solvent mixture and structurally characterized by x-ray crystallography. The molecule possesses the expected pseudo-square planar N2S2 metal coordination sphere; however, the copper center also interacts through its axial coordination site with the sulfur atom of an adjacent Cu(PTSM) molecule in the crystal lattice. The structure of this compound is compared with the structures of other metal complexes that have been proposed in the nuclear medicine literature as perfusion tracers. PMID:2621114

  18. Crystal structures of μ-oxalato-bis­[azido­(hista­mine)­copper(II)] and μ-oxalato-bis­[(dicyan­amido)(hista­mine)­copper(II)

    PubMed Central

    Liu, Chen; Abboud, Khalil A.

    2015-01-01

    The title compounds, μ-oxalato-κ4 O 1,O 2:O 1′,O 2′-bis­[[4-(2-amino­eth­yl)-1H-imid­azole-κ2 N 3,N 4](azido-κN 1)copper(II)], [Cu2(C2O4)(N3)2(C5H9N3)2], (I), and μ-ox­al­ato-κ4 O 1,O 2:O 1′,O 2′-bis­[[4-(2-amino­eth­yl)-1H-imidazole-κ2 N 3,N 4](dicyanamido-κN 1)copper(II)], [Cu2(C2O4)(C2N3)2(C5H9N3)2], (II), are two oxalate-bridged dinuclear copper complexes. Each CuII ion adopts a five-coordinate square-pyramidal coordination sphere where the basal N2O2 plane is formed by two O atoms of the oxalate ligand and two N atoms of a bidentate chelating histamine mol­ecule. The apical coordination site in compound (I) is occupied by a monodentate azide anion through one of its terminal N atoms. The apical coordination site in compound (II) is occupied by a monodentate dicyanamide anion through one of its terminal N atoms. The mol­ecules in both structures are centrosymmetric. In the crystals of compounds (I) and (II), the dinuclear complexes are linked through N—H⋯X and C—H⋯X (X = N, O) hydrogen bonds where the donors are provided by the histamine ligand and the acceptor atoms are provided by the azide, dicyanamide, and oxalate ligands. In compound (I), the coordinatively unsaturated copper ions inter­act with the histamine ligand via a C—H⋯Cu inter­action. The coordinatively unsaturated copper ions in compound (II) inter­act via a weak N⋯Cu inter­action with the dicyanamide ligand of a neighboring mol­ecule. The side chain of the histamine ligand is disordered over three sets of sites in (II). PMID:26594515

  19. Ternary copper(II) complexes with amino acid chains and heterocyclic bases: DNA binding, cytotoxic and cell apoptosis induction properties.

    PubMed

    Ma, Tieliang; Xu, Jun; Wang, Yuan; Yu, Hao; Yang, Yong; Liu, Yang; Ding, Weiliang; Zhu, Wenjiao; Chen, Ruhua; Ge, Zhijun; Tan, Yongfei; Jia, Lei; Zhu, Taofeng

    2015-03-01

    Nowadays, chemotherapy is a common means of oncology. However, it is difficult to find excellent chemotherapy drugs. Here we reported three new ternary copper(II) complexes which have potential chemotherapy characteristics with reduced Schiff base ligand and heterocyclic bases (TBHP), [Cu(phen)(TBHP)]H2O (1), [Cu(dpz)(TBHP)]H2O (2) and [Cu(dppz)(TBHP)]H2O (3) (phen=1,10-phenanthroline, dpz=dipyrido [3,2:2',3'-f]quinoxaline, dppz=dipyrido [3,2-a:2',3'-c]phenazine, H2TBHP=2-(3,5-di-tert-butyl-2-hydroxybenzylamino)-2-benzyl-acetic acid). The DNA-binding properties of the complexes were investigated by spectrometric titrations, ethidium bromide displacement experiments and viscosity measurements. The results indicated that the three complexes, especially the complex 13, can strongly bind to calf-thymus DNA (CT-DNA). The intrinsic binding constants Kb of the ternary copper(II) complexes with CT-DNA were 1.37×10(5), 1.81×10(5) and 3.21×10(5) for 1, 2 and 3 respectively. Comparative cytotoxic activities of the copper(II) complexes were also determined by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that the ternary copper(II) complexes had significant cytotoxic activity against the human lung cancer (A549), human esophageal cancer (Eca109) and human gastric cancer (SGC7901) cell lines. Cell apoptosis were detected by AnnexinV/PI flow cytometry and by Western blotting with the protein expression of p53, Bax and Bcl-2. All the three copper complexes can effectively induce apoptosis of the three human tumor cells. PMID:25555321

  20. Ternary copper(II) complexes with amino acid chains and heterocyclic bases: DNA binding, cytotoxic and cell apoptosis induction properties.

    PubMed

    Ma, Tieliang; Xu, Jun; Wang, Yuan; Yu, Hao; Yang, Yong; Liu, Yang; Ding, Weiliang; Zhu, Wenjiao; Chen, Ruhua; Ge, Zhijun; Tan, Yongfei; Jia, Lei; Zhu, Taofeng

    2015-03-01

    Nowadays, chemotherapy is a common means of oncology. However, it is difficult to find excellent chemotherapy drugs. Here we reported three new ternary copper(II) complexes which have potential chemotherapy characteristics with reduced Schiff base ligand and heterocyclic bases (TBHP), [Cu(phen)(TBHP)]H2O (1), [Cu(dpz)(TBHP)]H2O (2) and [Cu(dppz)(TBHP)]H2O (3) (phen=1,10-phenanthroline, dpz=dipyrido [3,2:2',3'-f]quinoxaline, dppz=dipyrido [3,2-a:2',3'-c]phenazine, H2TBHP=2-(3,5-di-tert-butyl-2-hydroxybenzylamino)-2-benzyl-acetic acid). The DNA-binding properties of the complexes were investigated by spectrometric titrations, ethidium bromide displacement experiments and viscosity measurements. The results indicated that the three complexes, especially the complex 13, can strongly bind to calf-thymus DNA (CT-DNA). The intrinsic binding constants Kb of the ternary copper(II) complexes with CT-DNA were 1.37×10(5), 1.81×10(5) and 3.21×10(5) for 1, 2 and 3 respectively. Comparative cytotoxic activities of the copper(II) complexes were also determined by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that the ternary copper(II) complexes had significant cytotoxic activity against the human lung cancer (A549), human esophageal cancer (Eca109) and human gastric cancer (SGC7901) cell lines. Cell apoptosis were detected by AnnexinV/PI flow cytometry and by Western blotting with the protein expression of p53, Bax and Bcl-2. All the three copper complexes can effectively induce apoptosis of the three human tumor cells.

  1. Demonstration of EIC's copper sulfate process for removal of hydrogen sulfide and other trace contaminants from geothermal steam at turbine inlet temperatures and pressures. Final report

    SciTech Connect

    Not Available

    1980-05-01

    The results obtained during the operation of an integrated, one-tenth commercial scale pilot plant using EIC's copper sulfate process for the removal of hydrogen sulfide and other contaminants from geothermal steam at turbine upstream conditions are discussed. The tests took place over a six month period at Pacific Gas and Electric Company's Unit No. 7 at The Geysers Power Plant. These tests were the final phase of a development effort which included the laboratory research and engineering design work which led to the design of the pilot plant. Broadly, the objectives of operating the pilot plant were to confirm the preliminary design criteria which had been developed, and provide data for their revisions, if appropriate, in a plant which contained all the elements of a commercial process using equipment of a size sufficient to provide valid scale-up data. The test campaign was carried out in four phases: water testing; open circuit, i.e., non integrated scrubbing, liquid-solid separation and regeneration testing; closed circuit short term; and closed circuit long term testing.

  2. Micellar-enhanced ultrafiltration of copper ions using sodium dodecyl sulfate and its mixture with Brij 35, Tween 80 and Triton X-100.

    PubMed

    Zhao, Baowei; Li, Ruirui; Zhong, Jinkui; Zhang, Li

    2013-01-01

    The performance of copper ion removal using sodium dodecyl sulfate (SDS) and its mixtures with Brij 35, Tween 80 (TW80) and Triton X-100 (TX100) by micellar-enhanced ultrafiltration (MEUF) was investigated. The effects of the molar ratio of nonionic surfactant to SDS on the critical micelle concentration (CMC) of SDS/Brij 35, SDS/TW80 and SDS/TX100, the removal efficiency of Cu(2+), the residual concentration of SDS in the permeate solution and the permeate flux were tested. The results showed that the CMCs of the mixed surfactants were sharply less than that of pure SDS. The removal efficiencies of Cu(2+) were up to the maximum values 98.3 and 95.8% when the molar ratios of Brij 35 and TW80 to SDS were 0.3, and it was 93.5% given 0.7 molar ratio of TX100 to SDS. The concentration of SDS in the permeate decreased dramatically with the addition of nonionic surfactant, and the permeate flux decreased slightly as the molar ratio increased. Compared with the performance by single SDS, the mixed SDS/Brij 35, SDS/TW80 and SDS/TX100 at an optimum composition could result in not only higher rejection of Cu(2+) but also much less dosage of surfactant and concentration of SDS in the permeate.

  3. Antiproliferative effects of copper(II)-polypyridyl complexes in breast cancer cells through inducing apoptosis.

    PubMed

    Salimi, Mona; Abdi, Khatereh; Kandelous, Hirsa Mostafapour; Hadadzadeh, Hassan; Azadmanesh, Kayhan; Amanzadeh, Amir; Sanati, Hassan

    2015-04-01

    Although cisplatin has been used for decades to treat human cancer, some toxic side effects and resistance are observed. Previous investigations have suggested copper complexes as a novel class of tumor-cell apoptosis inducers. The present study aimed to evaluate the anti-breast cancer activities of two polypyridyl-based copper(II) complexes, [Cu(tpy)(dppz)](NO3)2 (1) and [Cu(tptz)2](NO3)2 (2) (tpy = 2,2':6',2″-terpyridine, dppz = dipyrido[3,2-a:2',3'-c]phenazine, tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine), using human breast adenocarcinoma cell line (MCF-7). The ability of the complexes to cleave supercoiled DNA in the presence and absence of external agents was also examined. The apoptotic activities of the complexes were assessed using flow cytometry, fluorescence microscope and western blotting analysis. Our results indicated the high DNA affinity and nuclease activity of complexes 1 and 2. The cleavage mechanisms between the complexes and plasmid DNA are likely to involve a singlet oxygen or singlet oxygen-like entity as the reactive oxygen species. Complexes 1 and 2 also significantly inhibited the proliferation of MCF-7 cells in a dose-dependent manner (IC50 values = 4.57 and 1.98 μM at 24 h, respectively). Complex 2 remarkably induced MCF-7 cells to undergo apoptosis, which was demonstrated by cell morphology, annexin-V and propidium iodide staining. The caspase cascade was activated as shown by the proteolytic cleavage of caspase-3 after treatment of MCF-7 cells with complex 2. Additionally, complex 2 significantly increased the expression of the Bax-to-Bcl-2 ratio to induce apoptosis. In conclusion, these results revealed that complex 2 may be a potential and promising chemotherapeutic agent to treat breast cancer.

  4. Selective anticancer copper(II)-mixed ligand complexes: targeting of ROS and proteasomes.

    PubMed

    Ng, Chew Hee; Kong, Siew Ming; Tiong, Yee Lian; Maah, Mohd Jamil; Sukram, Nurhazwani; Ahmad, Munirah; Khoo, Alan Soo Beng

    2014-04-01

    Copper compounds can be alternatives to platinum-based anticancer drugs. This study investigated the effects of a series of ternary copper(II) complexes, [Cu(phen)(aa)(H2O)]NO3·xH2O 1-4 (phen = 1,10-phenanthroline; aa = gly (1), DL-ala (2), sar (3), C-dmg (4)), on metastatic and cisplatin-resistant MDA-MB-231 breast cancer cells and MCF10A non-cancerous breast cells, and some aspects of the mechanisms. These complexes were distinctively more antiproliferative towards and induced greater apoptotic cell death in MDA-MB-231 than in MCF10A cells. 2 and 4 could induce cell cycle arrest only in cancer cells. Further evidence from DCFH-DA assay showed higher induction of reactive oxygen species (ROS) in treated cancer cells but minimal ROS increase in normal cells. DNA double-strand breaks, via a γ-H2AX assay, were only detected in cancer cells treated with 5 μM of the complexes. These complexes poorly inhibited chymotrypsin-like activity in the 20S rabbit proteasome while they did not inhibit the three proteolytic sites of MDA-MB-231 cells at 10 μM. However, the complexes could inhibit degradation of ubiquinated proteins of MDA-MB-231 cells. In addition, compound 4 was found to be effective against cervical (Hela), ovarian (SKOV3), lung (A549, PC9), NPC (Hone1, HK1, C666-1), breast (MCF7, T47D), lymphoma and leukemia (Nalmawa, HL60) and colorectal (SW480, SW48, HCT118) cancer cell lines with IC50 values (24 h) in the 1.7-19.0 μM range. Single dose NCI60 screening of 4 showed the complex to be highly cytotoxic to most cancer cell types and more effective than cisplatin.

  5. Tetra-ammine-2κ(4) C-μ-cyanido-1:2κ(2) C:N-tricyanido-1κ(3) C-copper(II)palladium(II).

    PubMed

    Suchá, Veronika; Kuchár, Juraj; Harms, Klaus

    2013-05-01

    The title compound, [Cu(NH3)4-(μ2-NC)-Pd(CN)3], is a binuclear copper(II)palladium(II) complex, in which the Cu(II) coordination is defined by four ammine ligands and one bridging cyanide ligand. The Cu-N bond lengths in the base of the resulting CuN5 pyramid are in the range 2.016 (3)-2.024 (3) Å and the apical Cu-N( C) distance is 2.385 (4) Å. Based on the τ parameter, the shape of the coordination polyhedron is tetra-gonal-pyramidal (τ = 0). All atoms of the square-planar tetracyanidopalladate(II) moiety and the Cu(II) ion are located on a mirror plane. The electroneutral mol-ecules inter-act by N-H⋯N hydrogen bonds, resulting in the formation of a three-dimensional network. PMID:23723754

  6. Biochemical and morphological changes in carp (Cyprinus carpio L.) liver following exposure to copper sulfate and tannic acid.

    PubMed

    Varanka, Z; Rojik, I; Varanka, I; Nemcsók, J; Abrahám, M

    2001-03-01

    As a consequence of human activity various toxicants reach the aquatic ecosystems; humics may interact with them and may change their toxicity. Many fish are exposed to a considerable concentration of humics and pollutants. Because of paucity of data on the biochemical action of tannins in the presence of the fungicide CuSO4 a comparative study was undertaken. The alterations of redox-parameters in carp liver were monitored and tissue necrosis was followed by measuring the plasma transaminase activities and by electron microscopy. Tannic acid, a representative phenolic/humic compound, exerted prooxidant effects in carp, which may be partially due to formation of prooxidant intermediates/end-products via its biotransformation. Alternatively, tannic acid may partially inhibit the antioxidant enzymes of fish. The response to CuSO4 was more severe. Although tannic acid alone acted as a prooxidant in fish, electron micrographs demonstrated that it reduced the necrotizing effect of copper, which may be due to the complexing activity of tannic acid with the biomolecules of the hepatocytes and to the H2O2-degrading activity of tannin-CuSO4 combination. Our results indicate that the heavy metal-detoxifying capacity of tannin may be significant; however, tannin-exposure alone or combined with metals may be toxic for fish due to enzyme inhibition and oxidative stress induction. PMID:11255117

  7. Fixed-bed column studies on a modified chitosan hydrogel for detoxification of aqueous solutions from copper (II).

    PubMed

    Kavianinia, Iman; Plieger, Paul G; Kandile, Nadia G; Harding, David R K

    2012-10-01

    A new efficient, low cost chitosan based biosorbent was successfully prepared and employed for the biosorption of copper ions from an aqueous solution using a fixed bed column. Pyromellitic dianhydride crosslinked chitosan as the new adsorbent was characterized by SEM, FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis and solid state (13)C NMR analysis. Scanning electron microscopy coupled with an X-ray energy dispersed analysis for the copper-equilibrated biomass confirmed the presence of Cu(II) ions on the surface of the hydrogel. Thermogravimetric analysis showed a significant improvement in the thermal stability of the new hydrogel compared to pure chitosan. Kinetic models were applied to predict the breakthrough curves. This study shows that the prepared hydrogel based on modified chitosan could be utilized as an efficient bioadsorbent for the removal of copper ions from wastewater.

  8. 2-Benzoylpyridine thiosemicarbazone as a novel reagent for the single pot synthesis of dinuclear Cu(I)-Cu(II) complexes: formation of stable copper(II)-iodide bonds.

    PubMed

    Lobana, Tarlok S; Khanna, Sonia; Butcher, Ray J

    2012-04-28

    2-Benzoylpyridine thiosemicarbazone {R(1)R(2)C(2)=N(2)·N(3)H-C(1)(=S)-N(4)H(2), R(1) = py-N(1), R(2) = Ph; Hbpytsc} with copper(I) iodide in acetonitrile-dichloromethane mixture has formed stable Cu(II)-I bonds in a dark green Cu(II) iodo-bridged dimer, [Cu(2)(II)(μ-I)(2)(η(3)-N(1),N(2),S-bpytsc)(2)] 1. Copper(I) bromide also formed similar Cu(II)-Br bonds in a dark green Cu(II) bromo-bridged dimer, [Cu(2)(II)(μ-Br)(2)(η(3)-N(1),N(2),S-bpytsc)(2)] 3. The formation of dimers 1 and 3 appears to be due to a proton coupled electron transfer (PCET) process wherein copper(I) loses an electron to form copper(II), and this is accompanied by a loss of -N(3)H proton of Hbpytsc ligand resulting in the formation of anionic bpytsc(-). When copper(I) iodide was reacted with triphenylphosphine (PPh(3)) in acetonitrile followed by the addition of 2-benzoylpyridine thiosemicarbazone in dichloromethane (Cu : PPh(3) : Hbpytsc in the molar ratio 1:1:1), both Cu(II) dimer 1 and an orange Cu(I) sulfur-bridged dimer, [Cu(2)(I)I(2)(μ-S-Hbpytsc)(2)(PPh(3))(2)] 2 were formed. Copper(I) bromide with PPh(3) and Hbpytsc also formed Cu(II) dimer 3 and an orange Cu(I) sulfur-bridged dimer, [Cu(2)(I)Br(2)(μ-S-Hbpytsc)(2)(PPh(3))(2)] 4. While complexes 2 and 4 exist as sulfur-bridged Cu(I) dimers, 1 and 3 are halogen-bridged. The central Cu(2)S(2) cores of 2 and 4 as well as Cu(2)X(2) of 1 (X = I) and 3 (X = Br) are parallelograms. One set of Cu(II)-I and Cu(II)-Br bonds are short, while the second set is very long {1, Cu-I, 2.565(1), 3.313(1) Å; 3, Cu-Br, 2.391(1), 3.111(1) Å}. The Cu···Cu separations are long in all four complexes {1, 4.126(1); 2, 3.857(1); 3, 3.227(1); 4, 3.285(1) Å}, more than twice the van der Waals radius of a Cu atom, 2.80 Å. The pyridyl group appears to be necessary for stabilizing the Cu(II)-I bond, as this group can accept π-electrons from the metal. PMID:22395858

  9. Cytotoxicity of copper(II)-complexes with some S-alkyl derivatives of thiosalicylic acid. Crystal structure of the binuclear copper(II)-complex with S-ethyl derivative of thiosalicylic acid

    NASA Astrophysics Data System (ADS)

    Nikolić, Miloš V.; Mijajlović, Marina Ž.; Jevtić, Verica V.; Ratković, Zoran R.; Novaković, Slađana B.; Bogdanović, Goran A.; Milovanović, Jelena; Arsenijević, Aleksandar; Stojanović, Bojana; Trifunović, Srećko R.; Radić, Gordana P.

    2016-07-01

    The spectroscopically predicted structure of the obtained copper(II)-complex with S-ethyl derivative of thiosalicylic acid was confirmed by X-ray structural study and compared to previously reported crystal structure of the Cu complex with S-methyl derivative. Single crystals suitable for X-ray measurements were obtained by slow crystallization from a water solution. Cytotoxic effects of S-alkyl (R = benzyl (L1), methyl (L2), ethyl (L3), propyl (L4) and butyl (L5)) derivatives of thiosalicylic acid and the corresponding binuclear copper(II)-complexes on murine colon carcinoma cell lines, CT26 and CT26.CL25 and human colon carcinoma cell line HCT-116 were reported here. The analysis of cancer cell viability showed that all the tested complexes had low cytotoxic effect on murine colon carcinoma cell lines, but several times higher cytotoxicity on normal human colon carcinoma cells.

  10. Synthesis, structural characterization and antiproliferative and toxic bio-activities of copper(II) and nickel(II) citronellal N4-ethylmorpholine thiosemicarbazonates.

    PubMed

    Belicchi-Ferrari, Marisa; Bisceglie, Franco; Buschini, Annamaria; Franzoni, Susanna; Pelosi, Giorgio; Pinelli, Silvana; Tarasconi, Pieralberto; Tavone, Matteo

    2010-02-01

    This paper reports the syntheses and characterization of ethylmorpholine substituted citronellal thiosemicarbazone copper(II) and nickel(II) metal complexes. The compounds were characterized through elemental analyses and spectroscopic (IR, UV-Vis, NMR, MS) methods. The X-ray analysis of the two complexes shows that both Ni and Cu derivatives present a square planar coordination, where the coordinating homologous donor atoms bind in trans to each other. The compounds were tested for their biological activity after determination of their octanol-saline partition coefficients, followed by their radical scavenging properties. Eventually the complexes were tested for their proliferation inhibition on human histiocytic lymphoma U937 cell line. The GI(50) values resulted to be 2.3microM for the copper derivative and 12.3microM for the nickel derivative.

  11. Solid phase extraction of lead (II), copper (II), cadmium (II) and nickel (II) using gallic acid-modified silica gel prior to determination by flame atomic absorption spectrometry.

    PubMed

    Xie, Fazhi; Lin, Xucong; Wu, Xiaoping; Xie, Zenghong

    2008-01-15

    The immobilization of gallic acid on the surface of amino group-containing silica gel phases for the formation of a newly chelating matrix (GASG) is described. The newly synthesized extractant, characterized by the diffuse reflectance infrared Fourier transformation spectroscopy and elemental analysis, was used to preconcentrate Pb(II), Cu(II), Cd(II) and Ni(II). The pH ranges for quantitative sorption and the concentrations of HCl for eluting Pb(II), Cd(II), Cu(II) and Ni(II) were opimized, respectively. The sorption capacity of the matrix has been found to be 12.63, 6.09, 15.38, 4.62mg/g for Pb(II), Cd(II), Cu(II) and Ni(II), respectively, with the preconcentration factor of approximately 200 ( approximately 100 for Cd(II)). The effects of flow rates, the eluants, the electrolytes and cations on the metal ions extraction, as well as the chelating matrix stability and reusability, were also studied. The extraction behavior of the matrix was conformed with Langmuir's equation. The present preconcentration and determination method was successfully applied to the analysis of synthetic metal mixture solution and river water samples. The 3sigma detection limit and 10sigma quantification limit for Pb(II), Cu(II), Cd(II) and Ni(II) were found to be 0.58, 0.86, 0.65, 0.92microg/L and 1.08, 1.23, 0.87, 1.26microg/L, respectively. PMID:18371717

  12. Optimization of chemical displacement deposition of copper on porous silicon.

    PubMed

    Bandarenka, Hanna; Redko, Sergey; Nenzi, Paolo; Balucani, Marco; Bondarenko, Vitaly

    2012-11-01

    Copper (II) sulfate was used as a source of copper to achieve uniform distribution of Cu particles deposited on porous silicon. Layers of the porous silicon were formed by electrochemical anodization of Si wafers in a mixture of HF, C3H7OH and deionized water. The well-known chemical displacement technique was modified to grow the copper particles of specific sizes. SEM and XRD analysis revealed that the outer surface of the porous silicon was covered with copper particles of the crystal orientation inherited from the planes of porous silicon skeleton. The copper crystals were found to have the cubic face centering elementary cell. In addition, the traces of Cu2O cubic primitive crystalline phases were identified. The dimensions of Cu particles were determined by the Feret's analysis of the SEM images. The sizes of the particles varied widely from a few to hundreds of nanometers. A phenomenological model of copper deposition was proposed.

  13. Bismuth(III) and copper(II) oxides as catalysts for the electro-oxidation of organic compounds

    SciTech Connect

    Franklin, T.C.; Lee, K.H.; Manlangit, E.; Nnodimele, R.

    1996-11-01

    It was shown that copper(II) oxide bound to the anode with polystyrene containing a cationic surfactant acted as a catalyst for the oxidation of organic compounds in aqueous systems in a manner similar to powdered copper oxide suspended in aqueous systems containing the organic compounds and the cationic surfactant. Voltammetric measurements made with these electrodes were reproducible over an extended period of time, and it was possible to reproducibly use the polystyrene bound copper oxide as a catalyst for anodic destruction of several organic compounds. On the other hand, while bismuth(III) oxide bound to platinum with polystyrene was a catalyst for the oxidation of organic compounds in cationic surfactant suspensions, the results were not reproducible. The rate of renewal of the reactant adsorbed on the anode after oxidation was extremely slow. In addition, the Bi{sub 2}O{sub 3} gradually changed during the catalytic reaction to BiO(OH). Both of the bismuth compounds acted as catalysts for the oxidation reaction, but the potential for oxidation of Bi{sub 2}O{sub 3} was less anodic than the potential for BiO(OH). Previous coulometric experiments have indicated clearly that the catalytic intermediate for the copper oxidations is copper(III); however, the coulometric oxidations of bismuth indicate that the intermediate has a bismuth oxidation state slightly over 4. Most probably the intermediate is bismuth (V) and some of the bismuth had agglomerated so that not all of it has been oxidized.

  14. Dinuclear copper(II) complexes hold by crab-shaped pincer ligands: Syntheses, structures, luminescent and magnetic properties

    NASA Astrophysics Data System (ADS)

    Feng, Sisi; Ma, Ling; Feng, Guoqin; Jiao, Yuan; Zhu, Miaoli

    2014-02-01

    Two Cu(II) complexes with N,N‧-(2-hydroxy-5-R-1,3-xylylene)bis(N-(carboxymethyl)glycine (R-H5XTA, R = Cl and Br) ligands have been synthesized and their crystal structures have been analyzed by X-ray diffraction methods. The ligands provide a convenient dinucleating feature with the phenolate oxygen providing the bridging function. The complexes consist of dinuclear copper units, hexahydrate copper ion and solvent water molecules. Thereinto, dimer copper ions show two different geometries as Cu1 distorted octahedron and Cu2 square-based pyramid respectively, which has been confirmed by the solid-state electronic absorption spectrum. The thermal decomposition process consists of the loss of corresponding water molecules below 473 K and follow-up decomposition of the main structures. Under the excitation of 360 nm light, luminescence of ligands is quenched by the coordinated Cu(II) ions and heavy Br atom, respectively. Magnetic study shows that coupling of dinuclear copper ions displays ferromagnetic behavior with the J = +9.03 cm-1.

  15. Synthesis, characterization and DNA interaction of new copper(II) complexes of Schiff base-aroylhydrazones bearing naphthalene ring.

    PubMed

    Gökçe, Cansu; Gup, Ramazan

    2013-05-01

    Two new copper(II) complexes with the condensation products of methyl 2-naphthyl ketone with 4-hydroxybenzohydrazide, 4-hydroxy-N'-[(1Z)-1-(naphthalen-2-yl)ethylidene]benzohydrazide [HL(1)] and (Z)-ethyl 2-(4-(2-(1-(naphthalen-2-yl)ethylidene)hydrazinecarbonyl)phenoxy)acetate (HL(2)) were synthesized and characterized by elemental analysis, infrared spectra, UV-Vis electronic absorption spectra, magnetic susceptibility measurements, TGA, powder XRD and SEM-EDS. The binding properties of the copper(II) complexes with calf thymus DNA were studied by using the absorption titration method. DNA cleavage activities of the synthesized copper complexes were examined by using agarose gel electrophoresis. The effect of complex concentration on the DNA cleavage reactions in the absence and presence of H2O2 was also investigated. The experimental results suggest that the copper complexes bind significantly to calf thymus DNA by both groove binding and intercalation modes and cleavage effectively pBR322 DNA. The mechanistic studies demonstrate that a hydrogen peroxide-derived species and singlet oxygen ((1)O2) are the active oxidative species for DNA cleavage. PMID:23562627

  16. Antimicrobial effects of copper(II) bis(thiosemicarbazonato) complexes provide new insight into their biochemical mode of action.

    PubMed

    Djoko, Karrera Y; Paterson, Brett M; Donnelly, Paul S; McEwan, Alastair G

    2014-04-01

    The copper(II) complexes of bis-thiosemicarbazones (Cu(btsc)) such as Cu(atsm) and Cu(gtsm) are neutral, lipophilic compounds that show promise as therapeutics for the treatment of certain neurological diseases and cancers. Although the effects of these compounds have been described at the cellular level, there is almost no information about their biochemical mode of action. In this work, we showed that Cu(atsm) and Cu(gtsm) displayed antimicrobial activities against the human obligate pathogen Neisseria gonorrhoeae that were more than 100 times more potent than Cu(NO3)2 salt alone. Treatment with Cu(btsc) also produced phenotypes that were consistent with copper poisoning, but the levels of intracellular copper were undetectable by ICP MS. We observed that Cu(btsc) interacted with proteins in the cell membrane. Systematic measurements of O2 uptake further demonstrated that treatment with both Cu(atsm) and Cu(gtsm) led to dose-dependent inhibition of respiratory electron transfer processes via succinate and NADH dehydrogenases. These dehydrogenases were not inhibited by a non-btsc source of Cu(II). The results led us to conclude that the biochemical mechanism of Cu(btsc) action is likely more complex than the present, simplistic model of copper release into the cytoplasm. PMID:24435165

  17. Synthesis and application of surface-imprinted activated carbon sorbent for solid-phase extraction and determination of copper (II)

    NASA Astrophysics Data System (ADS)

    Li, Zhenhua; Li, Jingwen; Wang, Yanbin; Wei, Yajun

    2014-01-01

    A new Cu(II)-imprinted amino-functionalized activated carbon sorbent was prepared by a surface imprinting technique for selective solid-phase extraction (SPE) of Cu(II) prior to its determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of Cu(II) were optimized with respect to different experimental parameters using static and dynamic procedures in detail. Compared with non-imprinted sorbent, the ion-imprinted sorbent had higher selectivity and adsorption capacity for Cu(II). The maximum static adsorption capacity of the ion-imprinted and non-imprinted sorbent for Cu(II) was 26.71 and 6.86 mg g-1, respectively. The relatively selectivity factor values (αr) of Cu(II)/Zn(II), Cu(II)/Ni(II), Cu(II)/Co(II) and Cu(II)/Pb(II) were 166.16, 50.77, 72.26 and 175.77, respectively, which were greater than 1. Complete elution of the adsorbed Cu(II) from Cu(II)-imprinted sorbent was carried out using 2 mL of 0.1 mol L-1 EDTA solution. The relative standard deviation of the method was 2.4% for eleven replicate determinations. The method was validated for the analysis by two certified reference materials (GBW 08301, GBW 08303), the results obtained is in good agreement with standard values. The developed method was also successfully applied to the determination of trace copper in natural water samples with satisfactory results.

  18. Synthesis, characterization, antibacterial activity, SOD mimic and interaction with DNA of drug based copper(II) complexes.

    PubMed

    Patel, Mohan N; Dosi, Promise A; Bhatt, Bhupesh S; Thakkar, Vasudev R

    2011-02-01

    Novel metal complexes of the second-generation quinolone antibacterial agent enrofloxacin with copper(II) and neutral bidentate ligands have been prepared and characterized with elemental analysis reflectance, IR and mass spectroscopy. Complexes have been screened for their in-vitro antibacterial activity against two Gram(+ve) Staphylococcus aureus, Bacillus subtilis, and three Gram((-ve)) Serratia marcescens, Escherichia coli and Pseudomonas aeruginosa organisms using the double dilution technique. The binding of this complex with CT-DNA has been investigated by absorption titration, salt effect and viscosity measurements. Binding constant is ranging from 1.3×10(4)-3.7×10(4). The cleavage ability of complexes has been assessed by gel electrophoresis using pUC19 DNA. The catalytic activity of the copper(II) complexes towards the superoxide anion (O2.-) dismutation was assayed by their ability to inhibit the reduction of nitroblue tetrazolium (NBT).

  19. Synthesis, characterization, antibacterial activity, SOD mimic and interaction with DNA of drug based copper(II) complexes

    NASA Astrophysics Data System (ADS)

    Patel, Mohan N.; Dosi, Promise A.; Bhatt, Bhupesh S.; Thakkar, Vasudev R.

    2011-02-01

    Novel metal complexes of the second-generation quinolone antibacterial agent enrofloxacin with copper(II) and neutral bidentate ligands have been prepared and characterized with elemental analysis reflectance, IR and mass spectroscopy. Complexes have been screened for their in-vitro antibacterial activity against two Gram (+ve)Staphylococcus aureus, Bacillus subtilis, and three Gram (-ve)Serratia marcescens, Escherichia coli and Pseudomonas aeruginosa organisms using the double dilution technique. The binding of this complex with CT-DNA has been investigated by absorption titration, salt effect and viscosity measurements. Binding constant is ranging from 1.3 × 10 4-3.7 × 10 4. The cleavage ability of complexes has been assessed by gel electrophoresis using pUC19 DNA. The catalytic activity of the copper(II) complexes towards the superoxide anion (O 2rad -) dismutation was assayed by their ability to inhibit the reduction of nitroblue tetrazolium (NBT).

  20. Copper(II) cubanes with a {Cu4O} core and well defined S = 1 ground state.

    PubMed

    Escuer, A; Mayans, J; Font-Bardia, M

    2016-01-28

    The reaction of 2-pyridinemethanol with copper 4-fluorobenzoate has yielded a family of type II cubanes with formula [Cu4(pymO)4(4-F-PhCOO)3(NO3)] (), [Cu4(pymO)4(4-F-PhCOO)4] () and [Cu4(pymO)4(4-F-PhCOO)4(H2O)] (). These systems exhibit an unexpected S = 1 ground state and their magnetic properties have been unambiguously characterized and rationalized as a function of the asymmetry of the {Cu4O4} cage and Cu-O-Cu bond angles. Analysis of the coupling constants was performed applying new interaction schemes. Magneto-structural correlations have been performed from the analysis of previously reported type II copper cubanes. PMID:26687676

  1. Antimalarial evaluation of copper(II) nanohybrid solids: inhibition of plasmepsin II, a hemoglobin-degrading malarial aspartic protease from Plasmodium falciparum.

    PubMed

    Mohapatra, Subash Chandra; Tiwari, Hemandra Kumar; Singla, Manisha; Rathi, Brijesh; Sharma, Arun; Mahiya, Kuldeep; Kumar, Mukesh; Sinha, Saket; Chauhan, Shyam Singh

    2010-03-01

    A new class of copper(II) nanohybrid solids, LCu(CH(3)COO)(2) and LCuCl(2), have been synthesized and characterized by transmission electron microscopy, dynamic light scattering, and IR spectroscopy, and have been found to be capped by a bis(benzimidazole) diamide ligand (L). The particle sizes of these nanohybrid solids were found to be in the ranges 5-10 and 60-70 nm, respectively. These nanohybrid solids were evaluated for their in vitro antimalarial activity against a chloroquine-sensitive isolate of Plasmodium falciparum (MRC 2). The interactions between these nanohybrid solids and plasmepsin II (an aspartic protease and a plausible novel target for antimalarial drug development), which is believed to be essential for hemoglobin degradation by the parasite, have been assayed by UV-vis spectroscopy and inhibition kinetics using Lineweaver-Burk plots. Our results suggest that these two compounds have antimalarial activities, and the IC(50) values (0.025-0.032 microg/ml) are similar to the IC(50) value of the standard drug chloroquine used in the bioassay. Lineweaver-Burk plots for inhibition of plasmepsin II by LCu(CH(3)COO)(2) and LCuCl(2) show that the inhibition is competitive with respect to the substrate. The inhibition constants of LCu(CH(3)COO)(2) and LCuCl(2) were found to be 10 and 13 microM, respectively. The IC(50) values for inhibition of plasmepsin II by LCu(CH(3)COO)(2) and LCuCl(2) were found to be 14 and 17 microM, respectively. Copper(II) metal capped by a benzimidazole group, which resembles the histidine group of copper proteins (galactose oxidase, beta-hydroxylase), could provide a suitable anchoring site on the nanosurface and thus could be useful for inhibition of target enzymes via binding to the S1/S3 pocket of the enzyme hydrophobically. Both copper(II) nanohybrid solids were found to be nontoxic against human hepatocellular carcinoma cells and were highly selective for plasmepsin II versus human cathepsin D. The pivotal mechanism of

  2. Tetra­aqua­bis­(piperazin-1-ium)cobalt(II) bis­(sulfate) dihydrate

    PubMed Central

    Sahbani, Thameur; Smirani Sta, Wajda; Rzaigui, Mohamed

    2013-01-01

    In the centrosymmetric title compound, [Co(C4H11N2)2(H2O)4](SO4)2·2H2O, the CoII atom is coordinated in a distorted octa­hedral geometry by four water O atoms and two piperazinium N atoms. These four water O atoms define an equatorial plane with a maximum deviation of 0.0384 (1) Å while the two piperazinium N atoms complete the octa­hedron in the axial positions. Neighboring complex mol­ecules and sulfate anions are connected through an extensive network of N—H⋯O and O—H⋯O hydrogen bonds, which link the different chemical species into layers in the ab plane. Additional Owater—H⋯O hydrogen bonds involving the non-coordinating water mol­ecules and C—H⋯O inter­actions connect these layers into a three-dimensional supra­molecular structure. PMID:24454163

  3. Anion-induced structural transformation of a sulfate-incorporated 2D Cd(II)-organic framework

    NASA Astrophysics Data System (ADS)

    Lee, Li-Wei; Luo, Tzuoo-Tsair; Wang, Chih-Min; Lee, Gene-Hsiang; Peng, Shie-Ming; Liu, Yen-Hsiang; Lee, Sheng-Long; Lu, Kuang-Lieh

    2016-07-01

    A Cd(II)-organic framework {[Cd2(tpim)4(SO4)(H2O)2]·(SO4)·21H2O}n (1) was synthesized by reacting CdSO4·8/3H2O and 2,4,5-tri(4-pyridyl)imidazole (tpim) under hydrothermal conditions. A structural analysis showed that compound 1 adopts a layered structure in which the [Cd(tpim)2]n chains are linked by sulfate anions. These 2D layers are further packed into a 3D supramolecular framework via π-π interactions. The structure contains two types of SO42- anions, i.e., bridging SO42- and free SO42- anions, the latter of which are included in the large channels of the framework. Compound 1 exhibits interesting anion exchange behavior. In the presence of SCN- anions, both the bridging and free SO42- anions in 1 were completely exchanged by SCN- ligands to form a 1D species [Cd(tpim)2(SCN)2] (1A), in which the SCN- moieties function as a monodentate ligand. On the other hand, when compound 1 was ion exchanged with N3- anions in aqueous solution, the bridging SO42- moieties remained intact, and only the free guest SO42- were replaced by N3- anions. The gas adsorption behavior of the activated compound 1 was also investigated.

  4. Spectrophotometric determination of ascorbic acid using copper(II)-neocuproine reagent in beverages and pharmaceuticals.

    PubMed

    Güçlü, Kubilay; Sözgen, Kevser; Tütem, Esma; Ozyürek, Mustafa; Apak, Reşat

    2005-03-15

    The proposed method for ascorbic acid (Vitamin C) (AA) determination is based on the oxidation of AA to dehydroascorbic acid with a Cu(II)-2,9-dimethyl-1,10-phenanthroline (neocuproine (Nc)) reagent in ammonium acetate-containing medium at pH 7, where the absorbance of the formed bis(Nc)-copper(I) chelate is measured at 450nm. This chelate was formed immediately and the apparent molar absorptivity for AA was found to be 1.60 x 10(4)dm(3)mol(-1)cm(-1). Beer's law was obeyed between 8.0 x 10(-6) and 8.0 x 10(-5)M concentration range. The relative standard deviation for 90mug AA was 3%. The Cu(II)-Nc reagent is a milder and therefore more selective oxidant than the conventional Fe(III)-1,10-phenanthroline (phen) reagent used for the same assay. This feature makes the proposed method superior for real samples such as fruit juices containing weak reductants such as citrate, oxalate and tartarate that otherwise produce positive errors in the Fe(III)-phen method when equilibrium is achieved. The developed method was applied to a number of commercial fruit juices, pharmaceutical preparations containing Vitamin C, and red wine. The meta-bisulfite content of wine was removed with an anion exchanger at pH 3 prior to analysis, and a difference extractive-spectrophotometric method of AA assay in wine was developed so as to suppress the interferences caused by wine anthocyanins and polyphenols. The findings of the developed method for fruit juices and pharmaceuticals were also statistically compared with those of HPLC so as to establish it as a reliable novel method.

  5. Templated Synthesis of Silver(I) and Copper(II) Nanostructures: Solid State Reactions and Applications

    NASA Astrophysics Data System (ADS)

    Bourret, Gilles R.

    2011-12-01

    This Thesis presents the synthesis of novel 1D, 2D, and 3D Ag(I) and Cu(II) nanostructures and their use as sacrificial templates to make functional nanomaterials. New soft template methods were developed for the synthesis of AgCN and Cu(OH)2 nanostructures. Polymeric organic nanotubes were successfully used to synthesize AgCN nanowires, while the precipitation of Cu(OH)2 nanofibers was templated in water microdroplets. Both methods benefit from the versatility of soft templates and allows for a control of both the size and the morphology of the nanostructures produced. The conversion of these precursors into metallic and semi-conductive nanomaterials was achieved via chemical and electrochemical reduction, and thermolysis. Chemical reduction of the AgCN nanowires leads to the fabrication of conductive arrays on nylon filter substrates, while the thermolysis of the Cu(OH)2 spherical assemblies yields photoresponsive semi-conductive porous CuO spheres. The electrochemical reduction of the native Ag(I) and Cu(II) one-dimensional nanostructures was investigated in aqueous solution at gold/glass/gold junctions. The solid-solid conversion involved in the electrochemical reduction process was studied via cyclic voltammetry, chronoamperometry, and electronic microscopy. The strong influence of the reduction potential on the nanomaterials produced allowed for the fabrication of a range of Ag(0) nanostructures, including nanoparticles, nanoprisms, nanofibers and porous networks. Electrochemical reduction of Au/M2+/Au junctions leads to the formation of an excellent electrical contact between the two gold electrodes. This technique was expanded to include ionically-conductive Ag2S nanowires which form metallic/ionic-conductor heterojunctions. Keywords: nanostructure, nanowire, template, emulsion, electrochemistry, silver, cyanide, copper, oxide, heterojunction, sacrificial template.

  6. Human telomeric G-quadruplex DNA interactions of N-phenanthroline glycosylamine copper(II) complexes.

    PubMed

    Duskova, Katerina; Sierra, Sara; Arias-Pérez, María-Selma; Gude, Lourdes

    2016-01-01

    We report in this article the interactions of five N-(1,10-phenanthrolin-5-yl)-β-glycopyranosylamine copper(II) complexes with G-quadruplex DNA. Specifically, the interactions of these compounds with a human telomeric oligonucleotide have been assessed by fluorescence-based assays (FRET melting and G4-FID), circular dichroism and competitive equilibrium dialysis experiments. The metal complexes bind and stabilize G-quadruplex DNA structures with apparent association constants in the order of 10(4)-10(5)M(-1) and the affinity observed is dependent on the ionic conditions utilized and the specific nature of the carbohydrate moiety tethered to the 1,10-phenanthroline system. The compounds showed only a slight preference to bind G-quadruplex DNA over duplex DNA when the quadruplex DNA was folded in sodium ionic conditions. However, the binding affinity and selectivity, although modest, were notably increased when the G-quadruplex DNA was folded in the presence of potassium metal ions. Moreover, the study points towards a significant contribution of groove and/or loop binding in the recognition mode of quadruplex structures by these non-classical quadruplex ligands. The results reported herein highlight the potential and the versatility of carbohydrate bis-phenanthroline metal-complex conjugates to recognize G-quadruplex DNA structures. PMID:26678174

  7. Human telomeric G-quadruplex DNA interactions of N-phenanthroline glycosylamine copper(II) complexes.

    PubMed

    Duskova, Katerina; Sierra, Sara; Arias-Pérez, María-Selma; Gude, Lourdes

    2016-01-01

    We report in this article the interactions of five N-(1,10-phenanthrolin-5-yl)-β-glycopyranosylamine copper(II) complexes with G-quadruplex DNA. Specifically, the interactions of these compounds with a human telomeric oligonucleotide have been assessed by fluorescence-based assays (FRET melting and G4-FID), circular dichroism and competitive equilibrium dialysis experiments. The metal complexes bind and stabilize G-quadruplex DNA structures with apparent association constants in the order of 10(4)-10(5)M(-1) and the affinity observed is dependent on the ionic conditions utilized and the specific nature of the carbohydrate moiety tethered to the 1,10-phenanthroline system. The compounds showed only a slight preference to bind G-quadruplex DNA over duplex DNA when the quadruplex DNA was folded in sodium ionic conditions. However, the binding affinity and selectivity, although modest, were notably increased when the G-quadruplex DNA was folded in the presence of potassium metal ions. Moreover, the study points towards a significant contribution of groove and/or loop binding in the recognition mode of quadruplex structures by these non-classical quadruplex ligands. The results reported herein highlight the potential and the versatility of carbohydrate bis-phenanthroline metal-complex conjugates to recognize G-quadruplex DNA structures.

  8. Immobilized copper(II) macrocyclic complex on MWCNTs with antibacterial activity

    NASA Astrophysics Data System (ADS)

    Tarlani, Aliakbar; Narimani, Khashayar; Mohammadipanah, Fatemeh; Hamedi, Javad; Tahermansouri, Hasan; Amini, Mostafa M.

    2015-06-01

    In a new approach, a copper(II) tetraaza macrocyclic complex (CuTAM) was covalently bonded on modified multi-walled carbon nanotubes (MWCNTs). To achieve this purpose, MWCNTs were converted to MWCNT-COCl and then reacted to NH groups of TAM ligand. The prepared material was characterized by Fourier Transform Infrared (FT-IR), X-ray diffraction (XRD), Raman spectroscopy, thermal gravimetric analysis (TGA), and FESEM (field emission scanning electron microscopy). FT-IR and TGA demonstrated the presence of the organic moieties, and XRD proved that the structure of MWCNTs remained intact during the three modification steps. An increase in the ID/IG ratio in Raman spectra confirmed the surface modifications. Finally, the samples were subjected to an antibacterial assessment to compare their biological activity. The antibacterial test showed that the grafted complex on the surface of the nanotube (MWCNT-CO-CuTAM) has higher antibacterial activity against Bacillus subtilis ATCC 6633 than the MWCNT-COOH and CuTAM with 1000 and 2000 μg/mL.

  9. Poly[bis­{μ-N′-[(pyridin-4-yl)methyl­idene]benzohydrazidato}copper(II)

    PubMed Central

    Wu, Qiong; Chen, Da-Chi; Wu, Chu-Yi; Yan, Chang-Xiu; Liao, Jian-Zhen

    2013-01-01

    In the title complex, [Cu(C13H10N3O)2]n, the copper(II) cation is located on a crystallographic inversion centre and adopts an elongated octa­hedral coordination geometry with the equatorial plane provided by trans-arranged bis-N,O-chelating acyl­hydrazine groups from two ligands and the apices by the N atoms of two pyridine rings belonging to symmetry-related ligands. The ligand adopts a Z conformation about the C=N double bond. The dihedral angle between the pyridine and phenyl rings is 2.99 (13)°. An intra­ligand C—H⋯N hydrogen bond is observed. In the crystal, each ligand bridges two adjacent metal ions, forming a (4,4) grid layered structure. π–π stacking inter­actions [centroid–centroid distances in the range 3.569 (4)–3.584 (9) Å] involving rings of adjacent layers result in the formation of a three-dimensional supra­molecular network. PMID:24046562

  10. Synthesis, structure, spectroscopic and electrochemical properties of bis(histamine-saccharinate) copper(II) complex

    NASA Astrophysics Data System (ADS)

    Bulut, İclal; Uçar, İbrahim; Karabulut, Bünyamin; Bulut, Ahmet

    2007-05-01

    Crystal structure of [Cu(hsm) 2(sac) 2] (hsm is histamine and sac is saccharinate) complex has been determined by X-ray diffraction analyses and its magnetic environment has been identified by electron paramagnetic resonance (EPR) technique. The title complex crystallizes in the monoclinic system, space group P 21/ c with a = 7.4282(4), b = 22.5034(16), c = 8.3300(5) Å, β = 106.227(4)°, V = 1336.98(14) Å 3, and Z = 2. The structure consist of discrete [Cu(hsm) 2(sac) 2] molecules in which the copper ion is centrosymmetrically coordinated by two histamine ligands forming an equatorial plane [Cu-N hsm = 2.024(2) and Cu-N hsm = 2.0338(18) Å]. Two N atoms from the saccharinate ligands coordinate on the elongated axial positions with Cu-N sac being 2.609(5) Å. The complex is also characterized by spectroscopic (IR, UV/Vis) and thermal (TG, and TDA) methods. The cyclic voltammogram of the title complex investigated in DMSO (dimethylsulfoxide) solution exhibits only metal centred electroactivity in the potential range - 1.25-1.5 V versus Ag/AgCl reference electrode. The molecular orbital bond coefficients of Cu(II) ion in d 9 state is also calculated by using EPR and optical absorption parameters.

  11. Copper(II)-Catalyzed Alkoxyhalogenation of Alkynyl Ureas and Amides as a Route to Haloalkylidene-Substituted Heterocycles.

    PubMed

    Gazzola, Silvia; Beccalli, Egle M; Borelli, Tea; Castellano, Carlo; Chiacchio, Maria Assunta; Diamante, Daria; Broggini, Gianluigi

    2015-07-17

    A highly effective synthesis of haloalkylidene-substituted heterocycles by copper(II)-catalyzed cyclization of alkynyl ureas and secondary amides has been developed. The reaction, which involves a catalytic amount of CuCl2 and a stoichiometric amount of N-halosuccinimide, occurs selectively through an alkoxyhalogenation process. Alternatively, alkoxychlorination and alkoxybromination reactions can be performed working solely with stoichiometric CuCl2 and CuBr2, respectively. PMID:26111065

  12. Scalable room-temperature conversion of copper(II) hydroxide into HKUST-1 (Cu3 (btc)2).

    PubMed

    Majano, Gerardo; Pérez-Ramírez, Javier

    2013-02-20

    Copper(II) hydroxide is converted directly to HKUST-1 (Cu(3) (btc)(2) ) after only 5 min at room-temperature in aqueous ethanolic solution without the need of additional solvents. Scale up to the kilogram scale does not influence porous properties yielding pure-phase product with a remarkable total surface area exceeding 1700 m(2) g(-1) featuring aggregates of nanometer-sized crystals (<600 nm) and extremely high space-time yields.

  13. Copper(II)-Promoted Cyclization/Difunctionalization of Allenols and Allenylsulfonamides: Synthesis of Heterocycle-Functionalized Vinyl Carboxylate Esters.

    PubMed

    Casavant, Barbara J; Khoder, Zainab M; Berhane, Ilyas A; Chemler, Sherry R

    2015-12-18

    A unique method to affect intramolecular aminooxygenation and dioxygenation of allenols and allenylsulfonamides is described. These operationally simple reactions occur under neutral or basic conditions where copper(II) carboxylates serve as reaction promoter, oxidant, and carboxylate source. Moderate to high yields of heterocycle-functionalized vinyl carboxylate esters are formed with moderate to high levels of diastereoselectivity. Such vinyl carboxylate esters could serve as precursors to α-amino and α-oxy ketones and derivatives thereof. PMID:26624861

  14. Tunable DNA cleavage activity promoted by copper(ii) ternary complexes with N-donor heterocyclic ligands.

    PubMed

    Bortolotto, T; Silva-Caldeira, P P; Pich, C T; Pereira-Maia, E C; Terenzi, H

    2016-06-01

    Several small molecules have the capacity to cleave DNA promptly at high yields, even under mild conditions. Usually, this activity has no constraints, occurring without external or user control. Here, we demonstrate that UV-light exposure can greatly enhance the DNA cleavage activity promoted by four ternary copper(ii) complexes. A remarkable photocontrolled activity was achieved, which may be interesting for chemical and biochemical applications. PMID:27168172

  15. One-pot synthesis of indenonaphthopyrans catalyzed by copper(II) triflate: a comparative study of reflux and ultrasound methods.

    PubMed

    Turhan, Kadir; Ozturkcan, S Arda; Uluer, Mehmet; Turgut, Zuhal

    2014-01-01

    An effective and environment-friendly protocol for the synthesis of indenonaphthopyrans has been developed by one-pot reaction of 2-naphthol, various aromatic aldehydes and 1,3-indandione, in the presence of copper(II) triflate as the catalyst while using reflux (Method A) and ultrasound (Method B). The Method B approach offers the advantages of a simple reaction method, short reaction time, excellent yield, and showcases the economic importance of the catalysts for such processes. PMID:25286219

  16. Interactions of α-Factor-1, a Yeast Pheromone, and Its Analogue with Copper(II) Ions and Low-Molecular-Weight Ligands Yield Very Stable Complexes.

    PubMed

    Bossak, Karolina; Mital, Mariusz; Poznański, Jarosław; Bonna, Arkadiusz; Drew, Simon; Bal, Wojciech

    2016-08-15

    α-Factor-1 (WHWLQLKPGQPMY), a peptidic pheromone of Saccharomyces cerevisiae yeast, contains a XHX type copper(II) binding N-terminal site. Using a soluble analogue, WHWSKNR-amide, we demonstrated that the W(1)H(2)W(3) site alone binds copper(II) with a Kd value of 0.18 pM at pH 7.4 and also binds imidazole (Im) in a ternary complex (Kd of 1 mM at pH 7.4). This interaction boosts the ability of the peptide to sequester copper(II) depending on the Im concentration up to a subfemtomolar range, not available for any oligopeptidic system studied before. Therefore, α-factor-1 and other XHX-type peptides are likely copper(II) carriers in biological systems. PMID:27476515

  17. Mononuclear copper (II) salicylate complexes with 1,2-dimethylimidazole and 2-methylimidazole: Synthesis, spectroscopic and crystal structure characterization and their superoxide scavenging activities

    NASA Astrophysics Data System (ADS)

    Abuhijleh, A. Latif

    2010-09-01

    The complexes cis-bis (1,2-dimethylimidazole) bis (salicylato) copper (II) ( 1) and tris (2-methylimidazole) (salicylato) copper (II) ( 2) have been prepared by the reaction of appropriate methylimidazole derivative with binuclear copper (II) aspirinate. Spectral and X-ray structural studies for complex 1 showed that the copper ion is coordinated in a cis arrangement to two imidazole nitrogen atoms and two carboxylate oxygen atoms from the salicylate mono-anion ligands. The second carboxylate oxygen atoms form weak axial interactions with the copper ion. Spectral, magnetic and analytical data for complex 2 showed that the copper ion is bonded to three 2-methylimidazole nitrogen atoms and one doubly deprotonated salicylate di-anion, which is chelated to Cu (II) ion through one of its carboxylate oxygen atoms and the deprotonated hydroxyl oxygen atom to form distorted square-pyramidal geometry having CuN 3O + O chromophore. The superoxide dismutase (SOD) mimetic activities (IC 50) of the complexes 1, 2 and the structurally known mixture complexes Cu (imidazole) n(salicylato) 2( 3) (where n = 2, 5 and 6) were determined using the xanthine-xanthine oxidase assay and compared with those reported for other copper (II) complexes with anti-inflammatory drugs. The results obtained indicated that complexes 1- 3 have high SOD-like activities, which may act as good mimics for native Cu, Zn-SOD enzyme.

  18. Interesting copper(ii)-assisted transformations of 2-acetylpyridine and 2-benzoylpyridine.

    PubMed

    Kitos, Alexandros A; Efthymiou, Constantinos G; Manos, Manolis J; Tasiopoulos, Anastasios J; Nastopoulos, Vassilios; Escuer, Albert; Perlepes, Spyros P

    2016-01-21

    The reactions of various copper(ii) sources with 2-acetylpyridine, (py)(me)CO, and 2-benzoylpyridine, (py)(ph)CO, under strongly basic conditions have been studied and novel ligand transformations have been discovered. Reaction of Cu(ClO4)2·6H2O and (py)(me)CO in the presence of NBu4(n)OMe (1 : 1 : 1) in CHCl3 gave a mixture of [Cu2Cl2(HLA)2](ClO4)2 (1) and [Cu2Cl2(LB)2(ClO4)2] (2), where HLA is 3-hydroxy-1,3-di(pyridin-2-yl)-butane-1-one and LB is the zwitterionic-type ligand 3-hydroxy-1-methyl-3-(pyridin-2-yl)-3H-indolizin-4-ium. The ligand HLA is formed through an aldol reaction-type mechanism, while the formation of LB takes place via an intramolecular nucleophilic attack of the remote 2-pyridyl nitrogen atom on the positive carbonyl carbon of HLA, after the transformation of the latter through deprotonation and dehydration. The Cu(II) ions in 1 are bridged by two 2.1111 HLA ligands resulting in a long Cu(II)Cu(II) distance (5.338 Å); the metal ions in 2 are triply bridged by the alkoxide oxygen atoms of the two 2.21 LB ligands and one 2.1100 perchlorato group. The absence of α-hydrogens in (py)(ph)CO leads the reactivity of this ligand in the presence of Cu(II) to different pathways. The Cu(ClO4)2·6H2O/(py)(ph)CO/NBu4(n)OMe reaction mixture in MeOH/H2O (25 : 1 v/v) gave the dinuclear cationic complex [Cu2{(py)(ph)CO}2(LC)2](ClO4)2 (3), where LC(-) is the anion of (methoxy)(phenyl)(pyridin-2-yl)methanol formed in situ via the nucleophilic addition of MeO(-) to the carbonyl carbon of (py)(ph)CO upon Cu(II) coordination. The Cu(II) ions in the cation are doubly bridged by the deprotonated oxygen atoms of the two LC(-) ligands. Replacement of Cu(ClO4)2·6H2O with Cu(NO3)2·3H2O and NBu4(n)OMe with NMe4OH and the decrease of the H2O concentration in the above reaction system yielded the tetranuclear coordination cluster [Cu4(OMe)2(NO3)4{(py)(ph)CO}2(LC)2] (4). The Cu(II) centres in this complex define a parallelogram. Two parallel sides of the

  19. Atelosteogenesis type II is caused by mutations in the diastrophic dysplasia sulfate-transporter gene (DTDST): Evidence for a phenotypic series involving three chondrodysplasias

    SciTech Connect

    Haestbacka, J.; Lander, E.S.; Superti-Furga, A.

    1996-02-01

    Atelosteogenesis type II (AO II) is a neonatally lethal chondrodysplasia whose clinical and histological characteristics resemble those of another chondrodysplasia, the much less severe diastrophic dysplasia (DTD). The similarity suggests a shared pathogenesis involving lesions in the same biochemical pathway and perhaps the same gene. DTD is caused by mutations in the recently identified diastrophic dysplasia sulfate-transporter gene (DTDST). Here, we report that AOII patients also have DTDST mutations, which lead to defective uptake of inorganic sulfate and insufficient sulfation of macromolecules by patient mesenchymal cells in vitro. Together with our recent observation that a third even more severe chondrodysplasia, achondrogenesis type IB, is also caused by mutations in DTDST, these results demonstrate a phenotypic series of three chondrodysplasias of increasing severity caused by lesions in a single sulfate-transporter gene. The severity of the phenotype appears to be correlated with the predicted effect of the mutations on the residual activity of the DTDST protein. 24 refs., 6 figs., 1 tab.

  20. Atelosteogenesis type II is caused by mutations in the diastrophic dysplasia sulfate-transporter gene (DTDST): evidence for a phenotypic series involving three chondrodysplasias.

    PubMed Central

    Hästbacka, J.; Superti-Furga, A.; Wilcox, W. R.; Rimoin, D. L.; Cohn, D. H.; Lander, E. S.

    1996-01-01

    Atelosteogenesis type II (AO II) is a neonatally lethal chondrodysplasia whose clinical and histological characteristics resemble those of another chondrodysplasia, the much less severe diastrophic dysplasia (DTD). The similarity suggests a shared pathogenesis involving lesions in the same biochemical pathway and perhaps the same gene. DTD is caused by mutations in the recently identified diastrophic dysplasia sulfate-transporter gene (DTDST). Here, we report that AOII patients also have DTDST mutations, which lead to defective uptake of inorganic sulfate and insufficient sulfation of macromolecules by patient mesenchymal cells in vitro. Together with our recent observation that a third even more severe chondrodysplasia, achondrogenesis type IB, is also caused by mutations in DTDST, these results demonstrate a phenotypic series of three chondrodysplasias of increasing severity caused by lesions in a single sulfate-transporter gene. The severity of the phenotype appears to be correlated with the predicted effect of the mutations on the residual activity of the DTDST protein. Images Figure 1 Figure 2 Figure 4 Figure 5 Figure 3 Figure 6 PMID:8571951

  1. Membrane interactions and conformational preferences of human and avian prion N-terminal tandem repeats: the role of copper(II) ions, pH, and membrane mimicking environments.

    PubMed

    Di Natale, Giuseppe; Pappalardo, Giuseppe; Milardi, Danilo; Sciacca, Michele F M; Attanasio, Francesco; La Mendola, Diego; Rizzarelli, Enrico

    2010-11-01

    The flexible N-terminal domain of the prion protein (PrP(c)) is believed to play a pivotal role in both trafficking of the protein through the cell membrane and its pathogenic conversion into the β sheet-rich scrapie isoform (PrP(sc)). Unlike mammalian PrP(c), avian prion proteins are not known to undergo any pathogenic conformational conversions. Consequently, some critical advances in our understanding of the molecular mechanisms underlying prion pathogenesis are expected from comparative studies of the biophysical properties of the N-terminal domains of the two proteins. The present study addresses the role played by different environmental factors, i.e., copper(II), pH, and membrane-mimicking environments, in assisting the conformational preferences of huPrP60-91 and chPrP53-76, two soluble peptides encompassing the N-terminal copper(II) binding domains of the human and chicken prion proteins, respectively. Moreover, the membrane interactions of huPrP60-91, chPrP53-76, and their copper(II) complexes were evaluated by Trp fluorescence in conjunction with measurements of the variation in thermotropic properties of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) unilamellar vesicles. Circular dichroism experiments revealed that huPrP60-91 adopts a predominant polyproline II conformation in aqueous solution that is destabilized at basic pH or in the presence of trifluoroethanol (TFE). Unlike anionic sodium dodecyl sulfate (SDS), which seems to stabilize the polyproline II conformation further, zwitterionic dodecylphosphocholine (DPC) micelles do not affect the peptide structure. On the contrary, copper(II) promptly promotes an increase in β-turn-rich structures. Differential scanning calorimetry (DSC) and Trp fluorescence assays carried out on DPPC model membranes after incubation with huPrP60-91 showed a marked tendency of the peptide to slowly penetrate the lipid bilayer with a concomitant conformational transition toward an extended β-sheet-like structure

  2. Enhancement of antimicrobial activities of whole and sub-fractionated white tea by addition of copper (II) sulphate and vitamin C against Staphylococcus aureus; a mechanistic approach

    PubMed Central

    2011-01-01

    Background Enhancement of antimicrobial plant products e.g. pomegranate extract by copper (II) sulphate is known. Such combinations have applications in various settings, including the identification of novel compositions to study, treat and control infection. Methods A combination of white tea (WT) (made allowing 10 minutes infusion time at 100°C) was combined with 4.8 mM copper (II) sulphate and tested for antimicrobial effect on the viability of Staphylococcus aureus NCTC 06571. Comparisons were made with green (GT) and black (BT) teas. A WT sub-fraction (WTF < 1000 Da) was tested with copper (II) sulphate and 4.8 mM vitamin C. pH measurements of samples were taken for controls and to observe any changes due to tea/agent interaction. Catalase was used to investigate hydrogen peroxide release. UV-vis. was used to compare WT and WTF. Results A 30 minute incubation at room temperature of copper (II) sulphate alone and combined with WT reduced the viability of S. aureus NCTC 06571 by c.a 1 log10 cfu mL-1. GT and BT with copper (II) sulphate negated activity to buffer values. Combined with copper (II) sulphate, vitamin C, WTF and, vitamin C plus WTF all reduced the viability of S. aureus NCTC 06571 by c.a. 3.5 log10 cfu mL-1. Independent experiments showed the results were not due to pH effects. Adding WT or WTF to copper (II) sulphate resulted in increased acidity. Copper (II) sulphate alone and combined with WT required c.a 300 μg mL-1 (final concentration) catalase to restore S. aureus viability, WTF with copper (II) sulphate and added vitamin C required c.a 600 μg mL-1. WT and WTF UV-visible spectra were similar. Conclusions WT showed no efficacy in the combinations tested. WTF was enhanced with copper (II) sulphate and further with vitamin C. WT and WTF increased acidity of copper (II) sulphate possibly via the formation of chemical complexes. The difference in WT/WTF absorbance possibly represented substances less concentrated or absent in WTF

  3. A novel bis tridentate bipyridine carboxamide ligand and its complexation to copper(II): synthesis, structure, and magnetism.

    PubMed

    Wang, Jian; Djukic, Brandon; Cao, Jingyi; Alberola, Antonio; Razavi, Fereidoon S; Pilkington, Melanie

    2007-10-15

    A new bis tridentate ligand 2,2'-bipyridine-3,3'-[2-pyridinecarboxamide] H(2)L(1) which can bind transition metal ions has been synthesized via the condensation of 3,3'-diamino-2,2'-bipyridine together with 2-pyridine carbonyl chloride. Two copper(II) coordination compounds have been prepared and characterized: [Cu(2)(L(1))(hfac)(2)].3CH(3)CN.H(2)O (1) and [Cu(2)(L(1))Cl(2)].CH(3)CN (2). The single-crystal X-ray structures reveal that complex 1 crystallizes in the triclinic space group P1, with the unit cell parameters a = 12.7185(6) A, b = 17.3792(9) A, c = 19.4696(8) A, alpha = 110.827(2) degrees, beta = 99.890(3) degrees, gamma = 97.966(3) degrees, V = 3868.3(3) A3, Z = 4, R = 0.0321 and R(w) = 0.0826. Complex 2 crystallizes in the monoclinic space group P2(1)/n with the unit cell parameters a = 12.8622(12) A, b = 9.6100(10) A, c = 19.897(2) A, beta = 102.027(3) degrees, V = 2405.3(4) A(3), Z = 4, R = 0.0409 and R(w) = 0.1005. In both complexes the ligand is in the dianionic form and coordinates the divalent Cu(II) ions via one amido and two pyridine nitrogen donor atoms. In 1, the coordination geometry around both Cu(II) ions is best described as distorted trigonal bipyramidal where the remaining two coordination sites are satisfied by hexafluoroacetylacetonate counterions. In 2 both Cu(II )ions adopt a (4 + 1) distorted square pyramidal geometry. One copper forms a longer apical bond to an adjacent carbonyl oxygen atom, whereas the second copper is chelated to a neighboring Cu-Cl chloride ion to afford a mu-Cl-bridged dimerized [Cu(2)(L(1))Cl(2)](2) complex. The magnetic susceptibility data for 1 (2 -270 K), reveal the occurrence of weak antiferromagnetic interactions between the Cu(II) ions. In contrast, variable-temperature magnetic susceptibility measurements for 2 reveal more complex magnetic properties, with the presence of a weak antiferromagnetic exchange (J = -10.1 K) between the copper ions in each dinuclear copper complex and a stronger ferromagnetic

  4. Pyrrolidine and Piperidine Formation Via Copper(II) Carboxylate Promoted Intramolecular Carboamination of Unactivated Olefins: Diastereoselectivity and Mechanism

    PubMed Central

    Sherman, Eric S.; Fuller, Peter H.; Kasi, Dhanalakshmi; Chemler, Sherry R.

    2008-01-01

    An expanded substrate scope and in depth analysis of the reaction mechanism of the copper(II) carboxylate promoted intramolecular carboamination of unactivated alkenes is described. This method provides access to N-functionalized pyrrolidines and piperidines. Both aromatic and aliphatic γ- and δ-alkenyl N-arylsulfonamides undergo the oxidative cyclization reaction efficiently. N-Benzoyl-2-allylaniline also underwent the oxidative cyclization. The terminal olefin substrates examined were more reactive than those with internal olefins, and the latter terminated in elimination rather than carbon-carbon bond formation. The efficiency of the reaction was enhanced by the use of more organic soluble copper(II) carboxylate salts, copper(II) neodecanoate in particular. The reaction times were reduced by the use of microwave heating. High levels of diastereoselectivity were observed in the synthesis of 2,5-disubstituted pyrrolidines, wherein the cis substitution pattern predominates. The mechanism of the reaction is discussed in the context of the observed reactivity and in comparison to analogous reactions promoted by other reagents and conditions. Our evidence supports a mechanism wherein the N-C bond is formed via intramolecular syn aminocupration and the C-C bond is formed via intramolecular addition of a primary carbon radical to an aromatic ring. PMID:17428100

  5. Flocculation of copper(II) and tetracycline from water using a novel pH- and temperature-responsive flocculants.

    PubMed

    Yang, Zhen; Jia, Shuying; Zhuo, Ning; Yang, Weiben; Wang, Yuping

    2015-12-01

    Insufficient research is available on flocculation of combined pollutants of heavy metals and antibiotics, which widely exist in livestock wastewaters. Aiming at solving difficulties in flocculation of this sort of combined pollution, a novel pH- and temperature-responsive biomass-based flocculant, carboxymethyl chitosan-graft-poly(N-isoproyl acrylamide-co-diallyl dimethyl ammonium chloride) (denoted as CND) with two responsive switches [lower critical solution temperature (LCST) and isoelectric point (IEP)], was designed and synthesized. Its flocculation performance at different temperatures and pHs was evaluated using copper(II) and tetracycline (TC) as model contaminants. CND exhibited high efficiency for coremoval of both contaminants, whereas two commercial flocculants (polyaluminum chloride and polyacrylamide) did not. Especially, flocculation performance of the dual-responsive flocculant under conditions of temperature>LCST and IEP(contaminants)copper(II) and TC were present in bridging flocculation, including charge attraction, coordination and hydrophobic effect. Based on these pairwise interactions, copper(II) and TC exerted "aid" roles to each other's removal with the existence of CND, and preferable flocculation performance was thus achieved. PMID:26162528

  6. Mechanism of Formation of Copper(II) Chloro Complexes Revealed by Transient Absorption Spectroscopy and DFT/TDDFT Calculations.

    PubMed

    Mereshchenko, Andrey S; Olshin, Pavel K; Karabaeva, Kanykey E; Panov, Maxim S; Wilson, R Marshall; Kochemirovsky, Vladimir A; Skripkin, Mikhail Yu; Tveryanovich, Yury S; Tarnovsky, Alexander N

    2015-07-16

    Copper(II) complexes are extremely labile with typical ligand exchange rate constants on the order of 10(6)-10(9) M(-1) s(-1). As a result, it is often difficult to identify the actual formation mechanism of these complexes. In this work, using UV-vis transient absorption when probing in a broad time range (20 ps to 8 μs) in conjunction with DFT/TDDFT calculations, we studied the dynamics and underlying reaction mechanisms of the formation of extremely labile copper(II) CuCl4(2-) chloro complexes from copper(II) CuCl3(-) trichloro complexes and chloride ions. These two species, produced via photochemical dissociation of CuCl4(2-) upon 420 nm excitation into the ligand-to-metal-charge-transfer electronic state, are found to recombine into parent complexes with bimolecular rate constants of (9.0 ± 0.1) × 10(7) and (5.3 ± 0.4) × 10(8) M(-1) s(-1) in acetonitrile and dichloromethane, respectively. In dichloromethane, recombination occurs via a simple one-step addition. In acetonitrile, where [CuCl3](-) reacts with the solvent to form a [CuCl3CH3CN](-) complex in less than 20 ps, recombination takes place via ligand exchange described by the associative interchange mechanism that involves a [CuCl4CH3CN](2-) intermediate. In both solvents, the recombination reaction is potential energy controlled. PMID:26079181

  7. Flocculation of copper(II) and tetracycline from water using a novel pH- and temperature-responsive flocculants.

    PubMed

    Yang, Zhen; Jia, Shuying; Zhuo, Ning; Yang, Weiben; Wang, Yuping

    2015-12-01

    Insufficient research is available on flocculation of combined pollutants of heavy metals and antibiotics, which widely exist in livestock wastewaters. Aiming at solving difficulties in flocculation of this sort of combined pollution, a novel pH- and temperature-responsive biomass-based flocculant, carboxymethyl chitosan-graft-poly(N-isoproyl acrylamide-co-diallyl dimethyl ammonium chloride) (denoted as CND) with two responsive switches [lower critical solution temperature (LCST) and isoelectric point (IEP)], was designed and synthesized. Its flocculation performance at different temperatures and pHs was evaluated using copper(II) and tetracycline (TC) as model contaminants. CND exhibited high efficiency for coremoval of both contaminants, whereas two commercial flocculants (polyaluminum chloride and polyacrylamide) did not. Especially, flocculation performance of the dual-responsive flocculant under conditions of temperature>LCST and IEP(contaminants)copper(II) and TC were present in bridging flocculation, including charge attraction, coordination and hydrophobic effect. Based on these pairwise interactions, copper(II) and TC exerted "aid" roles to each other's removal with the existence of CND, and preferable flocculation performance was thus achieved.

  8. Two ferromagnetic azido-bridged copper(II) complexes studied by first-principle electronic-structure calculation

    NASA Astrophysics Data System (ADS)

    Zhang, Y. S.; Yao, K. L.; Liu, Z. L.

    2005-09-01

    The electronic structures of two ferromagnetic polynuclear copper(II) complexes, derived from end-to-end azido ligand and tridentate (NNN donor) Schiff base ligand, have been studied using the full-potential linearized augmented plane-wave method based on the density-functional theory. They are [Cu(L1)(μ-1,3-N3)]n(ClO4)n (1) and [Cu(L2)(μ-1,3-N3)]n(ClO4)n (2). The result shows that the spin populations in these two complexes are mainly distributed on the equatorial planes of a square pyramidal that surround the copper(II) ions. There are large and positive spin populations on copper(II) ions, small and positive spin populations on the three nitrogen atoms of tridentate Schiff base ligand, and the two terminal nitrogen atoms of asymmetrical end-to-end azido ligand, while weak and negative spin populations on the central nitrogen atoms of asymmetrical end-to-end azido ligand. Ferromagnetic coupling through the asymmetrical azido ligand in these two complexes has been mainly attributed to the spin delocalization, also with weak spin-polarization effect.

  9. Pyrrolidine and piperidine formation via copper(II) carboxylate-promoted intramolecular carboamination of unactivated olefins: diastereoselectivity and mechanism.

    PubMed

    Sherman, Eric S; Fuller, Peter H; Kasi, Dhanalakshmi; Chemler, Sherry R

    2007-05-11

    An expanded substrate scope and in-depth analysis of the reaction mechanism of the copper(II) carboxylate-promoted intramolecular carboamination of unactivated alkenes is described. This method provides access to N-functionalized pyrrolidines and piperidines. Both aromatic and aliphatic gamma- and delta-alkenyl N-arylsulfonamides undergo the oxidative cyclization reaction efficiently. N-Benzoyl-2-allylaniline also underwent the oxidative cyclization. The terminal olefin substrates examined were more reactive than those with internal olefins, and the latter terminated in elimination rather than carbon-carbon bond formation. The efficiency of the reaction was enhanced by the use of more organic soluble copper(II) carboxylate salts, copper(II) neodecanoate in particular. The reaction times were reduced by the use of microwave heating. High levels of diastereoselectivity were observed in the synthesis of 2,5-disubstituted pyrrolidines, wherein the cis substitution pattern predominates. The mechanism of the reaction is discussed in the context of the observed reactivity and in comparison to analogous reactions promoted by other reagents and conditions. Our evidence supports a mechanism wherein the N-C bond is formed via intramolecular syn aminocupration and the C-C bond is formed via intramolecular addition of a primary carbon radical to an aromatic ring.

  10. Melamine-formaldehyde-NTA chelating gel resin: Synthesis, characterization and application for copper(II) ion removal from synthetic wastewater.

    PubMed

    Baraka, Ahmad; Hall, P J; Heslop, M J

    2007-02-01

    A new chelating resin was synthesised by anchoring nitrilotriacetic acid (NTA) to melamine during the melamine-formaldehyde gelling reaction in the presence of water, using acetone and guaiacol as a porogen mixture. This technique gives a porous chelating gel resin capable of removing heavy metals from wastewater. FT-IR, XRD, elemental analysis, surface area and water regain measurements were conducted for characterization of the new chelating gel resin. A comprehensive adsorption study (kinetics isotherm, and thermodynamics) of Cu(II) removal from synthetic acidic aqueous solutions by adsorption on this resin was conducted regarding the effects of time, temperature, initial pH and copper(II) initial concentration.

  11. Acid-base interactions and complex formation while recovering copper(II) ions from aqueous solutions using cellulose adsorbent in the presence of polyvinylpyrrolidone

    NASA Astrophysics Data System (ADS)

    Nikiforova, T. E.; Kozlov, V. A.; Islyaikin, M. K.

    2012-12-01

    The sorption properties of nontreated cotton cellulose and cellulose modified with polyvinylpyrrolidone with respect to copper(II) ions are investigated. It is established that modified cellulose adsorbents have high sorption capability associated with the formation of new sorption centers during treatment with nitrogen-containing polymer. A mechanism is proposed for acid-base interactions in aqueous solutions of acids, bases, and salts during copper(II) cation recovery using cellulose adsorbent with the participation of polyvinylpyrrolidone.

  12. Maps showing distribution of pH, copper, zinc, fluoride, uranium, molybdenum, arsenic, and sulfate in water, Richfield 1 degree by 2 degrees Quadrangle, Utah

    USGS Publications Warehouse

    McHugh, J.B.; Miller, W.R.; Ficklin, W.H.

    1984-01-01

    These maps show the regional distribution of copper, zinc, arsenic, molybdenum, uranium, fluoride, sulfate, and pH in surface and ground water from the Richfield 1° x 2° quadrangle. This study supplements (Miller and others, 1984a-j) the regional drainage geochemical study done for the Richfield quadrangle under the U.S. Geological Survey’s Conterminuous United States Mineral Assessment Program (CUSMAP). Regional sampling was designed to define broad geochemical patterns and trends which can be used, along with geologic and geophysical data, to assess the mineral resource potential of the Richfield quadrangle. Analytical data used in compiling this report were published previously (McHugh and others, 1981). The Richfield quadrangle in west-central Utah covers the eastern part of the Pioche-Marysvale igneous and mineral belt that extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 250 km into central Utah. The western two-thirds of the Richfield quadrangle is in the Basin and Range Province, and the eastern third in the High Plateaus of Utah subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of latest Precambrian and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrane into a series of north-trending fault blocks; the uplifted mountain areas were deeply eroded and the resulting debris deposited in the adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed during igneous activity in the middle and late Cenozoic time.

  13. High-field 1H T1 and T2 NMR relaxation time measurements of H2O in homeopathic preparations of quartz, sulfur, and copper sulfate

    NASA Astrophysics Data System (ADS)

    Baumgartner, Stephan; Wolf, Martin; Skrabal, Peter; Bangerter, Felix; Heusser, Peter; Thurneysen, André; Wolf, Ursula

    2009-09-01

    Quantitative meta-analyses of randomized clinical trials investigating the specific therapeutic efficacy of homeopathic remedies yielded statistically significant differences compared to placebo. Since the remedies used contained mostly only very low concentrations of pharmacologically active compounds, these effects cannot be accounted for within the framework of current pharmacology. Theories to explain clinical effects of homeopathic remedies are partially based upon changes in diluent structure. To investigate the latter, we measured for the first time high-field (600/500 MHz) 1H T1 and T2 nuclear magnetic resonance relaxation times of H2O in homeopathic preparations with concurrent contamination control by inductively coupled plasma mass spectrometry (ICP-MS). Homeopathic preparations of quartz (10 c-30 c, n = 21, corresponding to iterative dilutions of 100-10-100-30), sulfur (13 x-30 x, n = 18, 10-13-10-30), and copper sulfate (11 c-30 c, n = 20, 100-11-100-30) were compared to n = 10 independent controls each (analogously agitated dilution medium) in randomized and blinded experiments. In none of the samples, the concentration of any element analyzed by ICP-MS exceeded 10 ppb. In the first measurement series (600 MHz), there was a significant increase in T1 for all samples as a function of time, and there were no significant differences between homeopathic potencies and controls. In the second measurement series (500 MHz) 1 year after preparation, we observed statistically significant increased T1 relaxation times for homeopathic sulfur preparations compared to controls. Fifteen out of 18 correlations between sample triplicates were higher for controls than for homeopathic preparations. No conclusive explanation for these phenomena can be given at present. Possible hypotheses involve differential leaching from the measurement vessel walls or a change in water molecule dynamics, i.e., in rotational correlation time and/or diffusion. Homeopathic preparations

  14. Sulfur and oxygen isotope study of the Vermont copper belt: evidence of seawater hydrothermal alteration and sulfate reduction in a high-grade metamorphic terrane

    SciTech Connect

    Shanks, W.C. III; Woodruff, L.G.; Slack, J.F.

    1985-01-01

    Massive sulfide deposits of the Orange County copper district, in east-central Vermont, consist of stratiform lenses of pyrrhotite, chalcopyrite, and minor sphalerite within amphibolite-facies rocks of Early Devonian (.) age. The deposits occur at several different stratigraphic levels. The two largest, Elizabeth and Ely, are in quartz-mica schists of the Gile Mountain Formation; the Pike Hill deposit occurs in calcareous quartz-mica schist of the underlying Waits River Formation. Two small deposits (Orange and Gove) are within the Standing Pond Volcanics, a thin tholeiitic amphibolite near the Gile Mountain-Waits River contact. The Elizabeth deposit in particularly distinctive, and contains a suite of unusual wall rocks rich in quartz, carbonate, muscovite, amphibole, phlogopite, tourmaline, spessartine, and sodic plagioclase. Sulfur isotope values at Elizabeth and Ely of 5.1 to 9.1 per thousands contrast with values for Gove (1.9 to 4.2) and Pike Hill (1.5 to 4.6). Disseminated sulfides in amphibolites of the Standing Pond Volcanics have sulfur isotope values in the range -0.1 to 1.7 per thousands, typical of MORB. These data require sulfur contributions to massive sulfide deposits both from basalt and from contemporaneous seawater sulfate sources. Whole-rock (carbonate free) oxygen isotope analyses of host lithologies range from 7.9 per thousands (Standing Pond Volcanics) to 19.9 per thousands (Waits River Formation). Detailed sampling of Elizabeth wall rocks (including those high in B, Na, Mg, Al, Si, Mn) yields a narrow range of oxygen isotope values (11.1 to 14.1); heavier values correlate with higher silica contents. Isotopically light wallrock lithologies are probably due to premetamorphic seawater hydrothermal alteration.

  15. Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of N'-(furan-3-ylmethylene)-2-(4-methoxyphenylamino)acetohydrazide.

    PubMed

    Emam, Sanaa M; El-Saied, Fathy A; Abou El-Enein, Saeyda A; El-Shater, Heba A

    2009-03-01

    Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of furan-2-carbaldehyde 4-methoxy-N-anilinoacetohydrazone were synthesized and characterized by elemental and thermal (TG and DTA) analyses, IR, UV-vis and (1)H NMR spectra as well as magnetic moment and molar conductivity. Mononuclear complexes are obtained with 1:1 molar ratio except complexes 3 and 9 which are obtained with 1:2 molar ratios. The IR spectra of ligand and metal complexes reveal various modes of chelation. The ligand behaves as a neutral bidentate one and coordination occurs via the carbonyl oxygen atom and azomethine nitrogen atom. The ligand behaves also as a monobasic tridentate one and coordination occurs through the enolic oxygen atom, azomethine nitrogen atom and the oxygen atom of furan ring. Moreover, the ligand behaves as a neutral tridentate and coordination occurs via the carbonyl oxygen, azomethine nitrogen and furan oxygen atoms as well as a monobasic bidentate and coordination occurs via the enolic oxygen atom and azomethine nitrogen atom. The electronic spectra and magnetic moment measurements reveal that all complexes possess octahedral geometry except the copper complex 10 possesses a square planar geometry. The thermal studies showed the type of water molecules involved in metal complexes as well as the thermal decomposition of some metal complexes.

  16. Spectrophotometric total protein assay with copper(II)-neocuproine reagent in alkaline medium.

    PubMed

    Sözgen, Kevser; Cekic, Sema Demirci; Tütem, Esma; Apak, Resat

    2006-02-28

    Total protein assay was made using copper(II)-neocuproine (Nc) reagent in alkaline medium (with the help of a hydroxide-carbonate-tartarate solution) after 30min incubation at 40 degrees C. The absorbance of the reduction product, Cu(I)-Nc complex, was recorded at 450nm against a reagent blank. The absorptivity of the developed method for bovine serum albumin (BSA) was 0.023lmg(-1)cm(-1), greater than that of Lowry assay (0.0098), and much greater than that of Cu(II)-bicinchoninic acid (BCA) assay (0.00077). The linear range of the developed method (8-100mgl(-1) BSA) was as wide as that of Lowry, and much wider than that of BCA (200-1000mgl(-1) BSA) assay. The sensitivity of the method was greater than those of Cu-based assays (biuret, Lowry, and BCA) with a LOD of 1mgl(-1) BSA. The within-run and between-run precisions as RSD were 0.73 and 1.01%, respectively. The selectivity of the proposed method for protein was much higher than those of dye-binding and Lowry assays: Most common interferents to other protein assays such as tris, ethanolamine, deoxycholate, CsCl, citrate, and triton X-100 were tolerated at 100-fold concentrations in the analysis of 10mgl(-1) BSA, while the tolerance limits for other interferents, e.g., (NH(4))(2)SO(4) and acetylsalicylic acid (50-fold), SDS (25-fold), and glycerol (20-fold) were at acceptable levels. The redox reaction of Cu(II)-Nc as an outer-sphere electron transfer agent with the peptide bond and with four amino acid residues (cystine, cysteine, tryptophan, and tyrosine) was kinetically more favourable than that of Cu(II) alone in the biuret assay. Since the reduction product of Cu(II) with protein, i.e., Cu(I), was coordinatively saturated with Nc in the stable Cu(Nc)(2)(+) chelate, re-oxidation of the formed Cu(I) with Fenton-like reactions was not possible, thereby preventing a loss of chromophore. After conventional protein extraction, precipitation, and redissolution procedures, the protein contents of the minced meat

  17. A photoreducible copper(II)-tren complex of practical value: generation of a highly reactive click catalyst.

    PubMed

    Harmand, Lydie; Lambert, Romain; Scarpantonio, Luca; McClenaghan, Nathan D; Lastécouères, Dominique; Vincent, Jean-Marc

    2013-11-25

    A detailed study on the photoreduction of the copper(II) precatalyst 1 to generate a highly reactive cuprous species for the copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) click reaction is presented. For the photoactive catalyst described herein, the activation is driven by a photoinduced electron transfer (PET) process harnessing a benzophenone-like ketoprofenate chromophore as a photosensitizer, which is equally the counterion. The solvent is shown to play a major role in the Cu(II) to Cu(I) reduction process as the final electron source, and the influence of the solvent nature on the photoreduction efficiency has been studied. Particular attention was paid to the use of water as a potential solvent, aqueous media being particularly appealing for CuAAC processes. The ability to solubilize the copper-tren complexes in water through the formation of inclusion complexes with β-CDs is demonstrated. Data is also provided on the fate of the copper(I)-tren catalytic species when reacting with O2, O2 being used to switch off the catalysis. These data show that partial oxidation of the secondary benzylamine groups of the ligand to benzylimines occurs. Preliminary results show that when prolonged irradiation times are employed a Cu(I) to Cu(0) over-reduction process takes place, leading to the formation of copper nanoparticles (NPs). Finally, the main objective of this work being the development of photoactivable catalysts of practical value for the CuAAC, the catalytic, photolatent, and recycling properties of 1 in water and organic solvents are reported. PMID:24127367

  18. Syntheses and structures of discrete copper(II) and cadmium(II) supramolecular complexes based on 1,4-diacylthiosemicarbazone ligands.

    PubMed

    Jiao, Chen; Zhang, Si-Si; Li, Zuo-Yin; Liu, Jian-Jun; Lin, Mei-Jin; Huang, Chang-Cang

    2016-02-01

    Thiosemicarbazides and their metal complexes have attracted considerable interest because of their biological activities and their flexibility, which allows the ligands to bend and rotate freely to accommodate the coordination geometries of various metal centres. Discrete copper(II) and cadmium(II) complexes have been prepared by crystallization of N-[2-(2-hydroxybenzoyl)hydrazinecarbonothioyl]propanamide (H3L) with Cu(CH3COO)2 or Cd(NO3)2 in a dimethylformamide/methanol mixed-solvent system at room temperature, affording the complexes di-μ-acetato-bis{μ4-1-[(2-oxidophenyl)carbonyl]-2-(propanamidomethanethioyl)hydrazine-1,2-diido}tetracopper(II) dimethylformamide disolvate, [Cu4(C11H10N3O3S)2(C2H3O2)2]·2C3H7NO, (I), and bis{μ2-[(2-hydroxyphenyl)formamido](propanamidomethanethioyl)azanido}bis[(4,4'-bipyridine)nitratocadmium(II)] dihydrate, [Cd2(C11H12N3O3S)2(NO3)2(C10H8N2)2]·2H2O, (II). Complex (I) consists of four Cu(II) cations, two μ4-bridging trianionic ligands and two μ2-bridging acetate ligands, while complex (II) is composed of two Cd(II) cations, two μ2-bridging monoanionic ligands, two nitrate ligands and two 4,4'-bipyridine ligands. These discrete complexes are connected by hydrogen bonds and van der Waals interactions to form a three-dimensional supramolecular architecture. Compared with (I), the phenolic hydroxy group and hydrazide N atom of the thiosemicarbazide ligand of (II) are not involved in coordination and lead to a binuclear Cd(II) complex. This different coordination mode may be attributed to the larger ionic radius of the Cd(II) ion compared with the Cu(II) ion. PMID:26846495

  19. Competitive adsorption of copper(II), cadmium(II), lead(II) and zinc(II) onto basic oxygen furnace slag.

    PubMed

    Xue, Yongjie; Hou, Haobo; Zhu, Shujing

    2009-02-15

    Polluted and contaminated water can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a solution system will be affected by the presence of other metals. In this study, we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto basic oxygen furnace slag (BOF slag) in single- and multi-element solution systems as a function of pH and concentration, in a background solution of 0.01M NaNO(3). In adsorption edge experiments, the pH was varied from 2.0 to 13.0 with total metal concentration 0.84mM in the single element system and 0.21mM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH(50) (the pH at which 50% adsorption occurs) was found to follow the sequence Zn>Cu>Pb>Cd in single-element systems, but Pb>Cu>Zn>Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on BOF slag. The adsorption and potentiometric titrations data for various slag-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 6.5 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II), Pb(II) and Zn(II) systems.

  20. Synthesis, characterization, electrochemical studies and DFT calculations of amino acids ternary complexes of copper (II) with isonitrosoacetophenone. Biological activities

    NASA Astrophysics Data System (ADS)

    Tidjani-Rahmouni, Nabila; Bensiradj, Nour el Houda; Djebbar, Safia; Benali-Baitich, Ouassini

    2014-10-01

    Three mixed complexes having formula [Cu(INAP)L(H2O)2] where INAP = deprotonated isonitrosoacetophenone and L = deprotonated amino acid such as histidine, phenylalanine and tryptophan have been synthesized. They have also been characterized using elemental analyses, molar conductance, UV-Vis, IR and ESR spectra. The value of molar conductance indicates them to be non-electrolytes. The spectral studies support the binding of the ligands with two N and two O donor sites to the copper (II) ion, giving an arrangement of N2O2 donor groups. Density Functional Theory (DFT) calculations were applied to evaluate the cis and trans coordination modes of the two water molecules. The trans form was shown to be energetically more stable than the cis one. The ESR data indicate that the covalent character of the metal-ligand bonding in the copper (II) complexes increases on going from histidine to phenylalanine to tryptophan. The electrochemical behavior of the copper (II) complexes was determined by cyclic voltammetry which shows that the chelate structure and electron donating effects of the ligands substituent are among the factors influencing the redox potentials of the complexes. The antimicrobial activities of the complexes were evaluated against several pathogenic microorganisms to assess their antimicrobial potentials. The copper complexes were found to be more active against Gram-positive than Gram-negative bacteria. Furthermore, the antioxidant efficiencies of the metal complexes were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The antioxidant activity of the complexes indicates their moderate scavenging activity against the radical DPPH.

  1. Influence of Alkyl Chain Length and Structure on the Extraction of Copper(II) from Aqueous Acid by 5-Alkyl-2-hydroxybenzaldoximes in Hydrocarbon Solvents: Diffusion Coefficients of Extractants and Their Complexes.

    PubMed

    Ainscow; Aldalur; Beezer; Connor; Garbett; Mitchell; Page; Tindale; Turner; Willson

    1999-05-01

    Measurement of the kinetics of extraction of copper(II) by 19 different 5-alkyl-2-hydroxybenzaldoximes (alkyl is C7H15 and C9H19) from acidic (hydrogen sulfate buffer) aqueous solution in the range pH 3.4-2.0, into 20% v/v toluene in n-hexane is reported. The lowering of the interfacial tension has been measured in some cases. The solubility of the extractants in water has been measured spectrophotometrically. A modified Taylor-Aris dispersion technique has been used to measure the diffusion coefficients in n-hexane and Orfom SX7 of some of the extractants and of the copper(II) complexes which they form. At low initial bulk concentrations (<10 mol m-3) of the extractants, the rate of extraction is controlled by the rate of diffusion of the extractant from the bulk to the organic-aqueous interface. The diffusion coefficient is related to the steric bulk of the alkyl substituent. At higher initial bulk concentrations (200 mol m-3) of the extractants, when the interface is saturated, the rate of extraction is inversely related to the apparent steric bulk of the alkyl substituent. Copyright 1999 Academic Press.

  2. Versatility of azide in serendipitous assembly of copper(II) magnetic polyclusters.

    PubMed

    Mukherjee, Sandip; Mukherjee, Partha Sarathi

    2013-11-19

    Engineering at the molecular level is one of the most exciting new developments for the generation of functional materials. However, the concept of designing polynuclear extended structures from bottom up is still not mature. Although progress has been made with secondary building units (SBUs) in metal organic frameworks (MOFs), the control seems to be just an illusion when it comes to bridging ligands such as the azide ion. When we say that the azido ligand is versatile in its bridging capabilities, what we mean is that it would be difficult to predict or control its bridging properties. However, this kind of serendipity is not always bad news. For example, scientists have shown that the azido ligand can mediate magnetic exchanges between paramagnetic metals in a predictable fashion (usually depending upon the bonding geometries). Therefore, it is a well-respected ligand in polynuclear assemblies. Serendipitous assemblies offer new magnetic structures that we may not otherwise even think about synthesizing. The azido ligand forms a variety of complexes with copper(II) using different blocking amines or pyridine based ligands. Its structural nature changes upon changing the substitution on amine, as well as the amount of blocking ligand. In principle, if we take any of these complexes and provide more coordination sites to the bridging azido ligands by removing a fraction of the blocking ligands, we can get new complexes with intricate structural networks and therefore different magnetic properties with the same components as used for the parent complex. In this Account, we mainly discuss the development of a number of new topological and magnetic exchange systems synthesized using this concept. Not all of these new complexes can be grouped according to their basic building structures or even by the ratio of the metal to blocking ligand. Therefore, we divided the discussion by the nuclearity of the basic building structures. Some of the complexes with the same

  3. Versatility of azide in serendipitous assembly of copper(II) magnetic polyclusters.

    PubMed

    Mukherjee, Sandip; Mukherjee, Partha Sarathi

    2013-11-19

    Engineering at the molecular level is one of the most exciting new developments for the generation of functional materials. However, the concept of designing polynuclear extended structures from bottom up is still not mature. Although progress has been made with secondary building units (SBUs) in metal organic frameworks (MOFs), the control seems to be just an illusion when it comes to bridging ligands such as the azide ion. When we say that the azido ligand is versatile in its bridging capabilities, what we mean is that it would be difficult to predict or control its bridging properties. However, this kind of serendipity is not always bad news. For example, scientists have shown that the azido ligand can mediate magnetic exchanges between paramagnetic metals in a predictable fashion (usually depending upon the bonding geometries). Therefore, it is a well-respected ligand in polynuclear assemblies. Serendipitous assemblies offer new magnetic structures that we may not otherwise even think about synthesizing. The azido ligand forms a variety of complexes with copper(II) using different blocking amines or pyridine based ligands. Its structural nature changes upon changing the substitution on amine, as well as the amount of blocking ligand. In principle, if we take any of these complexes and provide more coordination sites to the bridging azido ligands by removing a fraction of the blocking ligands, we can get new complexes with intricate structural networks and therefore different magnetic properties with the same components as used for the parent complex. In this Account, we mainly discuss the development of a number of new topological and magnetic exchange systems synthesized using this concept. Not all of these new complexes can be grouped according to their basic building structures or even by the ratio of the metal to blocking ligand. Therefore, we divided the discussion by the nuclearity of the basic building structures. Some of the complexes with the same

  4. Excessive Copper(II) and Zinc(II) Levels in Drinkable Water Sources in Areas Along the Lake Victoria Shorelines in Siaya County, Kenya.

    PubMed

    Wambu, Enos W; Omwoyo, Wesley N; Akenga, Teresa

    2016-01-01

    Copper(II) and zinc(II) levels in drinkable water sources in the alluvium areas of the Lake Victoria Basin in Siaya County of Kenya were evaluated to assess the risk posed to resident communities by hydrogeological accumulation of toxic residues in the sedimentary regions of the lake basin. The levels of the metals in water were analyzed by atomic absorption spectroscopy. Metal concentrations ranged from 0.11 to 4.29 mg/L for Cu(II) and 0.03 to 1.62 mg/L for Zn(II), which were both higher than those normally recorded in natural waters. The Cu(II) levels also exceeded WHO guidelines for drinking water in 27% of the samples. The highest prevalence of excessive Cu(II) was found among dams and open pans (38%), piped water (33%) and spring water (25%). It was estimated that 18.2% of the resident communities in the current study area are exposed to potentially toxic levels of Cu(II) through their drinking water. PMID:26615531

  5. Excessive Copper(II) and Zinc(II) Levels in Drinkable Water Sources in Areas Along the Lake Victoria Shorelines in Siaya County, Kenya.

    PubMed

    Wambu, Enos W; Omwoyo, Wesley N; Akenga, Teresa

    2016-01-01

    Copper(II) and zinc(II) levels in drinkable water sources in the alluvium areas of the Lake Victoria Basin in Siaya County of Kenya were evaluated to assess the risk posed to resident communities by hydrogeological accumulation of toxic residues in the sedimentary regions of the lake basin. The levels of the metals in water were analyzed by atomic absorption spectroscopy. Metal concentrations ranged from 0.11 to 4.29 mg/L for Cu(II) and 0.03 to 1.62 mg/L for Zn(II), which were both higher than those normally recorded in natural waters. The Cu(II) levels also exceeded WHO guidelines for drinking water in 27% of the samples. The highest prevalence of excessive Cu(II) was found among dams and open pans (38%), piped water (33%) and spring water (25%). It was estimated that 18.2% of the resident communities in the current study area are exposed to potentially toxic levels of Cu(II) through their drinking water.

  6. Template synthesis of novel carboxamide dinuclear copper (II) complex: spectral characterization and reactivity towards calf-thymus DNA.

    PubMed

    Mathur, Suvigya; Tabassum, Sartaj

    2008-06-01

    Dinuclear complexes Bis [aqua 1,8-(1,2-dicarboxamido benzene) 3,6-diazaoctane copper (II)/nickel (II)] tetrachloride (1 and 2) were synthesized by a two component one-pot metal template condensation between phthalic anhydride and 1,8-diamino 3,6-diazaoctane. Elemental analysis, molar conductance measurements, electronic absorption, infra-red, electron paramagnetic resonance, nuclear magnetic resonance, atomic absorption, and electron spray mass spectral studies have been performed to probe the nature and structure of the complexes. The interaction of copper (II) complex with calf thymus (CT-DNA) has been studied by using absorption, emission and circular dichoric spectral methods, viscometry, and cyclic voltammetry. A strong hyperchromism along with a red shift in UV bands and hypochromism in the ligand field band of the complex 1 on interaction with CT-DNA imply a covalent mode of DNA binding. This is further confirmed by studying the reactivity of complex 1 using circular dichroism and viscosity measurements. The variation in relative emission intensity of DNA-bound ethidium bromide observed upon treatment with the complex 1 parallel the trend of DNA binding studies. Cyclic voltammetry studies reveal that the complex 1 prefers to bind to DNA in Cu(II) rather than Cu(I) oxidation state.

  7. Interfacial behavior and film patterning of redox-active cationic copper(II)-containing surfactants.

    PubMed

    Driscoll, Jeffery A; Allard, Marco M; Wu, Libo; Heeg, Mary Jane; da Rocha, Sandro R P; Verani, Cláudio N

    2008-01-01

    Herein, we describe the synthesis and characterization of a novel series of single-tail amphiphiles LPyCn (Py=pyridine, Cn=C18, C16, C14, C10) and their copper(II)-containing complexes, which are of relevance for patterned films. The N-(pyridine-2-ylmethyl)alkyl-1-amine ligands and their complexes [CuIICl2(LPyC18)] (1), [CuIICl2(LPyC16)] (2), [CuIICl2(LPyC14)] (3), [CuIIBr2(LPyC18)] (4), [CuIIBr2(LPyC16)] (5), and [CuIIBr2(LPyC10)] (6) were synthesized, isolated, and characterized by means of mass spectrometry, IR and NMR spectroscopies, and elemental analysis. Complexes 1, 2, 3, and 6 had their molecular structure solved by X-ray diffraction methods, which showed that the local geometry around the metal center is distorted square planar. With the aim of using these species as precursors for redox-responsive films, an assessment of their electrochemical properties involved cyclic voltammetry in different solvents, with different supporting electrolytes and scan rates. Density functional theory calculations of relevant species in bulk and at interfaces were used to evaluate their electronic structure and dipole moments. The morphology and order of the resulting films at the air/water interface were studied by isothermal compression and Brewster angle microscopy. Biphasic patterned Langmuir films were observed for all complexes except 3 and 6, and dependence on the chain length and the nature of the halogen coligand determine the characteristics of the isotherms and their intricate topology. Complexes 3 and 6, which have shorter chain lengths, failed to exhibit organization. These results exemplify the first comprehensive study of the behavior of single-tail metallosurfactants, which are likely to lead to high-end technological applications based on their patterned films. PMID:18792023

  8. Targeted photocytotoxicity by copper(II) complexes having vitamin B6 and photoactive acridine moieties.

    PubMed

    Mukherjee, Nandini; Podder, Santosh; Banerjee, Samya; Majumdar, Shamik; Nandi, Dipankar; Chakravarty, Akhil R

    2016-10-21

    Copper(II) pyridoxal Schiff base complexes [Cu(L(1)/L(2))(B)]ClO4 (1-4), where HL(1) is 4-(((2-(1H-imidazol-4-yl)ethyl)imino)methyl)-5-(hydroxymethyl)-2-methylpyridin-3-ol (in 1 and 2), HL(2) is 2-(((2-(1H-imidazol-4-yl)ethyl)imino)methyl)phenol (in 3, 4), B is 11-(9-acridinyl)dipyrido[3,2-a:2',3'-c]phenazine (acdppz in 1 and 3), dipyrido[3,2-a:2',3'-c]phenazine (in 2) and 1,10-phenanthroline (in 4), were synthesized, characterized and their photocytotoxicity in visible light, intracellular localization, cellular uptake and DNA photocleavage activity were studied. Complex 4 was characterized by X-ray crystallography. Complexes 1 and 3 having acdppz as photosensitizer showed significant photocytotoxicity in visible light in HeLa and MCF7 cells giving IC50 value of <0.6 μM, while being relatively non-toxic in dark. The complexes were non-toxic to non-tumorigenic HPL1D cells both in light and dark conditions. Complex 1 showed significant localization in the cytoplasm of HeLa cells within 4 h of treatment, as evidenced from confocal microscopy. DCFDA assay on 1 suggested generation of intracellular reactive oxygen species in HeLa cells upon photo-exposure. Importantly, Annexin-V-FITC/PI assay indicated photo-induced apoptotic cell death. PMID:27423638

  9. Preparation and characterization of surfactant-modified hydroxyapatite/zeolite composite and its adsorption behavior toward humic acid and copper(II).

    PubMed

    Zhan, Yanhui; Lin, Jianwei; Li, Jia

    2013-04-01

    A novel composite material, i.e., surfactant-modified hydroxyapatite/zeolite composite, was used as an adsorbent to remove humic acid (HA) and copper(II) from aqueous solution. Hydroxyapatite/zeolite composite (HZC) and surfactant-modified HZC (SMHZC) were prepared and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscope. The adsorption of HA and copper(II) on SMHZC was investigated. For comparison purposes, HA adsorption onto HZC was also investigated. SMHZC exhibited much higher HA adsorption capacity than HZC. The HA adsorption capacity for SMHZC decreased slightly with increasing pH from 3 to 8 but decreased significantly with increasing pH from 8 to 12. The copper(II) adsorption capacity for SMHZC increased with increasing pH from 3 to 6.5. The adsorption kinetic data of HA and copper(II) on SMHZC obeyed a pseudo-second-order kinetic model. The adsorption of HA and copper(II) on SMHZC took place in three different stages: fast external surface adsorption, gradual adsorption controlled by both film and intra-particle diffusions, and final equilibrium stage. The equilibrium adsorption data of HA on SMHZC better fitted to the Langmuir isotherm model than the Freundlich isotherm model. The equilibrium adsorption data of copper(II) on SMHZC could be described by the Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. The presence of copper(II) in solution enhanced HA adsorption onto SMHZC. The presence of HA in solution enhanced copper(II) adsorption onto SMHZC. The mechanisms for the adsorption of HA on SMHZC at pH 7 may include electrostatic attraction, organic partitioning, hydrogen bonding, and Lewis acid-base interaction. The mechanisms for the adsorption of copper(II) on SMHZC at pH 6 may include surface complexation, ion exchange, and dissolution-precipitation. The obtained results indicate that SMHZC can be used as an effective adsorbent to simultaneously remove HA and

  10. Luminescence response of an osmium(II) complex to macromolecular polyanions for the detection of heparin and chondroitin sulfate in biomedical preparations.

    PubMed

    Wu, Hao; Wu, Jain; Saez, Christopher; Campana, Maria; Megehee, Elise G; Wang, Enju

    2013-12-01

    Heparin, dextran sulfate (DS), chondroitin sulfate (CS), and carrageenan are found to enhance the luminescence intensity of an osmium(II) carbonyl complex with phenanthroline (phen) and 4-phenylpyridine (4-phpy) ligands in aqueous and ethanol solutions. The enhancing effect of the polyanions on the luminescence of the complex is heavily dependent on the sulfate content and other factors such as structure, solubility, and counter ions of the polyanion. The highly sulfated dextran and ι-carrageenan have the most profound effect, while the low charged κ-carrageenan and CS have the least response in aqueous solution. All polyanions exhibited enhanced luminescence intensity of the complex in ethanol solutions, and even the low charged CS and κ-carrageenan enhanced the luminescence more than 4 times. DS contamination of the sodium heparin at 5% can show a significant increase in luminescence response. The osmium complex is found to be highly successful in the fast and sensitive detection of heparin in commercial injectable samples with various backgrounds as well as the detection of CS in over the counter food supplement tablets.

  11. Synthesis and spectral characterization of mono- and binuclear copper(II) complexes derived from 2-benzoylpyridine-N4-methyl-3-thiosemicarbazone: Crystal structure of a novel sulfur bridged copper(II) box-dimer

    NASA Astrophysics Data System (ADS)

    Jayakumar, K.; Sithambaresan, M.; Aiswarya, N.; Kurup, M. R. Prathapachandra

    2015-03-01

    Mononuclear and binuclear copper(II) complexes of 2-benzoylpyridine-N4-methyl thiosemicarbazone (HL) were prepared and characterized by a variety of spectroscopic techniques. Structural evidence for the novel sulfur bridged copper(II) iodo binuclear complex is obtained by single crystal X-ray diffraction analysis. The complex [Cu2L2I2], a non-centrosymmetric box dimer, crystallizes in monoclinic C2/c space group and it was found to have distorted square pyramidal geometry (Addison parameter, τ = 0.238) with the square basal plane occupied by the thiosemicarbazone moiety and iodine atom whereas the sulfur atom from the other coordinated thiosemicarbazone moiety occupies the apical position. This is the first crystallographically studied system having non-centrosymmetrical entities bridged via thiolate S atoms with Cu(II)sbnd I bond. The tridentate thiosemicarbazone coordinates in mono deprotonated thionic tautomeric form in all complexes except in sulfato complex, [Cu(HL)(SO4)]·H2O (1) where it binds to the metal centre in neutral form. The magnetic moment values and the EPR spectral studies reflect the binuclearity of some of the complexes. The spin Hamiltonian and bonding parameters are calculated based on EPR studies. In all the complexes g|| > g⊥ > 2.0023 and the g values in frozen DMF are consistent with the dx2-y2 ground state. The thermal stabilities of some of the complexes were also determined.

  12. Facile solid-phase synthesis of sulfated tyrosine-containing peptides: Part II. Total synthesis of human big gastrin-II and its C-terminal glycine-extended peptide (G34-Gly sulfate) by the solid-phase segment condensation approach.

    PubMed

    Kitagawa, K; Aida, C; Fujiwara, H; Yagami, T; Futaki, S

    2001-08-01

    Application of the fluoren-9-ylmethoxycarbonyl (Fmoc)-based solid-phase segment condensation approach to the preparation of sulfated peptides was investigated through the synthesis of human big gastrin-II, a 34-residue sulfated tyrosine [Tyr(SO3H)]-containing peptide. Highly acid-sensitive 2-chlorotrityl resin (Clt resin) was exclusively employed as an anchor-resin for the preparation of the three peptide segments having the C-terminal Pro residue as well as of the Tyr(SO3H)-containing resin-bound segment. By using the PyBOP-mediated coupling protocol [PyBOP=benzotriazolyloxytris(pyrrolidino)phosphonium hexafluorophosphatel, we successively condensed each segment and constructed the 34-residue peptide-resin without any difficulty. The final acid treatment of the fully protected peptide-resin at low temperature (90% aqueous TFA, 0 degree C for 8 h), which can detach a Tyr(SO3H)-containing peptide from the resin and remove the protecting groups concurrently with minimum deterioration of the sulfate, afforded a crude sulfated peptide. After one-step HPLC purification, a highly homogeneous human big gastrin-II was easily obtained in 14% yield from the protected peptide-resin. The sulfate form of the C-terminal glycine-extended gastrin (G34-Gly sulfate), a posttranslational processing intermediate of gastrin-II, was also successfully prepared with the segment condensation approach (11% yield). These results demonstrated the usefulness of the segment condensation protocol for preparing large Tyr(SO3H)-containing peptides.

  13. Chondroitin sulfate

    MedlinePlus

    ... is usually manufactured from animal sources, such as shark and cow cartilage. Chondroitin sulfate is used for ... contain chondroitin sulfate, in combination with glucosamine sulfate, shark cartilage, and camphor. Some people also inject chondroitin ...

  14. Copper(II) and lead(II) sorption from aqueous solution by non-living Spirogyra neglecta.

    PubMed

    Singh, Alpana; Kumar, Dhananjay; Gaur, J P

    2007-12-01

    Dried biomass of Spirogyra neglecta rapidly sorbed the test metals and the process became saturated in 10-20min. Maximum sorption of Pb(II) [116.1mgg(-1)] and Cu(II) [115.3mgg(-1)] occurred at 0.1gl(-1) biomass and 100mgl(-1) metal concentration in the solution. Sorption of Cu(II) and Pb(II) occurred optimally at pH 4.5 and 5.0, respectively. Lead(II) and Cu(II) sorption were lesser from binary metal solution than from single metal solution. Lead(II) more severely inhibited Cu(II) sorption than vice versa thus reflecting greater affinity of Pb(II) for the biomass. NaOH pretreatment slightly enhanced the metal removal ability of the biomass. During repeated sorption/desorption cycles, Pb(II) and Cu(II) sorption decreased by 11% and 27%, respectively, at the end of the fifth cycle due inter alia to 10-15% loss of biomass. Nevertheless, Spirogyra appears to be a good sorbent for removing metals Cu(II) and Pb(II) from wastewaters.

  15. Pharmacological Role of Anions (Sulphate, Nitrate, Oxalate and Acetate) on the Antibacterial Activity of Cobalt(II), Copper(II) and Nickel(II) Complexes With Nicotinoylhydrazine-Derived ONO, NNO and SNO Ligands

    PubMed Central

    Rauf, Abdur

    1996-01-01

    Mixed ligands biologically active complexes of cobalt(II), copper(II) and nickel(II) with nicotinoylhydrazine-derived ONO, NNO and SNO donor schiff-base ligands having the same metal ion but different anions such as sulphate, nitrate, oxalate and acetate have been synthesised and characterised on the basis of their physical, analytical and spectral data. In order to evaluate the role of anions on their bioability, these ligands and their synthesised metal complexes with various anions have been screened against bacterial species such as Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus and the title studies have proved a definative role of anions in increasing the biological activity PMID:18472896

  16. Sulfate in fetal development.

    PubMed

    Dawson, Paul A

    2011-08-01

    Sulfate (SO(4)(2-)) is an important nutrient for human growth and development, and is obtained from the diet and the intra-cellular metabolism of sulfur-containing amino acids, including methionine and cysteine. During pregnancy, fetal tissues have a limited capacity to produce sulfate, and rely on sulfate obtained from the maternal circulation. Sulfate enters and exits placental and fetal cells via transporters on the plasma membrane, which maintain a sufficient intracellular supply of sulfate and its universal sulfonate donor 3'-phosphoadenosine 5'-phosphosulfate (PAPS) for sulfate conjugation (sulfonation) reactions to function effectively. Sulfotransferases mediate sulfonation of numerous endogenous compounds, including proteins and steroids, which biotransforms their biological activities. In addition, sulfonation of proteoglycans is important for maintaining normal structure and development of tissues, as shown for reduced sulfonation of cartilage proteoglycans that leads to developmental dwarfism disorders and four different osteochondrodysplasias (diastrophic dysplasia, atelosteogenesis type II, achondrogenesis type IB and multiple epiphyseal dysplasia). The removal of sulfate via sulfatases is an important step in proteoglycan degradation, and defects in several sulfatases are linked to perturbed fetal bone development, including mesomelia-synostoses syndrome and chondrodysplasia punctata 1. In recent years, interest in sulfate and its role in developmental biology has expanded following the characterisation of sulfate transporters, sulfotransferases and sulfatases and their involvement in fetal growth. This review will focus on the physiological roles of sulfate in fetal development, with links to human and animal pathophysiologies.

  17. Sulfate in fetal development.

    PubMed

    Dawson, Paul A

    2011-08-01

    Sulfate (SO(4)(2-)) is an important nutrient for human growth and development, and is obtained from the diet and the intra-cellular metabolism of sulfur-containing amino acids, including methionine and cysteine. During pregnancy, fetal tissues have a limited capacity to produce sulfate, and rely on sulfate obtained from the maternal circulation. Sulfate enters and exits placental and fetal cells via transporters on the plasma membrane, which maintain a sufficient intracellular supply of sulfate and its universal sulfonate donor 3'-phosphoadenosine 5'-phosphosulfate (PAPS) for sulfate conjugation (sulfonation) reactions to function effectively. Sulfotransferases mediate sulfonation of numerous endogenous compounds, including proteins and steroids, which biotransforms their biological activities. In addition, sulfonation of proteoglycans is important for maintaining normal structure and development of tissues, as shown for reduced sulfonation of cartilage proteoglycans that leads to developmental dwarfism disorders and four different osteochondrodysplasias (diastrophic dysplasia, atelosteogenesis type II, achondrogenesis type IB and multiple epiphyseal dysplasia). The removal of sulfate via sulfatases is an important step in proteoglycan degradation, and defects in several sulfatases are linked to perturbed fetal bone development, including mesomelia-synostoses syndrome and chondrodysplasia punctata 1. In recent years, interest in sulfate and its role in developmental biology has expanded following the characterisation of sulfate transporters, sulfotransferases and sulfatases and their involvement in fetal growth. This review will focus on the physiological roles of sulfate in fetal development, with links to human and animal pathophysiologies. PMID:21419855

  18. Strong effect of copper(II) coordination on antiproliferative activity of thiosemicarbazone-piperazine and thiosemicarbazone-morpholine hybrids.

    PubMed

    Bacher, Felix; Dömötör, Orsolya; Chugunova, Anastasia; Nagy, Nóra V; Filipović, Lana; Radulović, Siniša; Enyedy, Éva A; Arion, Vladimir B

    2015-05-21

    In this study, 2-formylpyridine thiosemicarbazones and three different heterocyclic pharmacophores were combined to prepare thiosemicarbazone–piperazine mPip-FTSC (HL1) and mPip-dm-FTSC (HL2), thiosemicarbazone–morpholine Morph-FTSC (HL3) and Morph-dm-FTSC (HL4), thiosemicarbazone–methylpyrrole-2-carboxylate hybrids mPyrr-FTSC (HL5) and mPyrr-dm-FTSC (HL6) as well as their copper(II) complexes [CuCl(mPipH-FTSC-H)]Cl (1 + H)Cl, [CuCl(mPipH-dm-FTSC-H)]Cl (2 + H)Cl, [CuCl(Morph-FTSC-H)] (3), [CuCl(Morph-dm-FTSC-H)] (4), [CuCl(mPyrr-FTSC-H)(H2O)] (5) and [CuCl(mPyrr-dm-FTSC-H)(H2O)] (6). The substances were characterized by elemental analysis, one- and two-dimensional NMR spectroscopy (HL1–HL6), ESI mass spectrometry, IR and UV–vis spectroscopy and single crystal X-ray diffraction (1–5). All compounds were prepared in an effort to generate potential antitumor agents with an improved therapeutic index. In addition, the effect of structural alterations with organic hybrids on aqueous solubility and copper(II) coordination ability was investigated. Complexation of ligands HL2 and HL4 with copper(II) was studied in aqueous solution by pH-potentiometry, UV–vis spectrophotometry and EPR spectroscopy. Proton dissociation processes of HL2 and HL4 were also characterized in detail and microscopic constants for the Z/E isomers were determined. While the hybrids HL5, HL6 and their copper(II) complexes 5 and 6 proved to be insoluble in aqueous solution, precluding antiproliferative activity studies, the thiosemicarbazone–piperazine and thiosemicarbazone–morpholine hybrids HL1–HL4, as well as copper(II) complexes 1–4 were soluble in water enabling cytotoxicity assays. Interestingly, the metal-free hybrids showed very low or even a lack of cytotoxicity (IC50 values > 300 μM) in two human cancer cell lines HeLa (cervical carcinoma) and A549 (alveolar basal adenocarcinoma), whereas their copper(II) complexes were cytotoxic showing IC50 values from 25.5 to 65.1

  19. Excitation Wavelength Dependent O2 Release from Copper(II)-Superoxide Compounds: Laser Flash-Photolysis Experiments and Theoretical Studies

    PubMed Central

    Saracini, Claudio; Liakos, Dimitrios G.; Zapata Rivera, Jhon E.; Neese, Frank; Meyer, Gerald J.; Karlin, Kenneth D.

    2014-01-01

    Irradiation of the copper(II)-superoxide synthetic complexes [(TMG3tren)CuII(O2)]+ (1) and [(PV-TMPA)CuII(O2)]+ (2) with visible light resulted in direct photo-generation of O2 gas at low temperature (from −40 °C to −70°C for 1 and from −125 °C to −135 °C for 2) in 2-methyltetrahydrofuran (MeTHF) solvent. The yield of O2 release was wavelength dependent: λexc = 436 nm, ϕ = 0.29 (for 1), ϕ = 0.11 (for 2), and λexc = 683 nm, ϕ = 0.035 (for 1), ϕ = 0.078 (for 2), which was followed by fast O2-recombination with [(TMG3tren)CuI]+ (3) and [(PV-TMPA)CuI]+ (4). Enthalpic barriers for O2 re-binding to the copper(I) center (~ 10 kJ mol−1) and for O2 dissociation from the superoxide compound 1 (45 kJ mol−1) were determined. TD-DFT studies, carried out for 1, support the experimental results confirming the dissociative character of the excited states formed upon blue or red light laser excitation. PMID:24428309

  20. New tridentate azo-azomethines and their copper(II) complexes: Synthesis, solvent effect on tautomerism, electrochemical and biological studies

    NASA Astrophysics Data System (ADS)

    Sarigul, Munire; Deveci, Pervin; Kose, Muhammet; Arslan, Ugur; Türk Dagi, Hatice; Kurtoglu, Mukerrem

    2015-09-01

    In this study, three azo-azomethines and their copper(II) complexes were prepared and characterized by analytical and spectroscopic methods. The complexes prepared were found to be mononuclear and the chelation of the ligands to the copper(II) ions occurs through two phenolic oxygens and a nitrogen atom of the azomethine group of the ligand. The tautomeric behaviors of the azo-azomethines in solution were studied by UV-Vis. spectra in three organic solvents with different polarity (CHCl3, DMSO and DMF) at room temperature. The redox behaviors of the azo-azomethines and their Cu(II) complexes were investigated by cyclic voltammetry (CV) in DMSO solution containing 0.1 M tetrabutylammonium tetrafluoroborate (TBATFB) as supporting electrolyte. Additionally, the antibacterial activity was also evaluated by the broth microdilution methods against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. The compounds were found to be less effective against all bacteria tested than two reference antibiotics (ampicillin and gentamicin).

  1. Redox-controlled changes in cadmium solubility and solid-phase speciation in a paddy soil as affected by reducible sulfate and copper.

    PubMed

    Fulda, Beate; Voegelin, Andreas; Kretzschmar, Ruben

    2013-11-19

    The solubility of Cd in contaminated paddy soils controls Cd uptake by rice, which is an important food safety issue. We investigated the solution and solid-phase dynamics of Cd in a paddy soil spiked with ∼20 mg kg(-1) Cd during 40 days of soil reduction followed by 28 days of soil reoxidation as a function of the amounts of sulfate available for microbial reduction and of Cu that competes with Cd for precipitation with biogenic sulfide. At an excess of sulfate over (Cd + Cu), dissolved Cd decreased during sulfate reduction and Cd was transformed into a poorly soluble phase identified as Cd-sulfide using Cd K-edge X-ray absorption spectroscopy (XAS). The extent of Cd-sulfide precipitation decreased with decreasing sulfate and increasing Cu contents, even if sulfate exceeded Cd. When both Cu and Cd exceeded sulfate, dissolved and mobilizable Cd remained elevated after 40 days of soil reduction. During soil reoxidation, Cd-sulfide was readily transformed back into more soluble species. Our data suggest that Cd-sulfide formation in flooded paddy soil may be limited when the amounts of Cd and other chalcophile metals significantly exceed reducible sulfate Therefore, in multimetal contaminated paddy soils with low sulfate contents, Cd may remain labile during soil flooding, which enhances the risk for Cd transfer into rice. PMID:24171446

  2. Anti-cancer activity and mutagenic potential of novel copper(II) quinolinone Schiff base complexes in hepatocarcinoma cells.

    PubMed

    Duff, Brian; Thangella, Venkat Reddy; Creaven, Bernadette S; Walsh, Maureen; Egan, Denise A

    2012-08-15

    This study determined the cytotoxic, cyto-selective and mutagenic potential of novel quinolinone Schiff base ligands and their corresponding copper(II) complexes in human-derived hepatic carcinoma cells (Hep-G2) and non-malignant human-derived hepatic cells (Chang). Results indicated that complexation of quinolinone Schiff bases with copper served to significantly enhance cytotoxicity. Here, the complex of (7E)-7-(3-ethoxy-2-hydroxybenzylideamino)-4-methylquinolin-2(1H)-one (TV117-FM) exhibited the lowest IC(50) value (17.9 μM) following 96 h continuous exposure, which was comparable to cisplatin (15.0 μM). However, results revealed that TV117-FM lacked cytoselectivity over non-malignant cells. Additionally, the complex was minimally effluxed from cells via Pglycoprotein (P-gp) and was shown to be non-mutagenic in the Standard Ames test. Furthermore, BrdU incorporation assays showed that it was capable of inhibiting DNA synthesis in a concentrationand time-dependent manner. However, inhibition was not as a consequence of DNA intercalation, as illustrated in electrophoretic mobility shift assays. Interestingly, it was shown that the ligand was capable of inhibiting the action of topoisomerase II, but this was lost following complexation. This indicated that the mechanism of action of the novel copper(II) complex was different from that of the parent ligand and suggests that TV117-FM may have a therapeutic role to play in the treatment of hepatocellular carcinoma. Studies are currently underway to elucidate the exact in vitro mechanism of action of this novel, metal-based anti-cancer agent.

  3. Copper(II) imidazolate frameworks as highly efficient photocatalysts for reduction of CO2 into methanol under visible light irradiation

    NASA Astrophysics Data System (ADS)

    Li, Jingtian; Luo, Deliang; Yang, Chengju; He, Shiman; Chen, Shangchao; Lin, Jiawei; Zhu, Li; Li, Xin

    2013-07-01

    Three copper(II) imidazolate frameworks were synthesized by a hydrothermal (or precipitation) reaction. The catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption, transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectra (FTIR), thermogravimetry (TG). Meanwhile, the photocatalytic activities of the samples for reduction of CO2 into methanol and degradation of methylene blue (MB) under visible light irradiation were also investigated. The results show that the as-prepared samples exhibit better photocatalytic activities for the reduction of carbon dioxide into methanol with water and degradation of MB under visible light irradiation. The orthorhombic copper(II) imidazolate frameworks with a band gap of 2.49 eV and green (G) color has the best photocatalytic activity for reduction of CO2 into methanol, 1712.7 μmol/g over 5 h, which is about three times as large as that of monoclinic copper(II) imidazolate frameworks with a band gap 2.70 eV and blue (J) color. The degradation kinetics of MB over three photocatalysts fitted well to the apparent first-order rate equation and the apparent rate constants for the degradation of MB over G, J and P (with pink color) are 0.0038, 0.0013 and 0.0016 min-1, respectively. The synergistic effects of smallest band gap and orthorhombic crystal phase structure are the critical factors for the better photocatalytic activities of G. Moreover, three frameworks can also be stable up to 250 °C. The investigation of Cu-based zeolitic imidazolate frameworks maybe provide a design strategy for a new class of photocatalysts applied in degradation of contaminations, reduction of CO2, and even water splitting into hydrogen and oxygen under visible light.

  4. Thermodynamics of the complex formation of copper(II) with L-phenylalanine in aqueous ethanol solutions

    NASA Astrophysics Data System (ADS)

    Burov, D. M.; Ledenkov, S. F.; Vandyshev, V. N.

    2013-05-01

    Constants of the acid dissociation and complexation of L-phenylalanine (HPhe) with copper(II) ions are determined by potentiometry in aqueous ethanol solutions containing 0 to 0.7 molar fraction of alcohol. Changes in the Gibbs energy for the transfer from water to a binary solvent of L-phenylalanine, Phe- anion, and [CuPhe]+ complex are calculated. It is found that the weakening of solvation of the ligand donor groups in solvents with high ethanol contents is accompanied by an increase in the stability of [CuPhe]+ complex.

  5. Chemo-, Regio-, and Stereoselective Copper(II)-Catalyzed Boron Addition to Acetylenic Esters and Amides in Aqueous Media.

    PubMed

    Nelson, Amanda K; Peck, Cheryl L; Rafferty, Sean M; Santos, Webster L

    2016-05-20

    Aqueous conditions were developed for conducting an open-to-air, copper(II)-catalyzed addition of pinBBdan to alkynoates and alkynamides. The simple and mild β-borylation protocol proceeds in a remarkably chemo-, regio-, and stereoselective fashion to afford 1,8-diaminonaphthalene protected (Z)-β-boryl enoates and primary, secondary, and tertiary enamides in good to excellent yields. These reactions demonstrate a high tolerance toward a variety of alkyl, aryl, and heteroatom functional groups and provide convenient access to a diverse range of vinylboronic acid derivatives. PMID:27104638

  6. A Nanostructured Lipid System as a Strategy to Improve the in Vitro Antibacterial Activity of Copper(II) Complexes.

    PubMed

    Silva, Patricia B da; Bonifácio, Bruna V; Frem, Regina C G; Godoy Netto, Adelino V; Mauro, Antonio E; Ferreira, Ana M da Costa; Lopes, Erica de O; Raddi, Maria S G; Bauab, Tais M; Pavan, Fernando R; Chorilli, Marlus

    2015-01-01

    The aim of this study was to construct a nanostructured lipid system as a strategy to improve the in vitro antibacterial activity of copper(II) complexes. New compounds with the general formulae [CuX₂(INH)₂]·nH₂O (X = Cl(-) and n = 1 (1); X = NCS(-) and n = 5 (2); X = NCO(-) and n = 4 (3); INH = isoniazid, a drug widely used to treat tuberculosis) derived from the reaction between the copper(II) chloride and isoniazid in the presence or absence of pseudohalide ions (NCS(-) or NCO(-)) were synthesized and characterized by infrared spectrometry, electronic absorption spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, elemental analysis, melting points and complexometry with 2,2',2'',2'''-(Ethane-1,2-diyldinitrilo)tetraacetic acid (EDTA). The characterization techniques allowed us to confirm the formation of the copper(II) complexes. The Cu(II) complexes were loaded into microemulsion (MEs) composed of 10% phase oil (cholesterol), 10% surfactant [soy oleate and Brij® 58 (1:2)] and 80% aqueous phase (phosphate buffer pH = 7.4) prepared by sonication. The Cu(II) complex-loaded MEs displayed sizes ranging from 158.0 ± 1.060 to 212.6 ± 1.539 nm, whereas the polydispersity index (PDI) ranged from 0.218 ± 0.007 to 0.284 ± 0.034. The antibacterial activity of the free compounds and those that were loaded into the MEs against Staphylococcus aureus ATCC® 25923 and Escherichia coli ATCC® 25922, as evaluated by a microdilution technique, and the cytotoxicity index (IC50) against the Vero cell line (ATCC® CCL-81(TM)) were used to calculate the selectivity index (SI). Among the free compounds, only compound 2 (MIC 500 μg/mL) showed activity for S. aureus. After loading the compounds into the MEs, the antibacterial activity of compounds 1, 2 and 3 was significantly increased against E. coli (MIC's 125, 125 and 500 μg/mL, respectively) and S. aureus (MICs 250, 500 and 125 μg/mL, respectively). The loaded compounds were less toxic against the Vero

  7. A Nanostructured Lipid System as a Strategy to Improve the in Vitro Antibacterial Activity of Copper(II) Complexes.

    PubMed

    da Silva, Patricia B; Bonifácio, Bruna V; Frem, Regina C G; Godoy Netto, Adelino V; Mauro, Antonio E; Ferreira, Ana M da Costa; Lopes, Erica de O; Raddi, Maria S G; Bauab, Tais M; Pavan, Fernando R; Chorilli, Marlus

    2015-01-01

    The aim of this study was to construct a nanostructured lipid system as a strategy to improve the in vitro antibacterial activity of copper(II) complexes. New compounds with the general formulae [CuX₂(INH)₂]·nH₂O (X = Cl(-) and n = 1 (1); X = NCS(-) and n = 5 (2); X = NCO(-) and n = 4 (3); INH = isoniazid, a drug widely used to treat tuberculosis) derived from the reaction between the copper(II) chloride and isoniazid in the presence or absence of pseudohalide ions (NCS(-) or NCO(-)) were synthesized and characterized by infrared spectrometry, electronic absorption spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, elemental analysis, melting points and complexometry with 2,2',2'',2'''-(Ethane-1,2-diyldinitrilo)tetraacetic acid (EDTA). The characterization techniques allowed us to confirm the formation of the copper(II) complexes. The Cu(II) complexes were loaded into microemulsion (MEs) composed of 10% phase oil (cholesterol), 10% surfactant [soy oleate and Brij(®) 58 (1:2)] and 80% aqueous phase (phosphate buffer pH = 7.4) prepared by sonication. The Cu(II) complex-loaded MEs displayed sizes ranging from 158.0 ± 1.060 to 212.6 ± 1.539 nm, whereas the polydispersity index (PDI) ranged from 0.218 ± 0.007 to 0.284 ± 0.034. The antibacterial activity of the free compounds and those that were loaded into the MEs against Staphylococcus aureus ATCC(®) 25923 and Escherichia coli ATCC(®) 25922, as evaluated by a microdilution technique, and the cytotoxicity index (IC50) against the Vero cell line (ATCC(®) CCL-81(TM)) were used to calculate the selectivity index (SI). Among the free compounds, only compound 2 (MIC 500 μg/mL) showed activity for S. aureus. After loading the compounds into the MEs, the antibacterial activity of compounds 1, 2 and 3 was significantly increased against E. coli (MIC's 125, 125 and 500 μg/mL, respectively) and S. aureus (MICs 250, 500 and 125 μg/mL, respectively). The loaded compounds were less toxic against the

  8. A Nanostructured Lipid System as a Strategy to Improve the in Vitro Antibacterial Activity of Copper(II) Complexes.

    PubMed

    da Silva, Patricia B; Bonifácio, Bruna V; Frem, Regina C G; Godoy Netto, Adelino V; Mauro, Antonio E; Ferreira, Ana M da Costa; Lopes, Erica de O; Raddi, Maria S G; Bauab, Tais M; Pavan, Fernando R; Chorilli, Marlus

    2015-12-16

    The aim of this study was to construct a nanostructured lipid system as a strategy to improve the in vitro antibacterial activity of copper(II) complexes. New compounds with the general formulae [CuX₂(INH)₂]·nH₂O (X = Cl(-) and n = 1 (1); X = NCS(-) and n = 5 (2); X = NCO(-) and n = 4 (3); INH = isoniazid, a drug widely used to treat tuberculosis) derived from the reaction between the copper(II) chloride and isoniazid in the presence or absence of pseudohalide ions (NCS(-) or NCO(-)) were synthesized and characterized by infrared spectrometry, electronic absorption spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, elemental analysis, melting points and complexometry with 2,2',2'',2'''-(Ethane-1,2-diyldinitrilo)tetraacetic acid (EDTA). The characterization techniques allowed us to confirm the formation of the copper(II) complexes. The Cu(II) complexes were loaded into microemulsion (MEs) composed of 10% phase oil (cholesterol), 10% surfactant [soy oleate and Brij(®) 58 (1:2)] and 80% aqueous phase (phosphate buffer pH = 7.4) prepared by sonication. The Cu(II) complex-loaded MEs displayed sizes ranging from 158.0 ± 1.060 to 212.6 ± 1.539 nm, whereas the polydispersity index (PDI) ranged from 0.218 ± 0.007 to 0.284 ± 0.034. The antibacterial activity of the free compounds and those that were loaded into the MEs against Staphylococcus aureus ATCC(®) 25923 and Escherichia coli ATCC(®) 25922, as evaluated by a microdilution technique, and the cytotoxicity index (IC50) against the Vero cell line (ATCC(®) CCL-81(TM)) were used to calculate the selectivity index (SI). Among the free compounds, only compound 2 (MIC 500 μg/mL) showed activity for S. aureus. After loading the compounds into the MEs, the antibacterial activity of compounds 1, 2 and 3 was significantly increased against E. coli (MIC's 125, 125 and 500 μg/mL, respectively) and S. aureus (MICs 250, 500 and 125 μg/mL, respectively). The loaded compounds were less toxic against the

  9. A Nanostructured Lipid System as a Strategy to Improve the in Vitro Antibacterial Activity of Copper(II) Complexes.

    PubMed

    Silva, Patricia B da; Bonifácio, Bruna V; Frem, Regina C G; Godoy Netto, Adelino V; Mauro, Antonio E; Ferreira, Ana M da Costa; Lopes, Erica de O; Raddi, Maria S G; Bauab, Tais M; Pavan, Fernando R; Chorilli, Marlus

    2015-12-16

    The aim of this study was to construct a nanostructured lipid system as a strategy to improve the in vitro antibacterial activity of copper(II) complexes. New compounds with the general formulae [CuX₂(INH)₂]·nH₂O (X = Cl(-) and n = 1 (1); X = NCS(-) and n = 5 (2); X = NCO(-) and n = 4 (3); INH = isoniazid, a drug widely used to treat tuberculosis) derived from the reaction between the copper(II) chloride and isoniazid in the presence or absence of pseudohalide ions (NCS(-) or NCO(-)) were synthesized and characterized by infrared spectrometry, electronic absorption spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, elemental analysis, melting points and complexometry with 2,2',2'',2'''-(Ethane-1,2-diyldinitrilo)tetraacetic acid (EDTA). The characterization techniques allowed us to confirm the formation of the copper(II) complexes. The Cu(II) complexes were loaded into microemulsion (MEs) composed of 10% phase oil (cholesterol), 10% surfactant [soy oleate and Brij® 58 (1:2)] and 80% aqueous phase (phosphate buffer pH = 7.4) prepared by sonication. The Cu(II) complex-loaded MEs displayed sizes ranging from 158.0 ± 1.060 to 212.6 ± 1.539 nm, whereas the polydispersity index (PDI) ranged from 0.218 ± 0.007 to 0.284 ± 0.034. The antibacterial activity of the free compounds and those that were loaded into the MEs against Staphylococcus aureus ATCC® 25923 and Escherichia coli ATCC® 25922, as evaluated by a microdilution technique, and the cytotoxicity index (IC50) against the Vero cell line (ATCC® CCL-81(TM)) were used to calculate the selectivity index (SI). Among the free compounds, only compound 2 (MIC 500 μg/mL) showed activity for S. aureus. After loading the compounds into the MEs, the antibacterial activity of compounds 1, 2 and 3 was significantly increased against E. coli (MIC's 125, 125 and 500 μg/mL, respectively) and S. aureus (MICs 250, 500 and 125 μg/mL, respectively). The loaded compounds were less toxic against the Vero

  10. THE EVOLUTION OF SYNTHETICALLY PRECIPITATED COPPER SOLIDS

    EPA Science Inventory

    The objective of this study was to explore the effect of water quality, particularly chloride and sulfate, on copper mineral formation. Copper-sulfate and chloride compounds are often found on the surface of copper pipes in drinking water distribution systems. When attempting to ...

  11. Interaction with DNA and different effect on the nucleus of cancer cells for copper(II) complexes of N-benzyl di(pyridylmethyl)amine.

    PubMed

    Chen, Qiu-Yun; Fu, Hai-Jian; Zhu, Wei-Hua; Qi, Yan; Ma, Zheng-Ping; Zhao, Kai-Di; Gao, Jing

    2011-05-01

    Three new copper(II) complexes of N-benzyl di(pyridylmethyl)amine (phdpa) were synthesized and characterized by spectroscopic methods. The interaction between CT-DNA and the complexes was studied by UV and fluorescence titration methods. It was found that the complex [(phdpa)Cu(H(2)O)Ac)](Ac), with the non-planar aromatic heterocyclic ring ligand (phdpa), showed good anticancer properties and could cause the fragmentation of the nucleus, although its interaction with CT-DNA was weaker than that of 1,10-phenanthroline (phen)-based copper(II) complexes. The anticancer activities of copper(II) complexes with phdpa and phen based ligands are correlated to their binding constants with DNA, but phen-based copper(II) complexes did not cause the nucleus fragmentation of HeLa cells. [(phdpa)Cu(H(2)O)Ac)](Ac) can noticeably decrease the oxygen content of a culture solution and of HeLa cells, which make it a new nucleus and oxygen related anticancer copper(II) complex. Information obtained here would be helpful in the design of new antitumor complexes in oxidative therapy.

  12. Determination of copper (II) in foodstuffs based on its quenching effect on the fluorescence of N,N'-bis(pyridoxal phosphate)-o-phenylenediamine.

    PubMed

    Xu, Canhui; Liao, Lifu; He, Yunfei; Wu, Rurong; Li, Shijun; Yang, Yanyan

    2015-01-01

    A Schiff base-type fluorescence probe was prepared for the detection of copper (II) in foodstuffs. The probe is N,N'-bis(pyridoxal phosphate)-o-phenylenediamine (BPPP). It was synthesized by utilizing the Schiff base condensation reaction of pyridoxal 5-phosphate with 1,2-phenylenediamine. BPPP has the properties of high fluorescence stability, good water solubility and low toxicity. Its maximum excitation wavelength and maximum fluorescence emission wavelength are at 389 and 448 nm, respectively. When BPPP coexists with copper (II), its fluorescence is dramatically quenched. Under a certain condition, the fluorescence intensity decreased proportionally to the concentration of copper (II) by the quenching effect. Based on this fact, we established a fluorescence quenching method for the determination of copper (II). Under optimal conditions a linear range was found to be 0.5-50 ng/mL with a detection limit of 0.2 ng/mL. The method has been applied to determine copper (II) in foodstuff samples and the analytical results show good agreement with that obtained from atomic absorption spectrometry method. PMID:25985131

  13. Crystal structures of 6-[(2-hydroxy-1,1-bishydroxymethylethylamino)methylene]-2, 4-dinitrocyclohexa-2, 4-dienone hydrate and complexes of copper(II) chloride and copper(II) nitrate with this ligand

    SciTech Connect

    Chumakov, Yu. M. Tsapkov, V. I.; Jeanneau, E.; Bocelli, G.; Luneau, D.

    2006-07-15

    The crystal structures of 6-[(2-hydroxy-1,1-bishydroxymethylethylamino)methylene]-2, 4-dinitrocyclohexa-2, 4-dienone hydrate L . H{sub 2}O (I), chloro-(2-hydroxymethyl-2-methylpropane-1,3-diol-2-iminomethyl-4, 6-dinitrophenolo)aquacopper hydrate [Cu(H{sub 2}O)(L-H)Cl] . H{sub 2}O (II), and (2-hydroxymethyl-2-methylpropane-1,3-diol-2-iminomethyl-4,6-dinitrophenolo) aquacopper nitrate [Cu(H{sub 2}O)(L-H)]NO{sub 3} (III) are determined using X-ray diffraction. It is established that the salicylidene fragment of azomethine L in the structure of compound I is in a quinoid tautomeric form. In the crystal, molecules L and water molecules are joined together by hydrogen bonds into two-dimensional layers aligned parallel to the (010) plane. The copper atom in the structure of compound II coordinates the singly deprotonated tridentate molecule L (whose salicylidene fragment is in a benzenoid form), the chlorine ion, and the water molecule. The coordination polyhedron of the central copper atom is a distorted tetragonal pyramid. In the structure of compound III, the polymer chains are formed through the coordination bonds of the copper atom with two oxygen atoms of the amino alcohol fragment of azomethine L of the neighboring complex, which is related to the initial complex by the translation along the x axis. The coordination polyhedron of the central atom is an elongated tetragonal bipyramid. Polymers and nitro groups form a three-dimensional framework through hydrogen bonds.

  14. The precursor form of Hansenula polymorpha copper amine oxidase 1 in complex with CuI and CoII

    PubMed Central

    Klema, Valerie J.; Johnson, Bryan J.; Klinman, Judith P.; Wilmot, Carrie M.

    2012-01-01

    Copper amine oxidases (CAOs) catalyze the oxidative deamination of primary amines to their corresponding aldehydes, with the concomitant reduction of O2 to H2O2. Catalysis requires two cofactors: a mononuclear copper center and the cofactor 2,4,5-trihydroxyphenylalanine quinone (TPQ). TPQ is synthesized through the post-translational modification of an endogenous tyrosine residue and requires only oxygen and copper to proceed. TPQ biogenesis in CAO can be supported by alternate metals, albeit at decreased rates. A variety of factors are thought to contribute to the degree to which a metal can support TPQ biogenesis, including Lewis acidity, redox potential and electrostatic stabilization capability. The crystal structure has been solved of one of two characterized CAOs from the yeast Hansenula polymorpha (HPAO-1) in its metal-free (apo) form, which contains an unmodified precursor tyrosine residue instead of fully processed TPQ (HPAO-1 was denoted HPAO in the literature prior to 2010). Structures of apoHPAO-1 in complex with CuI and CoII have also been solved, providing structural insight into metal binding prior to biogenesis. PMID:22691777

  15. Prediction of the copper (II) ions dynamic removal from a medium by using mathematical models with analytical solution.

    PubMed

    Borba, Carlos Eduardo; da Silva, Edson Antônio; Fagundes-Klen, Márcia R; Kroumov, Alexander D; Guirardello, Reginaldo

    2008-03-21

    A copper (II) ions biosorption by Sargassum sp. biomass was studied in a fixed bed column at 30 degrees C and pH 3.5. The experimental curves were obtained for the following feed concentrations -2.08, 4.16, 6.42 and 12.72mmol/L of the copper ions. The mathematical models developed by Thomas and Bohart-Adams were used for description of ions sorption process in the column. The models principle hypothesis is that the mass transfer controlling stage of the process is the adsorption kinetics between sorbate and adsorbent. The phenomena such as intraparticle diffusion, a mass transfer external resistance and axial dispersion effects were out of considerations. Some of the models parameters were experimentally determined (rho(B), epsilon, u(0), C(0)) and the others were evaluated on the bases of the experimental data (k(a1), k(a2)). The unique fitting parameter in all models was the adsorption kinetic constant. The identification procedure was based on the least square statistical method. Simulation results show that the models describe well a copper ions sorption process in a fixed bed column. The used models can be considered as useful tools for adsorption process design and optimization in fixed bed column by using algae biomass of Sargassum sp. as an adsorbent.

  16. Anticancer activity and computational modeling of ternary copper (II) complexes with 3-indolecarboxylic acid and 1,10-phenanthroline.

    PubMed

    Zhang, Zhen; Wang, Huiyun; Wang, Qibao; Yan, Maocai; Wang, Huannan; Bi, Caifeng; Sun, Shanshan; Fan, Yuhua

    2016-08-01

    Metal-containing compounds have been extensively studied for many years as potent proteasome inhibitors. The 20S proteasome, the main component of the ubiquitin proteasome pathway, is one of the excellent targets in anticancer drug development. We recently reported that several copper complexes were able to inhibit cancer-special proteasome and induce cell death in human cancer cells. However, the involved molecular mechanism is not known yet. We therefore synthesized three copper complexes and investigated their abilities on inhibiting proteasome activity and inducting apoptosis in human breast cancer cells. Furthermore, we employed molecular dockings to analyze the possible interaction between the synthetic copper complexes and the β5 subunit of proteasome which only reflects the chymotrypsin-like activity. Our results demonstrate that three Cu(II) complexes possess potent proteasome inhibition capability in a dose-dependent and time-dependent manner in MDA-MB-231 human breast cancer cells. They could bind to the β5 subunit of the 20S proteasome, which consequently cause deactivation of the proteasome and tumor cell death. The present study is significant for providing important theoretical basis for design and synthesis of anticancer drugs with low toxicity, high efficiency and high selectivity. PMID:27278680

  17. Control of oxygen atom chirality and chelate ring conformation by protected/free sugar hydroxyl groups in glucose-pendant dipicolylamine-copper(II) complexes.

    PubMed

    Mikata, Yuji; Sugai, Yuko; Yano, Shigenobu

    2004-08-01

    A pair of copper(II) complexes 1 and 2 exhibit an enantiomeric chiral center at the oxygen atom that coordinates to the metal center. The configurations of the oxygen atom chirality and the chelate ring conformation are simply controlled by protected/free hydroxyl groups of the sugar moiety, yielding mirror image CD spectra. In this system, repulsive and attractive forces are used to regulate chirality on the copper-coordinated oxygen atom both in the solid state and in solution.

  18. Antibacterial, DNA interaction and cytotoxic activities of pendant-armed polyamine macrocyclic dinuclear nickel(II) and copper(II) complexes

    NASA Astrophysics Data System (ADS)

    Arthi, P.; Haleel, A.; Srinivasan, P.; Prabhu, D.; Arulvasu, C.; Kalilur Rahiman, A.

    2014-08-01

    A series of dinuclear nickel(II) and copper(II) complexes (1-6) of hexaaza macrocycles of 2,6-diformyl-4-methylphenol with three different benzoyl pendant-arms, 2,2‧-benzoyliminodi(ethylamine) trihydrochloride (L), 2,2‧-4-nitrobenzoyliminodi(ethylamine) trihydrochloride (L‧) and 2,2‧-3,5-dinitrobenzoyliminodi(ethylamine) trihydrochloride (L″) have been synthesized and characterized by spectral methods. The electrochemical studies of these complexes depict two irreversible one electron reduction processes around E1pc = -0.62 to -0.76 V and E2pc = -1.21 to -1.31, and nickel(II) complexes (1-3) exhibit two irreversible one electron oxidation processes around E1pa = 1.08 to 1.14 V and E2pa = 1.71 to 1.74 V. The room temperature magnetic moment values (μeff, 1.52-1.54 BM) indicate the presence of an antiferromagnetic interaction in the binuclear copper(II) complexes (4-6) which is also observed from the broad ESR spectra with a g value of 2.14-2.15. The synthesized complexes (1-6) were screened for their antibacterial activity. The results of DNA interaction studies indicate that the dinuclear complexes can bind to calf thymus DNA by intercalative mode and display efficient cleavage of plasmid DNA. Further, the cytotoxic activity of complexes 2, 5 and 6 on human liver adenocarcinoma (HepG2) cell line has been examined. Nuclear-chromatin cleavage has also been observed with PI staining and comet assays.

  19. Enhanced dechlorination of chlorinated methanes and ethenes by chloride green rust in the presence of copper(II).

    PubMed

    Maithreepala, R A; Doong, Ruey-an

    2005-06-01

    The enhanced removal of carbon tetrachloride (CCl4), tetrachloroethene (C2Cl4), and trichloroethene (C2HCl3) by chloride green rust (GR(Cl)) in the presence of copper ions was investigated. X-ray powder diffraction (XRPD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the crystallization and chemical speciation, respectively, of the secondary mineral phases produced in the GR(Cl)-Cu(II) system. The addition of Cu(II) to GR(Cl) suspensions resulted in enhanced dechlorination of the chlorinated hydrocarbons examined in this study. The degradation reactions followed pseudo-first-order kinetics and the pseudo-first-order rate constant (k(obs)) for CCl4 (20 microM) removal by GR(CI) at pH 7.2 was 0.0808 h(-1). Addition of 0.5 mM Cu(II) completely dechlorinated CCl4 within 35 min, and the k(obs) was 84 times greater than that in the absence of Cu(II). Chloroform (CHCl3), the major chlorinated product in CCl4 dechlorination, accumulated at a concentration up to 13 microM in the GR(Cl) system alone, but was completely dechlorinated within 9 h in the GR(Cl)-Cu(II) suspension. Also, rapid removal of C2Cl4 and C2HCl3 by GR(Cl) was observed when Cu(II) was added. The k(obs) values for the removal of chlorinated ethenes were 4.7-7 times higher than that obtained in the absence of Cu(II). In addition, the k(obs) for PCE removal increased linearly with respect to Cu(II) concentrations in the range from 0.1 to 1.0 mM. Addition of Cu(II) at a concentration higher than 1.0 mM decreased the k(obs) for the removal of both C2Cl4 and C2HCl3 due to the decrease in structural Fe(II) concentration in GR(Cl) and the changes in redox potentials and pH values. Moreover, the highest removal efficiency and rate of C2Cl4 was obtained at near-neutral pH when Cu(II) was added into the GR(Cl) suspension. XPS and XRPD results showed that the Fe(II) in the GR(Cl) suspension could reduce Cu(II) to both Cu(I) and metallic Cu. These findings are relevant to the better understanding

  20. 40 CFR 415.360 - Applicability; description of the copper salts production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... copper salts production subcategory. 415.360 Section 415.360 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Copper Salts Production Subcategory § 415.360 Applicability; description of the copper... copper salts, including (a) copper sulfate, copper chloride, copper iodide, and copper nitrate, and...

  1. 40 CFR 415.360 - Applicability; description of the copper salts production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... copper salts production subcategory. 415.360 Section 415.360 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Copper Salts Production Subcategory § 415.360 Applicability; description of the copper... copper salts, including (a) copper sulfate, copper chloride, copper iodide, and copper nitrate, and...

  2. 40 CFR 415.360 - Applicability; description of the copper salts production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... copper salts production subcategory. 415.360 Section 415.360 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Copper Salts Production Subcategory § 415.360 Applicability; description of the copper... copper salts, including (a) copper sulfate, copper chloride, copper iodide, and copper nitrate, and...

  3. 40 CFR 415.360 - Applicability; description of the copper salts production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... copper salts production subcategory. 415.360 Section 415.360 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Copper Salts Production Subcategory § 415.360 Applicability; description of the copper... copper salts, including (a) copper sulfate, copper chloride, copper iodide, and copper nitrate, and...

  4. Dissociations of copper(II)-containing complexes of aromatic amino acids: radical cations of tryptophan, tyrosine, and phenylalanine.

    PubMed

    Siu, Chi-Kit; Ke, Yuyong; Guo, Yuzhu; Hopkinson, Alan C; Siu, K W Michael

    2008-10-14

    The dissociations of two types of copper(II)-containing complexes of tryptophan (Trp), tyrosine (Tyr), or phenylalanine (Phe) are described. The first type is the bis-amino acid complex, [Cu(II)(M)(2)].(2+), where M = Trp, Tyr, or Phe; the second [Cu(II)(4Cl-tpy)(M)].(2+), where 4Cl-tpy is the tridendate ligand 4'-chloro-2,2':6',2''-terpyridine. Dissociations of the Cu(ii) bis-amino acid complexes produce abundant radical cation of the amino acid, M.(+), and/or its secondary products. By contrast, dissociations of the 4Cl-tpy-bearing ternary complexes give abundant M.(+) only for Trp. Density functional theory (DFT) calculations show that for Tyr and Phe, amino-acid displacement reactions by H(2)O and CH(3)OH (giving [Cu(II)(4Cl-tpy)(H(2)O)].(2+) and [Cu(II)(4Cl-tpy)(CH(3)OH)].(2+)) are energetically more favorable than dissociative electron transfer (giving M.(+) and [Cu(I)(4Cl-tpy)](+)). The fragmentation pathway common to all these [Cu(II)(4Cl-tpy)(M)].(2+) ions is the loss of NH(3). DFT calculations show that the loss of NH(3) proceeds via a "phenonium-type" intermediate. Dissociative electron transfer in [Cu(II)(4Cl-tpy)(M-NH(3))].(2+) results in [M-NH(3)].(+). The [Phe-NH(3)] (+) ion dissociates facilely by eliminating CO(2) and giving a metastable phenonium-type ion that rearranges readily into the styrene radical cation.

  5. Rapid Assessment of Human Amylin Aggregation and Its Inhibition by Copper(II) Ions by Laser Ablation Electrospray Ionization Mass Spectrometry with Ion Mobility Separation

    PubMed Central

    Donaldson, Robert P.; Jeremic, Aleksandar M.; Vertes, Akos

    2015-01-01

    Native electrospray ionization (ESI) mass spectrometry (MS) is often used to monitor noncovalent complex formation between peptides and ligands. The relatively low throughput of this technique, however, is not compatible with extensive screening. Laser ablation electrospray ionization (LAESI) MS combined with ion mobility separation (IMS) can analyze complex formation and provide conformation information within a matter of seconds. Islet amyloid polypeptide (IAPP) or amylin, a 37-amino acid residue peptide, is produced in pancreatic beta-cells through proteolytic cleavage of its prohormone. Both amylin and its precursor can aggregate and produce toxic oligomers and fibrils leading to cell death in the pancreas that can eventually contribute to the development of type 2 diabetes mellitus. The inhibitory effect of the copper(II) ion on amylin aggregation has been recently discovered, but details of the interaction remain unknown. Finding other more physiologically tolerated approaches requires large scale screening of potential inhibitors. Here, we demonstrate that LAESI-IMS-MS can reveal the binding stoichiometry, copper oxidation state, and the dissociation constant of human amylin–copper(II) complex. The conformations of hIAPP in the presence of copper(II) ions were also analyzed by IMS, and preferential association between the β-hairpin amylin monomer and the metal ion was found. The copper(II) ion exhibited strong association with the –HSSNN– residues of the amylin. In the absence of copper(II), amylin dimers were detected with collision cross sections consistent with monomers of β-hairpin conformation. When copper(II) was present in the solution, no dimers were detected. Thus, the copper(II) ions disrupt the association pathway to the formation of β-sheet rich amylin fibrils. Using LAESI-IMS-MS for the assessment of amylin–copper(II) interactions demonstrates the utility of this technique for the high-throughput screening of potential inhibitors of

  6. Kinetic and equilibrium studies for the adsorption process of cadmium(II) and copper(II) onto Pseudomonas aeruginosa using square wave anodic stripping voltammetry method.

    PubMed

    Kong, Bo; Tang, Biyu; Liu, Xiaoying; Zeng, Xiandong; Duan, Haiyan; Luo, Shenglian; Wei, Wanzhi

    2009-08-15

    A novel method for the simultaneous determination of cadmium(II) and copper(II) during the adsorption process onto Pseudomonas aeruginosa was developed. The concentration of the free metal ions was successfully detected by square wave anodic stripping voltammetry (SWASV) on the mercaptoethane sulfonate (MES) modified gold electrode, while the P. aeruginosa was efficiently avoided approaching to the electrode surface by the MES monolayer. And the anodic stripping peaks of Cd(2+) and Cu(2+) appear at -0.13 and 0.34V respectively, at the concentration range of 5-50 microM, the peak currents of SWASV present linear relationships with the concentrations of cadmium and copper respectively. As the determination of Cd(2+) and Cu(2+) was in real time and without pretreatment, the kinetic characteristics of the adsorption process were studied and all the corresponding regression parameters were obtained by fitting the electrochemical experimental data to the pseudo-second-order kinetic model. Moreover, Langmuir and Freundlich models well described the biosorption isotherms. And there were some differences in the amount of metal ion adsorbed at equilibrium (q(e)) and other kinetics parameters when the two ions coexisted were compared with the unaccompanied condition, which were also discussed in this paper. The proposed electrode system provides excellent platform for the simultaneous determination of trace metals in complex biosorption process.

  7. The role of copper(II) and zinc(II) in the degradation of human and murine IAPP by insulin-degrading enzyme.

    PubMed

    Bellia, Francesco; Grasso, Giuseppe

    2014-04-01

    Amylin or islet amyloid polypeptide (IAPP) is a 37-residue peptide hormone secreted from the pancreatic islets into the blood circulation and is cleared by peptidases in the kidney. IAPP aggregates are strongly associated with β-cell degeneration in type 2 diabetes, as demonstrated by the fact that more than 95% of patients exhibit IAPP amyloid upon autopsy. Recently, it has been reported that metal ions such as copper(II) and zinc(II) are implicated in the aggregation of IAPP as well as able to modulate the proteolytic activity of IAPP degrading enzymes. For this reason, in this work, the role of the latter metal ions in the degradation of IAPP by insulin-degrading enzyme (IDE) has been investigated by a chromatographic and mass spectrometric combined method. The latter experimental approach allowed not only to assess the overall metal ion inhibition of the human and murine IAPP degradation by IDE but also to have information on copper- and zinc-induced changes in IAPP aggregation. In addition, IDE cleavage site preferences in the presence of metal ions are rationalized as metal ion-induced changes in substrate accessibility.

  8. Synthesis, characterization, and catalytic properties of cationic hydrogels containing copper(II) and cobalt(II) ions.

    PubMed

    Lombardo Lupano, Lucía Victoria; Lázaro Martínez, Juan Manuel; Piehl, Lidia Leonor; Rubín de Celis, Emilio; Torres Sánchez, Rosa María; Campo Dall' Orto, Viviana

    2014-03-18

    Here, we report the synthesis and characterization of a hydrogel based on ethylene glycol diglycidyl ether (EGDE) and 1,8-diamino-3,6-dioxaoctane (DA). Chemically stable Co(II) and Cu(II) coordination complexes were prepared with this nonsoluble polyelectrolyte, poly(EGDE-DA), and studied by ss-NMR, FT-IR, thermogravimetry, and microscopy. Mesopores were found in all the samples, the thermal stability of the polymer matrix was highly affected by the presence of metal ions, and the (13)C CP-MAS spectrum for the Cu(II)-complex evidenced a significant increase in the reticulation degree by Cu(II) ions. The catalytic activity of these materials on H2O2 activation was studied by electron spin resonance (ESR). The Co(II)-poly(EGDE-DA)/H2O2 heterogeneous system produced O2, an anion superoxide (O2(•)¯), and a hydroxyl radical (OH(•)), which diffused into the solution at the time that a decrease in pH was detected. In the same way, the Cu(II)-poly(EGDE-DA)/H2O2 heterogeneous system produced O2 and OH(•). H2O2 activation by the poly(EGDE-DA) complexes with Co(II) and Cu(II) were applied on the decolorization of solutions of the azo-dye methyl orange (MO). In the presence of 63 mM H2O2, 87% of MO was removed in 10 min with Cu(II)-poly(EGDE-DA) and in 110 min with Co(II)-poly(EGDE-DA). In addition, the pharmaceutical product epinephrine was partially oxidized to adrenochrome by the O2(•)¯ released from the Co(II)-poly(EGDE-DA)/H2O2 heterogeneous system.

  9. Indole synthesis by conjugate addition of anilines to activated acetylenes and an unusual ligand-free copper(II)-mediated intramolecular cross-coupling.

    PubMed

    Gao, Detian; Back, Thomas G

    2012-11-12

    A versatile new synthesis of indoles was achieved by the conjugate addition of N-formyl-2-haloanilines to acetylenic sulfones, ketones, and esters followed by a copper-catalyzed intramolecular C-arylation. The conjugate addition step was conducted under exceptionally mild conditions at room temperature in basic, aqueous DMF. Surprisingly, the C-arylation was performed most effectively by employing copper(II) acetate as the catalyst in the absence of external ligands, without the need for protection from air or water. An unusual feature of this process, for the case of acetylenic ketones, is the ability of the initial conjugate-addition product to serve as a ligand for the catalyst, which enables it to participate in the catalysis of its further transformation to the final indole product. Mechanistic studies, including EPR experiments, indicated that copper(II) is reduced to the active copper(I) species by the formate ion that is produced by the base-catalyzed hydrolysis of DMF. This process also served to recycle any copper(II) that was produced by the adventitious oxidation of copper(I), thereby preventing deactivation of the catalyst. Several examples of reactions involving acetylenic sulfones attached to a modified Merrifield resin demonstrated the feasibility of solid-phase synthesis of indoles by using this protocol, and tricyclic products were obtained in one pot by employing acetylenic sulfones that contain chloroalkyl substituents. PMID:23019064

  10. Spectroscopic, solvent influence and thermal studies of ternary copper(II) complexes of diester and dinitrogen base ligands

    NASA Astrophysics Data System (ADS)

    Emara, Adel A. A.; Abu-Hussein, Azza A. A.; Taha, Ahmed A.; Mahmoud, Nelly H.

    2010-10-01

    New mixed-ligand copper(II) complexes containing the bidentate dinitrogen ligands [ N,N,N',N'-tetramethylethylenediamine (tmen), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen)] and the bidentate dioxygen ligands [diethylmalonate (DEM), ethylacetoacetate (EAA) and ethylbenzoylacetate (EBA)] were prepared. The complexes were characterized by elemental analysis, infrared, mass and ESR spectral data, magnetic and molar conductance measurements and thermal gravimetric analysis. From the investigation, the geometries of the complexes are square planar for perchlorate complexes and a square pyramid or octahedral for the nitrate complexes. Solvatochromic behavior of the Cu(II) complexes indicates strong solvatochromism of their solutions in polar and non-polar solvents. The observed solvatochromism is due to the solute-solvent interaction between the chelate cation and the solvent molecules.

  11. Spectroscopic, solvent influence and thermal studies of ternary copper(II) complexes of diester and dinitrogen base ligands.

    PubMed

    Emara, Adel A A; Abu-Hussein, Azza A A; Taha, Ahmed A; Mahmoud, Nelly H

    2010-10-15

    New mixed-ligand copper(II) complexes containing the bidentate dinitrogen ligands [N,N,N',N'-tetramethylethylenediamine (tmen), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen)] and the bidentate dioxygen ligands [diethylmalonate (DEM), ethylacetoacetate (EAA) and ethylbenzoylacetate (EBA)] were prepared. The complexes were characterized by elemental analysis, infrared, mass and ESR spectral data, magnetic and molar conductance measurements and thermal gravimetric analysis. From the investigation, the geometries of the complexes are square planar for perchlorate complexes and a square pyramid or octahedral for the nitrate complexes. Solvatochromic behavior of the Cu(II) complexes indicates strong solvatochromism of their solutions in polar and non-polar solvents. The observed solvatochromism is due to the solute-solvent interaction between the chelate cation and the solvent molecules. PMID:20688561

  12. [In vivo toxicity, and glutathione, ascorbic acid and copper level changes induced in mouse liver and kidney by copper(II) gluconate, a nutrient supplement].

    PubMed

    Hojo, Y; Hashimoto, I; Miyamoto, Y; Kawazoe, S; Mizutani, T

    2000-03-01

    While copper(II) gluconate (CuGL) is generally used as a nutrient supplement for infant foods and as an oral deodorant, little information is available regarding a toxic effect of CuGL on mammals. In this article, we examined in vivo induction of toxicity and change of level of glutathione and ascorbic acid, major biological antioxidants, lipid peroxide and copper (Cu) in liver and kidney 4 h after single intraperitoneal administration of CuGL at 0.05 and 0.10 mmol/kg to mice. Serum glutamic pyruvic transaminase (SGPT) activity, an indicator of hepatotoxicity, significantly increased compared to control in proportion to doses of CuGL. Hepatic level of glutathione measured as nonprotein sulfhydryl was not proportional to CuGL doses, but enhanced after dosing of 0.05 mmol/kg and lowered by 0.10 mmol/kg. Like SGPT activity, serum urea nitrogen (SUN) concentration, an indicator of nephrotoxicity, significantly increased in proportion to doses of CuGL. Renal glutathione level was not different from control after dosing of 0.05 mmol/kg and lowered by 0.10 mmol/kg. In both organs, relative organ weight and lipid peroxide level were not affected by the treatment with CuGL; ascorbic acid level was elevated after dosing of 0.05 mmol/kg and was not different from control after treatment with 0.10 mmol/kg; like SGPT activity and SUN concentration, Cu level significantly increased in proportion to doses of CuGL. These results suggest that in the liver and kidney after the treatment with CuGL Cu accumulated may induce toxicity, leading to level changes of glutathione and ascorbic acid and to no induction of oxidative damage.

  13. Ditopic boronic acid and imine-based naphthalimide fluorescence sensor for copper(II).

    PubMed

    Li, Meng; Ge, Haobo; Arrowsmith, Rory L; Mirabello, Vincenzo; Botchway, Stanley W; Zhu, Weihong; Pascu, Sofia I; James, Tony D

    2014-10-14

    Copper ions are essential for many biological processes. However, high concentrations of copper can be detrimental to the cell or organism. A novel naphthalimide derivative bearing a monoboronic acid group (BNP) was investigated as a Cu(2+) selective fluorescent sensor in living cells. This derivative is one of the rare examples of reversible fluorescent chemosensors for Cu(2+) which uses a boronic acid group for a binding site. Moreover, the adduct BNP-Cu(2+) displays a fluorescence enhancement with fructose. The uptake of this novel compound in HeLa cancer cells was imaged using confocal fluorescence microscopy techniques including two-photon fluorescence lifetime imaging microscopy. PMID:24919009

  14. Isotopic studies of the metal-ligand vibrations in histamine complexes with Copper(II)

    NASA Astrophysics Data System (ADS)

    Drożdżewski, Piotr; Kordon, Ewa

    2000-06-01

    Two known copper complexes of the formulae Cu(hm) 2(ClO 4) 2, Cu(hm)Cl 2 and new, Cu(hm)Br 2 (hm=histamine) have been investigated in the 600-50 cm -1 far-infrared region. Assignments of vibrations related to metal-ligand bonds have been made based on metal isotope substitution, partial deuteration and halogen sensitivity. Copper-hm stretching vibrations have been localised at 420, 417 and 411 cm -1 for modes involving amine nitrogen and at 282, 270, 259 cm -1 for those of imidazole nitrogen. Vibrational coupling between some metal-ligand modes has been postulated.

  15. Matrix effects on copper(II)phthalocyanine complexes. A combined continuous wave and pulse EPR and DFT study.

    PubMed

    Finazzo, Cinzia; Calle, Carlos; Stoll, Stefan; Van Doorslaer, Sabine; Schweiger, Arthur

    2006-04-28

    The effect of the electron withdrawing or donating character of groups located at the periphery of the phthalocyanine ligand, as well as the influence of polar and nonpolar solvents are of importance for the redox chemistry of metal phthalocyanines. Continuous wave and pulse electron paramagnetic resonance and pulse electron nuclear double resonance spectroscopy at X- and Q-band are applied to investigate the electronic structure of the complexes Cu(II)phthalocyanine (CuPc), copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (CuPc(t)), and copper(II) 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine (CuPc(F)) in various matrices. Isotope substitutions are used to determine the g values, the copper hyperfine couplings and the hyperfine interactions with the 14N, 1H and 19F nuclei of the macrocycle and the surrounding matrix molecules. Simulations and interpretations of the spectra are shown and discussed, and a qualitative analysis of the data using previous theoretical models is given. Density functional computations facilitate the interpretation of the EPR parameters. The experimental g, copper and nitrogen hyperfine and nuclear quadrupole values are found to be sensitive to changes of the solvent and the structure of the macrocycle. To elucidate the electronic, structural and bonding properties the changes in the g principal values are related to data from UV/Vis spectroscopy and to density functional theory (DFT) computations. The analysis of the EPR data indicates that the in-plane metal-ligand sigma bonding is more covalent for CuPc(t) in toluene than in sulfuric acid. Furthermore, the out-of-plane pi bonding is found to be less covalent in the case of a polar sulfuric acid environment than with nonpolar toluene or H2Pc environment, whereby the covalency of this bonding is increased upon addition of tert-butyl groups. No contribution from in-plane pi bonding is found.

  16. Matrix effects on copper(II)phthalocyanine complexes. A combined continuous wave and pulse EPR and DFT study.

    PubMed

    Finazzo, Cinzia; Calle, Carlos; Stoll, Stefan; Van Doorslaer, Sabine; Schweiger, Arthur

    2006-04-28

    The effect of the electron withdrawing or donating character of groups located at the periphery of the phthalocyanine ligand, as well as the influence of polar and nonpolar solvents are of importance for the redox chemistry of metal phthalocyanines. Continuous wave and pulse electron paramagnetic resonance and pulse electron nuclear double resonance spectroscopy at X- and Q-band are applied to investigate the electronic structure of the complexes Cu(II)phthalocyanine (CuPc), copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (CuPc(t)), and copper(II) 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine (CuPc(F)) in various matrices. Isotope substitutions are used to determine the g values, the copper hyperfine couplings and the hyperfine interactions with the 14N, 1H and 19F nuclei of the macrocycle and the surrounding matrix molecules. Simulations and interpretations of the spectra are shown and discussed, and a qualitative analysis of the data using previous theoretical models is given. Density functional computations facilitate the interpretation of the EPR parameters. The experimental g, copper and nitrogen hyperfine and nuclear quadrupole values are found to be sensitive to changes of the solvent and the structure of the macrocycle. To elucidate the electronic, structural and bonding properties the changes in the g principal values are related to data from UV/Vis spectroscopy and to density functional theory (DFT) computations. The analysis of the EPR data indicates that the in-plane metal-ligand sigma bonding is more covalent for CuPc(t) in toluene than in sulfuric acid. Furthermore, the out-of-plane pi bonding is found to be less covalent in the case of a polar sulfuric acid environment than with nonpolar toluene or H2Pc environment, whereby the covalency of this bonding is increased upon addition of tert-butyl groups. No contribution from in-plane pi bonding is found. PMID:16633682

  17. Potentiometric and spectroscopic study of the complexation of copper(II) ions by tripeptides containing aromatic side-chains

    NASA Astrophysics Data System (ADS)

    Ghalem, S.; Fan, B.-T.; Xiao, L.

    1998-01-01

    The complexation of copper(II) ions with L,L-Gly-Phe-Phe, L,L-Phe-Gly-Phe and L,L-Phe-Phe-Gly was studied by potentiometric and spectroscopic measurements. Only four complexes have been found for each copper(II)-tripeptide system, and no species with two ligand molecules was observed. The results show influences of aromatic side-chains. These influences are dependent upon the location of two aromatic rings in studied tripeptides. The stabilization or destabilization of a given complex is probably the result of several different effects, including steric hindrance, hydrophobic effect, electrodonor effect and π-d interaction. The spectroscopic measurements, e.s.r and electronic absorption, are useful to determine the complex structures. La complexation du cuivre(II) par Gly-Phe-Phe-L,L, Phe-Gly-Phe-L,L et Phe-Phe-Gly-L,L a été étudiée par potentiométrie et par spectroscopies. Seulement quatre espèces ont été mises en évidence pour chaque système Cu(II)-tripeptide. Aucun complexe contenant deux molécules de ligand n'a été observé. Les résultats obtenus montrent des influences évidentes liées aux chaînes latérales aromatiques. Ces influences dépendent des positions des résidus phénylalanines. La stabilisation ou déstabilisation d'un complexe est probablement le résultat d'un ensemble de différents effets : effet stérique, effet hydrophobe, électrodonneur et l'interaction π-d. Les spectroscopies RPE et visible ont été utilisées pour la détermination structurale des complexes.

  18. Electrorefining of copper from a cuprous ion complexing electrolyte. II. Experimental comparison of possible alternative electrolytes and preliminary cost engineering analysis

    SciTech Connect

    Brown, A.P.; Loutfy, R.O.; Cook, G.M.

    1980-04-01

    The energy saving potential and refining capability of three copper(I)/electrolyte systems for the electrorefining of copper were compared experimentally. The alternative electrolyte systems studied were copper(I)/acid chloride, copper(I)/acetonitrile and sulfuric acid, and copper(I)/ammonia solutions. These were compared to the conventional copper(II)/sulfuric acid electrolyte. All of the alternative electrolyte systems demonstrated at least some potential for saving energy when run at an equal deposition rate to the conventional process; the chloride electrolyte showed the greatest energy saving potential, about 70%, and the ammonia electrolyte showed the least, about 25%. All of the alternative electrolyte systems, however, exhibited performance problems, primarily with regard to inadequate separation of impurities. A preliminary capital cost estimate was made for the copper(I)/chloride system. This estimate showed that, for the alternative electrolyte system to be cost competitive (that is, a reduction of capital cost of about 15 to 20%) with the conventional electrorefining process, the refining cells would have to be operated at a current density of about 25 to 30 mA-cm/sup -2/. At this current density, the estimated energy saving potential for the copper(I)/chloride system was still about 50%.

  19. 21 CFR 184.1307 - Ferric sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Substances Affirmed as GRAS § 184.1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by treating ferric oxide or ferric hydroxide with sulfuric acid. (b) The ingredient must be of a...

  20. 21 CFR 184.1307 - Ferric sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Substances Affirmed as GRAS § 184.1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by treating ferric oxide or ferric hydroxide with sulfuric acid. (b) The ingredient must be of a...

  1. 21 CFR 184.1307 - Ferric sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Substances Affirmed as GRAS § 184.1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by treating ferric oxide or ferric hydroxide with sulfuric acid. (b) The ingredient must be of a...

  2. 21 CFR 184.1307 - Ferric sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Substances Affirmed as GRAS § 184.1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by treating ferric oxide or ferric hydroxide with sulfuric acid. (b) The ingredient must be of a...

  3. Indirect spectrophotometric determination of vanadium(IV) by flow injection analysis based on the redox reaction with copper(II) in the presence of neocuproine

    SciTech Connect

    Itabashi, Hideyuki; Umetsu, Kazuyuki; Satoh, Keiichi; Kawashima, Takujui )

    1991-07-01

    An indirect photometric method with a continuous-flow analysis is presented for the determination of trace amounts of vanadium(IV). It is based on the redox reaction of copper(II) with vanadium(IV) in the presence of neocuproine. In the presence of neocuproine, copper(II) is reduced easily by vanadium(IV) to a copper(I)-neocuproine complex, which shows an absorption maximum at 454 nm. By measuring the absorbance of the complex at this wavelength, vanadium(IV) in the range 2{times}10{sup {minus}6} - 8 {times} 10{sup {minus}5} mol dm{sup {minus}3} can be determined at a rate of 120 samples h{sup {minus}1}. The fractional determination of vanadium(IV) and iron(II) is also studied.

  4. Crystal structure of anhydrous poly[bis­(μ2-sarcosinato-κ3 O,N:O′)copper(II)

    PubMed Central

    Butcher, Ray J.; Brewer, Greg; Zemba, Matthew

    2014-01-01

    The title compound, [Cu(C3H6NO2)2]n, is a bis-complex of the anion of sarcosine (N-methyl­glycine). The asymmetric unit consists of a copper(II) ion, located on a center of inversion, and one mol­ecule of the uninegative sarcosinate anion. The copper(II) ion exhibits a typical Jahn–Teller distorted [4 + 2] coordination geometry. The four shorter equatorial bonds are to the nitro­gen and carboxyl­ate O atoms of two sarcosinate anions, and the longer axial bonds are to carboxyl­ate O atoms of neighboring complexes. The overall structure is made up from two chains formed by these longer axial Cu—O bonds, one extending parallel to [011] and the other parallel to [0-11]. Each one-dimensional array is connected by the equatorial bridging moieties to the chains on either side, creating an extended two-dimensional framework parallel to (100). There is a single inter­molecular hydrogen-bonding inter­action within the sheets between the amino NH group and an O atom of an adjacent mol­ecule. PMID:25484653

  5. Synthesis, immobilization and catalytic activity of a copper(II) complex with a chiral bis(oxazoline).

    PubMed

    Carneiro, Liliana; Silva, Ana R; Shuttleworth, Peter S; Budarin, Vitaly; Clark, James H

    2014-08-11

    A chiral bis(oxazoline) bearing CH2OH groups was synthesized from a commercial bis(oxazoline) and characterized by 1H- and 13C-NMR, high resolution ESI-mass spectrometry and FTIR. The corresponding copper(II) complex was immobilized onto the surface of a mesoporous carbonaceous material (Starbon® 700) in which the double bonds had been activated via conventional bromination. The materials were characterized by elemental analysis, ICP-OES, XPS, thermogravimetry and nitrogen adsorption at 77 K. The new copper(II) bis(oxazoline) was tested both in the homogeneous phase and once immobilized onto a carbonaceous support for the kinetic resolution of hydrobenzoin. Both were active, enantioselective and selective in the mono-benzoylation of hydrobenzoin, but better enantioselectivities were obtained in the homogeneous phase. The heterogeneous catalyst could be separated from the reaction media at the end of the reaction and reused in another catalytic cycle, but with loss of product yield and enantioselectivity.

  6. Concise Enantioselective Synthesis of Oxygenated Steroids via Sequential Copper(II)-Catalyzed Michael Addition/Intramolecular Aldol Cyclization Reactions.

    PubMed

    Cichowicz, Nathan R; Kaplan, Will; Khomutnyk, Yaroslav; Bhattarai, Bijay; Sun, Zhankui; Nagorny, Pavel

    2015-11-18

    A new scalable enantioselective approach to functionalized oxygenated steroids is described. This strategy is based on chiral bis(oxazoline) copper(II) complex-catalyzed enantioselective and diastereoselective Michael reactions of cyclic ketoesters and enones to install vicinal quaternary and tertiary stereocenters. In addition, the utility of copper(II) salts as highly active catalysts for the Michael reactions of traditionally unreactive β,β'-enones and substituted β,β'-ketoesters that results in unprecedented Michael adducts containing vicinal all-carbon quaternary centers is also demonstrated. The Michael adducts subsequently undergo base-promoted diastereoselective aldol cascade reactions resulting in the natural or unnatural steroid skeletons. The experimental and computational studies suggest that the torsional strain effects arising from the presence of the Δ(5)-unsaturation are key controlling elements for the formation of the natural cardenolide scaffold. The described method enables expedient generation of polycyclic molecules including modified steroidal scaffolds as well as challenging-to-synthesize Hajos-Parrish and Wieland-Miescher ketones.

  7. Concise Enantioselective Synthesis of Oxygenated Steroids via Sequential Copper(II)-Catalyzed Michael Addition/Intramolecular Aldol Cyclization Reactions

    PubMed Central

    Cichowicz, Nathan R.; Kaplan, Will; Khomutnyk, Yaroslav; Bhattarai, Bijay; Sun, Zhankui; Nagorny, Pavel

    2015-01-01

    A new scalable enantioselective approach to functionalized oxygenated steroids is described. This strategy is based on chiral bis(oxazoline) copper(II) complex-catalyzed enantioselective and diastereoselective Michael reactions of cyclic ketoesters and enones to install vicinal quaternary and tertiary stereocenters. In addition, the utility of copper(II) salts as highly active catalysts for the Michael reactions of traditionally unreactive ββ′-enones and substituted ββ′-ketoesters that results in unprecedented Michael adducts containing vicinal all-carbon quaternary centers is also demonstrated. The Michael adducts subsequently undergo base-promoted diastereoselective aldol cascade reactions resulting in the natural or unnatural steroid skeletons. The experimental and computational studies suggest that the torsional strain effects arising from the presence of the Δ5-unsaturation are key controling elements for the formation of the natural cardenolide scaffold. The described method enables expedient generation of polycyclic molecules including modified steroidal scaffolds as well as challenging-to-synthesize Hajos-Parrish and Wieland-Miescher ketones. PMID:26491886

  8. Synthesis of mononuclear copper(II) complexes of acyclic Schiff's base ligands: Spectral, structural, electrochemical, antibacterial, DNA binding and cleavage activity

    NASA Astrophysics Data System (ADS)

    Jayamani, Arumugam; Thamilarasan, Vijayan; Sengottuvelan, Nallathambi; Manisankar, Paramasivam; Kang, Sung Kwon; Kim, Young-Inn; Ganesan, Vengatesan

    2014-03-01

    The mononuclear copper(II) complexes (1&2) of ligands L1 [N,N";-bis(2-hydroxy-5-methylbenzyl)-1,4-bis(3-iminopropyl)piperazine] or L2 [N,N";-bis(2-hydroxy-5-bromobenzyl)-1,4-bis(3-iminopropyl) piperazine] have been synthesized and characterised. The single crystal X-ray study had shown that ligands L1 and L2 crystallize in a monoclinic crystal system with P21/c space group. The mononuclear copper(II) complexes show one quasireversible cyclic voltammetric response near cathodic region (-0.77 to -0.85 V) in DMF assignable to the Cu(II)/Cu(I) couple. Binding interaction of the complexes with calf thymus DNA (CT DNA) investigated by absorption studies and fluorescence spectral studies show good binding affinity to CT DNA, which imply both the copper(II) complexes can strongly interact with DNA efficiently. The copper(II) complexes showed efficient oxidative cleavage of plasmid pBR322 DNA in the presence of 3-mercaptopropionic acid as reducing agent through a mechanistic pathway involving formation of singlet oxygen as the reactive species. The Schiff bases and their Cu(II) complexes have been screened for antibacterial activities which indicates that the complexes exhibited higher antimicrobial activity than the free ligands.

  9. Copper-containing zeolite catalysts

    DOEpatents

    Price, G.L.; Kanazirev, V.

    1996-12-10

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, is formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl{sub 2}, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  10. Copper-containing zeolite catalysts

    DOEpatents

    Price, Geoffrey L.; Kanazirev, Vladislav

    1996-01-01

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl.sub.2, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  11. Ultrafast Photochemistry of Copper(II) Monochlorocomplexes in Methanol and Acetonitrile by Broadband Deep-UV-to-Near-IR Femtosecond Transient Absorption Spectroscopy.

    PubMed

    Mereshchenko, Andrey S; Olshin, Pavel K; Myasnikova, Olesya S; Panov, Maxim S; Kochemirovsky, Vladimir A; Skripkin, Mikhail Yu; Moroz, Pavel N; Zamkov, Mikhail; Tarnovsky, Alexander N

    2016-03-24

    Photochemistry of copper(II) monochlorocomplexes in methanol and acetonitrile solutions is studied by UV-pump/broadband deep-UV-to-near-IR probe femtosecond transient absorption spectroscopy. Upon 255 and 266 nm excitation, the complexes in acetonitrile and methanol, respectively, are promoted to the excited ligand-to-metal charge transfer (LMCT) state, which has a short (sub-250 fs) lifetime. From the LMCT state, the complexes decay via internal conversion to lower-lying ligand field (LF) d-d excited states or the vibrationally hot ground electronic state. A minor fraction of the excited complexes relaxes to the LF electronic excited states, which are relatively long-lived with lifetimes >1 ns. Also, in methanol solutions, about 3% of the LMCT-excited copper(II) monochlorocomplexes dissociate forming copper(I) solvatocomplexes and chlorine atoms, which then further react forming long-lived photoproducts. In acetonitrile, about 50% of the LMCT-excited copper(II) monochlorocomplexes dissociate forming radical and ionic products in a ratio of 3:2. Another minor process observed following excitation only in methanol solutions is the re-equilibration between several forms of the copper(II) ground-state complexes present in solutions. This re-equilibration occurs on a time scale from sub-nanoseconds to nanoseconds.

  12. Copper(II) and nickel(II) complexes of benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone: Synthesis, characterization and biological activity

    NASA Astrophysics Data System (ADS)

    Prathima, B.; Subba Rao, Y.; Adinarayana Reddy, S.; Reddy, Y. P.; Varada Reddy, A.

    2010-09-01

    Benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone ligand (L) has been synthesized from benzyloxybenzaldehyde and 4-phenyl-3-thiosemicarbazide. Complexes of this ligand with chlorides of Cu(II) and Ni(II) have been prepared. The structure of the ligand (L) is proposed based on elemental analysis, IR and 1H NMR spectra. Its complexes with Cu(II) and Ni(II) ions are characterized from the studies of electronic as well as EPR spectra. On the basis of electronic and EPR studies, rhombically distorted octahedral structure has been proposed for Cu(II) complex while the Ni(II) complex has been found to acquire an octahedral structure. The ligand and their metal complexes have been tested in vitro for their biological effects. Their antibacterial activities against Gram-negative bacteria ( Escherichia coli and Klebsiella pneumoniae) and Gram-positive bacteria ( Staphylococcus aureus and Bacillus subtilis) have been investigated. The prepared metal complexes exhibit higher antibacterial activities than the parent ligand. The in vitro antioxidant activity of free ligand and its metal(II) complexes have also been investigated and the results however reveal that the ligand exhibits greater antioxidant activity than its complexes.

  13. Characterization of implant materials in fetal bovine serum and sodium sulfate by electrochemical impedance spectroscopy. II. Coarsely sandblasted samples.

    PubMed

    Contu, F; Elsener, B; Böhni, H

    2003-10-01

    Electrochemical impedance spectroscopy is used to investigate the corrosion resistance of coarsely sandblasted implant alloys, commercially pure titanium, Ti6Al4V, Ti6Al7Nb, and CoCrMo in 0.1M sodium sulfate and fetal bovine serum. Coarsely sandblasted samples have a heterogeneous surface constituted by a large number of protrusions and recessions. Impedance spectra collected in sodium sulfate present two time constants (maxima in the phase-angle of the bode plot) associated with the total surface and with the tips, respectively. In bovine serum, the two maxima in the impedance spectra cannot be distinguished because of the formation of an adsorption layer of organic molecules, which causes a decrease in the values of both the total and tips' capacitances as well as an increase in the polarization resistance. Ti6Al4V and Ti6Al7Nb show the highest corrosion rate both in serum and in sodium sulfate. Based on the capacitance values obtained in sodium sulfate, the real surface area of the coarsely sandblasted electrodes has been estimated relative to mechanically polished surfaces. The values of the effective electrode area correlate with the mechanical properties of the samples: in fact, the softest electrode (commercially pure titanium) shows the largest effective electrode area, whereas the hardest material (CoCrMo alloy) shows the smallest surface area.

  14. N,N,O and N,O,N Meridional cis Coordination of Two Guanines to Copper(II) by d(CGCGCG)2.

    PubMed

    Rohner, Melanie; Medina-Molner, Alfredo; Spingler, Bernhard

    2016-06-20

    Many research groups study the generation of supramolecular n-dimensional arrays by combining metals with DNA building blocks. Most of the time, the natural nucleobases are modified to obtain higher-affinity metal binding sites. Using unmodified nucleobases avoids a potentially difficult synthesis; however, they have the possible disadvantage of a less defined and/or weaker coordination mode of the metal. Structural studies on the behavior of copper(II) as a linking metal and guanine as the natural ligand for metals in unmodified DNA are reported. Previously, the ability of mono- and dinuclear metal complexes to induce Z-DNA has been explored [Medina-Molner, A.; Spingler, B. Chem. Commun. 2012, 48, 1961; Medina-Molner, A.; Rohner, M.; Pandiarajan, D.; Spingler, B. Dalton Trans. 2015, 44, 3664]. Herein, X-ray crystallographic studies of the structures resulting from the combination of copper(II) ions with DNA hexamers of the general sequence d(CG)3 are presented. Three different packing motifs were observed in three crystal structures with resolutions ranging from 2.15 to 1.45 Å. The motifs are dependent upon other cations being present and/or the crystallization conditions. The first examples of intramolecular O6,N7-chelates of a neutral purine nucleobase to copper(II) were obtained as well as the first meridional N,N,O and N,O,N coordination modes of two guanines to copper(II). The fascinating coordination chemistry of copper(II) complexes generated by the Z-DNA oligonucleotides and the differences to simple nucleobases complexes with copper(II) are discussed in detail.

  15. N,N,O and N,O,N Meridional cis Coordination of Two Guanines to Copper(II) by d(CGCGCG)2.

    PubMed

    Rohner, Melanie; Medina-Molner, Alfredo; Spingler, Bernhard

    2016-06-20

    Many research groups study the generation of supramolecular n-dimensional arrays by combining metals with DNA building blocks. Most of the time, the natural nucleobases are modified to obtain higher-affinity metal binding sites. Using unmodified nucleobases avoids a potentially difficult synthesis; however, they have the possible disadvantage of a less defined and/or weaker coordination mode of the metal. Structural studies on the behavior of copper(II) as a linking metal and guanine as the natural ligand for metals in unmodified DNA are reported. Previously, the ability of mono- and dinuclear metal complexes to induce Z-DNA has been explored [Medina-Molner, A.; Spingler, B. Chem. Commun. 2012, 48, 1961; Medina-Molner, A.; Rohner, M.; Pandiarajan, D.; Spingler, B. Dalton Trans. 2015, 44, 3664]. Herein, X-ray crystallographic studies of the structures resulting from the combination of copper(II) ions with DNA hexamers of the general sequence d(CG)3 are presented. Three different packing motifs were observed in three crystal structures with resolutions ranging from 2.15 to 1.45 Å. The motifs are dependent upon other cations being present and/or the crystallization conditions. The first examples of intramolecular O6,N7-chelates of a neutral purine nucleobase to copper(II) were obtained as well as the first meridional N,N,O and N,O,N coordination modes of two guanines to copper(II). The fascinating coordination chemistry of copper(II) complexes generated by the Z-DNA oligonucleotides and the differences to simple nucleobases complexes with copper(II) are discussed in detail. PMID:27266259

  16. Metamagnetism in hydrophobically induced carboxylate (phenylmalonate)-bridged copper(II) layers.

    PubMed

    Pasán, Jorge; Sanchiz, Joaquín; Ruiz-Pérez, Catalina; Campo, Javier; Lloret, Francesc; Julve, Miguel

    2006-07-21

    Self-assembly of copper(l) ions, phenylmalonate and pyrimidine yields the layered compound [Cu(pym)(Phmal)n (1) where intralayer ferro- and interlayer antiferromagnetic interactions occur with three-dimensional antiferromagnetic ordering at T(c) = 2.15 K.

  17. Self-Assembly, Structures, and Magnetic Properties of Ladder-Like Copper(II) Coordination Polymers

    NASA Astrophysics Data System (ADS)

    Min, Kil Sik; Suh, Myunghyun Paik

    2000-06-01

    Two novel ladder-like copper(II) compounds, [Cu2(histamine)2(C2O4)(ClO4)2] (1) and [Cu2(histamine)2(C2O4)(H2O)2(NO3)2] (2), are prepared. Compound 1 crystallizes in the triclinic space group Poverline1, with a=7.450(4) Å, b=7.519(7) Å, c=9.646(5) Å, α=85.78(7)°, β=88.60(4)°, γ=76.78(7)°, V=524.5(6) Å3, and Z=1 with R=0.0789 (all data). In 1, the dinuclear units of [Cu2(histamine)2(C2O4)]2+ are linked together by the perchlorate anions to form a ladder-like chain. The chains interact each other by the π-π stacking interactions via the imidazole groups. Compound 2 crystallizes in the triclinic space group Poverline1, with a=7.579(2) Å, b=8.133(1) Å, c=9.161(3) Å, α=77.06(2)°, β=89.23(2)°, γ=82.54(1)°, V=545.6(2) Å3, and Z=1 with R=0.0751 (all data). In 2, each dinuclear unit [Cu2(histamine)2(C2O4)]2+ is coordinated with a nitrate anion and a water molecule, and they are held together by the hydrogen bonding interactions to form a ladder-like chain. The magnetic susceptibility data of 1 and 2 measured in 2-300 K provide the magnetic parameters, g=2.08, J=-166 cm-1, J‧=6.46 cm-1, ρ=0.0026, Nα=155×10-6 cm3 mol-1, and R=1.03×10-3 (g=2.05, J=-162 cm-1, J‧=10.5 cm-1, ρ=0.0029, and R=2.95×10-3 with the fixed value of Nα=120×10-6 cm3 mol-1) for 1 and g=2.00, J=-158 cm-1, J‧=26.5 cm-1, ρ=0.0020, Nα=136×10-6 cm3 mol-1, and R=7.31×10-4 (g=2.01, J=-157 cm-1, J‧=25.0 cm-1, ρ=0.0021, and R=1.32×10-3 with the fixed value of Nα=120×10-6 cm3 mol-1) for 2. These indicate that very strong antiferromagnetic interactions occur along the rungs of the ladder via the oxalate bridge and weak ferromagnetic interactions along the chains.

  18. Thermodynamics of the formation of complexes of copper(II) ions and glycylglycine in aqueous solutions at 298 K according to calorimetry data

    NASA Astrophysics Data System (ADS)

    Kochergina, L. A.; Emel'yanov, A. V.

    2015-04-01

    Heat effects of the interaction between glycylglycine and copper(II) nitrate solutions are measured by direct calorimetry at a [metal] : [ligand] ratio of 1 : 5 and at different pH values of the solution. The measurements are made at a temperature of 298.15 K and ionic strengths of 0.25, 0.50, and 0.75. KNO3 is used as a background electrolyte. The thermodynamic characteristics of complex formation by the peptide and copper(II) ions in aqueous solutions are determined. Standard enthalpies of the formation of complex particles in aqueous solutions are calculated.

  19. Targeting copper(II)-induced oxidative stress and the acetylcholinesterase system in Alzheimer's disease using multifunctional tacrine-coumarin hybrid molecules.

    PubMed

    Hamulakova, Slavka; Poprac, Patrik; Jomova, Klaudia; Brezova, Vlasta; Lauro, Peter; Drostinova, Lenka; Jun, Daniel; Sepsova, Vendula; Hrabinova, Martina; Soukup, Ondrej; Kristian, Pavol; Gazova, Zuzana; Bednarikova, Zuzana; Kuca, Kamil; Valko, Marian

    2016-08-01

    Alzheimer's disease is a multifactorial disease that is characterized mainly by Amyloid-β (A-β) deposits, cholinergic deficit and extensive metal (copper, iron)-induced oxidative stress. In this work we present details of the synthesis, antioxidant and copper-chelating properties, DNA protection study, cholinergic activity and amyloid-antiaggregation properties of new multifunctional tacrine-7-hydroxycoumarin hybrids. The mode of interaction between copper(II) and hybrids and interestingly, the reduction of Cu(II) to Cu(I) species (for complexes Cu-5e-g) were confirmed by EPR measurements. EPR spin trapping on the model Fenton reaction, using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trap, demonstrated a significantly suppressed formation of hydroxyl radicals for the Cu-5e complex in comparison with free copper(II). This suggests that compound 5e upon coordination to free copper ion prevents the Cu(II)-catalyzed decomposition of hydrogen peroxide, which in turn may alleviate oxidative stress-induced damage. Protective activity of hybrids 5c and 5e against DNA damage in a Fenton system (copper catalyzed) was found to be in excellent agreement with the EPR spin trapping study. Compound 5g was the most effective in the inhibition of acetylcholinesterase (hAChE, IC50=38nM) and compound 5b was the most potent inhibitor of butyrylcholinesterase (hBuChE, IC50=63nM). Compound 5c was the strongest inhibitor of A-β1-40 aggregation, although a significant inhibition (>50%) was detected for compounds 5b, 5d, 5e and 5g. Collectively, these results suggest that the design and investigation of multifunctional agents containing along with the acetylcholinesterase inhibitory segment also an antioxidant moiety capable of alleviating metal (copper)-induced oxidative stress, may be of importance in the treatment of Alzheimer's disease. PMID:27230386

  20. Complexation and Toxicity of Copper in Higher Plants. II. Different Mechanisms for Copper versus Cadmium Detoxification in the Copper-Sensitive Cadmium/Zinc Hyperaccumulator Thlaspi caerulescens (Ganges Ecotype)1[OA

    PubMed Central

    Mijovilovich, Ana; Leitenmaier, Barbara; Meyer-Klaucke, Wolfram; Kroneck, Peter M.H.; Götz, Birgit; Küpper, Hendrik

    2009-01-01

    The cadmium/zinc hyperaccumulator Thlaspi caerulescens is sensitive toward copper (Cu) toxicity, which is a problem for phytoremediation of soils with mixed contamination. Cu levels in T. caerulescens grown with 10 μm Cu2+ remained in the nonaccumulator range (<50 ppm), and most individuals were as sensitive toward Cu as the related nonaccumulator Thlaspi fendleri. Obviously, hyperaccumulation and metal resistance are highly metal specific. Cu-induced inhibition of photosynthesis followed the “sun reaction” type of damage, with inhibition of the photosystem II reaction center charge separation and the water-splitting complex. A few individuals of T. caerulescens were more Cu resistant. Compared with Cu-sensitive individuals, they recovered faster from inhibition, at least partially by enhanced repair of chlorophyll-protein complexes but not by exclusion, since the content of Cu in their shoots was increased by about 25%. Extended x-ray absorption fine structure (EXAFS) measurements on frozen-hydrated leaf samples revealed that a large proportion of Cu in T. caerulescens is bound by sulfur ligands. This is in contrast to the known binding environment of cadmium and zinc in the same species, which is dominated by oxygen ligands. Clearly, hyperaccumulators detoxify hyperaccumulated metals differently compared with nonaccumulated metals. Furthermore, strong features in the Cu-EXAFS spectra ascribed to metal-metal contributions were found, in particular in the Cu-resistant specimens. Some of these features may be due to Cu binding to metallothioneins, but a larger proportion seems to result from biomineralization, most likely Cu(II) oxalate and Cu(II) oxides. Additional contributions in the EXAFS spectra indicate complexation of Cu(II) by the nonproteogenic amino acid nicotianamine, which has a very high affinity for Cu(II) as further characterized here. PMID:19692532