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Sample records for bridged copperii coordination

  1. One novel 1D coordination polymer with parallel dinuclear copper(II) macrocyclic platforms bridged by trans dimeric half-water molecules and two dinuclear copper(II) macrocyclic complexes with different coordination geometry obtained from different solvents

    Science.gov (United States)

    Chu, Zhaolian; You, Wei; Huang, Wei

    2009-02-01

    Three dinuclear copper(II) macrocyclic complexes, formulated as [Cu 2L(N 3) 2(0.5H 2O) 2] n ( 1), [Cu 2L(ClO 4) 2(CH 3CH 2OH)] ( 2) and [Cu 2L(CH 3OH) 2](ClO 4) 2 ( 3) (LH 2 = [2+2] Schiff base macrocyclic ligand condensed from 4-chloro-2,6-diformylphenol and 1,3-diaminopropane), have been prepared and determined by X-ray single-crystal diffraction. Complex 1 shows two six-coordinate Cu(II) centers in which two monodentate N3- anions and two half-water molecules are bonded at the apical positions in the trans configuration. Furthermore, the dimeric half-water molecules serve as a μ2-bridge linking adjacent macrocyclic units together with the multiple O sbnd H…N hydrogen bonds with azide anions, forming a novel 1D chain-like coordination polymer. Complexes 2 and 3 are obtained from different solvents (ethanol and methanol) and they can be converted into each other. The molecular structures and packing mode of 2 and 3 are different where six-coordinate and five-coordinate copper(II) centers are present, respectively.

  2. The coordination structure of the extracted copper(II) complex with a synergistic mixture containing dinonylnaphthalene sulfonic acid and n-hexyl 3-pyridinecarboxylate ester

    Science.gov (United States)

    Zhu, Shan; Hu, Huiping; Hu, Jiugang; Li, Jiyuan; Hu, Fang; Wang, Yongxi

    2017-09-01

    In continuation of our interest in the coordination structure of the nickel(II) complex with dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexyl 4-pyridinecarboxylate ester (4PC), it was observed that the coordination sphere was completed by the coordination of two N atoms of pyridine rings in ligands 4PC and four water molecules while no direct interaction between Ni(II) and deprotonated HDNNS was observed. To investigate whether the coordination structure of nickel(II) with the synergistic mixture containing HDNNS and 4PC predominates or not in the copper(II) complex with the synergistic mixtures containing HDNNS and pyridinecarboxylate esters, a copper(II) synergist complex with n-hexyl 3-pyridinecarboxylate ester (L) and naphthalene-2-sulfonic acid (HNS, the short chain analogue of HDNNS), was prepared and studied by X-ray single crystal diffraction, elemental analyses and thermo gravimetric analysis (TGA), respectively. It was shown that the composition of the copper(II) synergist complex was [Cu(H2O)2(L)2(NS)2] and formed a trans-form distorted octahedral coordination structure. Two oxygen atoms of the two coordinated water molecules and two N atoms of the pyridine rings in the ligands L defined the basal plane while two O atoms from two sulfonate anions of the deprotonated HNS ligands occupied the apical positions by direct coordination with Cu(II), which was distinguished from the coordination structure of the nickel(II) synergist complex as reported in our previous work. In the crystal lattice, neighboring molecules [Cu(H2O)2L2(NS)2] were linked through the intermolecular hydrogen bonds between the hydrogen atoms of the coordinated water molecules and the oxygen atoms of the sulfonate anions in the copper(II) synergist complex to form a 2D plane. In order to bridge the gap between the solid state structure of the copper(II) synergist complex and the solution structure of the extracted copper(II) complex with the actual synergistic mixture containing

  3. Two different modes for copper(II ion coordination to quinine-type ligands

    Directory of Open Access Journals (Sweden)

    Rey Nicolás A.

    2006-01-01

    Full Text Available Three new copper(II complexes with the ligands quinuclidine [Cu(C7H13N2(OH2Cl]Cl.2H 2O (1, quinine [Cu(C20H23O2N2(OH 22]ClO4 (2, and hydroquinidine [Cu(C20H27O2N2(OH 2 Cl2]Cl.fraction one-halfH2O (3 have been isolated and characterized. The binding sites were assigned on the basis of vibrational spectroscopy, electron paramagnetic resonance, and thermal analysis results. The possibility of the involvement of the quinuclidinic nitrogen in the coordination was evidenced in complex 1, in which copper(II is coordinated to two quinuclidine molecules. In the case of quinine-type ligands, if the starting material is deprotonated in both nitrogens, copper(II coordination occurs through the quinuclidinic nitrogen, as in complex 2. In contrast, if the starting material is protonated in the quinuclidinic nitrogen the binding site is the quinolinic nitrogen, as in complex 3. Therefore, both nitrogens of quinine-type ligands constitute binding sites for copper(II ions.

  4. Syntheses, crystal structures and characterizations of three new copper(II) azide coordination polymers with 1,2,4-triazole ligands

    Science.gov (United States)

    Liu, Jing-Jing; He, Xiang; Shao, Min; Li, Ming-Xing

    2009-02-01

    Three new copper(II) azide coordination polymers with derivatives of 1,2,4-triazole as bridging coligands, namely [Cu 2(admtrz) 2(N 3) 4] n ( 1) (admtrz = 4-amino-3,5-dimethyl-1,2,4-triazole), [Cu(4-abpt)(N 3) 2] n·2 nH 2O ( 2) (4-abpt = 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole) and [Cu 3(2-ptrz) 2(N 3) 6] n ( 3) (2-ptrz = 4-(2-pyridyl)-1,2,4-triazole), were prepared and characterized by elemental analyses, IR spectra and X-ray structural analyses. Compound 1 has a 1D chain structure in which Cu(II) ions are bridged by end-on (EO) azides and admtrz ligands. This compound contains three kinds of coordination modes for Cu(II) ions, including tetrahedral, square pyramidal and octahedral geometries. Compound 2 displays an interesting 3D framework structure, in which the azide ligands link Cu(II) ions in end-to-end (EE) mode affording a 2D square layer. This 2D layers are further bridged by bent 4-abpt ligands to form an interesting 3D framework. Furthermore, this structure also exhibits an alpha-Po net topology. Compound 3 displays a 1D rectangle-like chain structure linked by azides adopting end-on (EO) and end-to-end (EE) modes and 2-ptrz ligands. The IR and thermal stabilities of these coordination polymers 1-3 have also been studied.

  5. Copper(II) complex as a precursor for formation of cyano-bridged ...

    Indian Academy of Sciences (India)

    chemsci

    Sample Magnetometer (VSM) system 7400. Synthesis safety note! Perchlorate salts of metal complexes with organic ligands are potentially explosive and should be handled with great caution. 2.2 Synthesis of [CuL(ClO4)2] (1). To a stirred solution of copper(II) chloride dihydrate. (0.171 g, 1 mmol) and ethylenediamine (2 ...

  6. Synthesis and properties of a trinuclear copper(II) complex with trithiocyanurate bridge

    Czech Academy of Sciences Publication Activity Database

    Kopel, P.; Čermáková, Š.; Doležal, Karel; Kalińska, B.; Bieńko, A.; Mroziński, J.

    2007-01-01

    Roč. 81, č. 3 (2007), s. 327-335 ISSN 0137-5083 Institutional research plan: CEZ:AV0Z50380511 Keywords : copper(II) * trithiocyanuric acid complexes * magnetic properties Subject RIV: CA - Inorganic Chemistry Impact factor: 0.483, year: 2007 http://ichf.edu.pl/pjch/pj-2007/pj-2007-03a.pdf

  7. Synthesis and crystal structure of binuclear copper(II) complex bridged by N-(2-hydroxyphenyl)-N'-[3-(diethylamino)propyl]oxamide: in vitro anticancer activity and reactivity toward DNA and protein.

    Science.gov (United States)

    Gao, Yang; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2013-08-01

    A new oxamido-bridged bicopper(II) complex, [Cu2(pdpox)(bpy)(CH3OH)](ClO4), where H3pdpox and bpy stand for N-(2-hydroxyphenyl)-N'-[3-(diethylamino)propyl]oxamide and 2,2'-bipyridine, respectively, has been synthesized and characterized by elemental analyses, molar conductivity measurements, infrared and electronic spectra studies, and X-ray single crystal diffraction. In the crystal structure, the pdpox(3-) ligand bridges two copper(II) ions as cisoid conformation. The inner copper(II) ion has a {N3O} square-planar coordination geometry, while the exo- one is in a {N2O3} square-pyramidal environment. There are two sets of interpenetrating two-dimensional hydrogen bonding networks parallel to the planes (2 1 0) and (21¯0), respectively, to form a three-dimensional supramolecular structure. The bicopper(II) complex exhibits cytotoxic activity against the SMMC7721 and A549 cell lines. The reactivity toward herring sperm DNA and bovine serum albumin revealed that the bicopper(II) complex can interact with the DNA by intercalation mode, and the complex binds to protein BSA responsible for quenching of tryptophan fluorescence by static quenching mechanism. © 2013 Wiley Periodicals, Inc.

  8. Strong effect of copper(II) coordination on antiproliferative activity of thiosemicarbazone-piperazine and thiosemicarbazone-morpholine hybrids.

    Science.gov (United States)

    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

  9. Nitrate-Bridged One-Dimension Coordination Polymer Self-Assembled from a N4O2-Tetraiminodiphenolate Dicopper(II Macrocyclic Complex

    Directory of Open Access Journals (Sweden)

    Julio Cesar da Rocha

    2015-01-01

    Full Text Available Herein we report on the synthesis and single crystal X-ray structure characterization of [{Cu2(tidf(μ-NO3}∞]ClO4 (tidf = a Robson type macrocyclic ligand obtained upon condensation of 2,6-diformyl-4-methylphenol and 1,3-diaminopropane. The coordination geometry around the copper(II is square-pyramidal and has [Cu2(tidf]2+ units connected to each other through nitrate bridges extending as a one-dimension coordination polymer. The compound exhibits an extensive supramolecular structure supported by nonclassic hydrogen bonding between C-H⋯Operchlorate and C-H⋯Onitrate.

  10. Conceptual Coordination Bridges Information Processing and Neurophysiology

    Science.gov (United States)

    Clancey, William J.; Norrig, Peter (Technical Monitor)

    2000-01-01

    Information processing theories of memory and skills can be reformulated in terms of how categories are physically and temporally related, a process called conceptual coordination. Dreaming can then be understood as a story understanding process in which two mechanisms found in everyday comprehension are missing: conceiving sequences (chunking categories in time as a categorization) and coordinating across modalities (e.g., relating the sound of a word and the image of its meaning). On this basis, we can readily identify isomorphisms between dream phenomenology and neurophysiology, and explain the function of dreaming as facilitating future coordination of sequential, cross-modal categorization (i.e., REM sleep lowers activation thresholds, "unlearning").

  11. and copper(II)

    Indian Academy of Sciences (India)

    Unknown

    characterization of several imidazolate-bridged binuclear copper(II) complexes have been reported 1–17. ... of the desired complex formed were collected, washed with ethanol and dried in vacuo at room temperature. .... 16. Sigel H (ed.) 1981 Metal ions in biological system (New York: Marcel Dekker) vol 13, p. 259. 17.

  12. A dinuclear end-on azide-bridged copper(II) compound with weak antiferromagnetic interaction - Synthesis, characterization, magnetism and X-ray structure of bis[(μ-azido-κN1)-(azido-κN1)(1,3-bis(benzimidazol-2-yl)-2-methylpropane)copper(II)

    Science.gov (United States)

    van Albada, Gerard A.; Mutikainen, Ilpo; Roubeau, Olivier; Reedijk, Jan

    2013-03-01

    The centrosymmetric dinuclear compound of formula [Cu(μ-N3-κN1)(N3-κN1)(bbmp)]2 is reported. Synthesis, characterization, physical properties are determined in detail, together with its 3D structure. The dinuclear end-on azide-bridged copper(II) compound displays a weak antiferromagnetic interaction, despite the fact that the magnetic orbitals overlap. The Cu-Cu contact distance is 3.1867(8) Å, while the Cu-Nazide-Cu angle is 103.41(14)°. The IR spectra of the azido ligands are as expected for such coordinated azides.

  13. Exogenous bridging and nonbridging in copper(II) complexes of a binculeating 2,6-bis((N-methylpiperazino)methyl)-4-chlorophenolate ligand. Crystal structures and magnetic properties of Bis(. mu. -acetato), dinitrito, and bis(azido) complexes. Possible relevance to the type 3 depleted laccase active site

    Energy Technology Data Exchange (ETDEWEB)

    Bertoncello, K.; Fallon, G.D.; Hodgkin, J.H.; Murray, K.S. (Monash Univ., Clayton (Australia))

    1988-12-28

    As part of a wide study of the structure/magnetism/redox relations {sup 1{minus}5} in binuclear copper(II) complexes, the authors have employed a binucleating ligand, LH, obtained by a Mannich reaction between a para-substituted phenol, formaldehye, and N-methylpiperazine{sup 6,7}. Molecular models are given which show that simultaneous coordination of the phenol oxygen and the four piperazine nitrogen atoms to two Cu(II) ions, in the presence of absence of an exogenous bridging ligand, would be difficult in view of the sterically constrained ligand conformation.

  14. Acid-base characterization, coordination properties towards copper(II) ions and DNA interaction studies of ribavirin, an antiviral drug.

    Science.gov (United States)

    Nagaj, Justyna; Starosta, Radosław; Jeżowska-Bojczuk, Małgorzata

    2015-01-01

    We have studied processes of copper(II) ion binding by ribavirin, an antiviral agent used in treating hepatitis C, which is accompanied usually by an increased copper level in the serum and liver tissue. Protonation equilibria and Cu(II) binding were investigated using the UV-visible, EPR and NMR spectroscopic techniques as well as the DFT (density functional theory) calculations. The spectroscopic data suggest that the first complex is formed in the water solution at pH as low as 0.5. In this compound Cu(II) ion is bound to one of the nitrogen atoms from the triazole ring. Above pH6.0, the metal ion is surrounded by two nitrogen and two oxygen atoms from two ligand molecules. The DFT calculations allowed to determine the exact structure of this complex. We found that in the lowest energy isomer two molecules of the ligand coordinate via O and N4 atoms in trans positions. The hypothetical oxidative properties of the investigated system were also examined. It proved not to generate plasmid DNA scission products. However, the calf thymus (CT)-DNA binding studies showed that it reacts with ribavirin and its cupric complex. Moreover, the interaction with the complex is much more efficient. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Copper(II) cyanido-bridged bimetallic nitroprusside-based complexes: Syntheses, X-ray structures, magnetic properties, 57Fe Moessbauer spectroscopy and thermal studies

    International Nuclear Information System (INIS)

    Travnicek, Zdenek; Herchel, Radovan; Mikulik, Jiri; Zboril, Radek

    2010-01-01

    Three heterobimetallic cyanido-bridged copper(II) nitroprusside-based complexes of the compositions [Cu(tet)Fe(CN) 5 NO].H 2 O (1), where tet=N,N'-bis(3-aminopropyl)ethylenediamine, [Cu(hto)Fe(CN) 5 NO].2H 2 O (2), where hto=1,3,6,9,11,14-hexaazatricyclo[12.2.1.1 6,9 ]octadecane and [Cu(nme) 2 Fe(CN) 5 NO].H 2 O (3), where nme=N-methylethylenediamine, were synthesized and characterized by elemental analyses, 57 Fe Moessbauer and FTIR spectroscopies, thermal analysis, magnetic measurements and single-crystal X-ray analysis. The products of thermal degradation processes of 2 and 3 were studied by XRD, 57 Fe Moessbauer spectroscopy, SEM and EDS, and they were identified as mixtures of CuFe 2 O 4 and CuO. - Three heterobimetallic cyano-bridged copper(II) nitroprusside-based complexes of the general compositions of [Cu(L)Fe(CN) 5 NO].xH 2 O, where L=N,N'-bis(3-aminopropyl)ethylenediamine (complex 1), 1,3,6,9,11,14-hexaazatricyclo[12.2.1.1 6,9 ]-octadecane (complex 2) and N-methylethylenediamine (complex 3), were synthesized, and fully structurally and magnetically characterized. SEM, EDS, XRD and 57 Fe Moessbauer experiments were used for characterization of thermal decomposition products of complexes 2 and 3.

  16. Vibrational and Electronic Circular Dichroism Monitoring of Copper(II) Coordination with a Chiral Ligand

    Czech Academy of Sciences Publication Activity Database

    Wu, T.; Zhang, X. P.; Li, C. H.; Bouř, Petr; Li, Y. Z.; You, X. Z.

    2012-01-01

    Roč. 24, č. 6 (2012), s. 451-458 ISSN 0899-0042 R&D Projects: GA ČR GAP208/11/0105 Institutional research plan: CEZ:AV0Z40550506 Keywords : circular dichroism * vibrational circular dichroism * coordination compounds * density functional theory computations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.718, year: 2012

  17. Synthesis, structure and characterization of two copper(II) supramolecular coordination polymers based on a multifunctional ligand 2-amino-4-sulfobenzoic acid.

    Science.gov (United States)

    Wei, Yan; Zhang, Lei; Wang, Meng-Jie; Chen, Si-Chun; Wang, Zi-Hao; Zhang, Kou-Lin

    2015-07-01

    Copper(II) coordination polymers have attracted considerable interest due to their catalytic, adsorption, luminescence and magnetic properties. The reactions of copper(II) with 2-amino-4-sulfobenzoic acid (H(2)asba) in the presence/absence of the auxiliary chelating ligand 1,10-phenanthroline (phen) under ambient conditions yielded two supramolecular coordination polymers, namely (3-amino-4-carboxybenzene-1-sulfonato-κO(1))bis(1,10-phenanthroline-κ(2)N,N')copper(II) 3-amino-4-carboxybenzene-1-sulfonate monohydrate, [Cu(C7H6N2O5S)(C12H8N2)2](C7H6N2O5S)·H2O, (1), and catena-poly[[diaquacopper(II)]-μ-3-amino-4-carboxylatobenzene-1-sulfonato-κ(2)O(4):O(4')], [Cu(C7H6N2O5S)(H2O)2]n, (2). The products were characterized by FT-IR spectroscopy, thermogravimetric analysis (TGA), solid-state UV-Vis spectroscopy and single-crystal X-ray diffraction analysis, as well as by variable-temperature powder X-ray diffraction analysis (VT-PXRD). Intermolecular π-π stacking interactions in (1) link the mononuclear copper(II) cation units into a supramolecular polymeric chain, which is further extended into a supramolecular double chain through interchain hydrogen bonds. Supramolecular double chains are then extended into a two-dimensional supramolecular double layer through hydrogen bonds between the lattice Hasba(-) anions, H2O molecules and double chains. Left- and right-handed 21 helices formed by the Hasba(-) anions are arranged alternately within the two-dimensional supramolecular double layers. Complex (2) exhibits a polymeric chain which is further extended into a three-dimensional supramolecular network through interchain hydrogen bonds. Complex (1) shows a reversible dehydration-rehydration behaviour, while complex (2) shows an irreversible dehydration-rehydration behaviour.

  18. and copper(II)

    Indian Academy of Sciences (India)

    Unknown

    that the imidazolate-bridged complex is stable over the pH-range 7⋅15–10⋅0. .... copper(II) complex. The observed room temperature magnetic moments are around. 1⋅79 BM, in agreement with a one-spin (S = 1/2) system. 3.2 EPR studies .... (SK) thanks the Council of Scientific & Industrial Research, New Delhi for an.

  19. A novel copper(II) coordination at His186 in full-length murine prion protein

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yasuko [Laboratory of Radiation Biology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan); Hiraoka, Wakako [Laboratory of Biophysics, School of Science and Technology, Meiji University, Kawasaki 214-8571 (Japan); Igarashi, Manabu; Ito, Kimihito [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020 (Japan); Shimoyama, Yuhei [Soft-Matter Physics Laboratory, Graduate School of Emergent Science, Muroran Institute of Technology, Muroran 050-8585 (Japan); Horiuchi, Motohiro [Laboratory of Prion Diseases, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan); Yamamori, Tohru; Yasui, Hironobu; Kuwabara, Mikinori [Laboratory of Radiation Biology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan); Inagaki, Fuyuhiko [Laboratory of Structural Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812 (Japan); Inanami, Osamu, E-mail: inanami@vetmed.hokudai.ac.jp [Laboratory of Radiation Biology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan)

    2010-04-09

    To explore Cu(II) ion coordination by His{sup 186} in the C-terminal domain of full-length prion protein (moPrP), we utilized the magnetic dipolar interaction between a paramagnetic metal, Cu(II) ion, and a spin probe introduced in the neighborhood of the postulated binding site by the spin labeling technique (SDSL technique). Six moPrP mutants, moPrP(D143C), moPrP(Y148C), moPrP(E151C), moPrP(Y156C), moPrP(T189C), and moPrP(Y156C,H186A), were reacted with a methane thiosulfonate spin probe and a nitroxide residue (R1) was created in the binding site of each one. Line broadening of the ESR spectra was induced in the presence of Cu(II) ions in moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) but not moPrP(D143R1). This line broadening indicated the presence of electron-electron dipolar interaction between Cu(II) and the nitroxide spin probe, suggesting that each interspin distance was within 20 A. The interspin distance ranges between Cu(II) and the spin probes of moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) were estimated to be 12.1 A, 18.1 A, 10.7 A, and 8.4 A, respectively. In moPrP(Y156R1,H186A), line broadening between Cu(II) and the spin probe was not observed. These results suggest that a novel Cu(II) binding site is involved in His186 in the Helix2 region of the C-terminal domain of moPrP{sup C}.

  20. Rare configuration of tautomeric benzimidazolecarboxylate ligands in cadmium(II) and copper(II) coordination polymers

    International Nuclear Information System (INIS)

    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

    2011-01-01

    Two Cd(HBimc)-based isomers, [Cd(HBimc N )(HBimc T )(H 2 O)].3.5H 2 O.EtOH (1a.3.5H 2 O.EtOH, H 2 Bimc=1H-benzimidazole-5-carboxylic acid) and [Cd(HBimc N )(HBimc T )(H 2 O)] (1b), and two Cu(HMBimc)-based coordination polymers, [Cu(HMBimc N ) 2 (H 2 O)].1/2H 2 O (2.1/2H 2 O, H 2 MBimc=2-methyl-1H-benzimidazole-5-carboxylic acid) and [Cu(HMBimc T ) 2 ].2THF.H 2 O (3.2THF.H 2 O), were self-assembled from Cd(ClO 4 ) 2 .6H 2 O/H 2 Bimc and Cu(ClO 4 ) 2 .6H 2 O/H 2 MBimc systems, respectively. Compound 1a adopts a ladder-like chain structure, comprised of a hydrogen-bond-stabilized Cd 2 (HBimc N ) 2 -metallocyclic stair and a 1D straight -(Cd-HBimc T ) n - edge, whereas compound 1b exhibits a 2D (4,4)-rhombus layered structure, intercrossed by 1D -(Cd-HBimc N ) n - chains and -(Cd-HBimc T ) n - chains. Compound 2 shows a 1D double-stranded wave-like chain from two single-stranded wave-like -(Cu-HMBimc N ) n - chains and compound 3 adopts a 2D (4,4)-topological layer structure, intercrossed by subunits of 1D -(Cu-HMBimc T ) n - chains. Interestingly, a pair of tautomeric HBimc building blocks-normal (N or HBimc N ) and tautomer (T or HBimc 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-based ligand is achieved for the first time. Highlights: →Benzimidazolecarboxylates could exhibit normal (N) and tautomer (T) configurations. → A pair of N- and T

  1. Mixed-ligand binuclear copper(II)

    Indian Academy of Sciences (India)

    A new mixed-ligand binuclear copper(II) complex [Cu(MS)(bpy)]2.(ClO4)2, built of 5-methylsalicylaldehyde and 2,2'-bipyridyl has been synthesized and characterized by using elemental analysis, IR and UV-Vis spectroscopy. Crystal structure of the complex shows that copper(II) ion lies in a square pyramidal coordination ...

  2. Unusual saccharin-N,O (carbonyl) coordination in mixed-ligand copper(II) complexes: Synthesis, X-ray crystallography and biological activity

    Science.gov (United States)

    Mokhtaruddin, Nur Shuhada Mohd; Yusof, Enis Nadia Md; Ravoof, Thahira B. S. A.; Tiekink, Edward R. T.; Veerakumarasivam, Abhi; Tahir, Mohamed Ibrahim Mohamed

    2017-07-01

    Three tridentate Schiff bases containing N and S donor atoms were synthesized via the condensation reaction between S-2-methylbenzyldithiocarbazate with 2-acetyl-4-methylpyridine (S2APH); 4-methyl-3-thiosemicarbazide with 2-acetylpyridine (MT2APH) and 4-ethyl-3-thiosemicarbazide with 2-acetylpyridine (ET2APH). Three new, binuclear and mixed-ligand copper(II) complexes with the general formula, [Cu(sac)(L)]2 (sac = saccharinate anion; L = anion of the Schiff base) were then synthesized, and subsequently characterized by IR and UV/Vis spectroscopy as well as by molar conductivity and magnetic susceptibility measurements. The Schiff bases were also spectroscopically characterized using NMR and MS to further confirm their structures. The spectroscopic data indicated that the Schiff bases behaved as a tridentate NNS donor ligands coordinating via the pyridyl-nitrogen, azomethine-nitrogen and thiolate-sulphur atoms. Magnetic data indicated a square pyramidal environment for the complexes and the conductivity values showed that the complexes were essentially non-electrolytes in DMSO. The X-ray crystallographic analysis of one complex, [Cu(sac)(S2AP)]2 showed that the Cu(II) atom was coordinated to the thiolate-S, azomethine-N and pyridyl-N donors of the S2AP Schiff base and to the saccharinate-N from one anion, as well as to the carbonyl-O atom from a symmetry related saccharinate anion yielding a centrosymmetric binuclear complex with a penta-coordinate, square pyramidal geometry. All the copper(II) saccharinate complexes were found to display strong cytotoxic activity against the MCF-7 and MDA-MB-231 human breast cancer cell lines.

  3. Dimensional modulation and magnetic properties of triazole- and bis(triazole)-based copper(II) coordination polymers tuned by aromatic polycarboxylates

    International Nuclear Information System (INIS)

    Zhang, Ju-Wen; Zhao, Wei; Lu, Qi-Lin; Luan, Jian; Qu, Yun; Wang, Xiu-Li

    2014-01-01

    Five new metal–organic coordination polymers ([Cu 3 (μ 2 -OH) 2 (atrz) 2 (nph) 2 (H 2 O) 2 ]·2H 2 O) n (1), ([Cu 2 (μ 3 -OH)(atrz)(1,2,4-btc)]·2H 2 O) n (2), ([Cu 2 (μ 3 -OH)(atrz)(1,2,4-btc)(H 2 O)]·H 2 O) n (3), [Cu(dth) 0.5 (nph)(H 2 O)] n (4) and [Cu(dth)(Hnip) 2 ] n (5) [atrz=4-amino-1,2,4-triazole, dth=N,N'-di(4H-1,2,4-triazole)hexanamide, H 2 nph=3-nitrophthalic acid, 1,2,4-H 3 btc=1,2,4-benzenetricarboxylic acid and H 2 nip=5-nitroisophthalic acid] were hydrothermally synthesized and structurally characterized. Polymer 1 shows a one-dimensional (1D) chain. Polymers 2 and 3 exhibit similar tetranuclear Cu II 4 cluster-based three-dimensional (3D) frameworks with the same components. Polymer 4 possesses a 3D framework with a 4 12 ·6 3 -pcu topology. Polymer 5 displays a 3D framework with a 4 4 ·6 10 ·8-mab topology. The magnetic properties of 1–4 were investigated. - Graphical abstract: Five triazole-based copper(II) polymers modulated by polycarboxylates were synthesized. Bis-triazole-bis-amide ligand and polycarboxylates play important roles in tuning dimensionality of polymers. Magnetic properties of polymers were investigated. - Highlights: • Five triazole- and bis(triazole)-based copper(II) coordination polymers tuned by aromatic polycarboxylates were obtained. • The aromatic polycarboxylates have an important influence on the dimensionality of five polymers. • The magnetic properties of four polymers were investigated

  4. Four triazole-bridging coordination polymers containing (m-phenol)-1,2,4-triazole: Syntheses, structures and properties of fluorescence and magnetism

    International Nuclear Information System (INIS)

    Liu Bing; Guo Guocong; Huang Jinshun

    2006-01-01

    Four triazole-bridging coordination complexes, [Zn 4 (ptr) 2 (SO 4 ) 3 (μ 3 -OH) 2 (H 2 O) 4 ] n (1), [Hg(CN) 2 (ptr)] n (2), [Hg(Cl) 2 (ptr)] n (3), and [Cu 2 (μ 2 -ptr) 2 (μ 2 -F) 2 ] n (SiF 6 ) n .2nH 2 O (4), were synthesized with (m-phenol)-1,2,4-triazole (ptr). Compounds 1-4 with extended structures of 4-substituted 1,2,4-triazole are rarely reported. The layered structure of 1 can be regarded as constructed from the 2-D inorganic backbone of SO 4 2- (2) anions bridging [Zn 4 (μ 3 -OH) 2 (H 2 O) 2 ] 6- subunits with the ptr ligands anchoring to both sides of backbone. Compounds 2 and 3 are the first mercury(II) complexes with 4-substituted 1,2,4-triazole, which feature the ptr ligand acting as a bidentate ligand bridging the Hg(II) atoms to form arciform -Hg-ptr-Hg-ptr chains. The structure of 4 is constructed from the F atoms bridging Cu atoms in symmetrical μ 2 -coordination mode to form a zigzag cationic chain with each ptr ligand bridging a pair of Cu atom on the both sides, resulting in a nonplanar 5-membered [Cu 2 N 2 F] ring. Fluorescent properties of 1-4 were characterized and the magnetic property of 4 shows antiferromagnetic interaction between the copper(II) ions. - Four triazole-bridging coordination complexes, [Zn 4 (ptr) 2 (SO 4 ) 3 (μ 3 -OH) 2 (H 2 O) 4 ] n (1), [Hg(CN) 2 (ptr)] n (2), [Hg(Cl) 2 (ptr)] n (3) and [Cu 2 (μ 2 -ptr) 2 (μ 2 -F) 2 ] n (SiF 6 ) n .2nH 2 O (4), were synthesized with (m-phenol)-1,2,4-triazole (ptr). Compounds 1-4 with extended structures of 4-substituted 1,2,4-triazole are rarely reported

  5. Electronic and Structural Effects of Inner Sphere Coordination of Chloride to a Homoleptic Copper(II) Diimine Complex.

    Science.gov (United States)

    Leandri, Valentina; Daniel, Quentin; Chen, Hong; Sun, Licheng; Gardner, James M; Kloo, Lars

    2018-04-02

    The reaction of CuCl 2 with 2,9-dimethyl-1,10-phenanthroline (dmp) does not lead to the formation of [Cu(dmp) 2 ](Cl) 2 but instead to [Cu(dmp) 2 Cl]Cl, a 5-coordinated complex, in which one chloride is directly coordinated to the metal center. Attempts at removing the coordinated chloride by changing the counterion by metathesis were unsuccessful and resulted only in the exchange of the noncoordinated chloride, as confirmed from a crystal structure analysis. Complex [Cu(dmp) 2 Cl]PF 6 exhibits a reversible cyclic voltammogram characterized by a significant peak splitting between the reductive and oxidative waves (0.85 and 0.60 V vs NHE, respectively), with a half-wave potential E 1/2 = 0.73 V vs NHE. When reduced electrochemically, the complex does not convert into [Cu(dmp) 2 ] + , as one may expect. Instead, [Cu(dmp) 2 ] + is isolated as a product when the reduction of [Cu(dmp) 2 Cl]PF 6 is performed with l-ascorbic acid, as confirmed by electrochemistry, NMR spectroscopy, and diffractometry. [Cu(dmp) 2 ] 2+ complexes can be synthesized starting from Cu(II) salts with weakly and noncoordinating counterions, such as perchlorate. Growth of [Cu(dmp) 2 ](ClO 4 ) 2 crystals in acetonitrile results in a 5-coordinated complex, [Cu(dmp) 2 (CH 3 CN)](ClO 4 ) 2 , in which a solvent molecule is coordinated to the metal center. However, solvent coordination is associated with a dynamic decoordination-coordination behavior upon reduction and oxidation. Hence, the cyclic voltammogram of [Cu(dmp) 2 (CH 3 CN)] 2+ is identical to the one of [Cu(dmp) 2 ] + , if the measurements are performed in acetonitrile. The current results show that halide ions in precursors to Cu(II) metal-organic coordination compound synthesis, and most likely also other multivalent coordination centers, are not readily exchanged when exposed to presumed strongly binding and chelating ligand, and thus special care needs to be taken with respect to product characterization.

  6. Coordination studies of copper(II), cobalt(II) and iron(II) with isomeric pyridyl-tetrazole ligands

    DEFF Research Database (Denmark)

    Bond, A. D.; Fleming, A.; Gaire, J.

    2012-01-01

    (II) compounds. X-ray crystal structures were obtained for complexes 1-5. In each complex, ligands L2 and L3 coordinate to the metal centre through the pyridyl N atom and the 1-N site of the tetrazole ring, and the pyridyl-tetrazole ligand remains planar in all cases except 3. Complexes 1 and 2 comprise......The reaction of 2-(2H-tetrazol-5-yl)pyridine (L1) with 1,6-dibromohexane results in formation of the isomers 2-(6 ''-bromohexyl)-(1-tetrazol-5-yl)pyridine (12) and 2-(6 ''-bromohexyl)-(2-tetrazol-5-yl)pyridine (L3). Coordination reactions of 12 and 13 with CuCl2 center dot 2H(2)O, Co(SCN)(2) and Fe...... a central Cu2Cl2 dimeric core with Cu(II) in an essentially square-pyramidal coordination environment. Complexes 3 and 4 contain co(II) in a distorted octahedral coordination environment. In 3, the pyridyl and tetrazole rings of L2 are twisted with respect to each other and the complex adopts a puckered...

  7. Identification of Copper(II) Complexes in Aqueous Solution by Electron Spin Resonance: An Undergraduate Coordination Chemistry Experiment.

    Science.gov (United States)

    Micera, G.; And Others

    1984-01-01

    Background, procedures, and results are provided for an experiment which examines, through electron spin resonance spectroscopy, complex species formed by cupric and 2,6-dihydroxybenzoate ions in aqueous solutions. The experiment is illustrative of several aspects of inorganic and coordination chemistry, including the identification of species…

  8. Copper(II) complexes with aroylhydrazones

    Indian Academy of Sciences (India)

    The coordination chemistry of copper(II) with tridentate aroylhydrazones is briefly discussed in this article. Two types of aroylhydrazones derived from aroylhydrazines and ortho-hydroxy aldehydes or 2-pyridine-carboxaldehyde have been used. The characterization of the complexes has been performed with the help of ...

  9. Coordination of different ligands to copper(II) and cobalt(III) metal centers enhances Zika virus and dengue virus loads in both arthropod cells and human keratinocytes.

    Science.gov (United States)

    Dutta, Shovan; Celestine, Michael J; Khanal, Supreet; Huddleston, Alexis; Simms, Colin; Arca, Jessa Faye; Mitra, Amlan; Heller, Loree; Kraj, Piotr J; Ledizet, Michel; Anderson, John F; Neelakanta, Girish; Holder, Alvin A; Sultana, Hameeda

    2018-01-01

    Trace elements such as copper and cobalt have been associated with virus-host interactions. However, studies to show the effect of conjugation of copper(II) or cobalt(III) metal centers to thiosemicarbazone ligand(s) derived from either food additives or mosquito repellent such as 2-acetylethiazole or citral, respectively, on Zika virus (ZIKV) or dengue virus (serotype 2; DENV2) infections have not been explored. In this study, we show that four compounds comprising of thiosemicarbazone ligand derived from 2-acetylethiazole viz., (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide (acetylethTSC) (compound 1), a copper(II) complex with acetylethTSC as a ligand (compound 2), a thiosemicarbazone ligand-derived from citral (compound 3) and a cobalt(III) complex with a citral-thiosemicarbazone ligand (compound 4) increased DENV2 and ZIKV replication in both mosquito C6/36 cells and human keratinocytes (HaCaT cells). Treatment of both cell lines with compounds 2 or 4 showed increased dengue viral titers at all three tested doses. Enhanced dengue viral plaque formation was also noted at the tested dose of 100μM, suggesting higher production of infectious viral particles. Treatment with the compounds 2 or 4 enhanced ZIKV and DENV2 RNA levels in HeLa cell line and primary cultures of mouse bone marrow derived dendritic cells. Also, pre- or post treatments with conjugated compounds 2 or 4 showed higher loads of ZIKV or DENV2 envelope (E) protein in HaCaT cells. No changes in loads of E-protein were found in ZIKV-infected C6/36 cells, when compounds were treated after infection. In addition, we tested bis(1,10-phenanthroline)copper(II) chloride ([Cu(phen) 2 ]Cl 2 , (compound 5) and tris(1,10-phenanthroline)cobalt(III) chloride ([Co(phen) 3 ]Cl 3 , (compound 6) that also showed enhanced DENV2 loads. Also, we found that copper(II) chloride dehydrate (CuCl 2 ·2H 2 O) or cobalt(II) chloride hexahydrate (CoCl 2 ·6H 2 O) alone had no effects as "free" cations

  10. Synthesis, structure and magnetic properties of cobalt(II) and copper(II) coordination polymers assembled by phthalate and 4-methylimidazole

    International Nuclear Information System (INIS)

    Baca, S.G.; Malinovskii, S.T.; Franz, Patrick; Ambrus, Christina; Stoeckli-Evans, Helen; Gerbeleu, Nicolae; Decurtins, Silvio

    2004-01-01

    New coordination polymers [M(Pht)(4-MeIm) 2 (H 2 O)] n (M=Co (1), Cu (2); Pht 2- =dianion of o-phthalic acid; 4-MeIm=4-methylimidazole) have been synthesized and characterized by IR spectroscopy, X-ray crystallography, thermogravimetric analysis and magnetic measurements. The crystal structures of 1 and 2 are isostructural and consist of [M(4-MeIm) 2 (H 2 O)] building units linked in infinite 1D helical chains by 1,6-bridging phthalate ions which also act as chelating ligands through two O atoms from one carboxylate group in the case of 1. In complex 1, each Co(II) atom adopts a distorted octahedral N 2 O 4 geometry being coordinated by two N atoms from two 4-MeIm, three O atoms of two phthalate residues and one O atom of a water molecule, whereas the square-pyramidal N 2 O 3 coordination of the Cu(II) atom in 2 includes two N atoms of N-containing ligands, two O atoms of two carboxylate groups from different Pht, and a water molecule. An additional strong O-H↑··O hydrogen bond between a carboxylate group of the phthalate ligand and a coordinated water molecule join the 1D helical chains to form a 2D network in both compounds. The thermal dependences of the magnetic susceptibilities of the polymeric helical Co(II) chain compound 1 were simulated within the temperature range 20-300 K as a single ion case, whereas for the Cu(II) compound 2, the simulations between 25 and 300 K, were made for a linear chain using the Bonner-Fisher approximation. Modelling the experimental data of compound 1 with MAGPACK resulted in: g=2.6, vertical bar D vertical bar=62 cm -1 . Calculations using the Bonner-Fisher approximation gave the following result for compound 2: g=2.18, J=-0.4 cm -1

  11. Dihydroxo-bridged dimeric Cu(II) system containing sandwiched non-coordinating phenylacetate anion: Crystal structure, spectroscopic, anti-bacterial, anti-fungal and DNA-binding studies of [(phen)(H2O)Cu(OH)2Cu(H2O)(phen)]2L.6H2O: (HL = phenylacetic acid; phen = 1,10-phenanthroline)

    Science.gov (United States)

    Iqbal, Muhammad; Ali, Saqib; Tahir, Muhammad Nawaz; Shah, Naseer Ali

    2017-09-01

    This paper reports the synthesis, X-ray crystal structure, DNA-binding, antibacterial and antifungal studies of a rare dihydroxo-bridged dinuclear copper(II) complex including 1,10-phenanthroline (Phen) ligands and phenylacetate (L) anions, [Cu2(Phen)2(OH)2(H2O)2].2L.6H2O. Structural data revealed distorted square-pyramidal geometry for each copper(II) atom with the basal plane formed by the two nitrogen atoms of the phenantroline ligand and the oxygen atoms of two bridging hydroxyl groups. The apical positions are filled by the oxygen atom from a water molecule. This forms a centrosymmetric cationic dimer where the uncoordinated phenylacetate ligands serve to balance the electrical charge. The dimers interact by means of hydrogen bonds aided by the coordinated as well as uncoordinated water molecules and phenyl-acetate moieties in the crystal lattice. The binding ability of the complex with salmon sperm DNA was determined using cyclic voltammetry and absorption spectroscopy yielding binding constants 2.426 × 104 M-1 and 1.399 × 104 M-1, respectively. The complex was screened against two Gram-positive (Micrococcus luteus and Bacillus subtilis) and one Gram-negative (Escherichia coli) bacterial strains exhibiting significant activity against all the three strains. The complex exhibited significant, moderate and no activity against fungal strains Mucor piriformis, Helminthosporium solani and Aspergillus Niger, respectively. These preliminary tests indicate the competence of the complex towards the development of a potent biological drug.

  12. Reappraisal of the amide coordination mode: solution properties of nickel(II) and copper(II) complexes of ligands involving simultaneously enamine and amide groups

    Energy Technology Data Exchange (ETDEWEB)

    Costes, J.P.; Laurent, J.P.

    1988-09-07

    The behavior of the Cu/sup 2+//L/sub 1/ system in solution was reappraised through the isolation and characterization of the copper(II) complexes involving the ligand L/sub 1/ in different states of protonation. Also included in the study are the homologous nickel(II) complexes and the copper(II) and nickel(II) complexes of related ligands L/sub 2/ and L/sub 3/. L/sub 1/ is the ligand 3,8-dimethyl-4,7-diazadeca-2,8-diene-1,10-diamide synthesized from acetoacetamide and 1,2,diaminoethane. L/sub 2/ and L/sub 3/ were similarly synthesized using acetoacetanilide and ethylacetoacetate instead of acetoamide. The complexes were studied by ESR and visible spectroscopy, and the data demonstrate that in all cases not only the ligand L/sub 3/ but also L/sub 1/ and L/sub 2/ are in the enamine form, and the first step of the protonation process concerns the proton of the enamine functions and not those of the amide group. 8 references, 2 tables.

  13. Nonlinear optical and G-Quadruplex DNA stabilization properties of novel mixed ligand copper(II) complexes and coordination polymers: Synthesis, structural characterization and computational studies

    Science.gov (United States)

    Rajasekhar, Bathula; Bodavarapu, Navya; Sridevi, M.; Thamizhselvi, G.; RizhaNazar, K.; Padmanaban, R.; Swu, Toka

    2018-03-01

    The present study reports the synthesis and evaluation of nonlinear optical property and G-Quadruplex DNA Stabilization of five novel copper(II) mixed ligand complexes. They were synthesized from copper(II) salt, 2,5- and 2,3- pyridinedicarboxylic acid, diethylenetriamine and amide based ligand (AL). The crystal structure of these complexes were determined through X-ray diffraction and supported by ESI-MAS, NMR, UV-Vis and FT-IR spectroscopic methods. Their nonlinear optical property was studied using Gaussian09 computer program. For structural optimization and nonlinear optical property, density functional theory (DFT) based B3LYP method was used with LANL2DZ basis set for metal ion and 6-31G∗ for C,H,N,O and Cl atoms. The present work reveals that pre-polarized Complex-2 showed higher β value (29.59 × 10-30e.s.u) as compared to that of neutral complex-1 (β = 0.276 × 10-30e.s.u.) which may be due to greater advantage of polarizability. Complex-2 is expected to be a potential material for optoelectronic and photonic technologies. Docking studies using AutodockVina revealed that complex-2 has higher binding energy for both G-Quadruplex DNA (-8.7 kcal/mol) and duplex DNA (-10.1 kcal/mol). It was also observed that structure plays an important role in binding efficiency.

  14. Spacer-dependent structural and physicochemical diversity in copper(II) complexes with salicyloyl hydrazones: a monomer and soluble polymers.

    Science.gov (United States)

    Matoga, Dariusz; Szklarzewicz, Janusz; Gryboś, Ryszard; Kurpiewska, Katarzyna; Nitek, Wojciech

    2011-04-18

    Complexation of copper(II) with a series of heterodonor chelating Schiff bases (LL) of salicylic acid hydrazide and aliphatic or cycloaliphatic ketones affords soluble one-dimensional (1D) metallopolymers containing Schiff bases as bridging ligands. Single-crystal X-ray diffraction results reveal nanometer-sized metallopolymeric wires [Cu(μ-LL)(2)](n) with off-axis linkers and a zigzag geometry. Octahedrally coordinated copper centers, exhibiting a Jahn-Teller distortion, are doubly bridged by two Schiff-base molecules in the μ(2)-η(1),η(2) coordination mode. The use of dibutylketone with long alkyl chains as a component for Schiff base formation leads to a distorted square planar monomeric copper(II) complex [Cu(LL)(2)], as evidenced by its X-ray crystal structure. The compounds are characterized by elemental analyses and IR and UV-vis spectroscopy, as well as magnetic susceptibility and cyclic voltammetry measurements. Electrochemical studies on the complexes reveal an existence of polymeric and monomeric forms in solution and the dependence of Cu(II)/Cu(I) reduction potentials on alkyl groups of salicyloyl hydrazone ligands. Polymeric complexes form conducting films on Pt electrodes upon multicycle potential sweeps.

  15. In vitro cytotoxic activities, DNA-, and BSA-binding studies of a new dinuclear copper(II) complex with N-[3-(dimethylamino)propyl]-N'-(2-carboxylatophenyl)-oxamide as ligand.

    Science.gov (United States)

    Jiao, Jing; Jiang, Man; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2014-02-01

    A new dinuclear copper(II) complex bridged by N-[3-(dimethylamino)propyl]-N'- (2-carbo-xylatophenyl)oxamide (H3 dmapob), and endcapped with 2,2'-diamino-4,4'-bithiazole (dabt), namely [Cu₂(dmapob)(dabt)(CH₃OH)(pic)]·(DMF)₀.₇₅ ·(CH₃OH)₀.₂₅ has been synthesized and characterized by elemental analysis, molar conductivity measurement, infrared and electronic spectra studies, and single-crystal X-ray diffraction. In the crystal structure, both copper(II) ions have square-pyramidal coordination geometries. The Cu···Cu separation through the oxamido bridge is 5.176(9) Å. A two-dimensional supramolecular framework is formed through hydrogen bonds and π-π stacking interactions. The reactivities toward herring sperm DNA and bovine serum albumin (BSA) show that the complex can interact with the DNA via intercalation mode and bind to the BSA responsible for quenching of tryptophan fluorescence by the static quenching mechanism. The in vitro anticancer activities suggest that the copper(II) complex is active against the selected tumor cell lines. The influence of different bridging ligands in dinuclear complexes on the DNA- and BSA-binding properties as well as anticancer activities is preliminarily discussed. © 2013 Wiley Periodicals, Inc.

  16. Synthesis, characterization and study of the magnetic properties of a coordination polymer containing cobalt(II) and copper(II); Sintese, caracterizacao e estudo das propriedades magneticas de um polimero de coordenacao contendo cobalto(II) e cobre(II)

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Tamyris T. da; Stumpf, Humberto O.; Pereira, Cynthia L.M., E-mail: cynthialopes@ufmg.br [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Pires, Heber S.; Oliveira, Luiz F.C. de [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Juiz de Fora, MG (Brazil); Pedroso, Emerson F. [Departamento de Quimica, Centro Federal de Educacao Tecnologica de Minas Gerais, Belo Horizonte, MG (Brazil); Nunes, Wallace C. [Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ (Brazil)

    2012-07-01

    This work describes the synthesis and characterization of two new compounds with ligand opy (N-(2-pyridyl)oxamate): the copper(II) precursor [Me{sub 4}N]{sub 2}[Cu(opy){sub 2}].5H{sub 2}O and Co{sup II} Cu{sup II} coordination polymer {l_brace}[Co Cu(opy){sub 2}]{r_brace}{sub n}x4nH{sub 2}O. This latter compound was obtained by reaction of [Me{sub 4}N]{sub 2}[Cu(opy){sub 2}].5H{sub 2}O and CoCl{sub 2}.6H{sub 2}O in water. The heterobimetallic Co{sup II} Cu{sup II} chain was characterized by elemental analysis, IR spectroscopy, thermogravimetry and magnetic measurements. Magnetic characterization revealed typical behavior of one-dimensional (1D) ferrimagnetic chain as shown in the curves of temperature (T) dependence of magnetic susceptibility ({chi}{sub M}), in the form of {chi}{sub M}T versus T, and dependence of magnetization (M) with applied field (H). (author)

  17. Lanthanide coordination polymers with tetrafluoroterephthalate as a bridging ligand: thermal and optical properties.

    Science.gov (United States)

    Seidel, Christiane; Lorbeer, Chantal; Cybińska, Joanna; Mudring, Anja-Verena; Ruschewitz, Uwe

    2012-04-16

    By slow diffusion of triethylamine into a solution of 2,3,5,6-tetrafluoroterephthalic acid (H2tfBDC) and the respective lanthanide salt in EtOH/DMF single crystals of seven nonporous coordination polymers, (∞)(2)[Ln(tfBDC)(NO(3))(DMF)(2)]·DMF (Ln(3+) = Ce, Pr, Nd, Sm, Dy, Er, Yb; C2/c, Z = 8) have been obtained. In the crystal structures, two-dimensional square grids are found, which are composed of binuclear lanthanide nodes connected by tfBDC(2-) as a linking ligand. The coordination sphere of each lanthanide cation is completed by a nitrate anion and two DMF molecules (CN = 9). This crystal structure is unprecedented in the crystal chemistry of coordination polymers based on nonfluorinated terephthalate (BDC(2-)) as a bridging ligand; as for tfBDC(2-), a nonplanar conformation of the ligand is energetically more favorable, whereas for BDC(2-), a planar conformation is preferred. Differential thermal analysis/thermogravimetric analysis (DTA/TGA) investigations reveal that the noncoordinating DMF molecule is released first at temperatures of 100-200 °C. Subsequent endothermal weight losses correspond to the release of the coordinating DMF molecules. Between 350 and 400 °C, a strong exothermal weight loss is found, which is probably due to a decomposition of the tfBDC(2-) ligand. The residues could not be identified. The emission spectra of the (∞)(2)[Ln(tfBDC)(NO(3))(DMF)(2)]·DMF compounds reveal intense emission in the visible region of light for Pr, Sm, and Dy with colors from orange, orange-red, to warm white. © 2012 American Chemical Society

  18. New 4-carboxylphthalhydrazidate-bridged Mn2+/In3+ coordination polymers

    Science.gov (United States)

    Jin, Juan; Yan, Wen-Fu; Yu, Xiao-Yang; Yang, Qing-Feng; Liu, Bing; Xu, Ji-Qing; Gao, Shan-Min; Li, Chuan-Zhao; Lin, Chen

    2017-04-01

    Based on the hydrothermal in situ acylation reaction of benzene-1,2,4-tricarboxylic acid (btca) with N2H4·H2O, two containing-4-carboxylphthalhydrazidate Mn2+/In3+ coordination polymers, [Mn(cpth)(phen)] 1 and [In(cpth)(ox)0.5(phen)]·H2O 2 (cpth = 4-carboxylphthalhydrazidate, phen = 1,10-phenanthroline, ox = oxalate), were obtained and characterized by elemental analysis, IR spectroscopy, X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), and single-crystal X-ray diffraction. In compound 1, the cpth ligands exhibit a μ4-bridging mode, which link Mn(II) centers into a 2-D layer structure with ancillary phen molecules. In compound 2, the cpth ligands exhibit a μ2-bridging mode, which link In(III) centers into a binuclear unit. Ox ligands act as the second linkers, extending binuclear unit into a 1-D chain with ancillary phen molecules. Via Nsbnd H⋯O interactions, compound 2 self-assembles into a 2-D supramolecular layer. The magnetic analysis indicates that there exists antiferromagnetic interactions between magnetic centers in compound 1. The photoluminescence properties of compounds 1 and 2 were also investigated in an aqueous solution.

  19. 76 FR 8788 - National Nanotechnology Coordination Office; Bridging NanoEHS Research Efforts: A Joint US-EU...

    Science.gov (United States)

    2011-02-15

    ... OFFICE OF SCIENCE AND TECHNOLOGY POLICY National Nanotechnology Coordination Office; Bridging Nano... Office (NNCO), on behalf of the Nanoscale Science, Engineering, and Technology (NSET) Subcommittee of the Committee on Technology, National Science and Technology Council (NSTC), will hold a workshop on March 10-11...

  20. Salicylaldimine Copper(II) complex catalyst: Pioneer for ring ...

    Indian Academy of Sciences (India)

    copper(II) solution with one molar equivalent of salicylaldimine Schiff-base ligand in methanol under nitrogen atmosphere. .... Here we report the synthe- sis and use of tetra-coordinated salicylaldimine copper complex in L-lactide polymerization. This complex is stable in air and easy to prepare. In addition, the steric.

  1. Structural, MALDI-TOF-MS, magnetic and spectroscopic studies of new dinuclear copper(II), cobalt(II) and zinc(II) complexes containing a biomimicking μ-OH bridge.

    Science.gov (United States)

    Núñez, Cristina; Bastida, Rufina; Macías, Alejandro; Valencia, Laura; Neuman, Nicolás I; Rizzi, Alberto C; Brondino, Carlos D; González, Pablo J; Capelo, José Luis; Lodeiro, Carlos

    2010-12-28

    The Py(2)N(4)S(2) octadentate coordinating ligand afforded dinuclear cobalt, copper and zinc complexes and the corresponding mixed metal compounds. The overall geometry and bonding modes have been deduced on the basis of elemental analysis data, MALDI-TOF-MS, IR, UV-vis and EPR spectroscopies, single-crystal X-Ray diffraction, conductivity and magnetic susceptibility measurements. In the copper and zinc complexes, a μ-hydroxo bridge links the two metal ions. In both cases, the coordination geometry is distorted octahedral. Magnetic and EPR data reveal weakly antiferromagnetic high spin Co(II) ions, compatible with a dinuclear structure. The magnetic characterization of the dinuclear Cu(II) compound indicates a ferromagnetically coupled dimer with weak antiferromagnetic intermolecular interactions. The intra-dimer ferromagnetic behaviour was unexpected for a Cu(II) dimer with such μ-hydroxo bridging topology. We discuss the influence on the magnetic properties of non-covalent interactions between the bridging moiety and the lattice free water molecules.

  2. One-dimensional homochiral cyano-bridged heterometallic chain coordination polymers with metamagnetic or ferroelectric properties.

    Science.gov (United States)

    Wen, He-Rui; Tang, Yun-Zhi; Liu, Cai-Ming; Chen, Jing-Lin; Yu, Chang-Lin

    2009-11-02

    Two couples of enantiomerically pure chiral cyano-bridged heterobimetallic chain coordination polymers, [Mn((R,R)-Salcy)Fe(Tp)(CN)(3) x H(2)O x 1/2 CH(3)CN](n) (1), [Mn((S,S)-Salcy)Fe(Tp)(CN)(3) x H(2)O x 1/2 CH(3)CN](n) (2), [Mn((R,R)-Salcy)Fe(bpca)(CN)(3) x H(2)O](n) (3), and [Mn((S,S)-Salcy)Fe(bpca)(CN)(3) x H(2)O](n) (4) [(R,R)-Salcy or (S,S)-Salcy = (R,R)- or (S,S)-N,N'-(1,2-cyclohexanediylethylene)bis(salicylideneiminato) dianion, Tp = tris(pyrazolyl)hydroborate, bpca = bis(2-pyridylcarbonyl)amidate anion], were synthesized using the modified cyanometalate building blocks [Fe(L)(CN)(3)](-) (L = Tp, bpca) and the chiral polydentate Schiff base manganese(III) complex fragments. The circular dichroism measurements showed Cotton effects of the opposite sign at the same wavelength for each pair of enantiomers. Magnetic property studies indicated that complexes 1 and 2 show not only intrachain but also interchain field-induced metamagnetic transitions from an antiferromagnetic to a ferromagnetic state and exhibit an antiferromagnetic long-range ordering with a T(N) of 3.2 K, while enantiomers 3 and 4 are typical antiferromagnetic coupling compounds. Furthermore, complex 3 exhibits a ferroelectric behavior that relates to the polar point group C(2), in which it crystallizes.

  3. Coordination of two high-affinity hexamer peptides to copper(II) and palladium(II) models of the peptide-metal chelation site on IMAC resins

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.; Pasquinelli, R.; Ataai, M.; Koepsel, R.R.; Kortes, R.A.; Shepherd, R.E.

    2000-03-20

    The coordination of peptides Ser-Pro-His-His-Gly-Gly (SPHHGG) and (His){sub 6} (HHHHHH) to [Pd{sup II}(mida)(D{sub 2}O)] (mida{sup 2{minus}} = N-methyliminodiacetate) was studied by {sup 1}H NMR as model reactions for Cu{sup II}(iminodiacetate)-immobilized metal affinity chromatography (IMAC) sites. This is the first direct physical description of peptide coordination for IMAC. A three-site coordination is observed which involves the first, third, and fourth residues along the peptide chain. The presence of proline in position 2 of SPHHGG achieves the best molecular mechanics and bonding angles in the coordinated peptide and enhances the interaction of the serine amino nitrogen. Histidine coordination of H{sub 1}, H{sub 3}, and H{sub 4} of (His){sub 6} and H{sub 3} and H{sub 4} of SPHHGG was detected by {sup 1}H NMR contact shifts and H/D exchange of histidyl protons. The EPR spectra of SPHHGG and HHHHHH attached to the [Cu{sup II}(mida)] unit were obtained for additional modeling of IMAC sites. EPR parameters of the parent [Cu(mida)(H{sub 2}O){sub 2}] complex are representative: g{sub zz} = 2.31; g{sub yy} = 2.086; g{sub xx} = 2.053; A{sub {vert_bar}{vert_bar}} = 161 G; A{sub N} = 19G (three line, one N coupling). Increased rhombic distortion is detected relative to the starting aqua complex in the order of [Cu(mida)L] for distortion of HHHHHH > SPHHGG > (H{sub 2}O){sub 2}. The lowering of symmetry is also seen in the decrease in the N-shf coupling, presumably to the imino nitrogen of mida{sup 2{minus}} in the order 19 G (H{sub 2}O), 16 G (SPHHGG) and 11 G (HHHHHH). Visible spectra of the [Cu(mida)(SPHHGG)] and [Cu(mida)(HHHHHH)] as a function of pH indicate coordination of one histidyl donor at ca. 4.5, two in the range of pH 5--7, and two chelate ring attachments involving the terminal amino donor for SPHHGG or another histidyl donor of HHHHHH in the pH domain of 7--8 in agreement with the [Pd{sup II}(mida)L] derivatives which form the two

  4. Synthesis and Crystal Structure of a Five-Coordinate Complex of Copper(II) with 4-Nitrobenzenesulfonate and 2, 2'-Bipyridine.

    Science.gov (United States)

    Sharif, Mahboubeh A; Tabatabaee, Masoumeh; Beik, Vahideh; Khavasi, Hamid Reza

    2012-06-01

    [Cu(bipy)2Cl](nbs) (1) (bipy = 2,2'-bipyridine, nbs = 4-nitrobenzenesulfonate) was obtained from the reaction of 4-nitrobenzenesulfonyl chloride and 2-amine-4-methylopyridine with CuCl2 in the presence of 2,2'-bipyridine and characterized by elemental analysis, IR spectra and X-ray single-crystal diffraction. The asymmetric unit of (1) contains the cationic complex [Cu(bipy)2Cl]+ and, in the outer coordination sphere, an (nbs)- counter ion.

  5. A copper complex (2,2¢-bipyridine)(salicyclideneglycinato) copper(II ...

    Indian Academy of Sciences (India)

    Administrator

    coordinated to 3 histidine residues in the equatorial position and two water molecules giving a CuN3O2 coordination sphere. In this paper, we report a copper(II) complex having a CuN3O2 coordination geometry which is found to be catalytically active in oxidising ascorbic acid in air. In aqueous–methanol, ascorbic acid ...

  6. COORDINATION COMPOUNDS OF NICKEL(II, COPPER(II AND COBALT(II BASED ON S-METHYLISOTHIOSEMICARBAZIDE AS DYES FOR THERMOPLASTIC POLYMERS

    Directory of Open Access Journals (Sweden)

    Ştefan Manole

    2011-12-01

    Full Text Available We have researched the color properties of coordination compounds synthesized by us previously [1] (8-(1',2'-naphthyl-1- R3-methyl-6-thiomethyl-4,5,7-triazaocta-1,3,5,7-tetraenato-1,1'-diolato(-O, O', N4, N7-M(II, where R=CH3, C6H5, M=Ni, Co, Cu, which can be used for coloring thermoplastic masses. They meet the requirements for use as a pigment for coloring thermoplastic masses.

  7. COORDINATION COMPOUNDS OF NICKEL(II), COPPER(II) AND COBALT(II) BASED ON S-METHYLISOTHIOSEMICARBAZIDE AS DYES FOR THERMOPLASTIC POLYMERS

    OpenAIRE

    Ştefan Manole; Maria Cocu

    2011-01-01

    We have researched the color properties of coordination compounds synthesized by us previously [1] (8-(1',2'-naphthyl)-1- R3-methyl-6-thiomethyl-4,5,7-triazaocta-1,3,5,7-tetraenato-1,1'-diolato(-)O, O', N4, N7-M(II), where R=CH3, C6H5, M=Ni, Co, Cu), which can be used for coloring thermoplastic masses. They meet the requirements for use as a pigment for coloring thermoplastic masses.

  8. Light-Induced Copper(II) Coordination by a Bicyclic Tetraaza Chelator through a Ligand-to-Metal Charge-Transfer Reaction

    DEFF Research Database (Denmark)

    Holm-Jørgensen, Jacob Rørdam; Jensen, Mikael; Bjerrum, Morten J.

    2011-01-01

    To enable utilization of the broad potential of copper isotopes in nuclear medicine, rapid and robust chelation of the copper is required. Bowl adamanzanes (bicyclic tetraaza ligands) can form kinetically stable copper complexes, but they are usually formed at low rates unless high pH values...... coordinated amine groups) at pH above 6. These findings are supported by pH titrations of mixtures of Cu2+ and [24.31]adz in water. Irradiation of this complex in the ligand-to-metal charge-transfer (LMCT) band by a diode-array spectrophotometer leads to photodeprotonation and subsequently to formation...

  9. A copper(II) paddle-wheel structure of tranexamic acid: di-chloro-tetra-kis-[μ-4-(ammonio-meth-yl)cyclo-hexane-1-carboxyl-ato-O,O']dicopper(II) dichloride hexa-hydrate.

    Science.gov (United States)

    Altaf, Muhammad; Stoeckli-Evans, Helen

    2017-10-01

    Tranexamic acid [systematic name: trans -4-(amino-meth-yl)cyclo-hexane-1-carb-oxy-lic acid], is an anti-fibrinolytic amino acid that exists as a zwitterion [ trans -4-(ammonio-meth-yl)cyclo-hexane-1-carboxyl-ate] in the solid state. Its reaction with copper chloride leads to the formation of a compound with a copper(II) paddle-wheel structure that crystallizes as a hexa-hydrate, [Cu 2 Cl 2 (C 8 H 15 NO 2 ) 4 ] 2+ ·2Cl - ·6H 2 O. The asymmetric unit is composed of a copper(II) cation, two zwitterionic tranexamic acid units, a coordinating Cl - anion and a free Cl - anion, together with three water mol-ecules of crystallization. The whole structure is generated by inversion symmetry, with the Cu⋯Cu axle of the paddle-wheel dication being located about a center of symmetry. The cyclo-hexane rings of the zwitterionic tranexamic acid units have chair conformations. The carboxyl-ate groups that bridge the two copper(II) cations are inclined to one another by 88.4 (8)°. The copper(II) cation is ligated by four carboxyl-ate O atoms in the equatorial plane and by a Cl - ion in the axial position. Hence, it has a fivefold O 4 Cl coordination sphere with a perfect square-pyramidal geometry and a τ 5 index of zero. In the crystal, the paddle-wheel dications are linked by a series of N-H⋯Cl hydrogen bonds, involving the coordinating and free Cl - ions, forming a three-dimensional network. This network is strengthened by a series of N-H⋯O water , O water -H⋯Cl and O water -H⋯O hydrogen bonds.

  10. Studies of viomycin, an anti-tuberculosis antibiotic: copper(ii) coordination, DNA degradation and the impact on delta ribozyme cleavage activity.

    Science.gov (United States)

    Stokowa-Sołtys, K; Barbosa, N A; Kasprowicz, A; Wieczorek, R; Gaggelli, N; Gaggelli, E; Valensin, G; Wrzesiński, J; Ciesiołka, J; Kuliński, T; Szczepanik, W; Jeżowska-Bojczuk, M

    2016-05-17

    Viomycin is a basic peptide antibiotic, which is among the most effective agents against multidrug-resistant tuberculosis. In this paper we provide the characteristics of its acid base properties, coordination preferences towards the Cu(ii) ions, as well as the reactivity of the resulting complexes against plasmid DNA and HDV ribozyme. Careful coordination studies throughout the wide pH range allow for the characterisation of all the Cu(ii)-viomycin complex species. The assignment of proton chemical shifts was achieved by NMR experiments, while the DTF level of theory was applied to support molecular structures of the studied complexes. The experiments with the plasmid DNA reveal that at the physiological levels of hydrogen peroxide the Cu(ii)-viomycin complex is more aggressive against DNA than uncomplexed metal ions. Moreover, the degradation of DNA by viomycin can be carried out without the presence of transition metal ions. In the studies of antigenomic delta ribozyme catalytic activity, viomycin and its complex are shown to modulate the ribozyme functioning. The molecular modelling approach allows the indication of two different locations of viomycin binding sites to the ribozyme.

  11. Synthesis and Characterization of Novel Copper(II 2D Coordination Polymers from a Fluorinated Flexible Ligand with Remarkable Clathration Ability

    Directory of Open Access Journals (Sweden)

    Kayoko Kasai

    2011-11-01

    Full Text Available Two-dimensional (2D grid coordination polymers were prepared by the reaction of 1,4-bis(4-pyridylmethyltetrafluorobenzene (bpf with Cu(NO32 in the presence of aromatic compounds. Crystal structures of {[Cu(bpf2(NO32]·(biphenyl2}n (1, {[Cu(bpf2(NO32]·(m-C6H4(OMe22}n (2, {[Cu(bpf2(NO32]·PhtBu}n (3 and {[Cu(bpf2(NO3(H2O]NO3·(bpf0.5}n (4 were determined. The grid networks were held together by C–H···O and C–H···F hydrogen bonds via the NO3− anions and the tetrafluorophenylene rings of bpf, respectively. Biphenyl, m-dimethoxybenzene, t-butylbenzene, and bpf molecules were clathrated in cyclic cavities of the grid networks through arene-perfluoroarene interactions. These coordination networks have remarkable clathration ability for aromatic compounds.

  12. Rational assembly of soluble copper(II) phosphonates: synthesis, structure and magnetism of molecular tetranuclear copper(II) phosphonates.

    Science.gov (United States)

    Chandrasekhar, Vadapalli; Senapati, Tapas; Dey, Atanu; Sañudo, E Carolina

    2011-02-21

    The reactions of the dinuclear copper complexes [Cu(2)(L)(OAc)] [H(3)L = N,N'-(2-hydroxypropane-1,3-diyl)bis(salicylaldimine) or [Cu(2)(L')(OAc)] (H(3)L' = N,N'-(2-hydroxypropane-1,3-diyl)bis(4,5-dimethylsalicylaldimine)] with various phosphonic acids, RPO(3)H(2) (R = t-Bu, Ph, c-C(5)H(9), c-C(6)H(11) or 2,4,6-i-Pr(3)-C(6)H(2)), leads to the replacement of the acetate bridge affording tetranuclear copper(II) phosphonates, [Cu(4)(L)(2)(t-BuPO(3))](CH(3)OH)(2)(C(6)H(6)) (1), [Cu(4)(L)(2)(PhPO(3))(H(2)O)(2)(NMe(2)CHO)](H(2)O)(2) (2), [Cu(4)(L')(2)(C(5)H(9)PO(3))](CH(3)OH)(2) (3), [Cu(4)(L')(2)(C(6)H(11)PO(3)](MeOH)(4)(H(2)O)(2) (4) and [Cu(4)(L')(2)(C(30)H(46)P(2)O(5))](PhCH(3)) (5). The molecular structures of 1-4 reveal that a [RPO(3)](2-) ligand is involved in holding the four copper atoms together by a 4.211 coordination mode. In 5, an in situ formed [(RPO(2))(2)O](4-) ligand bridges two pairs of the dinuclear subunits. Magnetic studies on these complexes reveal that the phosphonate ligand is an effective conduit for magnetic interaction among the four copper centers present; a predominantly antiferromagnetic interaction is observed at low temperatures.

  13. A novel Mn(II) oxalato-bridged 2D coordination polymer: synthesis ...

    Indian Academy of Sciences (India)

    Hiba Sehimi

    2018-02-28

    Feb 28, 2018 ... Keywords. 2D coordination polymer; manganese; oxalate; magnetism. 1. Introduction. Coordination polymers (CPs) are of rising interest because of their fascinating topologies and dimension- ality associated with both structural and functional ver- satility. Various attempts to build high-dimensional CPs.

  14. Crystal structures and luminescent properties of lanthanide nitrate coordination polymers with structurally related amide type bridging podands

    Science.gov (United States)

    Wang, Qing; Yan, Xuhuan; Zhang, Hongrui; Liu, Weisheng; Tang, Yu; Tan, Minyu

    2011-01-01

    A one-dimensional linear chain coordination polymer [ErL I(NO 3) 3(CH 3CO 2Et)] n (L I=1,2-bis{[(2'-furfurylaminoformyl)phenoxyl]methyl}benzene) and a one-dimensional zig-zag coordination polymer {[TbL II(NO 3) 3(H 2O)]·(H 2O)} n (L II=1,2-bis{[2'-(2-pyridylmethylaminoformyl)phenoxyl]methyl}benzene) were assembled by two structurally related bridging podands L I and L II which have uniform skeleton and different terminal groups. In {[TbL II(NO 3) 3(H 2O)]·(H 2O)} n, the neutral chains were linked by the hydrogen bonding interactions between the free and coordinated water molecules from two different directions to interpenetrate into a 3D supramolecular structure. At the same time, the luminescent properties of the solid Tb(III) nitrate complexes of these podands were investigated at room temperature. The lowest triplet state energy levels T 1 of the podands L I and L II indicate that the triplet state energy levels of the antennae are both above the lowest excited resonance level of 5D 4 of Tb 3+ ion. Thus the absorbed energy could be transferred from ligands to the central Tb 3+ ions. And the influence of the hydrogen bonding on the luminescence efficiencies of the coordination polymers was also discussed.

  15. Chelating Schiff base assisted azide-bridged Mn(II), Ni(II) and Cu(II) magnetic coordination polymers.

    Science.gov (United States)

    Bai, Shi-Qiang; Fang, Chen-Jie; He, Zheng; Gao, En-Qing; Yan, Chun-Hua; Hor, T S Andy

    2012-11-21

    Four new Mn(II), Ni(II) and Cu(II) coordination polymers [Mn2(L1)(μ(1,1)-N3)2(μ(1,3)-N3)2]n (1), [Ni(L2)2(μ(1,3)-N3)]n(ClO4)n (2), [Cu(L3)(μ(1,1)-N3)(N3)]n (3) and [Cu(L4)(μ(1,1)-N3)2]n (4) (L1 = N,N′-bis(2-pyridylmethylene)ethane-1,2-diamine, L2 = N-(2-pyridylmethylene)methylamine, L3 = N-(2-pyridylmethylene)-3-pyridylamine, L4 = N-(2-pyridylmethylene)-tbutylamine) have been synthesized and characterized by single-crystal X-ray analysis and magnetic measurements. Complex 1 indicates a stoichiometry-dependent structural change (based on Mn:L1:N3 = 2:1:4 molar ratio) and consists of two-dimensional (2-D) (4,4) net layers, in which Mn(II) centers are co-bridged by single end-to-end (EE), double end-on (EO) azide and chelate-bridging L1 ligands. Complex 2 shows a single EE azide-bridged one-dimensional (1-D) Ni(II) chain. Complexes 3 and 4 indicate single EO and double EO azide-bridged 1-D Cu(II) chains, respectively. Complex 1 exhibits weak ferromagnetism due to its intra-layer spin-canting with T(c) = 20 K. Complex 2 shows an unusual intra-chain ferromagnetic coupling and spin-canting behaviour. Both complexes 3 and 4 exhibit intra-chain antiferromagnetic interactions. Magneto-structural parameters for these related complexes were also discussed.

  16. Human topoisomerase IB is a target of a thiosemicarbazone copper(II) complex.

    Science.gov (United States)

    Vutey, Venn; Castelli, Silvia; D'Annessa, Ilda; Sâmia, Luciana B P; Souza-Fagundes, Elaine M; Beraldo, Heloisa; Desideri, Alessandro

    2016-09-15

    The human topoisomerase IB inhibition and the antiproliferative activity of 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone HPyCT4BrPh alone and its copper(II) complex [Cu(PyCT4BrPh)Cl] was investigated. [Cu(PyCT4BrPh)Cl] inhibits both the DNA cleavage and religation step of the enzyme, whilst the ligand alone does not display any effect. In addition we show that coordination to copper(II) improves the cytotoxicity of HPyCT4BrPh against THP-1 leukemia and MCF-7 breast cancer cells. The data indicate that the copper(II) thiosemicarbazone complex may hit human topoisomerase IB and that metal coordination can be useful to improve cytotoxicity of this versatile class of compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. A novel Mn(II) oxalato-bridged 2D coordination polymer: synthesis ...

    Indian Academy of Sciences (India)

    Hiba Sehimi

    2018-02-28

    Feb 28, 2018 ... o-phthalic acid5 and carboxylic acid,6 due to their excel- lent coordinating ability. And among this wide variety of ligands, the oxalate ion was proven to be ..... ganic Crystal Structure Database Acta Crystallogr., Sect. B 41 244. 30. Lethbridge Z A D, Congreve A F, Esslemont E, Slawin. A M Z and Lightfoot P ...

  18. New one-dimensional azido-bridged manganese(II) coordination polymers exhibiting alternating ferromagnetic-antiferromagnetic interactions: structural and magnetic studies.

    Science.gov (United States)

    Gao, En-Qing; Bai, Shi-Qiang; Yue, Yan-Feng; Wang, Zhe-Ming; Yan, Chun-Hua

    2003-06-02

    Five Mn(II)[bond]azido coordination polymers of formula [Mn(L)(N(3))(2)](n) have been synthesized and crystallographically characterized, and their magnetic properties studied, where L's are the bidentate Schiff bases obtained from the condensation of pyridine-2-carbaldehyde with aniline (1) and its derivatives p-toluidine (2), m-toluidine (3), p-chloroaniline (4), and m-chloroaniline (5). All the complexes consist of the zigzag Mn(II)[bond]azido chains in which the Mn(II) ions are alternately bridged by two end-to-end (EE) and two end-on (EO) azido ligands, the cis-octahedral coordination being completed by the two nitrogen atoms of the Schiff base ligands. Compound 2 is unique in that the Mn[bond](EE-N(3))(2)[bond]Mn ring adopts an unusual twist conformation with the two linear azido bridges crossing each other. By contrast, the rings in the other compounds take the usual chair conformation with the two azido bridges parallel. The double EO bridging fragments in the complexes are similar with the bridging angles (Mn[bond]N[bond]Mn) ranging from 99.6 degrees to 104.0 degrees. Magnetic analyses reveal that alternating ferro- and antiferromagnetic interactions are mediated through the alternating EO and EE azido bridges with the J(F) and J(AF) parameters in the ranges of 4.1-8.0 and -11.8 to -15.4 cm(-1), respectively. Finally, the magnetostructural correlations are investigated. The present complexes follow the general trend that the ferromagnetic interaction through the double EO bridge increases with the Mn[bond]N[bond]Mn bridging angle, while the antiferromagnetic interaction through the double EE bridge is dependent on the distortion of the Mn[bond](N(3))(2)[bond]Mn ring from planarity toward the chair conformation and the Mn[bond]N[bond]N angle.

  19. A novel asymmetric chair-like hydroxyl-bridged tetra-copper compound: Synthesis, supramolecular structure and magnetic property

    Science.gov (United States)

    Wang, Xiao-Feng; Du, Ke-Jie; Wang, Hong-Qing; Zhang, Xue-Li; Nie, Chang-Ming

    2017-06-01

    A new polynuclear Cu(II) compound, [Cu4(bpy)4(OH)4(H2O)(BTC)]NO3·8H2O (1), was prepared by self-assembly from the solution of copper(II) nitrate and two kinds of ligands, 2,2‧-bipyridine (bpy) and benzene-tricarboxylic acid (H3BTC). Single crystal structure analysis reveals that 1 features a rare asymmetric chair-like hydroxyl-bridged tetra-copper cluster: [Cu4(OH)4] core along with one H2O and one BTC3- occupied each terminal coordinated site. In addition, the magnetic property has been investigated.

  20. Synthesis and Crystal Structure of a 4,4'-bipyridine Linked Dinuclear Copper(II) Complex Derived from 2-{[2-(2-hydroxyethylamino)ethylimino]methyl}-6-methylphenol.

    Science.gov (United States)

    Zhang, Xiu-Zhen; Gu, Yitong; Li, Yuntong; Liu, Andong; Liu, Fuyao; You, Zhonglu; Zhu, Hai-Liang

    2016-12-01

    A novel 4,4'-bipyridine linked dinuclear copper(II) complex, [Cu2L2(bipy)](NO3)2·bipy (L = 2-[2-(2-hydroxyethylamino) ethylimino]methyl-6-methylphenol; bipy = 4,4'-bipyridine), was prepared and characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction. The Cu···Cu distance is 11.129(2) Å. The CuII atom is coordinated by one phenolate O, one imine N, and one amine N atoms of a Schiff base ligand, and one N atom of the bridging 4,4'-bipyridine ligand, forming a square planar geometry. In the crystal structure of the complex, the dinuclear copper complex cations are linked by 4,4'-bipyridine molecules through intermolecular O-H···N hydrogen bonds, to form 1D chains running in the [2 0 -1] direction.

  1. DNA binding, cytotoxicity and apoptosis induction activity of a mixed-ligand copper(II) complex with taurine Schiff base and imidazole

    Science.gov (United States)

    Li, Mei; kong, Lin Lin; Gou, Yi; Yang, Feng; Liang, Hong

    2014-07-01

    A novel binuclear copper(II) complex (complex 1) with taurine Schiff base and imidazole has been synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, ESI-MS spectrometry, UV-vis and IR spectroscopy. Single-crystal analysis revealed that 1 displays the sulfonate-bridged dinuclear copper(II) centers. Both copper atoms are five-coordinated and exhibit slightly distorted square pyramidal geometries. Each of copper atom is surrounded by three oxygen atoms and one nitrogen atom from different taurine Schiff base ligands, and one nitrogen atom from one imidazole ligand. The interaction between 1 and calf thymus DNA (CT-DNA) was investigated by UV-vis, fluorescence, circular dichroism (CD) spectra and agarose gel electrophoresis. The experimental results indicated that 1 could bind to CT-DNA via an intercalative mode and show efficient cleavage activity. In addition, 1 showed an antitumor effect on cell cycle and apoptosis. Flow cytometric analysis revealed that MGC-803 cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that 1 could induce apoptosis of MGC-803 cells.

  2. The Copper(I) / Copper(II) Transition in Complexes with 8-alkylthioquinoline Based Multidentate Ligands

    Czech Academy of Sciences Publication Activity Database

    Su, Ch. Y.; Liao, S.; Wanner, M.; Fiedler, Jan; Zhang, Ch.; Kang, B. S.; Kaim, W.

    - (2003), s. 189-202 ISSN 1472-7773 R&D Projects: GA MŠk OC D15.10 Institutional research plan: CEZ:AV0Z4040901 Keywords : X-ray structure * 5-coordinate copper(II) complexes * electron-transfer kinetics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.023, year: 2002

  3. RECOVERY OF COPPER(II) AND CHROMIUM(III) FROM NITRATE ...

    African Journals Online (AJOL)

    Guerdouh A and Barkat D

    2016-05-01

    May 1, 2016 ... terephthaldialdehyde and 5-amino-2-methoxy-phe is studied by Al Zoubi, Kandil and. Chebani [7]. It was found that .... show that the extraction of copper(II) increases with the concentration of salicylideneaniline. ..... approximately at constant frequency indicating that it hasn't affected any coordination to the.

  4. Crystal Structure and Band-Gap Engineering of a Semiconducting Coordination Polymer Consisting of Copper(I) Bromide and a Bridging Acceptor Ligand.

    Science.gov (United States)

    Okubo, Takashi; Himoto, Kento; Tanishima, Koki; Fukuda, Sanshiro; Noda, Yusuke; Nakayama, Masanobu; Sugimoto, Kunihisa; Maekawa, Masahiko; Kuroda-Sowa, Takayoshi

    2018-03-05

    A new semiconducting 3D coordination polymer, [Cu 2 Br 2 (ttz)] n (1), with an acceptor bridging ligand, 1,2,4,5-tetrazine (ttz), was synthesized. The complex shows large absorption bands extending to the near-IR region, indicating a small band gap in the coordination polymer. This complex shows higher conductivity than those of [CuBr(pyz)] n (2), including pyrazine (pyz) with a higher lowest unoccupied molecular orbital level. We performed density functional theory band calculations using the VASP program to understand the electronic states and conducting paths of the coordination polymer.

  5. Intramolecular electron transfer through a bridging carboxylate group coordinated to two cobalt(III)-ions

    International Nuclear Information System (INIS)

    Wieghardt, K.

    1978-01-01

    Reduction of the binuclear μ-p-nitrobenzoato -di-μ-hydroxo -bis[triammine cobalt(III)] cation with (CH 3 ) 2 COH radicals yields a radical cation with the p-nitrobenzoato radical being coordinated to two cobalt(III) ions at the carboxylic group. The unprotonated form of this species undergoes intramolecular electron transfer producing Co(II) (k = (3.3 +- 0.3). x 10 3 s -1 ). The role of the carboxylate group in the intramolecular electron transfer process is tentatively assessed in terms of an intramolecular outer-sphere reaction because of lack of overlap of the donor orbitals (π) and the acceptor orbital (sigma). The protonated form of the radical cation (pKsub(a) = 2.5) disproportionates via a bimolecular process without production of Co(II). The effect of two coordinated Co(III) ions as compared to only one on the properties of the nitrobenzoate radical anion are discussed. (orig.) 891 HK 892 GM [de

  6. Synthesis, structural characterization, cytotoxic properties and DNA binding of a dinuclear copper(II) complex.

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Changes in magnetic properties from solid state to solution in a trinuclear linear copper(II) complex

    NARCIS (Netherlands)

    Koval, I.A.; Akhideno, H.; Tanase, S.; Belle, C.; Duboc, C.; Saint-Aman, E.; Gamez, P.; Tooke, D.M.; Spek, A.L.; Pierre, J.-L.; Reedijk, J.

    2007-01-01

    A linear trinuclear copper(II) complex containing phenoxido- and alkoxido-bridges between the metal centers has been isolated and structurally characterized. The complex cation consists of a linear array of three copper ions, assembled by means of two doubly deprotonated ligands. The octahedral

  8. and copper(ii)

    African Journals Online (AJOL)

    DELL

    IR Spectra showed that the ligands coordinated in enol form through the deprotonated carbonyl bond (C=O) and the ... BDH and Sigma Aldrich quality and used without .... Infrared Spectra. The structurally significant IR bands for free ligand and its complexes are reported in Table 3. The diagnostic and relevant vibrational.

  9. Transition metal complexes of neocryptolepine analogues. Part I: Synthesis, spectroscopic characterization, and invitro anticancer activity of copper(II) complexes

    Science.gov (United States)

    Emam, Sanaa Moustafa; El Sayed, Ibrahim El Tantawy; Nassar, Nagla

    2015-03-01

    New generation of copper(II) complexes with aminoalkylaminoneocryptolepine as bidentate ligands has been synthesized and it is characterized by elemental analyses, magnetic moment, spectra (IR, UV-Vis, 1H NMR and ESR) and thermal studies. The IR data suggest the coordination modes for ligands which behave as a bidentate with copper(II) ion. Based on the elemental analysis, magnetic studies, electronic and ESR data, binuclear square planar geometry was proposed for complexes 7a, 7b, square pyramidal for 9a, 9b and octahedral for 8a, 8b, 10a, 10b. The molar conductance in DMF solution indicates that all complexes are electrolyte except 7a and 7b. The ESR spectra of solid copper(II) complexes in powder form showed an axial symmetry with 2B1g as a ground state and hyperfine structure. The thermal stability and degradation of the ligands and their metal complexes were studied employing DTA and TG methods. The metal-free ligands and their copper(II) complexes were tested for their in vitro anticancer activity against human colon carcinoma (HT-29). The results showed that the synthesized copper(II) complexes exhibited higher anticancer activity than their free ligands. Of all the studied copper(II) complexes, the bromo-substituted complex 9b exhibited high anticancer activity at low micromolar inhibitory concentrations (IC50 = 0.58 μM), compared to the other complexes and the free ligands.

  10. The ligational behavior of an isatinic quinolyl hydrazone towards copper(II- ions

    Directory of Open Access Journals (Sweden)

    Mousa Marwa A

    2011-04-01

    Full Text Available Abstract Background The importance of the isatinic quinolyl hydrazones arises from incorporating the quinoline ring with the indole ring. Quinoline ring has therapeutic and biological activities whereas, the indole ring occurs in Jasmine flowers and Orange blossoms. As a ligand, the isatin moiety is potentially ambidentate and can coordinate the metal ions either through its lactam or lactim forms. In a previous study, the ligational behavior of a phenolic quinolyl hydrazone towards copper(II- ions has been studied. As continuation of our interest, the present study is planned to check the ligational behavior of an isatinic quinolyl hydrazone. Results New homo- and heteroleptic copper(II- complexes were obtained from the reaction of an isatinic quinolyl hydrazone (HL with several copper(II- salts viz. Clˉ, Brˉ, NO3ˉ, ClO4-, SO42- and AcO-. The obtained complexes have Oh, Td and D4h- symmetry and fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO42- anions. Depending on the type of the anion, the ligand coordinates the copper(II- ions either through its lactam (NO3ˉ and ClO4- or lactim (the others forms. Conclusion The effect of anion for the same metal ion is obvious from either the geometry of the isolated complexes (Oh, Td and D4h or the various modes of bonding. Also, the obtained complexes fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO42- anions in consistency with the donor ability of the anions. In case of copper(II- acetate, a unique homoleptic complex (5 was obtained in which the AcO- anion acts as a base enough to quantitatively deprotonate the hydrazone. The isatinic hydrazone uses its lactim form in most complexes.

  11. Copper(II) and zinc(II) dinuclear enzymes model compounds: The nature of the metal ion in the biological function

    Science.gov (United States)

    Ferraresso, L. G.; de Arruda, E. G. R.; de Moraes, T. P. L.; Fazzi, R. B.; Da Costa Ferreira, A. M.; Abbehausen, C.

    2017-12-01

    First series transition metals are used abundantly by nature to perform catalytic transformations of several substrates. Furthermore, the cooperative activity of two proximal metal ions is common and represents a highly efficient catalytic system in living organisms. In this work three dinuclear μ-phenolate bridged metal complexes were prepared with copper(II) and zinc(II), resulting in a ZnZn, CuCu and CuZn with the ligand 2-ethylaminodimethylamino phenol (saldman) as model compounds of superoxide dismutase (CuCu and CuZn) and metallo-β-lactamases (ZnZn). Metals are coordinated in a μ-phenolate bridged symmetric system. Cu(II) presents a more distorted structure, while zinc is very symmetric. For this reason, [CuCu(saldman)] shows higher water solubility and also higher lability of the bridge. The antioxidant and hydrolytic beta-lactamase-like activity of the complexes were evaluated. The lability of the bridge seems to be important for the antioxidant activity and is suggested to because of [CuCu(saldman)] presents a lower antioxidant capacity than [CuZn(saldman)], which showed to present a more stable bridge in solution. The hydrolytic activity of the bimetallic complexes was assayed using nitrocefin as substrate and showed [ZnZn(saldman)] as a better catalyst than the Cu(II) analog. The series demonstrates the importance of the nature of the metal center for the biological function and how the reactivity of the model complex can be modulated by coordination chemistry.

  12. Heterobimetallic thiocyanato-bridged coordination polymers based on [Hg(SCN)4]2-: Synthesis, crystal structure, magnetic properties and ESR studies

    International Nuclear Information System (INIS)

    Jian Fangfang; Xiao Hailian; Liu Faqian

    2006-01-01

    Three new M/Hg bimetallic thiocyanato-bridged coordination polymers; [Hg(SCN) 4 Ni(Im) 3 ] ∞ 1, [Hg(SCN) 4 Mn(Im) 2 ] ∞ 2, and [Hg(SCN) 4 Cu(Me-Im) 2 Hg(SCN) 4 Cu(Me-Im) 4 ] ∞ 3, (Im=imidazole, Me-Im=N-methyl-imidazole), have been synthesized and characterized by means of elemental analysis, ESR, and single-crystal X-ray. X-ray diffraction analysis reveals that these three complexes all form 3D network structure, and their structures all contain a thiocyanato-bridged Hg...Hg chain (M=Mn, Ni, Cu) in which the metal and mercury centers exhibit different coordination environments. In complex 1, the [Hg(SCN) 4 ] 2- anion connects three [Ni(Im) 3 ] 2+ using three SCN ligands giving rise to a 3D structure, and in complex 2, four SCN ligands bridge [Hg(SCN) 4 ] 2- and [Mn(Im) 2 ] 2+ to form a 3D structure. The structure of 3 contains two copper atoms with distinct coordination environment; one is coordinated by four N-methyl-imidazole ligands and two axially elongated SCN groups, and another by four SCN groups (two elongated) and two N-methyl-imidazole ligands. The magnetic property of complex 1 has been investigated. The spin state structure in hetermetallic NiHgNi systems of complex 1 is irregular. The ESR spectra results of complex 3 demonstrate Cu 2+ ion lie on octahedral environment. -- Graphical abstract: Three new M/Hg bimetallic thiocyanato-bridged coordination polymers; [Hg(SCN) 4 Ni(Im) 3 ] ∞ 1, [Hg(SCN) 4 Mn(Im) 2 ] ∞ 2, and [Hg(SCN) 4 Cu(Me-Im) 2 Hg(SCN) 4 Cu(Me-Im) 4 ] ∞ 3, (Im=imidazole, Me-Im=N-methyl-imidazole), have been synthesized and characterized by single-crystal X-ray. All coordination polymers possess 3-D structures, and consist of organic base neutral ligands (imidazole and N-methyl-imidazole) and SCN -1 anions. Their structural difference is mainly caused by the role of the organic base and metal ions. The complex 1 shows the irregular spin state structure

  13. New therapy complexes of copper(II) with 2,2'-bipyridine (Bpy) and phosphocholine (PCh-) or the quaternary 1-(2-phosphonomethoxy)ethyl derivative of 2,4-diaminopyrimidine (PMEDAPy-)

    Czech Academy of Sciences Publication Activity Database

    Fernández-Botello, A.; Escuer, A.; Solans, X.; Font-Bardía, M.; Holý, Antonín; Sigel, H.; Moreno, V.

    -, č. 13 (2007), s. 1867-1873 ISSN 1434-1948 Institutional research plan: CEZ:AV0Z40550506 Keywords : ternary complexes * oxido bridges * phosphonate bridges * copper(II) Subject RIV: CC - Organic Chemistry Impact factor: 2.597, year: 2007

  14. Syntheses and Crystal Structures of Mercury(II) and Copper(II) Complexes of an 18-Membered NS{sub 4}-Macrocycle

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eunji; Lee, Shim Sung [Gyeongsang National University, Jinju (Korea, Republic of)

    2015-01-15

    An 18-membered NS{sub 4}-macrocycle was employed, and its complexation behaviors with hard and soft metal ions were investigated. Reactions of L with mercury(II) nitrate and thiocyanate afforded endocyclic mononuclear complexes [Hg(L)(NO{sub 3}){sub 2}] (1) and [Hg(L)(SCN){sub 2}] (2), respectively, with anion coordinations. In the nitrato complex 1, the mercury(II) center is six-coordinate, being bound to three S donors and one pyridine N atom in L, and the coordination sphere is completed by two monodentate nitrate ions from both sides of the macrocyclic plane adopting a distorted octahedral geometry. The thiocyanato complex 2, which contains two crystallographically independent but almost isostructural complex units is five-coordinate, being bound to NS{sub 2} donors in L and two monodentate thiocyanate ions on the same side of the bound macrocycle unlike 1, adopting a distorted square pyramidal geometry. Reaction of L with CuCl{sub 2} 2H{sub 2}O yielded a dark-green bis(macrocycle) trinuclear complex, [Cu{sub 3}(L){sub 2}Cl{sub 6}] 0.5CH{sub 2}Cl{sub 2} (3), in which two endocyclic monocopper (II) complex units are linked by an exocyclic one Cu and two bridging Cl atoms. In 3, interestingly, the local coordination environments of the three copper(II) atoms are different, with four, five, or six coordination, adopting a distorted square pyramidal, tetrahedral, or octahedral geometry, respectively. From these results, it is found that the ditopic ligand L reacts with both soft and hard metal-ion species to give diverse types of endocyclic complexes whose structures are also dependent on the anions used.

  15. A copper(II) thiosemicarbazone complex built on gold for the immobilization of lipase and laccase.

    Science.gov (United States)

    Rodríguez-Argüelles, M Carmen; Villalonga, Reynaldo; Serra, Carmen; Cao, Roberto; Sanromán, M Angeles; Longo, María A

    2010-08-01

    A self-assembled monolayer (SAM) of imidazole-2-carbaldehyde thiosemicarbazone (H(2)ImTSC) on gold was formed and characterized by ATR-FTIR, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray Photoelectron Spectroscopy (XPS). The self-assembly of the ligand through its thioenolate group was confirmed by ToF-SIMS and the presence of XPS peaks at 161.9 (S(2p1/2)) and 163.1eV (S(2p3/2)). The two nitrogen donor atoms of self-assembled HImTSC were able to coordinate (kappa(2)-N,N) copper(II) when set to interact with a CuCl(2) solution upon a second deprotonation of the ligand. This way, two types of modified gold sheets for the immobilization of lipase and laccase were obtained: (a) SAM of the ligand on gold (Au-HImTSC), and (b) SAM of HImTSC with a second monolayer of copper(II) (Au-ImTSC-Cu(II)). The highest immobilization of enzyme was achieved for laccase on Au-ImTSC-Cu(II) according to XPS and enzymatic activity determinations. Copper(II) played a an important recognition role through coordination to the enzyme and/or electrostatic interactions. Nevertheless, the positively charged surface of Au-ImTSC-Cu(II) affected the activity of laccase. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  16. Polyethyleneimine anchored copper(II) complexes: synthesis, characterization, in vitro DNA binding studies and cytotoxicity studies.

    Science.gov (United States)

    Lakshmipraba, Jagadeesan; Arunachalam, Sankaralingam; Riyasdeen, Anvarbatcha; Dhivya, Rajakumar; Akbarsha, Mohammad Abdulkader

    2015-01-01

    The water soluble polyethyleneimine-copper(II) complexes, [Cu(phen)(L-tyr)BPEI]ClO4 (where phen=1,10-phenanthroline, L-tyr=L-tyrosine and BPEI=branched polyethyleneimine) with various degree of copper(II) complex units in the polymer chain were synthesized and characterized by elemental analysis and electronic, FT-IR, EPR spectroscopic techniques. The binding of these complexes with CT-DNA was studied using UV-visible absorption titration, thermal denaturation, emission, circular dichroism spectroscopy and cyclic voltammetric methods. The changes observed in the physicochemcial properties indicated that the binding between the polymer-copper complexes and DNA was mostly through electrostatic mode of binding. Among these complexes, the polymer-copper(II) complex with the highest degrees of copper(II) complex units (higher degrees of coordination) showed higher binding constant than those with lower copper(II) complex units (lower degrees of coordination) complexes. The complex with the highest number of metal centre bound strongly due to the cooperative binding effect. Therefore, anticancer study was carried out using this complex. The cytotoxic activity for this complex on MCF-7 breast cancer cell line was determined adopting MTT assay, acridine orange/ethidium bromide (AO/EB) staining and comet assay techniques, which revealed that the cells were committed to specific mode of cell death either apoptosis or necrosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Copper(II) Chlorate Complexes: The Renaissance of a Forgotten and Misjudged Energetic Anion.

    Science.gov (United States)

    Wurzenberger, Maximilian H H; Szimhardt, Norbert; Stierstorfer, Jörg

    2018-03-07

    A convenient synthetic route toward new copper(II) chlorate complexes with potential use in modern advanced ignition or initiation systems is described. Obtained compounds were not only accurately characterized (XRD, IR, UV/Vis EA and DTA) but also investigated for their energetic character (sensitivities, initiation capability and laser ignition). The copper 4-aminotriazolyl chlorate complex showed excellent initiation of PETN, while also being thermally stable and safe to handle. Solid-state UV-Vis measurements were performed to get a possible insight toward the laser initiation mechanism. In contrast to expectations, the presented copper(II) chlorate energetic coordination compounds show manageable sensitivities that can be tamed or boosted by the appropriate choice of nitrogen-rich ligands.

  18. Coordination modes between copper(II) and N-acetylneuraminic (sialic) acid from a 2D-simulation analysis of EPR spectra. Implications for copper mediation of sialoglycoconjugate chemistry relevant to human biology.

    Science.gov (United States)

    Fainerman-Melnikova, Marina; Szabó-Plánka, Terézia; Rockenbauer, Antal; Codd, Rachel

    2005-04-04

    The equilibrium distribution of species formed between Cu(II) and N-acetylneuraminic (sialic) acid (I, LH) at 298 K has been determined using a two-dimensional (2D) simulation analysis of electron paramagnetic resonance (EPR) spectra. In acidic solutions (pH values 11. It is proposed that [CuL]+ most likely features I coordinated via the deprotonated carboxylic acid group (O1) and the endocyclic oxygen atom (OR) forming a five-membered chelate ring. Select Cu(II)-I species of the form [CuLH-1] may feature I acting as a dianionic tridentate chelate, via oxygen atoms derived from O1, OR, and one deprotonated hydroxy group (O7 or O8) from the glycerol tail. Alternatively, I may coordinate Cu(II) in a bidentate fashion as the tert-2-hydroxycarboxylato (O1,O2) dianion. Spectra predicted for Cu(II)-I complexes in which I is coordinated in either a O1,OR {I1-} or O1,O2 {I2-} bidentate fashion {e.g., [CuL]+ (O1,O R), [CuL2] (bis-O1,O R), [CuLH-1] (isomer: O1, O2), [CuL2H-1]- (O1, O R; O1, O2), and [CuL2H-2]2- (isomer: bis-O1, O2)} have "irregular" EPR spectra that are ascribed to the existence of Cu(II)-I(monomer) Cu(II)-I(polymer) equilibria. The formation of polymeric Cu(II)-I species will be favored in these complexes because the glycerol-derived hydroxyl groups at the complex periphery (O, 7O, 8O9) are available for further Cu(II) binding. The presence of polymeric Cu(II)-I species is supported by EPR spectral data from solutions of Cu(II) and the homopolymer of I, colominic acid (Ipoly). Conversely, spectra predicted for Cu(II)-I complexes where I is coordinated in a {I2-} tridentate {e.g., [CuLH-1] (isomer: O1, O R, O7, or O8) and [CuL2H-2]2- (isomer: bis-O1,O R,O7, or O8)} or tetradentate fashion {I3-} {e.g., [CuLH-3]2- (O1, O R, O, 8O9)} are typical for mononuclear tetragonally elongated Cu(II) octahedra. In this latter series of complexes, the tendency toward the formation of polymeric Cu(II)-I analogues is small because the polydentate I effectively wraps up the

  19. trans-Bis(perchlorato-κOtetrakis(1H-pyrazole-κN2copper(II

    Directory of Open Access Journals (Sweden)

    Viktor Zapol'skii

    2008-10-01

    Full Text Available The title compound, [Cu(ClO42(C3H4N24], was obtained unexpectedly by the reaction of copper(II perchlorate hexahydrate with equimolar amounts of 1-chloro-1-nitro-2,2,2-tripyrazolylethane in methanol solution. The crystal structure comprises octahedrally coordinated Cu2+ ions, located on an inversion centre, with four pyrazole ligands in the equatorial plane. The average Cu—N distance is 2.000 (1 Å. Two perchlorate ions are coordinated to copper in trans positions [Cu—O = 2.4163 (11 Å].

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

    Science.gov (United States)

    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.

  1. Fluorescent copper(II complexes: The electron transfer mechanism, interaction with bovine serum albumin (BSA and antibacterial activity

    Directory of Open Access Journals (Sweden)

    Madhumita Hazra

    2017-01-01

    Full Text Available Dinuclear copper(II complexes with formula [Cu2(L2(N32] (1 and [Cu2(L2(NCS2] (2 HL = (1-[(3-methyl-pyridine-2-ylimino-methyl]-naphthalen-2-ol were synthesized by controlling the molar ratio of Cu(OAC2·6H2O, HL, sodium azide (1 and ammonium thiocyanate (2. The end on bridges appear exclusively in azide and thiocyanate to copper complexes. The electron transfer mechanism of copper(II complexes is examined by cyclic voltammetry indicating copper(II complexes are Cu(II/Cu(I couple. The interactions of copper(II complexes towards bovine serum albumin (BSA were examined with the help of absorption and fluorescence spectroscopic tools. We report a superficial solution-based route for the synthesis of micro crystals of copper complexes with BSA. The antibacterial activity of the Schiff base and its copper complexes were investigated by the agar disc diffusion method against some species of pathogenic bacteria (Escherichia coli, Vibrio cholerae, Streptococcus pneumonia and Bacillus cereus. It has been observed that the antibacterial activity of all complexes is higher than the ligand.

  2. Synthesis and Crystal Structures of Copper(II) Complexes with Schiff Base Ligands: [Cu2(acpy-mdtc)2(HBA)(ClO4)]·H2O and [Cu2(acpy-phtsc)2(HBA)]·ClO4

    International Nuclear Information System (INIS)

    Koo, Bon Kweon

    2013-01-01

    Two new Cu(II) complexes, [Cu 2 (acpy-mdtc) 2 (HBA)(ClO 4 )]·H 2 O (1) (acpy-mdtc - = 2-acetylpyridine S-methyldithiocarbamate and HBA - = benzilic acid anion) and [Cu 2 (acpy-phtsc) 2 (HBA)]·ClO 4 (2) (acpy-phtsc - = 2-acetylpyridine 4-phenyl-3-thiosemicarbazate) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. The X-ray analysis reveals that the structures of 1 and 2 are dinuclear copper(II) complexes bridged by two thiolate sulfur atoms of Schiff base ligand and bidentate bridging HBA - anion. For 1, each of the two copper atoms has different coordination environments. Cu1 adopts a five-coordinate square-pyramidal with a N 2 OS 2 donor, while Cu 2 exhibits a distorted octahedral geometry in a N 2 O 2 S 2 manner. For 2, two Cu(II) ions all have a five-coordinate square-pyramidal with a N 2 OS 2 donor. In each complex, the Schiff base ligand is coordinated to copper ions as a tridentate thiol mode

  3. Synthesis and structure elucidation of new μ-oxamido-bridged dicopper(II) complex with in vitro anticancer activity: A combined study from experiment verification and docking calculation on DNA/protein-binding property.

    Science.gov (United States)

    Zhu, Ling; Zheng, Kang; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2016-02-01

    A new oxamido-bridged dicopper(II) complex with formula of [Cu2(deap)(pic)2], where H2deap and pic represent N,N'-bis[3-(diethylamino)propyl]oxamide and picrate, respectively, was synthesized and characterized by elemental analyses, molar conductance measurements, IR and electronic spectral study, and single-crystal X-ray diffraction. The crystal structure analyses revealed that the two copper(II) atoms in the dicopper(II) complex are bridged by the trans-deap(2-) ligand with the distances of 5.2116(17)Å, and the coordination environment around the copper(II) atoms can be described as a square-planar geometry. Hydrogen bonding and π-π stacking interactions link the dicopper(II) complex into a three-dimensional infinite network. The DNA/protein-binding properties of the complex are investigated by molecular docking and experimental assays. The results indicate that the dicopper(II) complex can interact with HS-DNA in the mode of intercalation and effectively quench the intrinsic fluorescence of protein BSA by 1:1 binding with the most possible binding site in the proximity of Trp134. The in vitro anticancer activities suggest that the complex is active against the selected tumor cell lines, and IC50 values for SMMC-7721 and HepG2 are lower than cisplatin. The effects of the electron density distribution of the terminal ligand and the chelate ring arrangement around copper(II) ions bridged by symmetric N,N'-bis(substituted)oxamides on DNA/BSA-binding ability and in vitro anticancer activity are preliminarily discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. (μ-O,O‧)-nitrito bridged 3-D coordination frameworks of M2+ (Mn Co, Zn) with mab and jsm topology

    Science.gov (United States)

    Paul, Rima; Guha, Ankur K.; Saikia, Lakshi; Bora, Sanchay J.

    2017-11-01

    Four new nitrito-bridged coordination polymers of formulation [Zn(NO2)2(H2O)2]n (1) and [M(bipy)(NO2)2]n [M = Zn (2), Co (3), Mn (4)] were synthesized under solvothermal condition using N,N-dimethylformamide (DMF) as a reducing solvent. Theoretical calculation suggests in situ reduction of nitrate to nitrite with high spontaneity and without any thermodynamic barrier (ΔG = -20.4 kcal/mol). All the complexes were characterized by elemental analysis, FT-IR spectroscopy, UV-vis spectroscopy, Raman Spectroscopy, TG analysis as well as by single crystal X-ray diffraction methods. TD-DFT approach has been employed to assign the electronic transitions occurring in the cobalt(II) complex (3) and were compared with those observed experimentally. This work also describes the preliminary studies on heterogeneous oxidation of cyclohexene by 2&3 in acetonitrile medium using TBHP.

  5. Heteronuclear, mixed-metal Ag(I)-Mn(II) coordination polymers with bridging N-pyridinylisonicotinohydrazide ligands: synthesis, crystal structures, magnetic and photoluminescence properties.

    Science.gov (United States)

    Bikas, Rahman; Hosseini-Monfared, Hassan; Vasylyeva, Vera; Sanchiz, Joaquín; Alonso, Javier; Barandiaran, Jose Manuel; Janiak, Christoph

    2014-08-21

    Mixed-metal dicyanoargentate-bridged coordination polymers of Ag(i)-Mn(ii) have been prepared and their structure and magnetic properties were determined. Reaction of manganese(ii) chloride and potassium dicyanoargentate(i) with (X)(pyridin-2-ylmethylene)isonicotinohydrazide ligands (HL(1) X = Ph, HL(2) X = Me, HL(3) X = H) produced the coordination polymer 2D-[Mn(μ-L(1))(Cl)(μ-NCAgCN)Mn0.5(CH3OH)]n (), 1D-{[Mn(L(2))(Cl)(μ-NCAgCN)Mn0.5(CH3OH)]CH3OH}n () and [Mn(L(3))(Cl)(μ-NCAgCN)Mn0.5(CH3OH)]n () in good yields. Trinuclear {Mn(μ-L(1))Mn(μ-L(1))Mn} and [Ag(CN)2](-) building units form a two-dimensional slab in and 1D strands in . Variable temperature magnetic susceptibility measurements showed that despite the long distance among the high spin Mn(ii) ions [10.4676(12) Å and 10.522(1) Å, for and , respectively], weak antiferromagnetic coupling takes place through the long NC-Ag-CN bridge. The best fit parameters to the model led to the magnetic coupling constant of J = -0.1 and J = -0.47 cm(-1) for and , respectively. The photoluminescence behaviour of compounds and was studied. The spectrum of compound shows a broad emission centered at about 450 nm and two excitation maxima at 270 and 310 nm.

  6. Hydrolytic activity of -alkoxide/acetato-bridged binuclear Cu (II ...

    Indian Academy of Sciences (India)

    Two -alkoxide/acetate-bridged small molecule binuclear copper(II) complexes were synthesized, and used to promote the hydrolysis of a classic carboxylic acid ester, -nitrophenyl picolinate (PNPP). Both binuclear complexes exhibited good hydrolytic reactivity, giving rise to . 15547- and 17462-fold acceleration over ...

  7. Construction of double-stranded metallosupramolecular polymers with a controlled helicity by combination of salt bridges and metal coordination.

    Science.gov (United States)

    Ikeda, Masato; Tanaka, Yoshie; Hasegawa, Takashi; Furusho, Yoshio; Yashima, Eiji

    2006-05-31

    We describe the construction of the first double-stranded metallosupramolecular helical polymers. We designed and synthesized a supramolecular duplex comprised of complementary m-terphenyl-based strands bearing a chiral amidine or achiral carboxylic acid together with two pyridine groups at the four ends. Supramolecular polymerization of the duplex with cis-PtPh2(DMSO)2 in 1,1,2,2-tetrachloroethane produced the double-stranded metallosupramolecular polymer with a controlled helicity of which the two complementary metallostrands are intertwined through the amidinium-carboxylate salt bridges. The structures and hydrodynamic dimensions of the metallosupramolecular polymers were characterized by 1H NMR, diffusion-ordered NMR, dynamic light scattering, absorption, and CD measurements. The polymeric structure was also visualized by atomic force microscopy.

  8. 1D Cu(II) coordination polymer derived from 2-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)benzenesulfonate chelator and pyrazine spacer

    Science.gov (United States)

    Mahmudov, Kamran T.; Haukka, Matti; Sutradhar, Manas; Mizar, Archana; Kopylovich, Maximilian N.; Pombeiro, Armando J. L.

    2013-02-01

    Reaction of 2-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)benzenesulfonic acid (H2L) with copper(II) nitrate hydrate in the presence of pyrazine (pz) in methanol affords the coordination polymer [Cu2(μ-L)2(H2O)2(μ-pz)]n (1), where the bidentate pz molecule links two Cu(II) centres of two different dimeric units, giving rise to a one-dimensional chain. The dimeric unit [Cu2(μ-L)2(H2O)2] consists of two distorted octahedral Cu(II) centres connected via oxygen atoms of the sulfo group of the bridging L2- ligand. The extensive hydrogen bonding between the coordinated water and pz molecules leads to the formation of a supramolecular 3D associate. Compound 1 has been characterized by elemental analysis, ESI-MS, IR spectroscopy and single-crystal X-ray diffraction analysis.

  9. Synthesis, characterization, electrical conductivity and luminescence properties of two copper(II) complexes with tridentate N2O chelating ligands containing imine bond

    Science.gov (United States)

    Gönül, İlyas; Ay, Burak; Karaca, Serkan; Şahin, Onur; Serin, Selahattin

    2018-03-01

    In the present study, we describe the synthesis and characterization of two tridentate N2O donor ligands, namely, (E)-2-(((2-(diethylamino)ethyl)imino)methyl)-6-methoxyphenol (HL1) and (E)-2-(((2-(diethylamino)ethyl)imino)methyl)-6-ethoxyphenol (HL2), and their copper(II) complexes, [Cu(L1)(CH3COO)] (1), [Cu(L2)(CH3COO)] (2). They have been synthesized under conventional methods and characterized by elemental analysis, FTIR, 1H and 13C NMR, ICP-OES, TGA and GC/MS analysis. For the morphological analysis field emission scanning electron microscopy (FESEM) was used. The geometry of the copper(II) complexes was determined by single crystal X-ray diffraction analysis. The copper(II) ions are in distorted square-pyramidal coordination environments. Complexes crystallize in monoclinic space group, P21/c. The electrical conductivity and luminescence properties of 1-2 have been investigated.

  10. Influence of inductive effects and steric encumbrance on the catecholase activities of copper(II) complexes of reduced Schiff base ligands.

    Science.gov (United States)

    Thio, Yude; Yang, Xiandong; Vittal, Jagadese J

    2014-03-07

    A series of copper(ii) complexes derived from reduced Schiff base ligands has been synthesized and characterized by single-crystal X-ray diffraction and spectroscopic analyses. With the exception of [Cu(Ala5NO2)(H2O)] (), which crystallized as a mononuclear repeating unit, [Cu2L2(H2O)x(DMSO)y]·solvent (L = Ala5H (), Ala5OMe (), Ala5Cl (), Ala5Br (), Gly5Br (), Val5Br () and Leu5Br (), x = 1 or 2, y = 0 or 1, solvent = MeOH or DMSO and H2O) crystallized as phenoxo-bridged dinuclear building units containing Cu2O2 cores. In , , , and , the axial positions are occupied by solvent ligands and carboxylate oxygen atoms from adjacent dimers, resulting in the formation of 1D helical coordination polymers. In , a 2D network is constructed by utilizing weak CuO interactions (∼2.7 Å) with carboxylate groups. All complexes have been investigated for their catecholase activities with 3,5-DTBC, and they show significant catalytic activities except for . The catalytic activities are also observed to increase with increasing +I effects, as well as increase with increasing steric bulkiness on the α-carbon of the carboxylate group.

  11. Photocleavage of DNA by copper(II) complexes

    Indian Academy of Sciences (India)

    The chemistry of ternary and binary copper(II) complexes showing efficient visible lightinduced DNA cleavage activity is summarized in this article. The role of the metal in photo-induced DNA cleavage reactions is explored by designing complex molecules having a variety of ligands. Ternary copper(II) complexes with amino ...

  12. Photocleavage of DNA by copper(II) complexes

    Indian Academy of Sciences (India)

    Abstract. The chemistry of ternary and binary copper(II) complexes showing efficient visible light- induced DNA cleavage activity is summarized in this article. The role of the metal in photo-induced. DNA cleavage reactions is explored by designing complex molecules having a variety of ligands. Ternary copper(II) complexes ...

  13. Synthesis, stereochemistry and antimicrobial activity of copper(II ...

    African Journals Online (AJOL)

    On the basis of the analytical data, magnetic moments and spectral data, a square-planar geometry has been proposed for the nickel(II) and copper(II) complexes with these ligands. Some representative complexes of copper(II) and nickel(II) were found to have remarkable antifungal and antibacterial activity. KEY WORDS: ...

  14. Synthesis, Characterization and Antimicrobial Activity of Copper(II ...

    African Journals Online (AJOL)

    This study presents the synthesis, characterization and antimicrobial activity of copper(II) complexes of some ortho-substituted aniline Schiff bases (L1–L8). The Schiff bases and their respective copper(II) complexes were characterized by a combination of elemental analysis, infrared and UV/Visible studies. The structures of ...

  15. Copper(II) coordination compounds with quinaldinate and alcoholamines

    OpenAIRE

    Trontelj, Primož

    2017-01-01

    The presented work describes reactions of [Cu(kinal)2(MeOH)]•MeOH (kinal– = quinaldinate) with diethanolamine (H2dea). Reactions at room temperature afforded a mononuclear compound cis [Cu(kinal)2(H2dea)]1/2H2dea. At 105 C, deprotonation of diethanolamine took place and the composition of the crystalline product was [Cu2(kinal)2(Hdea)2] (Hdea– stands for the anionic form of the ligand). Products of the reactions with panthenol remain to be identified.

  16. Synthesis and crystal structure of a ternary copper(II) complex of 2,2‧-bipyridine and picrate: Molecular docking, reactivity towards DNA and in vitro anticancer activity

    Science.gov (United States)

    Zheng, Kang; Jiang, Man; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2014-01-01

    A new mononuclear ternary copper(II) complex with mixed ligands of 2,2‧-bipyridine (bpy) and picrate (pic), namely [Cu(bpy)(pic)2], has been synthesized and characterized by elemental analysis, molar conductivity measurement, IR and electronic spectral studies, and single-crystal X-ray diffraction. The crystal structure analysis reveals the presence of two crystallographic independent molecules in an asymmetric unit. The copper(II) atoms are in elongated octahedral coordination geometries. A three-dimensional supermolecular network is formed through non-classical C-H⋯O hydrogen bonds. The DNA-binding properties of the copper(II) complex are investigated both theoretically and experimentally, revealing that the copper(II) complex can interact with HS-DNA in the mode of intercalation, and the molecular docking of the copper(II) complex with the self-complementary DNA duplex of sequence d(ACCGACGTCGGT)2 facilitates the binding events. The in vitro anticancer activities suggest that the copper(II) complex is active against the selected tumor cell lines.

  17. Crystal structure of di-μ-chlorido-bis[chloridobis(1,2-dimethyl-5-nitro-1H-imidazole-κN3copper(II] acetonitrile disolvate

    Directory of Open Access Journals (Sweden)

    Patrick J. Quinlivan

    2016-11-01

    Full Text Available 1,2-Dimethyl-5-nitroimidazole (dimetridazole, dimet is a compound that belongs to a class of nitroimidazole drugs that are effective at inhibiting the activity of certain parasites and bacteria. However, there are few reports that describe structures of compounds that feature metals complexed by dimet. Therefore, we report here that dimet reacts with CuCl2·H2O to yield a chloride-bridged copper(II dimer, [Cu2Cl4(C5H7N3O24] or [Cu(μ-ClCl(dimet2]2. In this molecule, the CuII ions are coordinated in an approximately trigonal–bipyramidal manner, and the molecule lies across an inversion center. The dihedral angle between the imidazole rings in the asymmetric unit is 4.28 (7°. Compared to metronidazole, dimetridazole lacks the hydroxyethyl group, and thus cannot form intermolecular O...H hydrogen-bonding interactions. Instead, [Cu(μ-ClCl(dimet2]2 exhibits weak intermolecular interactions between the hydrogen atoms of C—H groups and (i oxygen in the nitro groups, and (ii the terminal and bridging chloride ligands. The unit cell contains four disordered acetonitrile molecules. These were modeled as providing a diffuse contribution to the overall scattering by SQUEEZE [Spek (2015. Acta Cryst. C71, 9–18], which identified two voids, each with a volume of 163 Å3 and a count of 46 electrons, indicative of a total of four acetonitrile molecules. These acetonitrile molecules are included in the chemical formula to give the expected calculated density and F(000.

  18. Copper(II) complexes with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid: Syntheses, crystal structures and antifungal activities

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Pingping [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Li, Jie [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Bu, Huaiyu, E-mail: 7213792@qq.com [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Wei, Qing [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Zhang, Ruolin [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Chen, Sanping, E-mail: sanpingchen@126.com [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China)

    2014-07-01

    Reaction of Cu(II) with an asymmetric semi-rigid organic ligand 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid (HL), yielded five compounds, [Cu{sub 0.5}L]{sub n} (1), [Cu(HL){sub 2}Cl{sub 2}]{sub n} (2), [Cu(HL){sub 2}Cl{sub 2}(H{sub 2}O)] (3), [Cu(L){sub 2}(H{sub 2}O)]{sub n} (4) and [Cu(L)(phen)(HCO{sub 2})]{sub n} (5), which have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. As for compounds 1, 2 and 5, Cu(II) is bridged through HL, Cl{sup -}, and formic acid, respectively, featuring 1D chain-structure. In compound 3, Cu(II) with hexahedral coordination sphere is assembled through hydrogen-bonding into 3D supramolecular framework. In compound 4, 1D chain units –Cu–O–Cu–O– are ligand-bridged into a 3D network. All compounds were tested on fungi (Fusarium graminearum, Altemaria solani, Macrophoma kawatsukai, Alternaria alternata and Colletotrichum gloeosporioides). Compound 1 exhibits a better antifungal effect compared to other compounds. An effect of structure on the antifungal activity has also been correlated. - Graphical abstract: Copper(II) compounds with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid, were prepared, structurally characterized and investigated for antifungal activity. - Highlights: • The title compounds formed by thermodynamics and thermokinetics. • The five compounds show higher inhibition percentage than reactants. • The structure effect on the antifungal activity.

  19. Oligo-m-phenyleneoxalamide copper(II) mesocates as electro-switchable ferromagnetic metal-organic wires.

    Science.gov (United States)

    Pardo, Emilio; Ferrando-Soria, Jesús; Dul, Marie-Claire; Lescouëzec, Rodrigue; Journaux, Yves; Ruiz-García, Rafael; Cano, Joan; Julve, Miguel; Lloret, Francesc; Cañadillas-Delgado, Laura; Pasán, Jorge; Ruiz-Pérez, Catalina

    2010-11-15

    Double-stranded copper(II) string complexes of varying nuclearity, from di- to tetranuclear species, have been prepared by the Cu(II)-mediated self-assembly of a novel family of linear homo- and heteropolytopic ligands that contain two outer oxamato and either zero (1 b), one (2 b), or two (3 b) inner oxamidato donor groups separated by rigid 2-methyl-1,3-phenylene spacers. The X-ray crystal structures of these Cu(II) (n) complexes (n=2 (1 d), 3 (2 d), and 4 (3 d)) show a linear array of metal atoms with an overall twisted coordination geometry for both the outer CuN(2)O(2) and inner CuN(4) chromophores. Two such nonplanar all-syn bridging ligands 1 b-3 b in an anti arrangement clamp around the metal centers with alternating M and P helical chiralities to afford an overall double meso-helicate-type architecture for 1 d-3 d. Variable-temperature (2.0-300 K) magnetic susceptibility and variable-field (0-5.0 T) magnetization measurements for 1 d-3 d show the occurrence of S=nS(Cu) (n=2-4) high-spin ground states that arise from the moderate ferromagnetic coupling between the unpaired electrons of the linearly disposed Cu(II) ions (S(Cu)=1/2) through the two anti m-phenylenediamidate-type bridges (J values in the range of +15.0 to 16.8 cm(-1)). Density functional theory (DFT) calculations for 1 d-3 d evidence a sign alternation of the spin density in the meta-substituted phenylene spacers in agreement with a spin polarization exchange mechanism along the linear metal array with overall intermetallic distances between terminal metal centers in the range of 0.7-2.2 nm. Cyclic voltammetry (CV) and rotating-disk electrode (RDE) electrochemical measurements for 1 d-3 d show several reversible or quasireversible one- or two-electron steps that involve the consecutive metal-centered oxidation of the inner and outer Cu(II) ions (S(Cu)=1/2) to diamagnetic Cu(III) ones (S(Cu)=0) at relatively low formal potentials (E values in the range of

  20. Synthesis, Characterization, Crystal Structure and Antimicrobial Activity of Copper(II Complexes with the Schiff Base Derived from 2-Hydroxy-4-Methoxybenzaldehyde

    Directory of Open Access Journals (Sweden)

    Elena Pahonțu

    2015-04-01

    Full Text Available A novel Schiff base, ethyl 4-[(E-(2-hydroxy-4-methoxyphenylmethylene-amino]benzoate (HL, was prepared and structurally characterized on the basis of elemental analyses, 1H NMR, 13C NMR, UV-Vis and IR spectral data. Six new copper(II complexes, [Cu(L(NO3(H2O2] (1, [Cu(L2] (2, [Cu(L(OAc] (3, [Cu2 (L2Cl2(H2O4] (4, [Cu(L(ClO4(H2O] (5 and [Cu2(L2S(ClO4(H2O]ClO4·H2O (6 have been synthesized. The characterization of the newly formed compounds was done by IR, UV-Vis, EPR, FAB mass spectroscopy, elemental and thermal analysis, magnetic susceptibility measurements and molar electric conductivity. The crystal structures of Schiff base and the complex [Cu2(L2S(ClO4(H2O]ClO4·H2O (6 have been determined by single crystal X-ray diffraction studies. Both copper atoms display a distorted octahedral coordination type [O4NS]. This coordination is ensured by three phenol oxygen, two of which being related to the µ-oxo-bridge, the nitrogen atoms of the azomethine group and the sulfur atoms that come from the polydentate ligand. The in vitro antimicrobial activity against Escherichia coli ATCC 25922, Salmonella enteritidis, Staphylococcus aureus ATCC 25923, Enterococcus and Candida albicans strains was studied and compared with that of free ligand. The complexes 1, 2, 5 showed a better antimicrobial activity than the Schiff base against the tested microorganisms.

  1. End-to-end single cyanato and thiocyanato bridged Cu(II) polymers with a new tridentate Schiff base ligand: crystal structure and magnetic properties.

    Science.gov (United States)

    Talukder, Pritha; Datta, Amitabha; Mitra, Samiran; Rosair, Georgina; El Fallah, M Salah; Ribas, Joan

    2004-12-21

    A new tridentate Schiff base ligand HL (L = C14H19N2O), derived from the condensation of benzoylacetone and 2-dimethylaminoethylamine in a 1:1 ratio, reacts with copper(ii) acetate and cyanate, thiocyanate or azide, to give rise to several end-to-end polymeric complexes of formulae [CuL(mu(1,3)-NCO)]n 1, [CuL(mu(1,3)-NCS)]n 2 and the complex 3 has two crystallographically independent units of formula [CuL(N3)] in the asymmetric unit cell. Complex 3 exists in dimeric form rather than as a polymeric chain. Compound 1 is the first report of a singly end-to-end cyanate bridged polymeric chain of Cu(II) with a Schiff base as a co-ligand. There are many examples of double NCS bridged polymeric chains, but fewer singly bridged ones such as compound 2. We have characterized these complexes by analytical, spectroscopic, structural and variable temperature magnetic susceptibility measurements. The coordination geometry around the Cu(II) centers is distorted square pyramidal for 1 and 2 and square planar for complex 3. The magnetic susceptibility data show slight antiferromagnetic coupling for the polymers having J values -0.19 and -0.57 cm(-1) for complexes 1 and 2 respectively. The low values of J are consistent with the equatorial-axial disposition of the bridges in the polymers.

  2. Mixed-ligand binuclear copper(II) complex of 5 ...

    Indian Academy of Sciences (India)

    ligand binuclear copper(II) complex of 5-methylsalicylaldehyde and 2,2 -bipyridyl: Synthesis, crystal structure, DNA binding and nuclease activity. PERUMAL GURUMOORTHYa, JAYARAM RAVICHANDRANa,b and AZIZ KALILUR RAHIMANa,∗.

  3. Hydrolytic activity of μ-alkoxide/acetato-bridged binuclear Cu(II ...

    Indian Academy of Sciences (India)

    Abstract. Two μ-alkoxide/acetate-bridged small molecule binuclear copper(II) complexes were synthesized, and used to promote the hydrolysis of a classic carboxylic acid ester, p-nitrophenyl picolinate (PNPP). Both binuclear complexes exhibited good hydrolytic reactivity, giving rise to ca. 15547- and 17462-fold ...

  4. Spectroscopic and molecular docking studies on the interaction of human serum albumin with copper(II) complexes

    Science.gov (United States)

    Guhathakurta, Bhargab; Pradhan, Ankur Bikash; Das, Suman; Bandyopadhyay, Nirmalya; Lu, Liping; Zhu, Miaoli; Naskar, Jnan Prakash

    2017-02-01

    Two osazone based ligands, butane-2,3-dione bis(2‧-pyridylhydrazone) (BDBPH) and hexane-3,4-dione bis(2‧-pyridylhydrazone) (HDBPH), were synthesized out of the 2:1 M Schiff base condensation of 2-hydrazino pyridine respectively with 2,3-butanedione and 3,4-hexanedione. The X-ray crystal structures of both the ligands have been determined. The copper(II) complex of HDBPH has also been synthesized and structurally characterized. HDBPH and its copper(II) complex have thoroughly been characterized through various spectroscopic and analytical techniques. The X-ray crystal structure of the copper complex of HDBPH shows that it is a monomeric Cu(II) complex having 'N4O2' co-ordination chromophore. Interaction of human serum albumin (HSA) with these ligands and their monomeric copper(II) complexes have been studied by various spectroscopic means. The experimental findings show that the ligands as well as their copper complexes are good HSA binders. Molecular docking investigations have also been done to unravel the mode of binding of the species with HSA.

  5. Synthesis and Structure of a Ternary Copper(II) Complex with Mixed Ligands of Diethylenetriamine and Picrate: DNA/Protein-Binding Property and In Vitro Anticancer Activity Studies.

    Science.gov (United States)

    Shi, Ya-Ning; Zheng, Kang; Zhu, Ling; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2015-05-01

    Based on the importance of the design and synthesis of transition metal complexes with noncovalent DNA/protein-binding abilities in the field of metallo pharmaceuticals, a new mononuclear ternary copper(II) complex with mixed ligands of diethylenetriamine (dien) and picrate anion (pic), identified as [Cu(dien)(pic)](pic), was synthesized and characterized by elemental analysis, molar conductivity measurement, infrared spectrum, electronic spectral studies, and single-crystal X-ray diffractometry. The structure analysis reveals that the copper(II) complex crystallizes in the monoclinic space group P21 /c, and the copper(II) ion has a distorted square pyramidal coordination geometry. A two-dimensional supramolecular structure is formed through hydrogen bonds. The DNA/bovine serum albumin (BSA)-binding properties of the complex are explored, indicating that the complex can interact with herring sperm DNA via intercalation mode and bind to BSA responsible for quenching of tryptophan fluorescence by static quenching mechanism. The in vitro anticancer activity shows that the copper(II) complex is active against the selected tumor cell lines. © 2015 Wiley Periodicals, Inc.

  6. The electronic spectra and the structures of the individual copper(II) chloride and bromide complexes in acetonitrile according to steady-state absorption spectroscopy and DFT/TD-DFT calculations

    Science.gov (United States)

    Olshin, Pavel K.; Myasnikova, Olesya S.; Kashina, Maria V.; Gorbunov, Artem O.; Bogachev, Nikita A.; Kompanets, Viktor O.; Chekalin, Sergey V.; Pulkin, Sergey A.; Kochemirovsky, Vladimir A.; Skripkin, Mikhail Yu.; Mereshchenko, Andrey S.

    2018-03-01

    The results of spectrophotometric study and quantum chemical calculations for copper(II) chloro- and bromocomplexes in acetonitrile are reported. Electronic spectra of the individual copper(II) halide complexes were obtained in a wide spectral range 200-2200 nm. Stability constants of the individual copper(II) halide complexes in acetonitrile were calculated: log β1 = 8.5, log β2 = 15.6, log β3 = 22.5, log β4 = 25.7 for [CuCln]2-n and log β1 = 17.0, log β2 = 24.6, log β3 = 28.1, log β4 = 30.4 for [CuBrn]2-n. Structures of the studied complexes were optimized and electronic spectra were simulated using DFT and TD-DFT methodologies, respectively. According to the calculations, the more is the number of halide ligands the less is coordination number of copper ion.

  7. Enantiopure copper(II) complex of natural product rosin derivative: DNA binding, DNA cleavage and cytotoxicity.

    Science.gov (United States)

    Fei, Bao-Li; Yin, Bin; Li, Dong-Dong; Xu, Wu-Shuang; Lu, Yang

    2016-12-01

    To develop chiral anticancer drug candidates for molecular target DNA, the synthesis and characterization of a novel enantiomerically pure copper(II) complex [Cu 1 Cl 2 ] (2) of an optically pure ligand N-(pyridin-2-ylmethylene) dehydroabietylamine (1) was carried out. The coordination geometry of the copper center is a distorted square-planar arrangement. The interactions of 1 and 2 with salmon sperm DNA were investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. All the results reveal that 1 and 2 interacted with DNA through intercalation and 2 exhibited a higher DNA binding ability. Further, 1 and 2 could cleave supercoiled pBR322 DNA by single strand and 2 displayed stronger cleavage ability in the presence of ascorbic acid. In vitro cytotoxicity of 1 and 2 against HeLa, SiHa, HepG-2 and A431 cancer cell lines was studied using CCK-8 assay. The results indicate that 2 had a superior cytotoxicity than 1 and the widely used drug cisplatin under identical conditions. Flow cytometry analysis demonstrates 2 produced death of HeLa cancer cells through an apoptotic pathway. Cell cycle analysis shows that 2 mainly arrested HeLa cells at the S phase. A novel enantiomerically pure copper(II) complex [Cu 1 Cl 2 ] (2) of an optically pure ligand N-(pyridin-2-ylmethylene) dehydroabietylamine (1), based on natural product rosin has been synthesized. 2 has the potential to act as effective anticancer drug.

  8. Myocardial Bridge

    Science.gov (United States)

    ... Center > Myocardial Bridge Menu Topics Topics FAQs Myocardial Bridge Article Info En español Your heart is made ... surface of the heart. What is a myocardial bridge? A myocardial bridge is a band of heart ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Synthesis, characterization, and 3D-molecular modeling and analysis of some copper(II chelates in O, N-donor coordination pattern involving Schiff bases derived from 4-butyryl-3-methyl-1-phenyl-2-pyrazolin-5-one and some sulfa drugs

    Directory of Open Access Journals (Sweden)

    R.C. Maurya

    2015-03-01

    Full Text Available The synthesis of five new chelates of copper(II of the general formula[Cu(LH2(Cl2], where LH = N-(4′-butyrylidine-3′-methyl-1′-phenyl-2′-pyrazolin-5′-onesulfamethoxazole (bumphp-smzH, I, N-(4′-butyrylidine-3′-methyl-1′-phenyl-2′-pyrazolin-5′-onesulfadimidine (bumphp-sdmH, II, N-(4′-butyrylidine-3′-methyl-1′-phenyl-2′-pyrazolin-5′-onesulfanilamide (bumphp-snmH, III, N-(4′-butyrylidine-3′-methyl-1′-phenyl-2′-pyrazolin-5′-onesulfamoxole (bumphp-smlH, IV or N-(4′-butyrylidine-3′-methyl-1’-phenyl-2′-pyrazolin-5′-onesulfaguanidine (bumphp-sgdH, V has been carried out. The complexes have been characterized by elemental analyses, copper determination, molar conductance, magnetic and decomposition temperature measurements, electron spin resonance, thermogravimetry, infrared, and electronic spectral studies. A trans octahedral structure has been proposed for these complexes. The 3D molecular modeling and analysis for bond lengths and bond angles have also been carried out for one of the representative compound,[Cu(bumphp-snmH2(Cl2] (3 to substantiate the proposed structure.

  11. Selective EPR Detection of Primary Amines in Water with a Calix[6]azacryptand-Based Copper(II) Funnel Complex.

    Science.gov (United States)

    Inthasot, Alex; Le Poul, Nicolas; Luhmer, Michel; Colasson, Benoit; Jabin, Ivan; Reinaud, Olivia

    2018-04-02

    A water-soluble calix[6]arene-based azacryptand was synthesized. The corresponding tren [tris(2-aminoethyl)amine] cap grafted at the small rim coordinates strongly a copper(II) ion over a wide range of pH. The host-guest properties of the complex were explored by EPR spectroscopy. Due to second coordination sphere effects and the hydrophobic effect ascribed to the calixarene cavity, this funnel complex selectively binds neutral molecules (alcohols, nitriles, amines) versus anions in water near physiological pH. Among the coordinating guests, hydrophobic primary amines are preferentially recognized thanks to the combined effect of the better metal-ligand interaction and hydrogen bonding to the oxygen atoms present at the small rim. Hence, this Cu(II) calix[6]arene-based funnel complex behaves as a sensitive and selective EPR probe for primary amines, including biologically important molecules such as tyramine and tryptamine, in water, over a large pH window.

  12. Photocleavage of DNA by copper(II) complexes

    OpenAIRE

    Chakravarty, Akhil R

    2006-01-01

    The chemistry of ternary and binary copper(II) complexes showing efficient visible lightinduced DNA cleavage activity is summarized in this article. The role of the metal in photo-induced DNA cleavage reactions is explored by designing complex molecules having a variety of ligands. Ternary copper(II) complexes with amino acid like L-methionone or L-lysine and phenanthroline base are efficient photocleavers of DNA. Complexes of formulation $[Cu(L^n)(phen)](ClO_4)$ with NSO-donor Schiff base $(...

  13. Copper(II) complex of new non-innocent O-aminophenol-based ligand as biomimetic model for galactose oxidase enzyme in aerobic oxidation of alcohols

    Science.gov (United States)

    Safaei, Elham; Bahrami, Hadiseh; Pevec, Andrej; Kozlevčar, Bojan; Jagličić, Zvonko

    2017-04-01

    Mononuclear copper(II) complex of tetra-dentate o-aminophenol-based ligand (H2LBAPP) has been synthesized and characterized. The three dentate precursor (HLBAP) of the final ligand was synthesized first, while the title four-dentate copper bound ligand was synthesized in situ, isolated only in the final copper species [CuLBAPP]. This copper coordination complex reveals a distorted square-planar geometry around the copper(II) centre by one oxygen and three nitrogen atoms from the coordinating ligand. The ligand is thus twice deprotonated via hydroxy and amine groups. The complex is red, non-typical for copper(II), but the effective magnetic moment of 1.86 B M. and a single isotropic symmetry EPR signal with g 2.059 confirm a S = 1/2 diluted spin system, without copper-copper magnetic coupling. Electrochemical oxidation of this complex yields the corresponding Cu(II)-phenyl radical species. Finally, the title complex CuLBAPP has shown good and selective catalytic activity towards alcohol to aldehyde oxidation, at aerobic room temperature conditions, for a set of different alcohols.

  14. Antioxidant, DNA binding and nuclease activities of heteroleptic copper(II) complexes derived from 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols and diimines

    Science.gov (United States)

    Ravichandran, J.; Gurumoorthy, P.; Imran Musthafa, M. A.; Kalilur Rahiman, A.

    2014-12-01

    A series of heteroleptic copper(II) complexes of the type [CuL1-4(diimine)](ClO4)2 (1-8) [L1-4 = 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols, and diimine = 2,2‧-bipyridyl (bpy) or 1,10-phenanthroline (phen)], have been synthesized and characterized by spectroscopic methods. The IR spectra of complexes indicate the presence of uncoordinated perchlorate anions and the electronic spectra revealed the square pyramidal geometry with N4O coordination environment around copper(II) nuclei. Electrochemical studies of the mononuclear complexes evidenced one-electron irreversible reduction wave in the cathodic region. The EPR spectra of complexes with g|| (2.206-2.214) and A|| (154-172 × 10-4 cm-1) values support the square-based CuN3O coordination chromophore and the presence of unpaired electron localized in dx-y ground state. Antioxidant studies against DPPH revealed effective radical scavenging properties of the synthesized complexes. Binding studies suggest that the heteroleptic copper(II) complexes interact with calf thymus DNA (CT-DNA) through minor-groove and electrostatic interaction, and all the complexes display pronounced nuclease activity against supercoiled pBR322 DNA.

  15. ANTIMICROBIAL ACTIVITY OF COPPER(II COMPLEXES

    Directory of Open Access Journals (Sweden)

    Andrea Čongrádyová

    2014-02-01

    Full Text Available Two novel copper(II 5-chlorosalicylate complexes with either 1,10-phenantroline or its methyl derivative 2,9-dimethyl-1,10-phenanthroline (neocuproine have been prepared and studied. A potential antimicrobial or antifungal activity of both complexes has been tested on prokaryotic Escherichia coli and eukaryotic Saccharomyces cerevisiae model organisms. Crystal structure of [Cu(phen(5-Clsal(5-ClsalH2]2 a dimeric structure, whereas the second complex of formula [Cu(H2O(5-Clsal(Neo] has been shown to be monomeric. Our results confirmed the toxic effect of prepared copper complexes as well as bioactive ligands on the yeast and bacteria growth. The effect of copper complexes was stronger compared to the solutions of free ligands. Our preliminary results showed that the complex [Cu(H2O(5-Clsal(Neo] exhibited higher antimicrobial activity compared to the complex [Cu(phen(5-Clsal(5-ClsalH2]2.

  16. Extended X-ray absorption fine structure of copper(II) complexes at the air-water interface by a polarized total-reflection X-ray absorption technique.

    Science.gov (United States)

    Nagatani, Hirohisa; Tanida, Hajime; Watanabe, Iwao; Sagara, Takamasa

    2009-04-01

    Copper(II) complexes spread on an aqueous solution surface were studied by a polarized total-reflection X-ray absorption fine structure (TR-XAFS) technique. The polarized TR-XAFS spectra at the Cu-K edge for copper(II) porphyrins and copper(II) chlorophyllin in a monolayer were measured in situ at the air-water interface. The polarization dependences of X-ray absorption near-edge structure (XANES) involving a 1s-->4p(z) transition allowed us to estimate the molecular orientation and the local coordination structure around the copper(II) atom in the polarization plane selectively. The extended X-ray absorption fine structure (EXAFS) region of the polarized TR-XAFS spectra for the metal complexes present at the air-water interface was successfully analyzed for the first time. The relative coordination number for the copper center evaluated from the EXAFS analysis indicated larger values in the vertical polarization than in the horizontal one, in agreement with the standing-up molecular orientation at the air-water interface estimated from the XANES region.

  17. Railroad Bridges

    Data.gov (United States)

    Department of Homeland Security — Bridges-Rail in the United States According to The National Bridge Inspection Standards published in the Code of Federal Regulations (23 CFR 650.3), a bridge isA...

  18. A new 1D manganese(II) coordination polymer with end-to-end azide bridge and isonicotinoylhydrazone Schiff base ligand: Crystal structure, Hirshfeld surface, NBO and thermal analyses

    Science.gov (United States)

    Khani, S.; Montazerozohori, M.; Masoudiasl, A.; White, J. M.

    2018-02-01

    A new manganese (II) coordination polymer, [MnL2 (μ-1,3-N3)2]n, with co-ligands including azide anion and Schiff base based on isonicotinoylhydrazone has been synthesized and characterized. The crystal structure determination shows that the azide ligand acts as end-to-end (EE) bridging ligand and generates a one-dimensional coordination polymer. In this compound, each manganes (II) metal center is hexa-coordinated by four azide nitrogens and two pyridinic nitrogens for the formation of octahedral geometry. The analysis of crystal packing indicates that the 1D chain of [MnL2 (μ-1,3-N3)2]n, is stabilized as a 3D supramolecular network by intra- and inter-chain intermolecular interactions of X-H···Y (X = N and C, Y = O and N). Hirshfeld surface analysis and 2D fingerprint plots have been used for a more detailed investigation of intermolecular interactions. Also, natural bond orbital (NBO) analysis was performed to get information about atomic charge distributions, hybridizations and the strength of interactions. Finally, thermal analysis of compound showed its complete decomposition during three thermal steps.

  19. Synthesis, Characterization and DNA Cleavage of Copper(II ...

    African Journals Online (AJOL)

    Purpose: To study deoxyribonucleic acid (DNA) shearing capability of copper(II) complex of dithiothreitol (DTT) and to fevaluate its potential application in cancer therapy. Methods: A parrot green complex was synthesized by grinding copper acetate monohydrate and DTT in 1:2 molar ratio in a mortar until no fumes of acetic ...

  20. Photocytotoxic ternary copper(II) complexes of histamine Schiff base ...

    Indian Academy of Sciences (India)

    400-700 nm) with low dark toxicity. The photo-induced cell death is via ... The present work stems from our interest to design new copper(II) complexes that are ... measurements were made using a Control Dynamics. (India) conductivity meter.

  1. Preconcentration and extraction of copper(II) on activated carbon ...

    African Journals Online (AJOL)

    Activated carbon modified method was used for the preconcentration and determination of copper content in real samples such as tap water, wastewater and a synthetic water sample by flame atomic absorption spectrometry. The copper(II) was adsorbed quantitatively on activated carbon due to its complexation with ...

  2. Electrophoretic studies on biologically important copper(II ...

    African Journals Online (AJOL)

    Paper electrophoresis is used for the study of equilibria in binary complex systems in solution. The stability constants of ML and ML2 complex species of some metal ions copper(II), manganese(II) and uranyl(II) with a-aminobutenoic acid and hydroxyproline were determined at an ionic strength of 0.1 M and 35 ºC.

  3. X-ray Structure and Magnetic Properties of two new iron(II) 1D Coordination Polymers with Bis(imidazolyle)methane as bridging ligand

    OpenAIRE

    Weber , Birgit

    2009-01-01

    Abstract The reaction of iron(II) acetate with the tetradentate Schiff base like ligands H2L1 ((E,E)-[{diethyl 2,2'-[1,2-phenylenebis-(iminomethyl-idyne)]bis[3-oxobutanato]}]) and H2L2 ([([3,3']-[1,2-phenylene-bis(iminomethylidyne)]bis(2,4-pentane-dionato)(2-)-N,N',O2,O2']) leads to the formation of the octahedral N2O4 coordinated iron complexes [FeL1(MeOH)2] and [FeL2(MeOH)2], respectively. Conversion of both with bimm (bis(1-imidazolyle)methane) leads to the 1D coordination polym...

  4. Improvement of the antihypertensive capacity of candesartan and trityl candesartan by their SOD mimetic copper(II) complexes.

    Science.gov (United States)

    Islas, María S; Rojo, Teófilo; Lezama, Luis; Merino, Mercedes Griera; Cortes, María A; Puyol, Manuel Rodriguez; Ferrer, Evelina G; Williams, Patricia A M

    2013-06-01

    Two new complexes [Cu(Cand)(H2O)4] [1] and [Cu2(TCand)4(H2O)2]·4H2O [2] (Cand = candesartan; TCand = trityl candesartan) have been synthesized and thoroughly characterized. The FTIR, Raman, EPR and diffuse reflectance spectra of the solid compounds show a dimeric complex for [2] with carboxylate bridging of the type found in copper(II) acetate. Both elemental analysis and thermal measurements allow the determination of the total stoichiometries of both complexes. The stability measurements show that the compounds are stable in ethanolic solutions at least for 1h, while the preservation of the overall stochiometry for both species in solution has been determined by spectrophotometric titrations. By metal complexation the absence of antioxidant behavior of both sartans has been improved. Complexes [1] and [2] are strong superoxidedismutase mimetic compounds and complex [2] also behaves as a peroxyl radical scavenger. Furthermore, this higher antioxidant activity works in parallel with the improvement of the expansive activity over the angiotensin II-induced contracted human mesangial cells. These new complexes exhibit even higher efficiency as drugs in comparison with the free non-complexed medication with increased antioxidant ability expressing higher capacity to block the angiotensin II contractile effect. This study provides a new insight into the development of copper(II) complexes as potential drugs. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. The role of hospitals in bridging the care continuum: a systematic review of coordination of care and follow-up for adults with chronic conditions.

    Science.gov (United States)

    De Regge, Melissa; De Pourcq, Kaat; Meijboom, Bert; Trybou, Jeroen; Mortier, Eric; Eeckloo, Kristof

    2017-08-09

    Multiple studies have investigated the outcome of integrated care programs for chronically ill patients. However, few studies have addressed the specific role hospitals can play in the downstream collaboration for chronic disease management. Our objective here is to provide a comprehensive overview of the role of the hospitals by synthesizing the advantages and disadvantages of hospital interference in the chronic discourse for chronically ill patients found in published empirical studies. Systematic literature review. Two reviewers independently investigated relevant studies using a standardized search strategy. Thirty-two articles were included in the systematic review. Overall, the quality of the included studies is high. Four important themes were identified: the impact of transitional care interventions initiated from the hospital's side, the role of specialized care settings, the comparison of inpatient and outpatient care, and the effect of chronic care coordination on the experience of patients. Our results show that hospitals can play an important role in transitional care interventions and the coordination of chronic care with better outcomes for the patients by taking a leading role in integrated care programs. Above that, the patient experiences are positively influenced by the coordinating role of a specialist. Specialized care settings, as components of the hospital, facilitate the coordination of the care processes. In the future, specialized care centers and primary care could play a more extensive role in care for chronic patients by collaborating.

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

    Science.gov (United States)

    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…

  7. Mechanisms underlying reductant-induced reactive oxygen species formation by anticancer copper(II) compounds

    OpenAIRE

    Kowol, Christian R.; Heffeter, Petra; Miklos, Walter; Gille, Lars; Trondl, Robert; Cappellacci, Loredana; Berger, Walter; Keppler, Bernhard K.

    2011-01-01

    Intracellular generation of reactive oxygen species (ROS) via thiol-mediated reduction of copper(II) to copper(I) has been assumed as the major mechanism underlying the anticancer activity of copper(II) complexes. The aim of this study was to compare the anticancer potential of copper(II) complexes of Triapine (3-amino-pyridine-2-carboxaldehyde thiosemicarbazone; currently in phase II clinical trials) and its terminally dimethylated derivative with that of 2-formylpyridine thiosemicarbazone a...

  8. Improving the Response of Copper(II) Selective PVC Membrane Electrode by Modification of N2S2 Donor Ligand.

    Science.gov (United States)

    Brinić, Slobodan; Buzuk, Marijo; Generalić, Eni; Bralić, Marija

    2010-06-01

    S,S'-bis(2-aminophenyl)ethanebis(thioate), (APhET), is reported as N2S2 ligand which form chelate with copper of high stability as compared to the other metals. Two modification of APhET, simpler 1,2-di-(o-aminophenylthio)ethane (DAPhTE), and the complex one 1,2-di-(o-salicylaldiminophenylthio)ethane (SAPhTE), were examined as the active material for copper(II) ion selective PVC membrane electrodes, and observed results are correlated. The obtained results with DAPhTE based electrodes show that only coordination abilities of ligand are insufficient for preparing the efficient membrane material. On the other hand, the results that are achieved with electrodes based on SAPhTE actuate interaction of ligand with polymer membrane matrix and necessity of ionophore immobilization in membrane. Optimized SAPhTE based membrane electrode has a linear range down to 10-6 mol L-1, with slope of 27.0 mV per decade, very rapid response time (under 5 seconds) and detection limit of 5.1 × 10-7 mol L-1. Such electrode is suitable for determination of copper(II) in analytical measurements by direct potentiometry and in potentiometric titrations, within pH between 2 and 7. The electrode is selective for copper(II) ions over a large number of metal ions, with the exception on Hg2+ ion when is present in concentrations above 2 × 10-5 mol L-1.

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

    Science.gov (United States)

    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.

  10. Exploration of a Variety of Copper Molybdate Coordination Hybrids Based on a Flexible Bis(1,2,4-triazole) Ligand: A Look through the Composition-Space Diagram.

    Science.gov (United States)

    Senchyk, Ganna A; Lysenko, Andrey B; Domasevitch, Konstantin V; Erhart, Oliver; Henfling, Stefan; Krautscheid, Harald; Rusanov, Eduard B; Krämer, Karl W; Decurtins, Silvio; Liu, Shi-Xia

    2017-11-06

    We investigated the coordination ability of the bis(1,2,4-triazolyl) module, tr 2 pr = 1,3-bis(1,2,4-triazol-4-yl)propane, toward the engineering of solid-state structures of copper polyoxomolybdates utilizing a composition space diagram approach. Different binding modes of the ligand including [N-N]-bridging and N-terminal coordination and the existence of favorable conformation forms (anti/anti, gauche/anti, and gauche/gauche) resulted in varieties of mixed metal Cu I /Mo VI and Cu II /Mo VI coordination polymers prepared under hydrothermal conditions. The composition space analysis employed was aimed at both the development of new coordination solids and their crystallization fields through systematic changes of the reagent ratios [copper(II) and molybdenum(VI) oxide precursors and the tr 2 pr ligand]. Nine coordination compounds were synthesized and structurally characterized. The diverse coordination architectures of the compounds are composed of cationic fragments such as [Cu II 3 (μ 2 -OH) 2 (μ 2 -tr) 2 ] 4+ , [Cu II 3 (μ 2 -tr) 6 ] 6+ , [Cu II 2 (μ 2 -tr) 3 ] 4+ , etc., connected to polymeric arrays by anionic species (molybdate MoO 4 2- , isomeric α-, δ-, and β-octamolybdates {Mo 8 O 26 } 4- or {Mo 8 O 28 H 2 } 6- ). The inorganic copper(I,II)/molybdenum(VI) oxide matrix itself forms discrete or low-dimensional subtopological motifs (0D, 1D, or 2D), while the organic spacers interconnect them into higher-dimensional networks. The 3D coordination hybrids show moderate thermal stability up to 230-250 °C, while for the 2D compounds, the stability of the framework is distinctly lower (∼190 °C). The magnetic properties of the most representative samples were investigated. The magnetic interactions were rationalized in terms of analyzing the planes of the magnetic orbitals.

  11. Dinuclear bis-beta-diketonato ligand derivatives of iron(III) and copper(II) and use of the latter as components for the assembly of extended metallo-supramolecular structures.

    Science.gov (United States)

    Clegg, Jack K; Lindoy, Leonard F; McMurtrie, John C; Schilter, David

    2005-03-07

    A range of 1,3-aryl linked, bis-beta-diketone derivatives (LH2) has been employed to synthesise neutral bis(ligand), dinuclear complexes incorporating square-planar copper(II) and tris(ligand) dinuclear helical derivatives containing octahedral iron(III). The 1H NMR spectra of the free ligands contain singlet peaks at ca. 16.2 ppm, indicative of enolic protons, confirming that the (bis) enol tautomer is present in solution. An X-ray structure of a ligand from the series incorporating tert-butyl terminal substituents confirms that the same tautomer persists in the solid and that the relative orientation of the bis-beta-diketone fragments is such that the coordination vectors lie at approximately 120 degrees to each other. The planar, dinuclear copper complexes form 1 : 2 adducts with pyridine and 4-(dimethylamino)pyridine, confirmed by X-ray structures, that incorporate five-coordinate metal centres. Based on this behaviour, the prospect of linking copper centres in the dinuclear complexes using the difunctional heterocyclic bases, 4,4'-bipyridine, 4,4'-trans-azopyridine and pyrazine as co-ligands has been probed. However, 4,4'-bipyridine was observed to coordinate through only one of its heterocyclic nitrogen atoms in the solid state to form a 1 : 2 ([Cu2(L)2]: 4,4'-bipyridine) adduct, analogous to the structures obtained with the above mono-functional nitrogen bases. Nevertheless, an X-ray structure determination shows that the related difunctional base, 4,4'-trans-azopyridine, coordinates in a bridging fashion via both its heterocyclic nitrogen atoms on alternate sides of each planar [Cu2(L)2] unit to produce an infinite one dimensional metallo chain. In contrast, with pyrazine, a new neutral, discrete assembly of type [Cu4(L)4(pyrazine)2] is formed. The X-ray structure shows that two planar dinuclear complexes are linked by two pyrazine molecules in a sandwich arrangement such that the coordination environment of each copper ion is approximately square pyramidal

  12. XPS-Characterization of Heterometallic Coordination Compounds with Optically Active Ligands

    Directory of Open Access Journals (Sweden)

    Yenny Ávila-Torres

    2013-01-01

    Full Text Available The heterometallic optical complexes [Cu2Co(S,S(+cpse3(H2O3]·4H2O (1 and [Cu2Ni(S,S(+cpse3(H2O3]·10H2O (2 were obtained from the mononuclear copper(II compound by the addition of nickel(II or cobalt(II chlorides, where (H2cpse is the acetyl amino alcohol derivative N-[2-hydroxy-1(R-methyl-2(R-phenylethyl]-N-methylglycine. In comparison with the homotrinuclear copper(II compound [Cu3(S,S(+cpse3(H2O3]·8H2O reported previously, the substitution of a copper(II atom by one cobalt(II ion gave place to a heterotrinuclear compound 1, which presents ferromagnetic-antiferromagnetic behaviour. When substituting a copper(II by a nickel(II ion, the trinuclear compound 2 showed an antiferromagnetic coupling. The magnetic behaviour of the heterotrinuclear compounds is driven by the nature of the metal ion which was introduced in the copper(II triangular array. The ligand and its coordination compounds were characterized by IR, UV-Vis-NIR. Their chemical was confirmed by photoelectron spectroscopy (XPS.

  13. Dicynamide bridged two new zig-zag 1-D Zn(II) coordination polymers of pyrimidine derived Schiff base ligands: Synthesis, crystal structures and fluorescence studies

    Science.gov (United States)

    Konar, Saugata

    2015-07-01

    Two new zigzag 1-D polymeric Zn(II) coordination polymers {[Zn(L1)(μ1,5-dca)](H2O)}n (1), {[Zn(L2)(μ1,5-dca)](ClO4)}n (2) of two potentially tridentate NNO-, NNN-, donor Schiff base ligands [2-(2-(4,6-dimethylpyrimidin-2-yl)hydrazono)methyl)phenol] (L1), [1-(4,6-dimethylpyrimidin-2-yl)-2-(dipyridin-2ylmethylene)hydrazine] (L2) have been synthesized and characterized by elemental analyses, IR and 1H NMR, fluorescence spectroscopy and single crystal X-ray crystallography. The dicyanamide ions act as linkers (μ1,5 mode) in the formation of these coordination polymers. Both the complexes 1 and 2 have same distorted square pyramidal geometry around the Zn(II) centres. The weak forces like π⋯π, Csbnd H⋯π, anion⋯π interactions lead to various supramolecular architectures. Complex 1 shows high chelation enhanced fluorescence compared to that of 2. The fluorescence spectral changes observed high selectivity towards Zn(II) over other metal ions such as Mn(II), Co(II), Ni(II), Cu(II).

  14. COPPER(II) COMPLEXES OF o -VANILLIN ACETYLHYDRAZONE ...

    African Journals Online (AJOL)

    A hydrazonic ligand, o-vanillin acetylhydrazone (H2L) has been prepared and used as chelating agent towards copper(II) ion. The ligand acts like a tridentate ligand in the monodeprotonated (HL-) and dideprotonated (L2-) states. Monoanionic complexes [{Cu(HL)(H2O)}2]•2BF4 and [{Cu(HL)(Hpz)(H2O)}]•NO3 have been ...

  15. Werner coordination chemistry and neurodegeneration.

    Science.gov (United States)

    Telpoukhovskaia, Maria A; Orvig, Chris

    2013-02-21

    Neurodegenerative diseases are capturing the world's attention as being the next set of diseases we must tackle collectively. Not only are the patients experiencing gradual cognitive and physical decline in most cases, but these diseases are fatal with no prevention currently available. As these diseases are progressive, providing care and symptom treatment for the ageing population is becoming both a medical and a financial challenge. This review discusses how Werner coordination chemistry plays a role in three diseases - those of Alzheimer's, Parkinson's, and prions. Metal ions are considered to be involved in these diseases in part via their propensity to cause toxic aggregation of proteins. First, the coordination of metal ions, with emphasis on copper(II), to metalloproteins that are hallmarks of these diseases - amyloid β, α-synuclein, and prion, respectively - will be discussed. We will present the current understanding of the metal coordination environments created by the amino acids of these proteins, as well as metal binding affinity. Second, a diverse set of examples of rationally designed metal chelators to outcompete this deleterious binding will be examined based on coordination mode and affinity toward bio-relevant metal ions. Overall, this review will give a general overview of protein and metal chelator coordination environments in neurodegenerative diseases.

  16. Investigation of the interaction of copper(II) oxide and electron beam irradiation crosslinkable polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Bee, Soo-Tueen, E-mail: direct.beest@gmail.com [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Sin, Lee Tin, E-mail: direct.tinsin@gmail.com [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Ratnam, C.T. [Radiation Processing Technology Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Haraveen, K.J.S.; Tee, Tiam-Ting [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Rahmat, A.R. [Department of Polymer Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

    2015-10-01

    In this study, the effects of electron beam irradiation on the properties of copper(II) oxide when added to low-density polyethylene (LDPE) blends were investigated. It was found that the addition of low loading level of copper(II) oxide (⩽2 phr) to LDPE results in significantly poorer gel content and hot set results. However, the incorporation of higher loading level of copper(II) oxide (⩾3 phr) could slightly increase the degree of crosslinking in all irradiated LDPE composites. This is due to the fact that higher amounts of copper(II) oxide could slightly induce the formation of free radicals in LDPE matrix. Besides, increasing irradiation doses was also found to gradually increase the gel content of LDPE composites by generating higher amounts of free radicals. As a consequence, these higher amounts of free radicals released in the LDPE matrix could significantly increase the degree of crosslinking. The addition of copper(II) oxide could reduce the tensile strength and fracture strain (elongation at break) of LDPE composites because of poorer interfacial adhesion effect between copper(II) oxide particles and LDPE matrix. Meanwhile, increasing irradiation doses on all copper(II) oxide added LDPE composites could marginally increase the tensile strength. In addition, increasing irradiation dose could enhance the thermal stability of LDPE composites by increasing the decomposition temperature. The oxidation induction time (OIT) analysis showed that, because of the crosslinking network in the copper(II) oxide added LDPE composites, oxidation reaction is much delayed.

  17. Copper(II) Complexes of Phenanthroline and Histidine Containing Ligands: Synthesis, Characterization and Evaluation of their DNA Cleavage and Cytotoxic Activity.

    Science.gov (United States)

    Leite, Sílvia M G; Lima, Luís M P; Gama, Sofia; Mendes, Filipa; Orio, Maylis; Bento, Isabel; Paulo, António; Delgado, Rita; Iranzo, Olga

    2016-11-21

    Copper(II) complexes have been intensely investigated in a variety of diseases and pathological conditions due to their therapeutic potential. The development of these complexes requires a good knowledge of metal coordination chemistry and ligand design to control species distribution in solution and tailor the copper(II) centers in the right environment for the desired biological activity. Herein we present the synthesis and characterization of two ligands HL1 and H 2 L2 containing a phenanthroline unit (phen) attached to the amino group of histidine (His). Their copper(II) coordination properties were studied using potentiometry, spectroscopy techniques (UV-vis and EPR), mass spectrometry (ESI-MS) and DFT calculations. The data showed the formation of single copper complexes, [CuL1] + and [CuL2], with high stability within a large pH range (from 3.0 to 9.0 for [CuL1] + and from 4.5 to 10.0 for [CuL2]). In both complexes the Cu 2+ ion is bound to the phen unit, the imidazole ring and the deprotonated amide group, and displays a distorted square pyramidal geometry as confirmed by single crystal X-ray crystallography. Interestingly, despite having similar structures, these copper complexes show different redox potentials, DNA cleavage properties and cytotoxic activity against different cancer cell lines (human ovarian (A2780), its cisplatin-resistant variant (A2780cisR) and human breast (MCF7) cancer cell lines). The [CuL2] complex has lower reduction potential (E pc = -0.722 V vs -0.452 V for [CuL1] + ) but higher biological activity. These results highlight the effect of different pendant functional groups (carboxylate vs amide), placed out of the coordination sphere, in the properties of these copper complexes.

  18. Self-assembled 3D heterometallic Cu(II)/Fe(II) coordination polymers with octahedral net skeletons: structural features, molecular magnetism, thermal and oxidation catalytic properties.

    Science.gov (United States)

    Karabach, Yauhen Y; Guedes da Silva, M Fátima C; Kopylovich, Maximilian N; Gil-Hernández, Beatriz; Sanchiz, Joaquin; Kirillov, Alexander M; Pombeiro, Armando J L

    2010-12-06

    The new three-dimensional (3D) heterometallic Cu(II)/Fe(II) coordination polymers [Cu(6)(H(2)tea)(6)Fe(CN)(6)](n)(NO(3))(2n)·6nH(2)O (1) and [Cu(6)(Hmdea)(6)Fe(CN)(6)](n)(NO(3))(2n)·7nH(2)O (2) have been easily generated by aqueous-medium self-assembly reactions of copper(II) nitrate with triethanolamine or N-methyldiethanolamine (H(3)tea or H(2)mdea, respectively), in the presence of potassium ferricyanide and sodium hydroxide. They have been isolated as air-stable crystalline solids and fully characterized including by single-crystal X-ray diffraction analyses. The latter reveal the formation of 3D metal-organic frameworks that are constructed from the [Cu(2)(μ-H(2)tea)(2)](2+) or [Cu(2)(μ-Hmdea)(2)](2+) nodes and the octahedral [Fe(CN)(6)](4-) linkers, featuring regular (1) or distorted (2) octahedral net skeletons. Upon dehydration, both compounds show reversible escape and binding processes toward water or methanol molecules. Magnetic susceptibility measurements of 1 and 2 reveal strong antiferromagnetic [J = -199(1) cm(-1)] or strong ferromagnetic [J = +153(1) cm(-1)] couplings between the copper(II) ions through the μ-O-alkoxo atoms in 1 or 2, respectively. The differences in magnetic behavior are explained in terms of the dependence of the magnetic coupling constant on the Cu-O-Cu bridging angle. Compounds 1 and 2 also act as efficient catalyst precursors for the mild oxidation of cyclohexane by aqueous hydrogen peroxide to cyclohexanol and cyclohexanone (homogeneous catalytic system), leading to maximum total yields (based on cyclohexane) and turnover numbers (TONs) up to about 22% and 470, respectively.

  19. Kinetic bridges.

    Science.gov (United States)

    1980-01-01

    This report on kinetic bridges is essentially a state-of-the-art study on two types of bridges whose location or physical characteristics are designed to be time dependent. The first type, called a "relocatable bridge", is essentially for use as a te...

  20. Copper(II) complexes with aroylhydrazones

    Indian Academy of Sciences (India)

    Unknown

    symmetry due to the Jahn–Teller distortion is very common. Such complexes with different ligands are attractive mainly due to the variation in the coordination ..... The corresponding centroid-to-centroid distances are 3⋅754 and. 4⋅246 Å, respectively. Thus the pyridine rings are more slipped compared to the aroyl benzene ...

  1. Metal-dependent assembly of a tetranuclear copper(II) complex versus a 1D chain coordination polymer of cobalt(III) complex with N.sub.2./sub.O.sub.2./sub.-chelating Schiff-base ligand: Synthesis, characterization and crystal structures

    Czech Academy of Sciences Publication Activity Database

    Khalaji, A.D.; Hadadzadeh, H.; Fejfarová, Karla; Dušek, Michal

    2010-01-01

    Roč. 29, č. 2 (2010), s. 807-812 ISSN 0277-5387 Grant - others:AV ČR(CZ) AP0701 Program:Akademická prémie - Praemium Academiae Institutional research plan: CEZ:AV0Z10100521 Keywords : Schiff bases * crystal structure * Jana2006 * coordination chemistry Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.033, year: 2010

  2. Potentiometric and spectrometric study: Copper(II), nickel(II) and ...

    Indian Academy of Sciences (India)

    taking potentially tridentate ligands, viz. L-cysteine, L-threonine, salicylglycinate and salicylvalinate, three metal ions (Cu2+, Ni2+ and Zn2+) and imidazole. The aqueous coordination chemistry of simple imidazolate bridged metal complexes is explored using. pH-potentiometric and UV/Vis spectroscopic techniques.

  3. Multitarget trehalose-carnosine conjugates inhibit Aβ aggregation, tune copper(II) activity and decrease acrolein toxicity.

    Science.gov (United States)

    Grasso, Giuseppa Ida; Bellia, Francesco; Arena, Giuseppe; Satriano, Cristina; Vecchio, Graziella; Rizzarelli, Enrico

    2017-07-28

    Increasing evidence is accumulating, showing that neurodegenerative disorders are somehow associated with the toxicity of amyloid aggregates, metal ion dyshomeostasis as well as with products generated by oxidative stress. Within the biological oxidation products, acrolein does have a prominent role. A promising strategy to deal with the above neurogenerative disorders is to use multi-functions bio-molecules. Herein, we show how a class of bio-conjugates takes advantage of the antiaggregating, antioxidant and antiglycating properties of trehalose and carnosine. Their ability to sequester acrolein and to inhibit both self- and metal-induced aggregation is here reported. The copper(II) coordination properties of a new trehalose-carnosine conjugate and the relative antioxidant effects have also been investigated. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Preparation of CuO nanoparticles by thermal decomposition of double-helical dinuclear copper(II Schiff-base complexes

    Directory of Open Access Journals (Sweden)

    Aliakbar Dehno Khalaji

    2015-12-01

    Full Text Available In this paper, two double helical dinuclear copper(II complexes of bis-N,O-bidentate Schiff base ligands bis(3-methoxy-N-salicylidene-4,4'-diaminodiphenylsulfone (L1 and bis(5-bromo-N-salicylidene-4,4'-diaminodiphenylsulfone (L2 were prepared and characterized by elemental analyses (CHN, as well as thermal analysis. Elemental analyses (CHN suggested that the reaction between ligands and copper salt has been occurred in 1:1 molar ratio. In these complexes the Schiff base ligands behaves as an anionic and bis-bidentate chelate and is coordinated to the copper(II ion via two phenolic oxygen and two iminic nitrogen atoms. In these double helical dinuclear complexes, each copper(II center has a pseudo-tetrahedral coordination sphere two-wrapped ligands. Thermal analysis of ligands and their complexes were studied in the range of room temperature to 750 °C with a heating rate of 10 °C min-1. TG plots show that the ligands and their complexes are thermally decomposed via 2 and 3 thermal steps, respectively. In addition, the complexes thermally decomposed in air at 520 °C for 3 h. The obtained solids characterized by Fourier transform infrared spectroscopy (FT-IR, X-ray powder diffraction (XRD and transmission electron microscopy (TEM. The X-ray pattern result shows that the CuO nanoparticles are pure and single phase. The TEM result shows the as prepared CuO nanoparticles were very small and similar shape with particle size about

  5. Myocardial Bridging

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    2016-02-01

    Full Text Available Abstract Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results.

  6. Dimeric and different polymeric copper(II) salicylates - Crystal structure and spectral properties

    Science.gov (United States)

    Puchoňová, Miroslava; Mazúr, Milan; Moncol, Ján; Růžičková, Zdeňka; Valigura, Dušan

    2017-06-01

    The small differences in synthesis condition led to formation of four new copper(II) salicylatocomplexes - two differently polymeric [Cu(4-MeOSal)2(μ-H2O)2]n1, [Cu(μ-3,5-Br2Sal)2(H2O)2]n2 and two dimeric [Cu(5-MeSal)2(MeOH)]2ṡ2MeOH 3 [Cu(4-MeSal)2(EtOH)2]24 compounds, where 4-MeOSal = 4-methoxysalicylate, 3,5-Br2Sal = 3, 5-dibromsalicylate, 5-MeSal = 5-methylsalicylate, and 4-MeSal = 4-methoxysalicylate monoanion. Complexes were characterized by elemental analysis, UV-Vis, infrared, EPR spectra and single crystal X-ray analysis. Spectral properties are in good agreement with structural information. Intermolecular interactions are responsible for building supramolecular structure. The complexes 1 and 2 build up 2D supramolecular structures by the O-H⋯O hydrogen bonds formation while the complexes 3 and 4 are forming 1D supramolecular chain of paddle wheel units and coordinated solvent molecules.

  7. DNA binding and cleavage studies of copper(II) complexes with 2'-deoxyadenosine modified histidine moiety.

    Science.gov (United States)

    Borowska, Justyna; Sierant, Malgorzata; Sochacka, Elzbieta; Sanna, Daniele; Lodyga-Chruscinska, Elzbieta

    2015-09-01

    This work is focused on the study of DNA binding and cleavage properties of 2'-deoxyadenosines modified with ester/amide of histidine (his(6)dA ester, his(6)dA amide) and their copper(II) complexes. To determine the coordination mode of the complex species potentiometric and spectroscopic (UV-visible, CD, EPR) studies have been performed. The analysis of electronic absorption and fluorescence spectra has been used to find the nature of the interactions between the compounds and calf thymus DNA (CT-DNA). There is significant influence of the -NH2 and -OCH3 groups on binding of the ligands or the complexes to DNA. Only amide derivative and its complex reveal intercalative ability. In the case of his(6)dA ester and Cu(II)-his(6)dA ester the main interactions can be groove binding. DNA cleavage activities of the compounds have been examined by gel electrophoresis. The copper complexes have promoted the cleavage of plasmid DNA, but none of the ligands exhibited any chemical nuclease activity. The application of different scavengers of reactive oxygen species provided a conclusion that DNA cleavage caused by copper complexes might occur via hydrolytic pathway.

  8. A facile, sensitive, and rapid spectrophotometric method for copper(II) ion detection in aqueous media using polyethyleneimine

    OpenAIRE

    Wen, Ting; Qu, Fei; Li, Nian Bing; Luo, Hong Qun

    2013-01-01

    In this work, we developed a facile, sensitive, and rapid spectrophotometric method for copper(II) ion detection in aqueous media using polyethyleneimine. Polyethyleneimine is a cationic polymer that has no absorption in the wavelength range of 250–800 nm. When trace amounts of copper(II) ion was added to the colorless polyethyleneimine solution, copper(II) ion could react with the amino groups of the polyethyleneimine to form a dark blue cuprammonium complex whose absorption spectrum exhibit...

  9. Novel copper(II) complexes with hydrazides and heterocyclic bases: Synthesis, structure and biological studies.

    Science.gov (United States)

    Paixão, Drielly A; Marzano, Ivana M; Jaimes, Edgar H L; Pivatto, Marcos; Campos, Débora L; Pavan, Fernando R; Deflon, Victor M; Maia, Pedro Ivo da S; Da Costa Ferreira, Ana M; Uehara, Isadora A; Silva, Marcelo J B; Botelho, Françoise V; Pereira-Maia, Elene C; Guilardi, Silvana; Guerra, Wendell

    2017-07-01

    Five new copper(II) complexes of the type [Cu(NO)(NN)(ClO 4 ) 2 ], in which NO=4-fluorophenoxyacetic acid hydrazide (4-FH) or 4-nitrobenzoic hydrazide (4-NH) and NN=1,10-phenanthroline (phen), 4-4'-dimethoxy-2-2'-bipyridine (dmb) or 2,2-bipyridine (bipy) were synthesized and characterized using various spectroscopic methods. The X-ray structural analysis of one representative compound indicates that the geometry around the copper ion is distorted octahedron, in which the ion is coordinated to hydrazide via the terminal nitrogen and the carbonyl oxygen, and to heterocyclic bases via their two nitrogen atoms. Two perchlorate anions occupy the apical positions, completing the coordination sphere. The cytotoxic activity of compounds was investigated in three tumor cell lines (K562, MDA-MB-231 and MCF-7). Concerning K562 cell line, the complexes with 1,10-phenanthroline exhibit high cytotoxic activity and are more active than carboplatin, free ligands and [Cu(phen) 2 ] 2+ . Considering the cytotoxicity results, further investigations for the compounds [Cu(4-FH)(phen)(ClO 4 ) 2 ] I and [Cu(4-NH)(phen)(ClO 4 ) 2 ]∙H 2 O III were performed. Flow cytometric analysis revealed that these complexes induce apoptotic cell death in MDA-MB-231 cell line and bind to DNA with K values of 4.38×10 4 and 2.62×10 4 , respectively. These compounds were also evaluated against wild type Mycobacterium tuberculosis (ATCC 27294) and exhibited antimycobacterial activity, displayed MIC values lower than those of the corresponding free ligands. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way.......In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way....

  11. Synthetic bioactive novel ether based Schiff bases and their copper(II) complexes

    Science.gov (United States)

    Shabbir, Muhammad; Akhter, Zareen; Ismail, Hammad; Mirza, Bushra

    2017-10-01

    Novel ether based Schiff bases (HL1- HL4) were synthesized from 5-chloro-2-hydroxy benzaldehyde and primary amines (1-amino-4-phenoxybenzene, 4-(4-aminophenyloxy) biphenyl, 1-(4-aminophenoxy) naphthalene and 2-(4-aminophenoxy) naphthalene). From these Schiff bases copper(II) complexes (Cu(L1)2-Cu(L4)2)) were synthesized and characterized by elemental analysis and spectroscopic (FTIR, NMR) techniques. The synthesized Schiff bases and copper(II) complexes were further assessed for various biological studies. In brine shrimp assay the copper(II) complexes revealed 4-fold higher activity (LD50 3.8 μg/ml) as compared with simple ligands (LD50 12.4 μg/ml). Similar findings were observed in potato disc antitumor assay with higher activities for copper(II) complexes (IC50 range 20.4-24.1 μg/ml) than ligands (IC50 range 40.5-48.3 μg/ml). DPPH assay was performed to determine the antioxidant potential of the compounds. Significant antioxidant activity was shown by the copper(II) complexes whereas simple ligands have shown no activity. In DNA protection assay significant protection behavior was exhibited by simple ligand molecules while copper(II) complexes showed neutral behavior (neither protective nor damaging).

  12. Study on potential antitumor mechanism of a novel Schiff base copper(II) complex: synthesis, crystal structure, DNA binding, cytotoxicity and apoptosis induction activity.

    Science.gov (United States)

    Qiao, Xin; Ma, Zhong-Ying; Xie, Cheng-Zhi; Xue, Fei; Zhang, Yan-Wen; Xu, Jing-Yuan; Qiang, Zhao-Yan; Lou, Jian-Shi; Chen, Gong-Jun; Yan, Shi-Ping

    2011-05-01

    A new cytotoxic copper(II) complex with Schiff base ligand [Cu(II)(5-Cl-pap)(OAc)(H(2)O)]·2H(2)O (1) (5-Cl-pap=N-2-pyridiylmethylidene-2-hydroxy-5-chloro-phenylamine), was synthesized and structurally characterized by X-ray diffraction. Single-crystal analysis revealed that the copper atom shows a 4+1 pyramidal coordination, a water oxygen appears in the apical position, and three of the basal positions are occupied by the NNO tridentate ligand and the fourth by an acetate oxygen. The interaction of Schiff base copper(II) complex 1 with DNA was investigated by UV-visible spectra, fluorescence spectra and agarose gel electrophoresis. The apparent binding constant (K(app)) value of 6.40×10(5) M(-1) for 1 with DNA suggests moderate intercalative binding mode. This copper(II) complex displayed efficient oxidative cleavage of supercoiled DNA, which might indicate that the underlying mechanism involve hydroxyl radical, singlet oxygen-like species, and hydrogen peroxide as reactive oxygen species. In addition, our present work showed the antitumor effect of 1 on cell cycle and apoptosis. Flow cytometric analysis revealed that HeLa cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that complex 1 can induce apoptosis of HeLa cells, whose process was mediated by intrinsic mitochondrial apoptotic pathway owing to the activation of caspase-9 and caspase-3. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. New Cu(II) coordination polymer by chiral tridentate Schiff base ligand

    Science.gov (United States)

    Messai, Amel; Bilge, Duygu; Bilge, Metin; Parlak, Cemal

    2017-06-01

    The present research reports the synthesis, X-ray, magnetic and electronic properties for novel coordination polymer based upon copper (II) with chiral tridentate Schiff base ligand synthesized at condensation of acetylacetone and L-leucine amino acid. The investigation was also conducted by quantum mechanical calculations. The large energy gap indicates a high kinetic stability. Magnetic measurement gives predominant antiferromagnetic interactions within the chain. Results reveals further insight into copper(II) chiral tridentate Schiff base complexes.

  14. National Bridge Inventory (NBI) Bridges

    Data.gov (United States)

    Department of Homeland Security — The NBI is a collection of information (database) describing the more than 600,000 of the Nation's bridges located on public roads, including Interstate Highways,...

  15. Copper(II) complex as a precursor for formation of cyano-bridged ...

    Indian Academy of Sciences (India)

    chemsci

    interesting magnetic properties.9 The terminal nitrogen atoms of the ... Experimental. 2.1 Materials and physical measurements. All chemicals and solvents were of reagent grade and used without further purification. Complex 1 was prepared accord- ing to the ... analyzer. The thermal curves (TGA) were recorded using a.

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

    Science.gov (United States)

    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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Building Bridges

    DEFF Research Database (Denmark)

    The report Building Bridges adresses the questions why, how and for whom academic audience research has public value, from the different points of view of the four working groups in the COST Action IS0906 Transforming Audiences, Transforming Societies – “New Media Genres, Media Literacy and Trust...

  18. Bridging Anticoagulation

    Science.gov (United States)

    ... Procedure? The BRIDGE Study Investigators Download PDF https://doi.org/10.1161/CIRCULATIONAHA.111.084517 Circulation. 2012; 125: ... e496-e498 , originally published March 26, 2012 https://doi.org/10.1161/CIRCULATIONAHA.111.084517 Citation Manager Formats ...

  19. Crossing Bridges

    Indian Academy of Sciences (India)

    Perhaps we are not smart enough. How would we go about establishing that the problem has no solution? One possibility is to enumerate all possible ... Even if we do this for the bridges of Konigsberg, we would learn nothing about other similar situations. Consider for example the fictitious city of Lutetia at the confluence of.

  20. Self-assembly of mixed-valence Co(II/III) and Ni(II) clusters: azide-bridged 1D single chain coordination polymers comprised of tetranuclear units, tetranuclear Co(II/III) complexes, ferromagnetically coupled azide-bridged tetranuclear, and hexanuclear Ni(II) complexes: synthesis, structural, and magnetic properties.

    Science.gov (United States)

    Tandon, Santokh S; Bunge, Scott D; Rakosi, Robert; Xu, Zhiqiang; Thompson, Laurence K

    2009-09-07

    One-pot reactions between 2,6-diformyl-4-methylphenol (DFMP) and 2-aminoethanol (AE) in the presence of cobalt(II) salts [Co(ClO4)2, CoCl2, Co(CH3CO2)2, Co(NO3)2] and sodium azide result in the self-assembly of novel one-dimensional single chain mixed-valence cobalt coordination polymers {[Co2(II)Co2(III) (HL)2(OCH3)2(N3)3]ClO(4).5H2O.CH3OH}n (1), {[Co2(II)Co2(III) (HL)2(OCH3)2(N3)3]Cl.H2O}n (2) in which tetra-cobalt cationic units are bridged by symmetrical 1,3-azides, forming single chains; mixed valence neutral tetranuclear clusters [Co2(II)Co2(III) (HL)2(OCH3)2(N3)4]CH3OH.2H2O (3), [Co2(II)Co2(III)(HL)2(OCH3)2(N3)2(CH3CO2)2].2CH3OH.2H2O (4), and the cationic cluster [Co2(II) Co2(III) (HL)2(OCH3)2(CH3OH)2(N3)2](NO3)2 (5). In all these reactions, H3L, the potentially pentadentate (N2O3), trianionic double Schiff base ligand 2,6-bis[(2-hydroxy-ethylimino)-methyl]-4-methylphenol is formed. The reaction between DFMP and AE in the presence of nickel(ii) salts and sodium azide in methanol-water mixture results in the self-assembly of ferromagnetically coupled hexanuclear complexes [Ni6(H2L)2(HL-1)2(H2O)2(N3)6](ClO4)(2).2CH3OH (6), and [Ni6(H2L)2(HL-1)2(CH3OH)2(N3)6](BF4)2 (7), involving double (H3L) and single (H2L-1) Schiff base ligands, and a neutral tetranuclear complex [Ni4(H2L)2(OCH3)2(CH3CO2)2(N3)2] (8) with only double Schiff-base (H3L). In these complexes, the nature of the anion and the reaction conditions seem to play an important role in directing the formation of tetranuclear, hexanuclear or polymeric clusters. All complexes involve divacant double cubane-type cores containing three to four different types of bridging ligands (phenoxy, azido, methoxy/alkoxy, and acetate). Variable temperature magnetic properties of these spin coupled clusters have been investigated and magneto-structural correlations have been established.

  1. Complexation between the fungicide tebuconazole and copper(II) probed by electrospray ionization mass spectrometry.

    Science.gov (United States)

    Dytrtová, Jana Jaklová; Jakl, Michal; Schröder, Detlef; Čadková, Eva; Komárek, Michael

    2011-04-30

    Electrospray ionization mass spectrometry (ESI-MS) is used to probe the complex formation between tebuconazole (1) and copper(II) salts, which both are commonly used fungicides in agriculture. Experiments with model solutions containing 1 and CuCl(2) reveal the initial formation of the copper(II) species [(1)CuCl](+) and [(1)(2)CuCl](+) which undergo reduction to the corresponding copper(I) ions [(1)Cu](+) and [(1)(2)Cu](+) under more drastic ionization conditions in the ESI source. In additional experiments, copper/tebuconazole complexes were also detected in samples made from soil solutions of various origin and different amount of mineralization. The direct sampling of such solutions via ESI-MS is thus potentially useful for understanding of the interactions between copper(II) salts and tebuconazole in environmental samples. Copyright © 2011 John Wiley & Sons, Ltd.

  2. Mathematical bridges

    CERN Document Server

    Andreescu, Titu; Tetiva, Marian

    2017-01-01

    Building bridges between classical results and contemporary nonstandard problems, Mathematical Bridges embraces important topics in analysis and algebra from a problem-solving perspective. Blending old and new techniques, tactics and strategies used in solving challenging mathematical problems, readers will discover numerous genuine mathematical gems throughout that will heighten their appreciation of the inherent beauty of mathematics. Most of the problems are original to the authors and are intertwined in a well-motivated exposition driven by representative examples. The book is structured to assist the reader in formulating and proving conjectures, as well as devising solutions to important mathematical problems by making connections between various concepts and ideas from different areas of mathematics. Instructors and educators teaching problem-solving courses or organizing mathematics clubs, as well as motivated mathematics students from high school juniors to college seniors, will find Mathematical Bri...

  3. Surface Structures Formed by a Copper(II Complex of Alkyl-Derivatized Indigo

    Directory of Open Access Journals (Sweden)

    Akinori Honda

    2016-10-01

    Full Text Available Assembled structures of dyes have great influence on their coloring function. For example, metal ions added in the dyeing process are known to prevent fading of color. Thus, we have investigated the influence of an addition of copper(II ion on the surface structure of alkyl-derivatized indigo. Scanning tunneling microscope (STM analysis revealed that the copper(II complexes of indigo formed orderly lamellar structures on a HOPG substrate. These lamellar structures of the complexes are found to be more stable than those of alkyl-derivatized indigos alone. Furthermore, 2D chirality was observed.

  4. A facile, sensitive, and rapid spectrophotometric method for copper(II ion detection in aqueous media using polyethyleneimine

    Directory of Open Access Journals (Sweden)

    Ting Wen

    2017-05-01

    Full Text Available In this work, we developed a facile, sensitive, and rapid spectrophotometric method for copper(II ion detection in aqueous media using polyethyleneimine. Polyethyleneimine is a cationic polymer that has no absorption in the wavelength range of 250–800 nm. When trace amounts of copper(II ion was added to the colorless polyethyleneimine solution, copper(II ion could react with the amino groups of the polyethyleneimine to form a dark blue cuprammonium complex whose absorption spectrum exhibited two absorption peaks at 275 and 630 nm, respectively. The effects of parameters such as polyethyleneimine concentration, pH, temperature, reaction time, and the most suitable medium for the reaction were investigated. A linear relationship (R2 = 0.9997 between absorbance and the concentration of copper(II ion was found at the maximum absorption peak of 275 nm in the concentration range of 2–400 μM. The detection limit for copper(II ion was 566 nM. The response of polyethyleneimine toward different metal ions was investigated, and polyethyleneimine displayed a high selectivity for the copper(II ion among the metal ions examined. This biocompatible and sensitive sensor may find applications in copper(II ion detection in environmental and biological processes.

  5. Absorption of copper(II) by creosote bush (Larrea tridentata): use of atomic and x-ray absorption spectroscopy.

    Science.gov (United States)

    Gardea-Torresdey, J L; Arteaga, S; Tiemann, K J; Chianelli, R; Pingitore, N; Mackay, W

    2001-11-01

    Larrea tridentata (creosote bush), a common North American native desert shrub, exhibits the ability to take up copper(II) ions rapidly from solution. Following hydroponic studies, U.S. Environmental Protection Agency method 200.3 was used to digest the plant samples, and flame atomic absorption spectroscopy (FAAS) was used to determine the amount of copper taken up in different parts of the plant. The amount of copper(II) found within the roots, stems, and leaves was 13.8, 1.1, and 0.6 mg/g, respectively, after the creosote bush was exposed to a 63.5-ppm copper(II) solution for 48 h. When the plant was exposed to a 635-ppm copper(II) solution, the roots, stems, and leaves contained 35.0, 10.5, and 3.8 mg/g, respectively. In addition to FAAS analysis, x-ray microfluorescence (XRMF) analysis of the plant samples provided further confirmation of copper absorption by the various plant parts. X-ray absorption spectroscopy (XAS) elucidated the oxidation state of the copper absorbed by the plants. The copper(II) absorbed from solution remained as copper(II) bound to oxygen-containing ligands within the plant samples. The results of this study indicate that creosote bush may provide a useful and novel method of removing copper(II) from contaminated soils in an environmentally friendly manner.

  6. Synthesis, spectroscopic characterization, crystallographic studies and antibacterial assays of new copper(II) complexes with sulfathiazole and nimesulide

    Science.gov (United States)

    Nunes, Julia Helena Bormio; de Paiva, Raphael Enoque Ferraz; Cuin, Alexandre; da Costa Ferreira, Ana Maria; Lustri, Wilton Rogério; Corbi, Pedro Paulo

    2016-05-01

    New ternary copper(II) complexes of sulfathiazole (SFT, C9H8N3O2S2) or nimesulide (NMS, C13H11N2O5S) and 2,2‧-bipyridine (bipy) were synthesized, and characterized by chemical and spectroscopic techniques. Elemental analyses indicated a 2:1:1 sulfonamide/copper/bipy composition for both complexes. Mass spectrometric measurements permitted identifying the molecular ions [Cu(SFT)2(bipy)+H]+ and [Cu(NMS)2(bipy)+H]+ at m/z 728 and 835, respectively, confirming the proposed compositions. Crystal structure of the [Cu(SFT)2(bipy)] complex was solved by powder X-ray diffraction analysis (PXRD), attesting that the Cu(II) ion is hexacoordinated in a distorted octahedral geometry. Each SFT molecule coordinates to the metal ion by the nitrogen atoms of the SO2-N group and of the heterocyclic ring. The coordination sphere is completed by a bipyridine. Electronic paramagnetic resonance (EPR) studies were carried out for the [Cu(NMS)2(bipy)] complex, indicating a tetragonal environment around the metal ion. It was suggested that NMS coordinates to Cu(II) by the nitrogen and oxygen atoms of the SO2-N group, which was confirmed by infrared spectroscopic studies. Biological studies showed the antibacterial activity of both Cu-SFT and Cu-NMS complexes, with the minimum inhibitory concentration (MIC) values ranging from 0.10 to 0.84 mmol L-1 against Gram-negative bacteria for [Cu(SFT)2(bipy)], and from 1.50 to 3.00 mmol L-1 against Gram-positive and -negative bacteria for [Cu(NMS)2(bipy)].

  7. Poly[bis(μ-2,6-dimethylpyridinium-3,5-dicarboxylato-κ2O3:O5copper(II

    Directory of Open Access Journals (Sweden)

    Guang-Feng Hou

    2008-12-01

    Full Text Available In the title coordination polymer, [Cu(C9H8NO42]n, the Cu atom, located on a twofold rotation axis, is four coordinate in a distorted square-planar environment. Each 2,6-dimethylpyridinium-3,5-dicarboxylate anion bridges two Cu atoms, forming a two-dimensional coordination polymer. A three-dimensional supramolecular network is built from N—H...O hydrogen bonds involving the pyridinium NH and the carboxyl COO groups.

  8. Cytotoxic activity, albumin and DNA binding of new copper(II) complexes with chalcone-derived thiosemicarbazones.

    Science.gov (United States)

    Da Silva, Jeferson G; Recio Despaigne, Angel A; Louro, Sonia R W; Bandeira, Cristiano C; Souza-Fagundes, Elaine M; Beraldo, Heloisa

    2013-07-01

    [Cu(HL)Cl2] complexes of chalcone-derived thiosemicarbazones were obtained with 3-phenyl-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCTPh), complex (1), 3-(4-chlorophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4ClPh), complex (2), 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4BrPh), complex (3), and 3-(4-nitrophenyl-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4NO2Ph), complex (4). 1-3 showed interaction with bovine serum albumin (BSA) and deoxyribonucleic acid from calf thymus (CT-DNA). The cytotoxic activities of the thiosemicarbazones and complexes (1-4) were tested against HL60 (wild type human promyelocytic leukemia), Jurkat (human immortalized line of T lymphocyte), MDA-MB 231 (human breast carcinoma) and HCT-116 (human colorectal carcinoma) tumor cell lineages. Upon coordination to copper(II) cytotoxicity significantly increased in Jurkat, MDA-MB 231 and HCT-116 cells. Unlike the free thiosemicarbazones, 1-4 induced DNA fragmentation in solid tumor cells indicating their pro-apoptotic potential. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  9. The crystal structure of paramagnetic copper(ii) oxalate (CuC2O4):

    DEFF Research Database (Denmark)

    Christensen, Axel Nørlund; Lebech, Bente; Andersen, Niels Hessel

    2014-01-01

    the composition CuC2O4·0.44H2O. Time resolved in situ investigations of the thermal decomposition of copper(ii) oxalate using synchrotron X-ray powder diffraction showed that in air the compound converts to Cu2O at 215 °C and oxidizes to CuO at 345 °C. Thermo gravimetric analysis performed in an inert Ar...... diffraction data using one neutron diffraction pattern obtained at 5 K (λ = 1.5949(1) Å) combined with one conventional and two synchrotron X-ray diffraction patterns obtained at ambient temperature using λ = 1.54056, 1.0981 and λ = 0.50483(1) Å, respectively. Based on the X-ray synchrotron data the resulting...... crystal structure is described in the monoclinic space group P21/c (#14) in the P121/n1 setting with unit cell parameters a = 5.9598(1) Å, b = 5.6089(1) Å, c = 5.1138 (1) Å, β = 115.320(1)°. The composition is CuC2O4 with atomic coordinates determined by FullProf refinement of the neutron diffraction data...

  10. Determination of HCl and VOC Emission from Thermal Degradation of PVC in the Absence and Presence of Copper, Copper(II) Oxide and Copper(II) Chloride

    OpenAIRE

    Jafari, Ahamad J.; Donaldson, John D.

    2009-01-01

    Polyvinyl chloride (PVC) has played a key role in the development of the plastic industry over the past 40 years. Thermal degradation of PVC leads to formation of many toxic pollutants such as HCl, aromatic and volatile organic carbon vapors. Thermal degradation of PVC and PVC in the present of copper, cupric oxide and copper(II) chloride were investigated in this study using a laboratory scale electrical furnace. HCl and Cl- ion were analyzed by a Dionex ion chromatograph and VOCs compounds ...

  11. Experimental Investigation on the Mechanism of Chelation-Assisted, Copper(II) Acetate-Accelerated Azide-Alkyne Cycloaddition

    Science.gov (United States)

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

    2011-01-01

    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 1H NMR assays are developed for monitoring the reaction progress in two different solvents – methanol and acetonitrile. Solvent kinetic isotopic effect and pre-mixing 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

  12. Synthesis, Crystal Structure, Spectroscopic Properties and Potential Biological Activities of Salicylate‒Neocuproine Ternary Copper(II Complexes

    Directory of Open Access Journals (Sweden)

    Lenka Kucková

    2015-01-01

    Full Text Available Mixed ligand copper(II complexes containing derivatives of salicylic acid and heterocyclic ligands with nitrogen donor atoms have been the subject of various studies and reviews. In this paper, synthesis and characterization of the ternary copper(II complexes of neocuproine (2,9-dimethyl-1,10-phenanthroline, Neo and salicylate ligands (Sal are reported. In addition, the crystal structures of ([Cu(H2O(5-Cl-Sal(Neo] (1, [Cu(μ-Sal(Neo]2 (2, Cu2(μ-5-Cl-Sal(5-Cl-HSal2(Neo2]·EtOH (3 were determined. In order to compare structural and biological properties of the prepared complexes, spectroscopic and biological studies were performed. Results of X-ray diffraction show that prepared complexes form three types of crystal structures in a given system: monomeric, dimeric and dinuclear complex. The preliminary study on the DNA cleavage activity has shown that the complexes under study behave as the chemical nucleases in the presence of added hydrogen peroxide with slight differences in the activity (1 > 2 > 3. The complexes 1 and 2 exhibited nuclease activity itself indicating the interaction of complexes with the DNA. It has been proposed that the enhanced destructive effect of the complexes 1 and 2 on the DNA is a result of two possible mechanisms of action: (i the conversion of closed circular DNA (form I to the nicked DNA (form II caused by the copper complex itself and (ii damage of DNA by Reactive Oxygen Species (ROS—products of the interaction of copper with hydrogen peroxide by means of Fenton reaction (hydroxyl radicals. Thus the biological activity of the prepared Cu(II complexes containing derivatives of salicylic acid and phenanthroline molecules is substantiated by two independent mechanisms. While derivatives of salicylic acids in the coordination sphere of copper complexes are responsible for radical-scavenging activity (predominantly towards superoxide radical anion, the presence of chelating ligand 2,9-dimethyl-1,10-phenanthroline

  13. Mechanisms for biosorption of chromium(III), copper(II) and mercury ...

    African Journals Online (AJOL)

    This shows that the softer metal ions, copper(II) and mercury(II), form complexes with oxygen and/or nitrogen donor ligands in the MO extracts, while the harder and more highly charged chromium(III) ion becomes hydrolysed. The study therefore suggests that the successful biosorption of heavy metals by Moringa, ...

  14. Catalytic aspects of a copper(II) complex: biological oxidase to ...

    Indian Academy of Sciences (India)

    BISWAJIT CHOWDHURY

    2017-10-03

    Oct 3, 2017 ... been synthesized and crystallographically characterized. X-ray structure analysis revealed that this ... 2.2 Synthesis of [Cu(dpa)2(O Ac)](ClO4)(1). The copper(II) complex was synthesized by addition of aque- ..... 2,2'-bipyridine host: synthesis, crystal structure, DNA cleavage, molecular docking and ...

  15. Iron(III) and copper(II) complexes of trans-bis(ferrocenyl)porphyrin

    Indian Academy of Sciences (India)

    Iron(III) and copper(II) complexes of trans-bis(ferrocenyl)porphyrin: Effect of metal ions on long-range electronic communication. Dipankar Sahoo Sankar Prasad Rath. Volume 127 Issue ... Keywords. Ferrocenylporphyrin; electrochemistry; spectro-electrochemistry; electrochemical conjugation; X-ray structure determination.

  16. Iron(III) and copper(II) complexes of trans-bis(ferrocenyl)porphyrin ...

    Indian Academy of Sciences (India)

    Iron(III) and copper(II) complexes of trans-bis(ferrocenyl)porphyrin: Effect of metal ions on long-range electronic communication. DIPANKAR SAHOO and SANKAR PRASAD RATH∗. Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India e-mail: sprath@iitk.ac.in. MS received 12 December ...

  17. Interesting properties of some iron(II), copper(I) and copper(II ...

    Indian Academy of Sciences (India)

    Administrator

    Tridendate ligands with nitrogen centers, generally well-known as the tripod ligands, have been of considerable interest to inorganic chemists dealing with the preparation of model compounds for hemocyanin, tyrosinase etc. We have found that such ligands when complexed with iron(II) and copper(II) and copper(I) ions ...

  18. Mixed-ligand copper(II) complexes of dipicolylamine and 1,10 ...

    Indian Academy of Sciences (India)

    Unknown

    DNA repair mechanism.13,14 Copper(II) complexes containing heterocyclic bases have received consid- erable current interest in nucleic acid chemistry due to their diverse applications following the discovery of the “chemical nuclease” activity of the [Cu. (phen)2]+ (phen = 1,10-phenanthroline) complex in the presence of ...

  19. Removal of copper(II) ion from aqueous solution by high-porosity ...

    African Journals Online (AJOL)

    The removal of copper(II) ion from aqueous solution by the granular activated carbon, obtained from hazelnut shells (ACHS) (Corylus avellana L. var. lunga istriana), was investigated. The ACHS was prepared from ground dried hazelnut shells by specific method carbonisation and water steam activation at 950oC for 2 h.

  20. Recovery of copper(II) and chromium(III) from nitrate medium with ...

    African Journals Online (AJOL)

    The solvent extraction of copper(II) and chromium(III) from nitrate medium with salicylideneaniline (HL) is studied as a function of various parameters: pH, concentration of salicylideneaniline, contact time and the nature of anoin (nitrate and sulfate) in aqueous phase. Chromium(III) is not extracted by salicylideneaniline ...

  1. Mechanisms for biosorption of chromium(III), copper(II) and mercury ...

    African Journals Online (AJOL)

    4) Å. Furthermore, a CuC distance at 2.96 Å, and a corresponding Cu-O-C 3-leg scattering path at 3.10 Å are observed as well, strongly supporting that a large fraction of carboxylate groups are bound to the copper(II) ion on the equatorial ...

  2. copper(I) and copper(II) complexes with tridentate ligands

    Indian Academy of Sciences (India)

    Administrator

    Tridendate ligands with nitrogen centers, generally well-known as the tripod ligands, have been of considerable interest to inorganic chemists dealing with the preparation of model compounds for hemocyanin, tyrosinase etc. We have found that such ligands when complexed with iron(II) and copper(II) and copper(I) ions ...

  3. Ion Flotation of Copper(II) and Lead(II) from Environmental Water ...

    African Journals Online (AJOL)

    The present study aims to develop a simple, rapid and economic procedure for copper(II) and lead(II) removal under the optimum conditions investigated. It is based on the complex formation between Cu2+ and Pb2+ ions and diphenylcarbazone (HDPC) followed by flotation with oleic acid (HOL) surfactant. The different ...

  4. Biosorption of copper(II) and lead(II) onto potassium hydroxide treated pine cone powder.

    Science.gov (United States)

    Ofomaja, A E; Naidoo, E B; Modise, S J

    2010-08-01

    Pine cone powder surface was treated with potassium hydroxide and applied for copper(II) and lead(II) removal from solution. Isotherm experiments and desorption tests were conducted and kinetic analysis was performed with increasing temperatures. As solution pH increased, the biosorption capacity and the change in hydrogen ion concentration in solution increased. The change in hydrogen ion concentration for lead(II) biosorption was slightly higher than for copper(II) biosorption. The results revealed that ion-exchange is the main mechanism for biosorption for both metal ions. The pseudo-first order kinetic model was unable to describe the biosorption process throughout the effective biosorption period while the modified pseudo-first order kinetics gave a better fit but could not predict the experimentally observed equilibrium capacities. The pseudo-second order kinetics gave a better fit to the experimental data over the temperature range from 291 to 347 K and the equilibrium capacity increased from 15.73 to 19.22 mg g(-1) for copper(II) and from 23.74 to 26.27 for lead(II). Activation energy was higher for lead(II) (22.40 kJ mol(-1)) than for copper(II) (20.36 kJ mol(-1)). The free energy of activation was higher for lead(II) than for copper(II) and the values of DeltaH* and DeltaS* indicate that the contribution of reorientation to the activation stage is higher for lead(II) than copper(II). This implies that lead(II) biosorption is more spontaneous than copper(II) biosorption. Equilibrium studies showed that the Langmuir isotherm gave a better fit for the equilibrium data indicating monolayer coverage of the biosorbent surface. There was only a small interaction between metal ions when simultaneously biosorbed and cation competition was higher for the Cu-Pb system than for the Pb-Cu system. Desorption studies and the Dubinin-Radushkevich isotherm and energy parameter, E, also support the ion-exchange mechanism. Copyright 2010 Elsevier Ltd. All rights reserved.

  5. Bridge resource program.

    Science.gov (United States)

    2013-09-01

    The mission of Rutgers Universitys Center for Advanced Infrastructure and Transportation (CAIT) Bridge Resource Program (BRP) is to provide bridge engineering support to the New Jersey Department of Transportation (NJDOT)s Bridge Engineering an...

  6. Bio-affinity of copper(II) complexes with nitrogen and oxygen donor ligands: Synthesis, structural studies and in vitro DNA and HSA interaction of copper(II) complexes.

    Science.gov (United States)

    Jain, Surbhi; Khan, Tanveer A; Patil, Yogesh P; Pagariya, Darshana; Kishore, Nand; Tapryal, Suman; Naik, Anil D; Naik, Sunil G

    2017-09-01

    Reported herein the binding affinity between Human Serum Albumin and the DNA binding and cleavage activity of three copper(II) complexes, [Cu(phen)(o-van)ClO 4 ] (1), [Cu(phen)(gly)]ClO 4 (2) and [Cu(L 1 ) 2 (H 2 O) 2 ] (3) wherein 1 and 2 are synthesized with 1,10-phenanthroline (phen) and co-ligands (o-van: o-vanillin; gly: glycine) and 3 with a ligand 2-hydroxy-3-methoxybenzylidene-4H-1,2,4-triazol-4-amine (H 1 L 1 ). Complex 2 crystallizes in monoclinic (P21/n) space group shows square pyramidal geometry. The complex 3 crystallizes in monoclinic (P21/a) space group. All the three complexes exhibit binding affinity towards the transport protein Human Serum albumin (HSA). Quantitative evaluation of the thermodynamics of interaction and the results obtained from fluorescence spectroscopy suggest that metal coordinated glycynate, o-vanillin and perchlorate groups have a major role to play in the binding process, the latter two being stronger in the binding of complex 1. The coordinated water in complex 3 also plays an important role in the binding, which makes binding of complex 3 with HSA stronger than that of complex 2. Experimental results indicate that the binding affinity of the complexes towards CT-DNA is in the order 1>3>2 implying that complex 1 binds stronger than complex 3 and 2.The DNA cleaving activity of all the three complexes was explored in the presence of reactive oxygen compound, H 2 O 2 . All the three complexes have primarily shown the DNA cleaving activity. Copyright © 2017. Published by Elsevier B.V.

  7. Synthesis, and structural characterization of mixed ligand copper(II) complexes of N,N,N‧,N'-tetramethylethylenediamine incorporating carboxylates

    Science.gov (United States)

    Batool, Syeda Shahzadi; Gilani, Syeda Rubina; Tahir, Muhammad Nawaz; Rüffer, Tobias

    2017-11-01

    Two ternary copper(II) complexes of N,N,N‧,N'-tetramethylethylenediamine (tmen = C6H16N2) with benzoic acid and p-aminobenzoic acid, having the formula [Cu(tmen)(BA)2(H2O)2] (1), and [Cu(tmen)(pABA)2]. 1/2 CH3OH (2) {(Where BA1- = benzoate1- (C6H5CO21-), pABA1- = p-aminobenzoate1- (p-H2NC6H5CO21-)} have been prepared and characterized by elemental combustion analysis, Uv-Visible spectroscopy, FT-IR spectroscopy, thermal, and single crystal X-ray diffraction analyses. The complex 1 is a monomer with distorted octahedral geometry. In its CuN2O4 chromophore, the Cu(II) centre is coordinated by two N atoms of a symmetrically chelating tmen ligand, by two carboxylate-O atoms from two monodentate benzoate1- anions, and by two apical aqua-O atoms, which define the distorted octahedral structure. The complex 2 is a monomer with a distorted square planar coordination geometry. In CuN2O2 chromophore, tmen is coordinated to Cu(II) ion in a chelating bidentate fashion, while the two p-aminobenzoate1- anions coordinate to Cu(II) centre through their carboxylate-O atoms in a monodentate manner, forming a square planar structure. The observed difference between asymmetric ѵas(OCO) and symmetric ѵs(OCO) stretching IR vibrations of the carboxylate moieties for 1 and 2 is 220 cm-1 and 232 cm-1, respectively, which suggests monodentate coordination mode (Δν OCO>200) of the carboxylate groups to Cu(II) ion. Thermogravimetric studies of 1 indicates removal of two water molecules at 171 °C, elimination of a tmen upto 529 °C and of two benzoate groups upto 931 °C. In tga curve of 2, methanol is lost upto 212 °C, while tmen is lost from 212 to 993 °C. The antibacterial activities of these new compounds against various bacterial strains were also investigated.

  8. Crystal structure, characterization and magnetic properties of a 1D ...

    Indian Academy of Sciences (India)

    Single crystal X-ray structural characterization revealsthat the side arm carboxylate group of the coordinated Schiff base exhibits a μ 1 , 3 -bridging mode and connectsthe neighbouring copper(II) ions leading to a zigzag 1D chain structure where the copper(II) ions displaydistorted square pyramidal geometries. Variable ...

  9. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Single crystal X-ray structural characterization revealsthat the side arm carboxylate group of the coordinated Schiff base exhibits a μ 1 , 3 -bridging mode and connectsthe neighbouring copper(II) ions leading to a zigzag 1D chain structure where the copper(II) ions displaydistorted square pyramidal geometries. Variable ...

  10. Binary and ternary copper(II) complexes of a tridentate ONS ligand derived from 2-aminochromone-3 carboxaldehyde and thiosemicarbazide: Synthesis, spectral studies and antimicrobial activity

    Science.gov (United States)

    Shebl, Magdy; Ibrahim, M. A.; Khalil, Saied M. E.; Stefan, S. L.; Habib, H.

    2013-11-01

    A tridentate ONS donor ligand, HL, was synthesized by the condensation of 2-aminochromone-3-carboxaldehyde with thiosemicarbazide. The structure of the ligand was elucidated by elemental analyses, IR, 1H and 13C NMR, electronic and mass spectra. Reaction of the ligand with several copper(II) salts, including AcO-, NO3-, SO42-, Cl-, Br- and ClO4- afforded different metal complexes that reflect the non-coordinating or weakly coordinating power of the ClO4- and Br- anions as compared to the strongly coordinating power of AcO-, SO42-, Cl- and NO3- anions. Also, the ligand was allowed to react with Cu(II) ion in the presence of a secondary ligand (L‧) [N,O-donor; 8-hydroxyquinoline or N,N-donor; 1,10-phenanthroline]. Characterization and structure elucidation of the prepared complexes were achieved by elemental and thermal analyses, IR, electronic, mass and EPR spectra as well as conductivity and magnetic susceptibility measurements. The EPR spin Hamiltonian parameters of some complexes were calculated. The metal complexes exhibited octahedral and square planar geometrical arrangements depending on the nature of the anion. The ligand and most of its metal complexes showed antibacterial activity towards Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Salmonella typhimurium and Escherichia coli), yeast (Candida albicans) and fungus (Aspergillus fumigatus).

  11. Cyanuric chloride reagent as a chloride ion donor: synthesis, crystal structure, and magnetic properties of [Cu.sub.2./sub.(2-APM).sub.2./sub.(μ-Cl).sub.2./sub.(μ-OCH.sub.3./sub.).sub.2./sub.].sub.n./sub. coordination polymer

    Czech Academy of Sciences Publication Activity Database

    Hosseini-Monfared, H.; Mojtabazadeh, F.; Bikas, R.; Eigner, Václav; Dušek, Michal; Gutiérrez, A.

    2014-01-01

    Roč. 67, č. 21 (2014), s. 3510-3518 ISSN 0095-8972 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : copper(II) coordination polymer * in situ reaction * cyanuric chloride * structure * magnetic study Subject RIV: CA - Inorganic Chemistry Impact factor: 2.012, year: 2014

  12. Extraction of silver(I) from aqueous solutions in the absence and presence of copper(II) with a methimazole-based ionic liquid.

    Science.gov (United States)

    Reyna-González, Juan M; Torriero, Angel A J; Siriwardana, Amal I; Burgar, Iko M; Bond, Alan M

    2011-08-21

    The ionic liquid (IL) 2-butylthiolonium bis(trifluoromethanesulfonyl)amide, [mimSBu][NTf(2)], facilitates the efficient extraction of silver(I) from aqueous media via interaction with both the cation and anion components of the IL. Studies with a conventional aqueous-IL two phase system as well as microextraction of silver(I) by a thick IL film adhered to an electrode monitored in situ by cyclic voltammetry, established that [mimSBu][NTf(2)] can extract electroactive silver(I) ions from an aqueous solution. The pH of the aqueous phase decreases upon addition of [mimSBu](+), which is attributed to partial release of the hydrogen attached to the N(3) nitrogen atom of the imidazolium ring. The presence of silver(I) further increase the acidity of the aqueous phase as a consequence of coordination with the IL cation component. Voltammetric and (1)H and (13)C NMR techniques have been used to establish the nature of the silver(I) complexes extracted, and show that the form of interaction with the IL differs from that outlined previously for the extraction of copper(II). Insights on the competition established when silver(I) is extracted in the presence of copper(II) are provided. Finally, it is noted that metallic silver can be directly electrodeposited at the electrode surface after extraction of silver(I) into [mimSBu][NTf(2)] and that back extraction of silver(I) into aqueous media is achieved by addition of an acidic aqueous solution.

  13. Mixed-ligand copper(ii) Schiff base complexes: the role of the co-ligand in DNA binding, DNA cleavage, protein binding and cytotoxicity.

    Science.gov (United States)

    Lian, Wen-Jing; Wang, Xin-Tian; Xie, Cheng-Zhi; Tian, He; Song, Xue-Qing; Pan, He-Ting; Qiao, Xin; Xu, Jing-Yuan

    2016-05-31

    Four novel mononuclear Schiff base copper(ii) complexes, namely, [Cu(L)(OAc)]·H2O (), [Cu(HL)(C2O4)(EtOH)]·EtOH (), [Cu(L)(Bza)] () and [Cu(L)(Sal)] () (HL = 1-(((2-((2-hydroxypropyl)amino)ethyl)imino)methyl)naphthalene-2-ol), Bza = benzoic acid, Sal = salicylic acid), were synthesized and characterized by X-ray crystallography, elemental analysis and infrared spectroscopy. Single-crystal diffraction analysis revealed that all the complexes were mononuclear molecules, in which the Schiff base ligand exhibited different coordination modes and conformations. The N-HO and O-HO inter- and intramolecular hydrogen bonding interactions linked these molecules into multidimensional networks. Their interactions with calf thymus DNA (CT-DNA) were investigated by UV-visible and fluorescence spectrometry, as well as by viscosity measurements. The magnitude of the Kapp values of the four complexes was 10(5), indicating a moderate intercalative binding mode between the complexes and DNA. Electrophoresis results showed that all these complexes induced double strand breaks of pUC19 plasmid DNA in the presence of H2O2 through an oxidative pathway. In addition, the fluorescence spectrum of human serum albumin (HSA) with the complexes suggested that the quenching mechanism of HSA by the complexes was a static process. Moreover, the antiproliferative activity of the four complexes against HeLa (human cervical carcinoma) and HepG-2 (human liver hepatocellular carcinoma) cells evaluated by colorimetric cell proliferation assay and clonogenic assay revealed that all four complexes had improved cytotoxicity against cancer cells. Inspiringly, complex , with salicylic acid as the auxiliary ligand, displayed a stronger anticancer activity, suggesting that a synergistic effect of the Schiff base complex and the nonsteroidal anti-inflammatory drug may be involved in the cell killing process. The biological features of mixed-ligand copper(ii) Schiff base complexes and how acetic auxiliary

  14. Cable Supported Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    Cable supported bridges in the form of suspension bridges and cable-stayed bridges are distinguished by their ability to overcome large spans.The book concentrates on the synthesis of cable supported bridges, covering both design and construction aspects. The analytical part covers simple methods...

  15. New cyclic tetranuclear copper(II) complexes containing quadrilateral cores: Synthesis, structure, spectroscopy and their interactions with DNA in aqueous solution

    Science.gov (United States)

    Giri, Gopal C.; Haldar, Shobhraj; Ghosh, Aloke Kumar; Chowdhury, Priyanka; Carrella, Luca; Ghosh, Utpal; Bera, Manindranath

    2017-08-01

    Three new cyclic tetranuclear copper(II) complexes, Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetrachloro)tetracopper(II)methanolhydrate (1·CH3OH·H2O), Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetrathiocyanato)tetracopper(II) (2) and Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetraazido)tetracopper(II) (3) have been synthesized by exploiting the chelating ability and bridging potential of a carboxyamine functionalized tridentate ligand, HL (HL = 3-[(2-Pyridylmethyl)-amino]-propionic acid). Complexes 1, 2 and 3 have been synthesized by carrying out reaction of the ligand HL with stoichiometric amounts of CuCl2·2H2O, CuCl2·2H2O/NH4SCN, and CuCl2·2H2O/NaN3, respectively, in the presence of NMe4OH at ambient temperature. Various analytical techniques have been employed to characterize the complexes, including single crystal X-ray diffraction study of 1. Structures of complexes 2 and 3 have been optimized by DFT calculation at B3LYP/6-311G level. Analysis of X-ray crystal structure reveals that the metallic core of complex 1 contains four distorted square pyramidal Cu(II) ions. The Cu(II) ions in each complex are arranged at the corners of a quadrilateral showing a μ2:η1:η1syn-anti bidentate bridging mode of four carboxylate groups of L- ligands with each bridging between two Cu(II) ions. These complexes represent a new family of 16-MCCuII-4 metallocoronates with repeating -[CuIIsbnd Osbnd Csbnd O]- units. In aqueous solution (pH∼7.5), the interactions of complexes with DNA have been investigated by UV-Vis and fluorescence titration spectroscopy, and viscosity measurements.

  16. Two new hexacoordinated coordination polymers of cadmium (II ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 128; Issue 9. Two new hexacoordinated coordination polymers of cadmium(II) containing bridging units only: Syntheses, structures and molecular properties. DIPU SUTRADHAR HABIBAR CHOWDHURY SUSHOVAN KONER SUBHASIS ROY BARINDRA KUMAR ...

  17. A serials of sandwich-like trinuclear and one-dimensional chain cyanide-bridged iron(III)-copper(II) complexes: Syntheses, crystal structures and magnetic properties

    Science.gov (United States)

    Shi, Jingwen; Lan, Wenlong; Ren, Yanjie; Liu, Qingyun; Liu, Hui; Dong, Yunhui; Zhang, Daopeng

    2018-04-01

    Four pyridinecarboxamide trans-dicyanideiron(III) building blocks and one macrocyclic copper(II) compound have been employed to assemble cyanide-bridged heterometallic complexes, resulting in a serials of cyanide-bridged FeIII-CuII complexes with different structure types. The series of complexes can be formulated as: {[Cu(Cyclam)][Fe(bpb)(CN)2]2}·4H2O (1), {{[Cu(Cyclam)][Fe(bpb)(CN)2]}ClO4}n·nH2O (2), and {[Cu(Cyclam)][Fe(bpmb)(CN)2]2}·4H2O (3), {[Cu(Cyclam)][Fe(bpClb)(CN)2]2}·4H2O (4) and {{[Cu(Cyclam)][Fe(bpdmb)(CN)2]}ClO4}n·2nCH3OH (5) (bpb2- = 1,2-bis(pyridine-2-carboxamido)benzenate, bpmb2- = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate, bpClb2- = 1,2-bis(pyridine-2-carboxamido)-4-chloro-benzenate, bpdmb2- = 1,2-bis(pyridine-2-carboxamido)-4,5-dimethyl-benzenate, Cyclam = 1,4,8,11-tetraazacyclotetradecane). All the complexes have been characterized by elemental analysis, IR spectra and structural determination. Single X-ray diffraction analysis shows the similar neutral sandwich-like structures for complexes 1, 3 and 4, in which the two cyano precursors acting as monodentate ligand through one of their two cyanide groups were coordinated face to face to central Cu(II) ion. The complexes 2 and 5 can be structurally characterized as one-dimensional cationic single chain consisting of alternating units of [Cu(Cyclam)]2+ and [Fe(bpb/bpdmb)(CN)2]- with free ClO4- as balanced anion. Investigation over magnetic properties of the whole serials of complexes reveals the antiferromagnetic magnetic coupling between the neighboring cyanide-bridged Fe(III) and Cu(II) ions in complexes 3 and 4 and the ferromagnetic interaction in complexes 1, 2 and 5, respectively.

  18. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    2008-01-01

    Roč. 63, č. 1 (2008), s. 308-327 ISSN 0899-8256 Institutional research plan: CEZ:AV0Z70850503 Keywords : global games * coordination * crises * cycles and fluctuations Subject RIV: AH - Economics Impact factor: 1.333, year: 2008

  19. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    -, č. 274 (2005), s. 1-26 ISSN 1211-3298 Institutional research plan: CEZ:AV0Z70850503 Keywords : coordination * crises * cycles and fluctuations Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp274.pdf

  20. Binuclear complexes of technetium. Evidence for bis(terdentate)bidentate coordination by the bridging ligand 2,3,5,6-tetrakis(2-pyridyl)pyrazine to technetium(V)

    International Nuclear Information System (INIS)

    Du Preez, J.G.H.; Gerber, T.I.A.; Gibson, M.L.; Geyser, R.

    1990-01-01

    The authors have used the potentially bis(terdentate) nitrogen aromatic heterocyclic ligand 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tppz) to prepare mono- and bimetallic technetium(V) complexes bound to tppz. The stimulus for the development of the coordination chemistry of the man-made element technetium is provided by the use of complexes of this element as anatomical imaging agents in nuclear medicine. Although the chemistry of technetium(V) with nitrogen donor ligands is well understood, no complexes have been prepared using potentially terdentate neutral nitrogen donor ligands of this metal in the +5 oxidation state

  1. A detailed study on the interaction of a novel water-soluble glycine bridged zinc(II) Schiff base coordination polymer with BSA: synthesis, crystal structure, molecular docking and cytotoxicity effect against A549, Jurkat and Raji cell lines

    Czech Academy of Sciences Publication Activity Database

    Asadi, Z.; Golchin, M.; Eigner, Václav; Dušek, Michal; Amirghofran, Z.

    2017-01-01

    Roč. 465, Aug (2017), s. 50-60 ISSN 0020-1693 R&D Projects: GA MŠk LO1603; GA ČR(CZ) GA14-03276S EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : water-soluble * coordination polymer * BSA * docking study * anticancer activity Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 2.002, year: 2016

  2. Bridges in complex networks.

    Science.gov (United States)

    Wu, Ang-Kun; Tian, Liang; Liu, Yang-Yu

    2018-01-01

    A bridge in a graph is an edge whose removal disconnects the graph and increases the number of connected components. We calculate the fraction of bridges in a wide range of real-world networks and their randomized counterparts. We find that real networks typically have more bridges than their completely randomized counterparts, but they have a fraction of bridges that is very similar to their degree-preserving randomizations. We define an edge centrality measure, called bridgeness, to quantify the importance of a bridge in damaging a network. We find that certain real networks have a very large average and variance of bridgeness compared to their degree-preserving randomizations and other real networks. Finally, we offer an analytical framework to calculate the bridge fraction and the average and variance of bridgeness for uncorrelated random networks with arbitrary degree distributions.

  3. Copper(II tetrafluoroborate as mild and versatile catalyst for the

    Directory of Open Access Journals (Sweden)

    Jihillu. S. Yadav

    2008-12-01

    Full Text Available A variety of -acetamido ketones and ketoesters are readily prepared in high yields under extremelymild conditions via a three component coupling of aromatic aldehydes, enolizable ketones or -ketoesters andnitriles in the presence of 10 mol% of copper(II tetrafluoroborate and a stoichiometric amount of acetylchloride. A solution of 10 mol% of Cu(BF42 in acetonitrile provides a convenient reaction medium to carry out athree component reaction under mild conditions

  4. Characterisation of the interactions between substrate, copper(II) complex and DNA and their role in rate acceleration in DNA-based asymmetric catalysis

    NARCIS (Netherlands)

    Draksharapu, Apparao; Boersma, Arnold J; Browne, Wesley R; Roelfes, Gerard

    2015-01-01

    Interactions of the azachalcone derived substrate Aza with copper(II) complexes in the presence and absence of st-DNA were studied in detail by UV/Vis absorption, EPR and Raman and (UV and vis) resonance Raman spectroscopies. The binding of Aza to the Lewis acidic copper(II) complexes, which results

  5. Mechanisms underlying reductant-induced reactive oxygen species formation by anticancer copper(II) compounds.

    Science.gov (United States)

    Kowol, Christian R; Heffeter, Petra; Miklos, Walter; Gille, Lars; Trondl, Robert; Cappellacci, Loredana; Berger, Walter; Keppler, Bernhard K

    2012-03-01

    Intracellular generation of reactive oxygen species (ROS) via thiol-mediated reduction of copper(II) to copper(I) has been assumed as the major mechanism underlying the anticancer activity of copper(II) complexes. The aim of this study was to compare the anticancer potential of copper(II) complexes of Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone; currently in phase II clinical trials) and its terminally dimethylated derivative with that of 2-formylpyridine thiosemicarbazone and that of 2,2'-bipyridyl-6-carbothioamide. Experiments on generation of oxidative stress and the influence of biologically relevant reductants (glutathione, ascorbic acid) on the anticancer activity of the copper complexes revealed that reductant-dependent redox cycling occurred mainly outside the cells, leading to generation and dismutation of superoxide radicals resulting in cytotoxic amounts of H(2)O(2). However, without extracellular reductants only weak intracellular ROS generation was observed at IC(50) levels, suggesting that cellular thiols are not involved in copper-complex-induced oxidative stress. Taken together, thiol-induced intracellular ROS generation might contribute to the anticancer activity of copper thiosemicarbazone complexes but is not the determining factor.

  6. Synthesis, characterization, cellular uptake and interaction with native DNA of a bis(pyridyl)-1,2,4-oxadiazole copper(II) complex.

    Science.gov (United States)

    Terenzi, Alessio; Barone, Giampaolo; Piccionello, Antonio Palumbo; Giorgi, Gianluca; Guarcello, Annalisa; Portanova, Patrizia; Calvaruso, Giuseppe; Buscemi, Silvestre; Vivona, Nicolò; Pace, Andrea

    2010-10-14

    The copper(II) complex of 3,5-bis(2'-pyridyl)-1,2,4-oxadiazole was synthesized and characterized. X-Ray crystallography revealed that the complex consists of a discrete [Cu(3,5-bis(2'-pyridyl)-1,2,4-oxadiazole)(2)(H(2)O)(2)](2+) cation and two ClO(4)(-) anions. The Cu(II) coordination sphere has a distorted octahedral geometry and each ligand chelates the copper ion through the N(4) nitrogen of the oxadiazole ring and the nitrogen of one pyridine moiety. The coordinated water molecules are in cis position and each of them is H-bonded to the 5-pyridyl nitrogen of the oxadiazole ligand and to an oxygen of the perchlorate anion. Biological assays showed that, despite the free ligand not being effective, [Cu(3,5-bis(2'-pyridyl)-1,2,4-oxadiazole)(2)(H(2)O)(2)](2+) reduced the vitality of human hepatoblastoma HepG2 and colorectal carcinoma HT29 cells in a dose- and time-dependent manner. The interaction of the cationic copper complex with native DNA was investigated by variable-temperature UV-vis spectroscopy, circular dichroism, viscosity and gel electrophoresis, indicating that it is a groove binder with binding constant K(b) = 2.2 × 10(4) M(-1).

  7. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    Overview From a technical perspective, CMS has been in “beam operation” state since 6th November. The detector is fully closed with all components operational and the magnetic field is normally at the nominal 3.8T. The UXC cavern is normally closed with the radiation veto set. Access to UXC is now only possible during downtimes of LHC. Such accesses must be carefully planned, documented and carried out in agreement with CMS Technical Coordination, Experimental Area Management, LHC programme coordination and the CCC. Material flow in and out of UXC is now strictly controlled. Access to USC remains possible at any time, although, for safety reasons, it is necessary to register with the shift crew in the control room before going down.It is obligatory for all material leaving UXC to pass through the underground buffer zone for RP scanning, database entry and appropriate labeling for traceability. Technical coordination (notably Stephane Bally and Christoph Schaefer), the shift crew and run ...

  8. Synthesis, crystal structures, and magnetic properties of cyanide-bridged W(V)Mn(III) anionic coordination polymers containing divalent cationic moieties: slow magnetic relaxations and spin crossover phenomenon.

    Science.gov (United States)

    Yoon, Jung Hee; Lim, Kwang Soo; Ryu, Dae Won; Lee, Woo Ram; Yoon, Sung Won; Suh, Byoung Jin; Hong, Chang Seop

    2014-10-06

    Two trimetallic coordination complexes were prepared by self-assembly of [W(CN)8](3-) and the Mn(III) Schiff base followed by the addition of a Zn(II) or Fe(II) cationic unit. The octacyanotungstate connects neighboring Mn(III) centers to form a one-dimensional chain. The anionic chain requires cationic units of Zn(II) or Fe(II) to maintain charge balance in the structure. The Zn-containing complex shows ferrimagnetic behavior originating from the antiparallel alignment of W(V) and Mn(III) spins within the chain, which leads to slow magnetic relaxation at low temperatures. For the Fe(II)-containing compound, Fe(II) moieties are integrated into the ferrimagnetic chains, altering their spin states depending on the temperature. It appears that the coexistence of high- and low-spin states in the low temperature regime is responsible for the slower and faster relaxations of the magnetization.

  9. Synthesis, Characterization and Antimicrobial Activity of Copper(II ...

    African Journals Online (AJOL)

    NICO

    2014-03-03

    Mar 3, 2014 ... Many Schiff base metal complexes have been prepared and screened for their antimicrobial activity. Ortho-hydroxysalicylaldimines possess N2O2 donor atoms and consequently, form stable chelates with metal ions.15,21,23–24. The configuration of the chelate group in the four coordinate complexes may ...

  10. Synthesis and structure of copper(II) complexes: Potential cyanide ...

    Indian Academy of Sciences (India)

    ing the oxidase models. The necessity to make progress in developing copper oxidase models requires synthesis of appropriate copper complexes to rationalize the func- tions of such oxidases unequivocally.46–52 Therefore, to study the coordination chemistry of Cu(II) incorpo- rating the new azo ligands,53 HLa and HLb, ...

  11. Bridge element deterioration rates.

    Science.gov (United States)

    2008-10-01

    This report describes the development of bridge element deterioration rates using the NYSDOT : bridge inspection database using Markov chains and Weibull-based approaches. It is observed : that Weibull-based approach is more reliable for developing b...

  12. Movable bridge maintenance monitoring.

    Science.gov (United States)

    2013-10-01

    Movable bridges have particular maintenance issues, which cost considerably more than those of fixed bridges, : mostly because of the complex interaction of the mechanical, electrical and structural components. In order to track : maintenance and ope...

  13. LTBP bridge performance primer.

    Science.gov (United States)

    2013-12-01

    "The performance of bridges is critical to the overall performance of the highway transportation system in the United States. However, many critical aspects of bridge performance are not well understood. The reasons for this include the extreme diver...

  14. Bridge vehicle impact assessment.

    Science.gov (United States)

    2011-12-01

    Bridges in New York State have been experiencing close to 200 bridge hits a year. These : accidents are attributed to numerous factors including: improperly stored equipment on trucks; : violation of vehicle posting signs; illegal commercial vehicles...

  15. Improving bridge load rating accuracy.

    Science.gov (United States)

    2013-06-01

    Nearly one-quarter of Alabamas bridges are deemed structurally deficient or functionally obsolete. An : additional seven percent of Alabamas bridges were posted bridges in 2010. (Federal Highway Administration, : 2011) Accurate bridge load rati...

  16. Coordinated unbundling

    DEFF Research Database (Denmark)

    Timmermans, Bram; Zabala-Iturriagagoitia, Jon Mikel

    2013-01-01

    Public procurement for innovation is a matter of using public demand to trigger innovation. Empirical studies have demonstrated that demand-based policy instruments can be considered to be a powerful tool in stimulating innovative processes among existing firms; however, the existing literature has...... not focused on the role this policy instrument can play in the promotion of (knowledge-intensive) entrepreneurship. This paper investigates this link in more detail and introduces the concept of coordinated unbundling as a strategy that can facilitate this purpose. We also present a framework on how...... to organise public procurement for innovation around this unbundling strategy and provide a set of challenges that need to be addressed....

  17. FEATURES OF INITIATION OF STYRENE POLYMERIZATION BY CUMENE HYDROPEROXIDE IN PRESENCE OF ACETULACETONATE OF COPPER(II

    Directory of Open Access Journals (Sweden)

    A. V. Grekova

    2016-04-01

    Full Text Available Kinetics of sectional styrene polymerization initiated by cumene hydroperoxide, acetylacetonate of copper(II and by the system of cumene hydroperoxide — acetylacetonate of copper(II in a temperature range 333-363 K is studied. Kinetic parameters of polymerization process are determined. It is shown, that system of cumene hydroperoxide — acetylacetonate of copper(II is in 5-6 times more effective on the initiating ability comparatively to application of its individual components. From findings ensues that decline of energy of activating of initiation from 110 kdzh/mol’ to 87 kdzh/mol’ for cumene hydroperoxide at the use of the studied system is caused with participating of monomer in preliminary complexation facilitating formation of free radicals.

  18. Synthesis and ferromagnetically coupled heterodinuclear oxamido-bridged copper(II)-oxovanadium(IV) complexes

    International Nuclear Information System (INIS)

    Li Yantuan; Yan Cuiwei; Wu Zhiyong; Zhu Chunyuan

    2005-01-01

    Three novel copper(II)-oxovanadium(IV) heterodinuclear complexes bridged by dianions of N,N'-oxamidobis(propionato)cuprate, [Cu(obp)], and endcapped with 2,9-dimethyl-1,10-phenanthroline (Me 2 phen), 4,7-diphenyl-1,10-phenanthroline (Ph 2 phen) or 5-methyl-1,10-phenanthroline (Mephen), respectively, have been synthesized and identified as [Cu(obp)VO(Me 2 phen)] (1), [Cu(obp)VO(Ph 2 phen)] (2) and [Cu(obp)VO(Mephen)] (3). The three dinuclear complexes have not yet been isolated in crystalline form suitable for X-ray structure analysis, but based on elemental analyses, IR and electronic spectra studies, magnetic moments at room temperature and molar conductivity measurements, these complexes are proposed to have an extended oxamido-bridged structure consisting of planar copper(II) and square-pyramidal oxovanadium(IV) ions. The three heterodinuclear complexes were further characterized by variable-temperature magnetic susceptibility (4.2-300K) measurements and the magnetic data have been used to deduce the indicated heterodinuclear structure. The results derived from least-squares fit of the experimental data have confirmed that the operation of a ferromagnetic interaction between the adjacent copper(II) and oxovanadium(IV) ions through the oxamido bridge within each molecule takes place. Based on spin Hamiltonian, H at=-2JS at 1 .S at 2 , the exchange integral (J) was evaluated as J=+21.9cm -1 for (1), J=+18.8cm -1 for (2) and +26.5cm -1 for (3). The influence of the symmetry of the magnetic orbitals and different terminal ligands on the nature and magnitude of the magnetic interaction between the paramagnetic centers is also discussed

  19. Unusual 4-arsonoanilinium cationic species in the hydrochloride salt of (4-aminophenyl)arsonic acid and formed in the reaction of the acid with copper(II) sulfate, copper(II) chloride and cadmium chloride.

    Science.gov (United States)

    Smith, Graham; Wermuth, Urs D

    2017-04-01

    Structures having the unusual protonated 4-arsonoanilinium species, namely in the hydrochloride salt, C 6 H 9 AsNO 3 + ·Cl - , (I), and the complex salts formed from the reaction of (4-aminophenyl)arsonic acid (p-arsanilic acid) with copper(II) sulfate, i.e. hexaaquacopper(II) bis(4-arsonoanilinium) disulfate dihydrate, (C 6 H 9 AsNO 3 ) 2 [Cu(H 2 O) 6 ](SO 4 ) 2 ·2H 2 O, (II), with copper(II) chloride, i.e. poly[bis(4-arsonoanilinium) [tetra-μ-chlorido-cuprate(II)

  20. Synthesis, crystal structure and magnetic properties of a novel copper(II) complex with sulfoisophthalic acid

    Science.gov (United States)

    Kurc, Teresa; Videnova-Adrabinska, Veneta; Turowska-Tyrk, Ilona; Duczmal, Marek; Jerzykiewicz, Maria

    2013-12-01

    A new Cu(II) complex, [Cu2(μ2-OH2)2(HSIP)2(H2O)6] (H3SIP = 5-sulfoisophthalic acid), has been synthesized and characterized by single crystal X-ray diffraction, EPR spectroscopy (X- (9.5 GHz) and Q-band (35 GHz)) and magnetic measurements. The solid state structure of the complex consists of coordination dimers [Cu2(μ2-OH2)2(HSIP)2(H2O)6] which are hydrogen bonded into 3D network. The neighbouring metal ions form a rare example of centrosymetric dinuclear core [Cu2(μ2-OH2)2] with equatorial - axial positions of the bridging ligands. The coordination dimers are organized into inorganic monolayers via water-sulfonate hydrogen bond intractions, and further linked in 3D structure via carboxylic-carboxylic hydrogen bond intractions. The magnetic properties and EPR spectra are discussed in terms of crystal structure features. The X- and Q-band EPR spectra exhibit fine structure signals due to S = 1 and the simulated parameters indicate small zero field splitting parameter Dexp (-0.035 cm-1) dominated by Ddip (-0.031 cm-1). A usually forbidden ΔMs = 2 line of lower intensity is observed in the half field region at about 150 mT. The susceptibility data have been analyzed using a spin-ladder model with both ferromagnetic (rungs) and antiferromagnetic (legs) coupling.

  1. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    2010-01-01

    Operational Experience At the end of the first full-year running period of LHC, CMS is established as a reliable, robust and mature experiment. In particular common systems and infrastructure faults accounted for <0.6 % CMS downtime during LHC pp physics. Technical operation throughout the entire year was rather smooth, the main faults requiring UXC access being sub-detector power systems and rack-cooling turbines. All such problems were corrected during scheduled technical stops, in the shadow of tunnel access needed by the LHC, or in negotiated accesses or access extensions. Nevertheless, the number of necessary accesses to the UXC averaged more than one per week and the technical stops were inevitably packed with work packages, typically 30 being executed within a few days, placing a high load on the coordination and area management teams. It is an appropriate moment for CMS Technical Coordination to thank all those in many CERN departments and in the Collaboration, who were involved in CMS techni...

  2. New nickel(II) and copper(II) complexes with unsymmetrical Schiff bases derived from (1R,2R)(-)cyclohexanediamine and the application of Cu(II) complexes for hybrid thin layers deposition.

    Science.gov (United States)

    Barwiolek, M; Szlyk, E; Surdykowski, A; Wojtczak, A

    2013-08-28

    New unsymmetrical Schiff bases obtained by condensation of (1R,2R)(-)cyclohexanediamine with 2-hydroxy-3,5-di-tert-butylbenzaldehyde (3,5-(t)bba) and 2-hydroxy-3-methoxybenzaldehyde (3-metoxba) or 2-hydroxy-5-nitrobenzaldehyde (5-nba) and 2-hydroxyacetophenone (hacphen) were used for the synthesis of Cu(ii) and Ni(ii) complexes. The ligands and complexes were characterized by circular dichroism (CD), UV-vis, IR, (1)H (NOE diff) (ligand) and (13)C NMR (ligand) spectra. The X-ray crystal structures solved for Ni(II)(1R,2R)(-)chxn(3,5-(t)bba)(hacphen) exhibit distortion of the coordination sphere towards tetrahedral in the solid phase. The complex crystallized in the orthorhombic non-centrosymmetric P2(1)2(1)2(1) space group. Thin layers of copper(II) complexes were deposited on Si(111) by a spin coating technique and characterized by scanning electron microscopy (SEM/EDS), atomic force microscopy (AFM) and fluorescence spectroscopy. Layer deposition conditions were studied and optimal parameters were found (1500 rpm, time 30 s). For copper(ii) layers the most intensive fluorescence band from intraligand transition at 514 nm was observed. CD spectra of complexes in MeCN suggest the tetrahedral distortion from the square planar geometry of the central ion of the coordination sphere in solution. The (1)H NMR NOE diff. spectra of ligands were measured and the positions of the nearest hydrogen atoms in the cyclohexane and aromatic rings were discussed.

  3. Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of N'-(furan-3-ylmethylene)-2-(4-methoxyphenylamino)acetohydrazide.

    Science.gov (United States)

    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.

  4. Extraction of copper(II) ions from aqueous solutions with a methimazole-based ionic liquid.

    Science.gov (United States)

    Reyna-González, Juan M; Torriero, Angel A J; Siriwardana, Amal I; Burgar, Iko M; Bond, Alan M

    2010-09-15

    The recently synthesized ionic liquid (IL) 2-butylthiolonium bis(trifluoromethanesulfonyl)amide, [mimSBu][NTf(2)], has been used for the extraction of copper(II) from aqueous solution. The pH of the aqueous phase decreases upon addition of [mimSBu](+), which is attributed to partial release of the hydrogen attached to the N(3) nitrogen atom of the imidazolium ring. The presence of sparingly soluble water in [mimSBu][NTf(2)] also is required in solvent extraction studies to promote the incorporation of Cu(II) into the [mimSBu][NTf(2)] ionic liquid phase. The labile copper(II) system formed by interacting with both the water and the IL cation component has been characterized by cyclic voltammetry as well as UV-vis, Raman, and (1)H, (13)C, and (15)N NMR spectroscopies. The extraction process does not require the addition of a complexing agent or pH control of the aqueous phase. [mimSBu][NTf(2)] can be recovered from the labile copper-water-IL interacting system by washing with a strong acid. High selectivity of copper(II) extraction is achieved relative to that of other divalent cobalt(II), iron(II), and nickel(II) transition-metal cations. The course of microextraction of Cu(2+) from aqueous media into the [mimSBu][NTf(2)] IL phase was monitored in situ by cyclic voltammetry using a well-defined process in which specific interaction with copper is believed to switch from the ionic liquid cation component, [mimSBu], to the [NTf(2)] anion during the course of electrochemical reduction from Cu(II) to Cu(I). The microextraction-voltammetry technique provides a fast and convenient method to determine whether an IL is able to extract electroactive metal ions from an aqueous solution.

  5. Immobilized copper(II) macrocyclic complex on MWCNTs with antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Tarlani, Aliakbar, E-mail: Tarlani@ccerci.ac.ir [Inorganic Nanostructures and Catalysts Research Lab., Chemistry & Chemical Engineering Research Center of Iran, Pajoohesh Blvd., km 17, Karaj Hwy, Tehran 14968-13151 (Iran, Islamic Republic of); Narimani, Khashayar [Inorganic Nanostructures and Catalysts Research Lab., Chemistry & Chemical Engineering Research Center of Iran, Pajoohesh Blvd., km 17, Karaj Hwy, Tehran 14968-13151 (Iran, Islamic Republic of); Mohammadipanah, Fatemeh; Hamedi, Javad [Department of Microbial Biotechnology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran 14155-6455 (Iran, Islamic Republic of); University of Tehran Biocompound Collection (UTBC), Microbial Technology and Products Research Center, University of Tehran, Tehran (Iran, Islamic Republic of); Tahermansouri, Hasan [Department of Chemistry, Ayatollah Amoli Branch, Islamic Azad University, Amol (Iran, Islamic Republic of); Amini, Mostafa M. [Department of Chemistry, Shahid Behshti University, 1983963113, Tehran (Iran, Islamic Republic of)

    2015-06-30

    Graphical abstract: In an antibacterial test, grafted copper(II) macrocyclic complex on the surface of MWCNT showed higher antibacterial activity against Bacillus subtilis compared to the individual MWCNT-COOH and the complex. - Highlights: • Copper(II) tetraaza macrocyclic complex covalently bonded to modified MWCNT. • Grafting of the complex carried out via an interaction between −C(=O)Cl group and NH of the ligand. • The samples were subjected in an antibacterial assessment to compare their activity. • Immobilized complex showed higher antibacterial activity against Bacillus subtilis ATCC 6633 compared to separately MWCNT-C(C=O)-OH and CuTAM. - Abstract: 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 I{sub D}/I{sub G} 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.

  6. Biologically active Schiff bases containing thiophene/furan ring and their copper(II) complexes: Synthesis, spectral, nonlinear optical and density functional studies

    Science.gov (United States)

    Gündüzalp, Ayla Balaban; Özsen, İffet; Alyar, Hamit; Alyar, Saliha; Özbek, Neslihan

    2016-09-01

    Schiff bases; 1,8-bis(thiophene-2-carboxaldimine)-p-menthane (L1) and 1,8-bis(furan-2-carboxaldimine)-p-menthane (L2) have been synthesized and characterized by elemental analysis, 1Hsbnd 13C NMR, UV-vis, FT-IR and LC-MS methods. 1H and 13C shielding tensors for L1 and L2 were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The vibrational band assignments, nonlinear optical (NLO) activities, frontier molecular orbitals (FMOs) and absorption spectrum have been investigated by the same basis set. Schiff base-copper(II) complexes have been synthesized and structurally characterized with spectroscopic methods, magnetic and conductivity measurements. The spectroscopic data suggest that Schiff base ligands coordinate through azomethine-N and thiophene-S/furan-O donors (as SNNS and ONNO chelating systems) to give a tetragonal geometry around the copper(II) ions. Schiff bases and Cu(II) complexes have been screened for their biological activities on different species of pathogenic bacteria, those are, Gram positive bacteria: Bacillus subtitilus, Yersinia enterotica, Bacillus cereus, Listeria monocytogenes, Micrococcus luteus and Gram negative bacteria: Escherichia coli, Pseudomonas aeroginosa, Shigella dysenteriae, Salmonella typhi, Klebsiella pseudomonas by using microdilution technique (MIC values in mM). Biological activity results show that Cu(II) complexes have higher activities than parent ligands and metal chelation may affect significantly the antibacterial behavior of the organic ligands.

  7. Binary and ternary new water soluble copper(II) complexes of L-tyrosine and substituted 1,10-phenanthrolines: Effect of substitution on DNA interactions and cytotoxicities

    Science.gov (United States)

    İnci, Duygu; Aydın, Rahmiye; Vatan, Özgür; Yılmaz, Dilek; Gençkal, Hasene Mutlu; Zorlu, Yunus; Cavaş, Tolga

    2015-06-01

    Binary and ternary water soluble copper(II) complexes - [Cu(nphen)2(H2O)](NO3)2·H2O (1), [Cu(phen)2(H2O)](NO3)2 (2), [Cu(nphen)(L-tyr)(H2O)]NO3·2H2O (3), [Cu(phen)(tyr)(H2O)] NO3·2H2O (4) - and diquarternary salts of nphen and phen (nphen = 5-nitro-1,10-phenanthroline, phen = 1,10-phenanthroline and tyr = L-tyrosine) have been synthesized and characterized by CHN analysis, 1H NMR, 13C NMR and IR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. The CT-DNA binding properties of these compounds have been investigated by thermal denaturation measurements, absorption and emission spectroscopy. The supercoiled pUC19 plasmid DNA cleavage activity of these compounds has been explored by agarose gel electrophoresis. The cytotoxicity of these compounds against MCF-7, Caco-2, A549 cancer cells and BEAS-2B healthy cells was also studied by using XTT method. The complexes 1-4 exhibit significant high cytotoxicity with low IC50 values in compared with cisplatin. The effect of the substituents of phen and coordinated amino acid in the above complexes are presented and discussed.

  8. Evaluation of DNA/Protein interactions and cytotoxic studies of copper(II) complexes incorporated with N, N donor ligands and terpyridine ligand.

    Science.gov (United States)

    Tummalapalli, Kiran; C S, Vasavi; Munusami, Punnagai; Pathak, Madhvesh; M M, Balamurali

    2017-02-01

    A series of four new copper(II) heteroleptic complexes, [Cu(2‴-pytpy) (L)] (NO 3 ) 2 ·2H 2 O (1-4), where 2‴-pytpy=4'-(2'''-Pyridyl)-2, 2':6', 2''-terpyridine, L=bipyridyl (bpy), 1, 10 phenanthroline(phen), dipyridoquinoxaline(dpq) and dipyridophenazine (dppz) were synthesized and characterized by spectroscopic techniques. Further, the molecular structure of the complex (2) was confirmed by single crystal X-ray diffraction technique and the data revealed a penta coordinated, distorted square-pyramidal geometry with triclinic system. The interactions of four complexes with calf thymus DNA and bovine serum albumin (BSA) were investigated by electronic absorption, fluorescence and circular dichroism spectroscopy techniques. Spectral studies substantiated an intercalative binding mode of metal complexes with ct-DNA. Significant binding interactions of the complexes with protein have been further revealed from fluorescence studies. Furthermore, all the four complexes show potential cytotoxicity towards the human liver carcinoma cell line (HepG-2). Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Templated synthesis of copper(II) azacyclam complexes using urea as a locking fragment and their metal-enhanced binding tendencies towards anions.

    Science.gov (United States)

    Boiocchi, Massimo; Fabbrizzi, Luigi; Garolfi, Mauro; Licchelli, Maurizio; Mosca, Lorenzo; Zanini, Cristina

    2009-10-26

    Copper(II) azacyclam complexes 3(2+) and 4(2+) were obtained through a metal-templated procedure involving the pertinent open-chain tetramine, formaldehyde and a phenylurea derivative as a locking fragment. Both metal complexes can establish interactions with anions through the metal centre and the amide NH group. Equilibrium studies in DMSO by a spectrophotometric titration technique were carried out to assess the affinity of 3(2+) and 4(2+) towards anions. While the NH group of an amide model compound and the metal centre of the plain Cu(II)(azacyclam)(2+) complex do not interact at all with anions, 3(2+) and 4(2+) establish strong interactions with oxo anions, profiting from a pronounced cooperative effect. In particular, 1) they form stable 1:1 and 1:2 complexes with H(2)PO(4) (-) ions in a stepwise mode with both hydrogen-bonding and metal-ligand interactions, and 2) in the presence of CH(3)COO(-), they undergo deprotonation of the amido NH group and thus profit from axial coordination of the partially negatively charged carbonyl oxygen atom in a scorpionate binding mode.

  10. An X-ray photoelectron spectroscopy and quantum chemical study of copper(II) β-diketonates and Cu(HFA){sub 2} complexes with imidazoline ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kryuchkova, Natalya A., E-mail: knatali@ngs.ru [Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentyev Av., 3, RU-630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova Street, 2, RU-630090 Novosibirsk (Russian Federation); Stabnikov, Pavel A. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentyev Av., 3, RU-630090 Novosibirsk (Russian Federation); Kalinkin, Alexander V. [Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Lavrentyev Av., 5, RU-630090 Novosibirsk (Russian Federation); Fursova, Elena Yu. [International Tomography Center, Siberian Branch, Russian Academy of Sciences, Institutskaya Street, 3a, RU-630090 Novosibirsk (Russian Federation)

    2016-10-15

    Highlights: • The charge and spin states of Cu(II) β-diketonates and Cu(hfa){sub 2}(imidazoline) are investigated by the XPS and DFT calculations. • The |2p{sup 5}3d{sup 9}> and | 2p{sup 5}3d{sup 10}L> electronic states are asigned to X-ray photoelectron spectra of copper. - Abstract: An X-ray photoelectron spectroscopy study of the charge and spin state of copper(II) β-diketonates and Cu(hfa){sub 2} (hfa–hexafluoroacetylacetonate) complexes with imidazoline ligands is performed with comparison to the data of quantum chemical calculations. It is shown that the structure of the spectra of copper is described by a superposition of the |2p{sup 5}3d{sup 9}> and | 2p{sup 5}3d{sup 10}L> electronic states determined by electron transfer processes between copper and L ligand atoms. It is found that during the coordination of imidazoline ligands to the Cu(hfa){sub 2} complex the spin density is redistributed through the chain of chemical bonds from the ligand nitroxyl group to the copper atom.

  11. RUN COORDINATION

    CERN Multimedia

    C. Delaere

    2013-01-01

    Since the LHC ceased operations in February, a lot has been going on at Point 5, and Run Coordination continues to monitor closely the advance of maintenance and upgrade activities. In the last months, the Pixel detector was extracted and is now stored in the pixel lab in SX5; the beam pipe has been removed and ME1/1 removal has started. We regained access to the vactank and some work on the RBX of HB has started. Since mid-June, electricity and cooling are back in S1 and S2, allowing us to turn equipment back on, at least during the day. 24/7 shifts are not foreseen in the next weeks, and safety tours are mandatory to keep equipment on overnight, but re-commissioning activities are slowly being resumed. Given the (slight) delays accumulated in LS1, it was decided to merge the two global runs initially foreseen into a single exercise during the week of 4 November 2013. The aim of the global run is to check that we can run (parts of) CMS after several months switched off, with the new VME PCs installed, th...

  12. RUN COORDINATION

    CERN Multimedia

    Christophe Delaere

    2013-01-01

    The focus of Run Coordination during LS1 is to monitor closely the advance of maintenance and upgrade activities, to smooth interactions between subsystems and to ensure that all are ready in time to resume operations in 2015 with a fully calibrated and understood detector. After electricity and cooling were restored to all equipment, at about the time of the last CMS week, recommissioning activities were resumed for all subsystems. On 7 October, DCS shifts began 24/7 to allow subsystems to remain on to facilitate operations. That culminated with the Global Run in November (GriN), which   took place as scheduled during the week of 4 November. The GriN has been the first centrally managed operation since the beginning of LS1, and involved all subdetectors but the Pixel Tracker presently in a lab upstairs. All nights were therefore dedicated to long stable runs with as many subdetectors as possible. Among the many achievements in that week, three items may be highlighted. First, the Strip...

  13. Synthesis and characterization of nickel(II), cobalt(II), copper(II), manganese(II), zinc(II), zirconium(IV), dioxouranium(VI) and dioxomolybdenum(VI) complexes of a new Schiff base derived from salicylaldehyde and 5-methylpyrazole-3-carbohydrazide

    International Nuclear Information System (INIS)

    Syamal, A.; Maurya, M.R.

    1986-01-01

    Synthesis of a new Schiff base derived from salicylaldehyde and 5-methylpyrazole-3-carbohydrazide, and its coordination compounds with nickel(II), cobalt(II), copper(II), manganese(II), zinc(II), zirconium(IV), dioxouranium(VI) and dioxomolybdenum(VI) are described. The ligand and the complexes have been characterized on the basis of analytical, conductance, molecular weight, i.r., electronic and n.m.r. spectra and magnetic susceptibility measurements. The stoichiometries of the complexes are represented as NiL . 3H 2 O, CoL . 2H 2 O, CuL, MnL . 2H 2 O, ZnL . H 2 O, Zr(OH) 2 (LH) 2 , Zr(OH) 2 L . 2MeOH, UO 2 L . MeOH and MoO 2 L . MeOH (where LH 2 =Schiff base). The copper(II) complex shows a subnormal magnetic moment due to antiferromagnetic exchange interaction while the nickel(II), cobalt(II) and manganese(II) complexes show normal magnetic moments at room temperature. The i.r. and n.m.r. spectral studies show that the Schiff base behaves as a dibasic and tridentate ligand coordinating through the deprotonated phenolic oxygen, enolic oxygen and azomethine nitrogen. (orig.)

  14. Cobalt(II), nickel(II), copper(II), and zinc(II) complexes with [3(5)]adamanzane, 1,5,9,13-tetraazabicyclo[7.7.3]nonadecane and [(2.3)(2).2(1)]adamanzane, 1,5,9,12-tetraazabicyclo[7.5.2]hexadecane

    DEFF Research Database (Denmark)

    Broge, Louise; Pretzmann, Ulla; Jensen, Nicolai

    2001-01-01

    Isolation of the free bicyclic tetraamine, [3(5)]adamanzane .H2O (1,5,9,13-tetraazabicyclo[7.7.3]nonadecane .H2O), is reported along with the synthesis and characterization of a copper(II) complex of the smaller macrocycle [(2.3)(2).2(1)]-adamanzane (1,5,9,12-tetraazabicyclo[7.5.2]hexadecane......) and of three cobalt(II), four nickel(II), one copper(II), and two zinc(II) complexes with [3(5)]adamanzane. For nine of these compounds (2-8, 10b, and 12) the single-crystal X-ray structures were determined. The coordination geometry around the metal ion is square pyramidal in [Cu([(2.3)(2).2(1)]adz)Br]ClO4 (2......) and trigonal bipyramidal in the isostructural structures [Cu([3(5)]adz)Br]Br (3), [Ni-([3(5)]adz)Cl]Cl (5), [Ni([3(5)]adz)Br]Br (6), and [Co([3(5)]adz)Cl]Cl (8). In [Ni([3(5)]adz)(NO3)]NO3 (4) and [Ni([3(5)]-adz)(ClO4)]ClO4 (7) the coordination geometry around nickel(II) is a distorted octahedron...

  15. Copper(II) complexes of neuropeptide gamma with point mutations (S8,16A) products of metal-catalyzed oxidation.

    Science.gov (United States)

    Błaszak, Marta; Jankowska, Elżbieta; Kowalik-Jankowska, Teresa

    2013-12-01

    To obtain the information about the influence of the serine residues (S8,S16) on the acid-base properties of the neuropeptide gamma, the peptide with point mutations (S8,16A) and its N-acetyl derivative were synthesized. Any additional deprotonations were not observed. It means that the presence of serine residues is necessary in the amino acid sequence of the neuropeptide gamma to have its acid-base properties. The stability constants, stoichiometry and solution structures of copper(II) complexes of the neuropeptide gamma mutants D(1)AGH(4)GQIA(8)H(9)KRH(12)KTDA(16)FVGLM(21)-NH2 (S8,16A) 2ANPG and its N-acetyl derivative Ac-2ANPG were determined in aqueous solution. The equilibrium and structural properties of copper(II) complexes have been characterized by pH-metric, spectroscopic (UV-visible, CD, EPR) and mass spectrometric (MS) methods. At physiological pH7.4 the 2ANPG forms the CuH2L and CuHL complexes in equilibrium with 3N {NH2,βCOO(-)-D(1),2NIm} and 4N {NH2,N(-),2NIm} binding sites, respectively. The exchange Ser on Ala residues does not alter the coordination mode of the peptide. To elucidate the products of the copper(II)-catalyzed oxidation of 2ANPG and Ac-2ANPG the liquid chromatography-mass spectrometry method (LC-MS) and the Cu(II)/H2O2 as a model oxidizing system were employed. For solutions containing a 1:4 peptide-hydrogen peroxide molar ratio oxidation of the methionine residue to methionine sulphoxide was observed. For the 1:1:4 Cu(II)-2ANPG-H2O2 system oxidation of two His residues and cleavage of the G(3)H(4) peptide bond was observed, while for the 1:1:4 Cu(II)-Ac-2ANPG-H2O2 system oxidation of three histidine residues to 2-oxohistidines was also observed. © 2013.

  16. Bridging the Gap

    DEFF Research Database (Denmark)

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures.......Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures....

  17. Effect of Phosphorylation and Copper(II or Iron(II Ions Enrichment on Some Physicochemical Properties of Spelt Starch

    Directory of Open Access Journals (Sweden)

    Jacek Rożnowski

    Full Text Available ABSTRACT: This paper provides an assessment of the effect of saturation of spelt starch and monostarch phosphate with copper or iron ions on selected physicochemical properties of the resulting modified starches. Native and modified spelt starch samples were analyzed for selected mineral element content using Atomic Absorption Spectroscopy (AAS. Thermodynamic properties were measured using DSC, and pasting properties by RVA. Flow curves of 5% pastes were plotted and described using the Herschel-Bulkley model. The structure recovery ratio was measured. AAS analysis established the presence of iron(II and copper(II ions in the samples of modified starches and that potassium and magnesium ions had leached from them. In comparison to unfortified samples, enriching native starch with copper(II ions decreases value of all temperatures of phase transformation about 1.3-2.7 °C, but in case of monostarch phosphates bigger changes (2.8-3.7 °C were observed. Fortified native spelt starch with copper(II ions caused increasing the final viscosity of paste from 362 to 429 mPa·s. However, presence iron(II ions in samples caused reduced its final viscosity by 170 (spelt starch and 103 mPa·s (monostarch phosphate. Furthermore, enriching monostarch phosphate contributed to reduce degree of structure recovery of pastes from 70.9% to 66.6% in case of copper(II ions and to 59.9% in case of iron(II ions.

  18. ESBRI: a web server for evaluating salt bridges in proteins.

    Science.gov (United States)

    Costantini, Susan; Colonna, Giovanni; Facchiano, Angelo M

    2008-01-01

    Salt bridges can play important roles in protein structure and function and have stabilizing and destabilizing effects in protein folding. ESBRI is a software available as web tool which analyses the salt bridges in a protein structure, starting from the atomic coordinates. In the case of protein complexes, the salt bridges between protein chains can be evaluated, as well as those among specific charged amino acids and the different protein subunits, in order to obtain useful information regard the protein-protein interaction. The service is available at the URL: http://bioinformatica.isa.cnr.it/ESBRI/

  19. Long-term bridge performance high priority bridge performance issues.

    Science.gov (United States)

    2014-10-01

    Bridge performance is a multifaceted issue involving performance of materials and protective systems, : performance of individual components of the bridge, and performance of the structural system as a whole. The : Long-Term Bridge Performance (LTBP)...

  20. Bridge health monitoring metrics : updating the bridge deficiency algorithm.

    Science.gov (United States)

    2009-10-01

    As part of its bridge management system, the Alabama Department of Transportation (ALDOT) must decide how best to spend its bridge replacement funds. In making these decisions, ALDOT managers currently use a deficiency algorithm to rank bridges that ...

  1. Biosorption of copper(II) by Marrubium globosum subsp. globosum leaves powder: effect of chemical pretreatment.

    Science.gov (United States)

    Yazici, Hüseyin; Kiliç, Mehmet; Solak, Murat

    2008-03-01

    The study was aimed at determining the effect of chemical pretreatment on copper(II) biosorption by Marrubium globosum subsp. globosum leaves. The uptake capacity of the biomass was increased by chemical pretreatment when compared with the raw biomass. The results of biosorption experiments, carried out at the conditions of 50 mg l(-1) initial metal concentration and pH 5.5, showed that pretreating the biomass with alkali solutions (laundry detergent, sodium hydroxide and sodium bicarbonate, 0.5 M) improved the biosorption capacity of biomass (45.90, 45.78 and 43.91%, respectively) compared with raw biomass. Pretreatment with sulfuric and nitric acid solutions, 0.5 M, increased the biosorption capacity of biomass by 11.82 and 10.18%, respectively, while there was no considerable change in the biosorption capacity of biomass (0.35%) after pretreatment with formic acid solution, 0.5 M. Furthermore, sodium chloride and calcium chloride, 0.5 M, pretreatments resulted in the improvement in biosorption capacity of biomass (31.38 and 26.69%, respectively). FT-IR analysis revealed that hydroxyl and carboxyl functional groups were mainly responsible for copper(II) biosorption.

  2. Coordination compounds of cobalt(II), nickel(II), copper(II), and zinc(II) with pantothenic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shabilalov, A.A.; Yunuskhodzhaev, A.N.; Khodzhaev, O.F.; Azizov, M.A.

    1986-11-01

    The compounds Ni(PANA - H)/sub 2/ x 4H/sub 2/O (PANA stands for pantothenic acid, and - H indicates a deprotonated ligand), Cu(PANA - H)/sub 2/ x 2H/sub 2/O, Zn(PANA - H)/sub 2/ x H/sub 2/O, Co(PANA - H)Cl x H/sub 2/O, and Ni(PANA - H)Cl x 3H/sub 2/O have been synthesized on the basis of pantothenic acid and Co(II), Ni(II), Cu(II), and Zn(II) salts in aqueous media. The compounds have been identified by elemental and x-ray diffraction analysis. Some physicochemical properties (solubility, melting point, molar conductivity) of the compounds obtained have been studied. The structure of the compounds isolated has been established on the basis of an analysis of their IR, ESR, and electronic spectra, as well as derivatograms.

  3. Load rating of complex bridges.

    Science.gov (United States)

    2010-07-01

    The National Bridge Inspection Standards require highway departments to inspect, evaluate, and determine load ratings for : structures defined as bridges located on all public roads. Load rating of bridges is performed to determine the live load that...

  4. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated...

  5. Covered Bridge Security Manual

    Science.gov (United States)

    Brett Phares; Terry Wipf; Ryan Sievers; Travis Hosteng

    2013-01-01

    The design, construction, and use of covered timber bridges is all but a lost art in these days of pre-stressed concrete, high-performance steel, and the significant growth both in the volume and size of vehicles. Furthermore, many of the existing covered timber bridges are preserved only because of their status on the National Registry of Historic Places or the...

  6. The floating water bridge

    International Nuclear Information System (INIS)

    Fuchs, Elmar C; Woisetschlaeger, Jakob; Gatterer, Karl; Maier, Eugen; Pecnik, Rene; Holler, Gert; Eisenkoelbl, Helmut

    2007-01-01

    When high voltage is applied to distilled water filled in two glass beakers which are in contact, a stable water connection forms spontaneously, giving the impression of a floating water bridge. A detailed experimental analysis reveals static and dynamic structures as well as heat and mass transfer through this bridge

  7. Active-bridge oscillator

    Science.gov (United States)

    Wessendorf, Kurt O.

    2001-01-01

    An active bridge oscillator is formed from a differential amplifier where positive feedback is a function of the impedance of one of the gain elements and a relatively low value common emitter resistance. This use of the nonlinear transistor parameter h stabilizes the output and eliminates the need for ALC circuits common to other bridge oscillators.

  8. Students design composite bridges

    NARCIS (Netherlands)

    Stark, J.W.B.; Galjaard, J.C.; Brekelmans, J.W.P.M.

    1999-01-01

    The paper gives an overview of recent research on steel-concrete composite bridge design by students of Delft University of Technology doing their master's thesis. Primary objective of this research was to find possibilities for application of steel-concrete composite bridges in the Netherlands,

  9. Virtual Bridge Design Challenge

    Science.gov (United States)

    Mitts, Charles R.

    2013-01-01

    This design/problem-solving activity challenges students to design a replacement bridge for one that has been designated as either structurally deficient or functionally obsolete. The Aycock MS Technology/STEM Magnet Program Virtual Bridge Design Challenge is an authentic introduction to the engineering design process. It is a socially relevant…

  10. Superconductivity in a copper(II)-based coordination polymer with perfect kagome structure

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xing; Liu, Liyao; Xu, Wei; Zhu, Daoben [Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing (China); University of Chinese Academy of Sciences, Beijing (China); Zhang, Shuai [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing (China); Yu, Lei [Department of Chemistry, University of Kentucky, Lexington, KY (United States); Chen, Genfu [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing (China); University of Chinese Academy of Sciences, Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2018-01-02

    A highly crystalline copper(II) benzenehexathiolate coordination polymer (Cu-BHT) has been prepared. The two-dimensional kagome structure has been confirmed by powder X-ray diffraction, high-resolution transmission electron microscopy, and high-resolution scanning transmission electron microscopy. The as-prepared sample exhibits bulk superconductivity at about 0.25 K, which is confirmed by the zero resistivity, AC magnetic susceptibility, and specific heat measurements. Another diamagnetic transition at about 3 K suggests that there is a second superconducting phase that may be associated with a single layer or few layers of Cu-BHT. It is the first time that superconductivity has been observed in a coordination polymer. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Carboxylate-bridged Cu(II) coordination polymeric complex ...

    Indian Academy of Sciences (India)

    SABITHAKALA THATITURI

    An in vitro antibacterial activity study of BIGH and Cu-BIG showed moderate activity against Bacillus subtilis. ..... ure 10. Thermogram of the complex shows only one stage of weight loss between 250 and 275 .... ligands: Syntheses, structures, and physical properties. CrystEngComm 17 3181. 15. Fan L M, Zhang X T, Sun Z, ...

  12. Carboxylate-bridged Cu (II) coordination polymeric complex ...

    Indian Academy of Sciences (India)

    BIG was formed by the reaction of Cu(ClO₄)₂ ·6H₂O and tridentate benzimidazole-glycine conjugate ligand, 2-((1H-benzimidazol- 2-yl)methylamino) acetic acid, BIGH and its structure has been determined by IR, UV, powder XRD, VSM, CV, ...

  13. Carboxylate-bridged Cu(II) coordination polymeric complex ...

    Indian Academy of Sciences (India)

    SABITHAKALA THATITURI

    BIG was formed by the reaction ... researchers, for their potential application as advanced .... Crystallographic data and structure refinement parameters are presented in. Table 1. Table 1. Crystal data and structure refinement details for Cu-BIG.

  14. Sustainable Bridge Infrastructure Procurement

    DEFF Research Database (Denmark)

    Safi, Mohammed; Du, Guangli; Simonsson, Peter

    2016-01-01

    The lack of a flexible but systematic approach for integrating lifecycle aspects into bridge investment decisions is a major obstacle hindering the procurement of sustainable bridge infrastructures. This paper addresses this obstacle by introducing a holistic approach that agencies could use to p...... to procure the most “sustainable” (lifecycle-efficient) bridge through a fair design-build (D-B) tendering process, considering all the main aspects: life-cycle cost (LCC), service life-span, aesthetic demands and environmental impacts (LCA)....

  15. Bridge technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. As LANs have proliferated, new technologies and system concepts have come to the fore. One of the key issues is how to interconnect networks. One means of interconnection is to use a 'bridge'. Other competing technologies are repeaters, routers, and gateways. Bridges permit traffic isolation, connect network segments together and operate at the MAC layer. Further, because they operate at the MAC layer, they can handle a variety of protocols such as TCP/IP, SNA, and X.25. This report focuses on the specific technology of bridging two netw

  16. Cu(II) coordination polymers constructed by tetrafluoroterephthalic acid and varied imidazole-containing ligands: Syntheses, structures and properties

    Science.gov (United States)

    Liu, Kang; Sun, Yayong; Deng, Liming; Cao, Fan; Han, Jishu; Wang, Lei

    2018-02-01

    Six new copper(II) coordination polymers combining 2,3,5,6-tetrafluoroterephthalatic acid (H2tfBDC) and diverse imidazole-containing ligands, {[Cu(tfBDC)(1,2-bix)2]·2(H2O)}n (1), {Cu(tfBDC)(Im)2}n (2), {[Cu(1,4-bmimb)2(H2O)]·(tfBDC)·2(H2O)}n (3), {Cu(1,4-bimb)2(H2O)2·(tfBDC)}n (4), {[Cu(1,3-bix)2(H2O)2]·(tfBDC)·6(H2O)}n (5) and {[Cu(1,4-bix)2(H2O)2]·(tfBDC)·(1,4-bix)·4(H2O)}n (6) (1,2-bix = 1,2-bis(imidazole-1-ylmethyl)-benzene, Im = imidazole, 1,4-bmimb = 1,4-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene, 1,4-bimb = 1,4-bis(imidazol-1-yl)-butane, 1,3-bix = 1,3-bis(imidazole-1-ylmethyl)-benzene, 1,4-bix = 1,4-bis(imidazole-1-ylmethyl)-benzene), have been obtained and structurally verified by single-crystal X-ray diffraction analyses and further characterized by powder X-ray diffraction (PXRD), elemental analyses and infrared spectroscopy (IR). Single crystal X-ray diffraction analysis revealed that 1 is 2D 4-connected sql topology (point symbol: {44·62}) based on a single metal ion node. Compound 2 is characterized as an infinite 1D chain structure, which is further extended into a 2D layer through N-H···O hydrogen bonds and then a 3D supramolecular architecture via π···π stacking interactions. Note that 2 was prepared through an in situ ligand reaction in which N,N'-carbonyldiimidazole (cdi) broke up into imidazole ligand. Compound 3 possesses a 3D 4-fold interpenetrated architecture with 4-connected dia topology (Schläfli symbol: {66}) in which tfBDC2- is stabilized in the channel by hydrogen bonds. Compounds 4-6 are all linear 1D coordination polymers. In 4, the free tfBDC2- ligand acts as a μ4-bridge to link four coordinated water molecules from the chain to construct a 2D structure via hydrogen bonds. While in 5 and 6, the uncoordinated tfBDC2- ligands and multimeric water clusters is responsible for the conversion of these 1D coordination polymers into 3D supramolecular assemblies through O-H⋯O hydrogen bonding interactions. Moreover

  17. Synthesis and Polymerizability of Atom-Bridged Bicyclic Monomers

    Directory of Open Access Journals (Sweden)

    Henry K. Hall

    2012-12-01

    Full Text Available ¨The synthesis and polymerizability of atom-bridged bicyclic monomers was surveyed. The monomers included lactams, ureas, urethanes, lactones, carbonates, ethers, acetals, orthoesters, and amines. Despite widely-varying structures, they almost all polymerized to give polymers with monocyclic rings in the chain. The polymerizations are grouped by mechanism: uncoordinated anionic, coordinated anionic, and cationic.

  18. Solvent Extraction Studies on Copper(II and Silver(I Complexes of Bis(4-hydroxypent-2-ylidenediaminoethane: Composition of Extracted Copper(II Species

    Directory of Open Access Journals (Sweden)

    P. O. Ukoha

    2011-01-01

    Full Text Available Copper(II complexes of bis(4-hydroxypent-2-ylidenediaminoethane (BHPDE were prepared by extractive method. Job’s continuous variation and equilibrium constant methods, as well as spectral and elemental analyses were applied in the determination of the nature of extracted species. The results indicate the formation of mixed ionic complexes of the types Cu(H2LX2, Cu(H2L2X2 and CuL (where H2L = BHPDE and X = NO3-, CIO4-, Cl- or ½SO42-. Cu(H2LX2 and Cu(H2L2X2 predominate at low pH extractions while CuL chelate predominates at high pH extraction. The complexes exist in two isomeric forms, the blue readily-water-soluble and the violet less water-soluble forms. Both complexes show maximum absorption at 540 nm and molar absorptivity values of about 2.0 x 102 dm3 mole-1 cm-1.

  19. Bridging Humanism and Behaviorism.

    Science.gov (United States)

    Chu, Lily

    1980-01-01

    Humanistic behaviorism may provide the necessary bridge between behaviorism and humanism. Perhaps the most humanistic approach to teaching is to learn how certain changes will help students and how these changes can be accomplished. (Author/MLF)

  20. Skewed highway bridges.

    Science.gov (United States)

    2013-07-01

    Many highway bridges are skewed and their behavior and corresponding design analysis need to be furthered to fully accomplish design objectives. This project used physical-test and detailed finite element analysis to better understand the behavior of...

  1. Bridge removal plan requirements.

    Science.gov (United States)

    2011-04-15

    This report provides resources that detail specifications and guidelines related to bridge removal plans across the : United States. We have organized the information into three sections: : ! National Guidance : Includes language from AASHTO specific...

  2. Forward Affect Bridge.

    Science.gov (United States)

    Bonshtein, Udi; Torem, Moshe

    2017-01-01

    This article presents a modification of the affect bridge technique. The Forward Affect Bridge enables practitioners to create and maintain hope when it is missing. Hope is relevant for diminishing avoidance and being involved with necessary activities. The main idea is to build up a positive atmosphere in the here and now (relying on rapport), to amplify it, and to project it forward. By using clinical vignettes, the authors illustrate these techniques.

  3. Copper(II) complexes of salicylaldehyde hydrazones: synthesis, structure, and DNA interaction.

    Science.gov (United States)

    Wu, La-Mei; Teng, Han-Bing; Ke, Xian-Bing; Xu, Wen-Jin; Su, Jiang-Tao; Liang, Shu-Cai; Hu, Xian-Ming

    2007-09-01

    Three hydrazone ligands, H2L1-H2L3, made from salicylaldehyde and ibuprofen- or naproxen-derived hydrazides, were prepared and transformed into the corresponding copper(II) complexes [Cu(II)L1] x H2O, [Cu(II)L2], and [(Cu(II))2(L3)2] x H2O x DMF (Scheme). The X-ray crystal structure of the last-mentioned complex was solved (Fig. 1), showing a square-planar complexation geometry, and the single units were found to form a one-dimensional chain structure (Fig. 2). The interactions of these complexes with CT-DNA were studied by different techniques, indicating that they all bind to DNA by classical and/or non-classical intercalation modes.

  4. Nanostructured lipid carriers for incorporation of copper(II complexes to be used against Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Sato MR

    2017-03-01

    Full Text Available Mariana R Sato,1 João A Oshiro Junior,1 Rachel TA Machado,1 Paula C de Souza,2 Débora L Campos,2 Fernando R Pavan,2 Patricia B da Silva,1,* Marlus Chorilli1,* 1Department of Drugs and Medicines, Faculdade de Ciências Farmacêuticas, UNESP – Univ Estadual Paulista, Campus Araraquara, Araraquara, SP, Brazil; 2Department of Biological Sciences, Faculdade de Ciências Farmacêuticas, UNESP – Univ Estadual Paulista, Campus Araraquara, Araraquara, SP, Brazil *These authors contributed equally to this work Abstract: Tuberculosis (TB is a disease caused by Mycobacterium tuberculosis. Cessation of treatment before the recommended conclusion may lead to the emergence of multidrug-resistant strains. The aim of this study was to develop nanostructured lipid carriers (NLCs for use in the treatment of M. tuberculosis. The NLCs comprised the following lipid phase: 2.07% polyoxyethylene 40 stearate, 2.05% caprylic/capric triglyceride, and 0.88% polyoxyl 40 hydrogenated castor oil; the following aqueous phase: 3.50% poloxamer 407 (F1–F6, and 0.50% cetyltrimethylammonium bromide (F7–F12; and incorporated the copper(II complexes [CuCl2(INH2]·H2O (1, [Cu(NCS2(INH2]·5H2O (2, and [Cu(NCO2(INH2]·4H2O (3 to form compounds F11.1, F11.2, and F11.3, respectively. The mean diameter of F11, F11.1, F11.2, and F11.3 ranged from 111.27±21.86 to 134.25±22.72 nm, 90.27±12.97 to 116.46±9.17 nm, 112.4±10.22 to 149.3±15.82 nm, and 78.65±6.00 to 122.00±8.70 nm, respectively. The polydispersity index values for the NLCs ranged from 0.13±0.01 to 0.30±0.09. The NLCs showed significant changes in zeta potential, except for F11.2, with F11, F11.1, F11.2, and F11.3 ranging from 18.87±4.04 to 23.25±1.13 mV, 17.03±1.77 to 21.42±1.87 mV, 20.51±1.88 to 22.60±3.44 mV, and 17.80±1.96 to 25.25±7.78 mV, respectively. Atomic force microscopy confirmed the formation of nanoscale spherical particle dispersions by the NLCs. Differential scanning calorimetry determined

  5. Biosorption of copper(II) by nonliving lichen biomass of Cladonia rangiformis hoffm

    Energy Technology Data Exchange (ETDEWEB)

    Ekmekyapar, Fatma [Engineering Faculty, Department of Environmental Engineering, Atatuerk University, Erzurum 25240 (Turkey)]. E-mail: fyapar@atauni.edu.tr; Aslan, Ali [Education Faculty, Department of Biology, Atatuerk University, Erzurum 25240 (Turkey); Bayhan, Y. Kemal [Engineering Faculty, Department of Environmental Engineering, Atatuerk University, Erzurum 25240 (Turkey); Cakici, Avni [Engineering Faculty, Department of Environmental Engineering, Atatuerk University, Erzurum 25240 (Turkey)

    2006-09-01

    Biosorption of heavy metals can be an effective process for the removal of heavy metal ions from aqueous solutions. In this study, the adsorption properties of lichen biomass of Cladonia rangiformis hoffm. for copper(II) were investigated by using batch adsorption techniques. The effects of initial metal ion concentration, initial pH, biosorbent concentration, stirring speed and contact time on biosorption efficiency were studied. In the experiments the optimum pH value was found out 5.0 which was the native pH value of solution. The experimental adsorption data were fitted to the Langmuir adsorption model. The highest metal uptake was calculated from Langmuir isotherm and found to be 7.6923 mg Cu(II)/g inactivated lichen at 15 deg. C. The results indicated that the biomass of C. rangiformis is a suitable biosorbent for removing Cu(II) from aqueous solutions.

  6. Antimalarial, antimicrobial, cytotoxic, DNA interaction and SOD like activities of tetrahedral copper(II) complexes

    Science.gov (United States)

    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.

  7. Correlation of Electronic and Geometric Structure in Mononuclear Copper(II) Superoxide Complexes

    Science.gov (United States)

    Ginsbach, Jake W.; Peterson, Ryan L.; Cowley, Ryan E.; Karlin, Kenneth D.; Solomon, Edward I.

    2013-01-01

    The geometry of mononuclear copper(II) superoxide complexes has been shown to determine their ground state where side-on bonding leads to a singlet ground state and end-on complexes have triplet ground states. In apparent contrast to this trend, the recently synthesized (HIPT3tren)CuII–O2•− (1) was proposed to have an end-on geometry and a singlet ground state. However, re-examination of 1 with resonance Raman (rR), magnetic circular dichroism (MCD), and 2H NMR spectroscopy indicates that 1 is in fact an end-on superoxide species with a triplet ground state that results from the single CuII–O2•− bonding interaction being weaker than the spin pairing energy. PMID:24164429

  8. Long Span Bridges in Scandinavia

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1998-01-01

    The first Scandinavian bridge with a span of more than 500 m was the Lillebælt Suspension Bridge opened to traffic in 1970.Art the end of the 20th century the longest span of any European bridge is found in the Storebælt East Bridge with a main span of 1624 m. Also the third longest span in Europe...... is found in Scandinavia - the 1210 m span of the Höga Kusten Bridge in Sweden.The Kvarnsund Bridge in Norway was at the completion in 1991 the longest cable-stayed bridge in the world, and the span of 530 m is still thge longest for cable-stayed bridges in concrete. The Øresund Bridge with its sapn of 490...... m is the longest among cable-stayed bridges for both road and railway traffic....

  9. Coordination control of distributed systems

    CERN Document Server

    Villa, Tiziano

    2015-01-01

    This book describes how control of distributed systems can be advanced by an integration of control, communication, and computation. The global control objectives are met by judicious combinations of local and nonlocal observations taking advantage of various forms of communication exchanges between distributed controllers. Control architectures are considered according to  increasing degrees of cooperation of local controllers:  fully distributed or decentralized control,  control with communication between controllers,  coordination control, and multilevel control.  The book covers also topics bridging computer science, communication, and control, like communication for control of networks, average consensus for distributed systems, and modeling and verification of discrete and of hybrid systems. Examples and case studies are introduced in the first part of the text and developed throughout the book. They include: control of underwater vehicles, automated-guided vehicles on a container terminal, contro...

  10. Cooperativity of complex salt bridges

    OpenAIRE

    Gvritishvili, Anzor G.; Gribenko, Alexey V.; Makhatadze, George I.

    2008-01-01

    The energetic contribution of complex salt bridges, in which one charged residue (anchor residue) forms salt bridges with two or more residues simultaneously, has been suggested to have importance for protein stability. Detailed analysis of the net energetics of complex salt bridge formation using double- and triple-mutant cycle analysis revealed conflicting results. In two cases, it was shown that complex salt bridge formation is cooperative, i.e., the net strength of the complex salt bridge...

  11. Structural assessment of concrete bridges

    OpenAIRE

    Plos, Mario; Gylltoft, Kent; Lundgren, Karin; Cervenka, Jan; Herwig, Andrin; Brühwiler, Eugen; Thelandersson, Sven; Elfgren, Lennart; Rosell, Ebbe

    2008-01-01

    The paper summarizes the work on concrete bridges performed in the EU project Sustainable Bridges. The work provides enhanced assessment methods that are able to provide higher load-carrying capacities and longer fatigue lives for exixixting concrete railway bridges. The work is also presented in a Guideleine available at http://www.sustainablebridges.net/ The paper summarizes the work on concrete bridges performed in the EU project Sustainable Bridges. The work provides enhanced assessmen...

  12. Synthesis, characterization, antibacterial activity, SOD mimic and interaction with DNA of drug based copper(II) complexes

    Science.gov (United States)

    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).

  13. RECOVERY OF COPPER(II AND CHROMIUM(III FROM NITRATE MEDIUM WITH SALICYLIDENEANILINE DISSOLVED IN 1-OCTANOL

    Directory of Open Access Journals (Sweden)

    A. Guerdouh

    2016-05-01

    Full Text Available The solvent extraction of copper(II and chromium(III from nitrate medium with salicylideneaniline (HL is studied as a function of various parameters: pH, concentration of salicylideneaniline, contact time and the nature of anoin (nitrate and sulfate in aqueous phase. Chromium(III is not extracted by salicylideneaniline  diluted in 1-octanol. Copper(II is only extracted by salicylideneaniline and it was found that the highest extractability achieved to 95% at pH 4.9, The stoichiometry of the extracted species was determined by using the method of slope analysis. Elemental analysis, UV–vis and IR-spectra were used to confirm the structure. It is found that the copper (II is extracted as CuL2.2H2O Their equilibrium constant, distribution coefficient, percentage extraction (%E and free energy are also calculated.

  14. Ternary copper(II) complexes with amino acid chains and heterocyclic bases: DNA binding, cytotoxic and cell apoptosis induction properties.

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. CFD simulation of copper(II) extraction with TFA in non-dispersive hollow fiber membrane contactors.

    Science.gov (United States)

    Muhammad, Amir; Younas, Mohammad; Rezakazemi, Mashallah

    2018-01-27

    This study presents computational fluid dynamics (CFD) simulation of dispersion-free liquid-liquid extraction of copper(II) with trifluoroacetylacetone (TFA) in hollow fiber membrane contactor (HFMC). Mass and momentum balance Navier-Stokes equations were coupled to address the transport of copper(II) solute across membrane contactor. Model equations were simulated using COMSOL Multiphysics™. The simulation was run to study the detailed concentration distribution of copper(II) and to investigate the effects of various parameters like membrane characteristics, partition coefficient, and flow configuration on extraction efficiency. Once-through extraction was found to be increased from 10 to 100% when partition coefficient was raised from 1 to 10. Similarly, the extraction efficiency was almost doubled when porosity to tortuosity ratio of membrane was increased from 0.05 to 0.81. Furthermore, the study revealed that CFD can be used as an effective optimization tool for the development of economical membrane-based dispersion-free extraction processes.

  16. Synthesis, structure characterization, DNA binding, and cleavage properties of mononuclear and tetranuclear cluster of copper(II) complexes.

    Science.gov (United States)

    Vafazadeh, Rasoul; Hasanzade, Naime; Heidari, Mohammad Mehdi; Willis, Anthony C

    2015-01-01

    Two copper(II) complexes, cluster 1, and mononuclear 2, have been synthesized by reacting acetylacetone and benzohydrazide (1:1 ratio for 1 and 1:2 ratio for 2) with CuCl(2) in a methanol solution. In 2, which is a new complex, the ligand acts as a tetradentate which binds the metal ion via two amide-O atoms and two imine-N atoms providing an N(2)O(2) square-planar around the copper(II) ion. The absorption spectra data evidence strongly suggested that the two copper(II) compounds could interact with CT-DNA (intrinsic binding constant, K(b) = 0.45×10(4) M-1 for 1 and K(b) = 2.39×10(4) M-1 for 2). The super coiled plasmid pBR322 DNA cleavage ability was studied with 1 and 2 in the presence and absence of H(2)O(2) as an oxidant. In both the absence and the presence of an oxidizing agent, complex 2 exhibited no nuclease activity. However, even in the absence of an oxidant, complex 1 exhibited significant DNA cleavage activity.

  17. Porous phosphorescent coordination polymers for oxygen sensing.

    Science.gov (United States)

    Xie, Zhigang; Ma, Liqing; deKrafft, Kathryn E; Jin, Athena; Lin, Wenbin

    2010-01-27

    Phosphorescent cyclometalated iridium tris(2-phenylpyridine) derivatives were designed and incorporated into coordination polymers as tricarboxylate bridging ligands. Three different crystalline coordination polymers were synthesized using a solvothermal technique and were characterized using a variety of methods, including single-crystal X-ray diffraction, PXRD, TGA, IR spectroscopy, gas adsorption measurements, and luminescence measurements. The coordination polymer built from Ir[3-(2-pyridyl)benzoate](3), 1, was found to be highly porous with a nitrogen BET surface area of 764 m(2)/g, whereas the coordination polymers built from Ir[4-(2-pyridyl)benzoate](3), 2 and 3, were nonporous. The (3)MLCT phosphorescence of each of the three coordination polymers was quenched in the presence of O(2). However, only 1 showed quick and reversible luminescence quenching by oxygen, whereas 2 and 3 exhibited gradual and irreversible luminescence quenching by oxygen. The high permanent porosity of 1 allows for rapid diffusion of oxygen through the open channels, leading to efficient and reversible quenching of the (3)MLCT phosphorescence. This work highlights the opportunity of designing highly porous and luminescent coordination polymers for sensing other important analytes.

  18. Nonlinearity in oscillating bridges

    Directory of Open Access Journals (Sweden)

    Filippo Gazzola

    2013-09-01

    Full Text Available We first recall several historical oscillating bridges that, in some cases, led to collapses. Some of them are quite recent and show that, nowadays, oscillations in suspension bridges are not yet well understood. Next, we survey some attempts to model bridges with differential equations. Although these equations arise from quite different scientific communities, they display some common features. One of them, which we believe to be incorrect, is the acceptance of the linear Hooke law in elasticity. This law should be used only in presence of small deviations from equilibrium, a situation which does not occur in widely oscillating bridges. Then we discuss a couple of recent models whose solutions exhibit self-excited oscillations, the phenomenon visible in real bridges. This suggests a different point of view in modeling equations and gives a strong hint how to modify the existing models in order to obtain a reliable theory. The purpose of this paper is precisely to highlight the necessity of revisiting the classical models, to introduce reliable models, and to indicate the steps we believe necessary to reach this target.

  19. Coordinators in Safaliba

    OpenAIRE

    Bodua-Mango, Kenneth

    2012-01-01

    This study examines the Safaliba coordinators „ní‟ / „aní‟, „á‟, „ka‟, „chɛ‟ and „bíí‟ in their naturally occurring environments. Safaliba is a Gur language spoken by some 5000 -7000 people in the north-western part of Ghana. The main areas of study include the syntactic categories that each coordinator can coordinate, the semantic properties of each of the coordinators and the pragmatic effect that the use of theses coordinators can have. Combinations of the individual coordinators calle...

  20. Active Control of Suspension Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper some recent research on active control of very long suspension bridges, is presented. The presentation is based on research work at Aalborg University, Denmark. The active control system is based on movable flaps attached to the bridge girder. Wind load on bridges with or without...... flaps attached to the girder is briefly presented. A simple active control system is discussed. Results from wind tunnel experiments with a bridge section show that flaps can be used effectively to control bridge girder vibrations. Flutter conditions for suspension bridges with and without flaps...... are presented. The theory is illustrated by an example....

  1. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Bridge-to-Bridge Act § 80.1007 Bridge-to-bridge radiotelephone installation. Use of the bridge-to-bridge...

  2. The influence of structural factors on the solvation and coordination unsaturation of metal complexes of several structurally related alkyl substituted dipyrrolylmethenes-2,2' and porphin

    Science.gov (United States)

    Antina, E. V.; Guseva, G. B.; v'yugin, A. I.; Berezin, M. B.

    2008-05-01

    The literature data and new results of calorimetric studies of the solution of copper(II), cobalt(II), zinc(II), nickel(II), and mercury(II) complexes with 3,3',4,4',5,5'-hexamethyldipyrrolylmethene-2,2'; 3,3',5,5'-tetramethyl-4,4'-diethyldipyrrolylmethene-2,2'; 3,3',5,5'-tetramethyl-4,4'-dibutyldipyrrolylmethene-2,2' (A), and 2,8,12,18-tetramethyl-3,7,13,17-tetrabutylporphin in various organic solvents were used to calculate the enthalpies of transfer Δtr H o from benzene and estimate the contribution of specific solvation caused by the additional coordination (Δc H o) of electron donor solvent molecules (pyridine and dimethylformamide). The greatest degree of coordination unsaturation and ability to extracoordination was characteristic of copper(II) and mercury(II) complexes with ligand A. The influence of the nature of the complex-forming metal, differences in the alkylation of the ligands, solvent properties, and the macrocyclization effect on the solvation and coordination unsaturation of metal complexes was discussed.

  3. Macroemulsion-based dispersive magnetic solid phase extraction for preconcentration and determination of copper(II) in gasoline.

    Science.gov (United States)

    Cunha, Francisco Antônio S; Ferreira, Danilo Tadeu S; Andrade, Willy C R; Fernandes, Julys Pablo A; Lyra, Wellington S; Pessoa, Amália G G; de Araujo, Mario Cesar Ugulino

    2018-01-10

    A new method referred to as microemulsion-based Dispersive Magnetic Solid-Phase Extraction (MDM-SPE) is presented for use in the extraction and preconcentration of metal ions from complex organic matrices. MDM-SPE combines the features of magnetic nanoparticles (MNPs) and microemulsions. It was successfully applied to the extraction of copper(II) from gasoline prior to its determination by Graphite Furnace Atomic Absorption Spectrometry (GF-AAS). The material for use in MDM-SPE was obtained by first functionalizing MNPs of the type Fe 3 O 4 @Al 2 O 3 with sodium dodecyl sulfate and the chelator 1-(2-pyridylazo)-2-naphthol (PAN) dispersed in 1-propanol. The resulting functionalized magnetic MNPs were dispersed in a microemulsion prepared from gasoline, buffer, and 1-propanol. After waiting for 5 s (during which the formation of the copper complex on the MNPs is complete), the MNPs are magnetically separated. The complex was then eluted with 2 mol L -1 HNO 3 , and the eluate submitted to GF-AAS. Various parameters were optimized. Copper(II) can be quantified by this method over a linear range that extends from 2.0 to 10.0 μg·L -1 . Other figures of merit include (a) a 37 ng·L -1 detection limit, (b) a repeatability of 1.1%, (c) a reproducibility of 2.1%, and (d) an enrichment factor of nine. The high surface-to-volume ratio of the microemulsion containing the dispersed magnetic sorbent warrants an efficient contact for reaction between copper(II) and the complexing agent, and this results in fast (about 40 s) extraction and pre-concentration of copper(II). MDM-SPE is accurate, precise and efficient. Microemulsions do not break down, and phase separation, heating, laborious, and time-consuming sample preparation, and incorporation of impurities into the graphite furnace (which can generate inaccuracies in GF-AAS analysis) are not needed. Graphical abstract Schematic of a new method for Microemulsion-based Dispersive Magnetic Solid-Phase Extraction (MDMSPE

  4. Copper(II) imidazolate frameworks as highly efficient photocatalysts for reduction of CO2 into methanol under visible light irradiation

    International Nuclear Information System (INIS)

    Li, Jingtian; Luo, Deliang; Yang, Chengju; He, Shiman; Chen, Shangchao; Lin, Jiawei; Zhu, Li; Li, Xin

    2013-01-01

    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 CO 2 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 CO 2 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 CO 2 , and even water splitting into hydrogen and oxygen under visible light. - Graphical abstract: Carbon dioxide was reduced into methanol with water over copper(II) imidazolate frameworks under visible light irradiation. - Highlights: • Three copper(II) imidazolate

  5. Istanbul Bridge Conference 2014

    CERN Document Server

    Gülkan, Polat; Mahmoud, Khaled

    2016-01-01

      The book includes peer-reviewed contributions selected from presentations given at the Istanbul Bridge Conference 2014, held from August 11 – 13 in Istanbul, Turkey. It reports on the current challenges in bridge engineering faced by professionals around the globe, giving a special emphasis to recently developed techniques, innovations and opportunities. The book covers key topics in the field, including modeling and analysis methods; construction and erection techniques; design for extreme events and condition assessment and structural health monitoring. There is a balanced presentation of theory, research and practice. This book, which provides the readers with a comprehensive and timely reference guide on current practices in bridge engineering, is intended for professionals, academic researchers and students alike.

  6. Bridge deterioration models to support Indiana's bridge management system.

    Science.gov (United States)

    2016-02-01

    An effective bridge management system that is equipped with reliable deterioration models enables agency engineers to carry out : monitoring and long-term programming of bridge repair actions. At the project level, deterioration models help the agenc...

  7. Development of bridge girder movement criteria for accelerated bridge construction.

    Science.gov (United States)

    2014-06-01

    End diaphragms connect multiple girders to form a bridge superstructure system for effective resistance to earthquake loads. Concrete : girder bridges that include end diaphragms consistently proved to perform well during previous earthquake events. ...

  8. Linguistic Barriers and Bridges

    DEFF Research Database (Denmark)

    Thuesen, Frederik

    2016-01-01

    The influence of language on social capital in low-skill and ethnically diverse workplaces has thus far received very limited attention within the sociology of work. As the ethnically diverse workplace is an important social space for the construction of social relations bridging different social...... and intercultural communication, this article analyses interviews with 31 employees from two highly ethnically diverse Danish workplaces. The article shows how linguistic barriers such as different levels of majority language competence and their consequent misunderstandings breed mistrust and hostility, whilst...... communication related to collaboration and ‘small talk’ may provide linguistic bridges to social capital formation....

  9. Bridge the Gap

    DEFF Research Database (Denmark)

    Marselis, Randi

    2017-01-01

    This article focuses on photo projects organised for teenage refugees by the Society for Humanistic Photography (Berlin, Germany). These projects, named Bridge the Gap I (2015), and Bridge the Gap II (2016), were carried out in Berlin and brought together teenagers with refugee and German-majorit...... was produced – and sometimes not produced - within the projects. The importance of memory work in the context of refugee resettlement is often overlooked, but is particularly relevant when cultural encounters are organised in museums and exhibition galleries....

  10. Trunk muscle activity in healthy subjects during bridging stabilization exercises

    Directory of Open Access Journals (Sweden)

    Vanderstraeten Guy G

    2006-09-01

    Full Text Available Abstract Background Trunk bridging exercises are often used as therapeutic exercises for lumbopelvic stabilization. These exercises focus on the retraining of muscle coordination patterns in which optimal ratios between local segmental stabilizing and global torque producing muscle activity are assumed to be essential. However, a description of such ratios is lacking. The purpose of this study was to investigate both relative (as a percentage of maximal voluntary isometric contraction muscle activity levels and ratios of local to global muscle activity, during bridging stabilization exercises. Methods Thirty healthy university students (15 men, 15 women with a mean age of 19.6 year volunteered to perform 3 bridging exercises (single bridging, ball bridge and unilateral bridging. The surface electromyographic activity of different trunk muscles was evaluated on both sides. Results During all bridging exercises, the ratio of the internal oblique to the rectus abdominis was very high due to minimal relative activity of the rectus abdominis. In general, the ratio of the internal/external abdominal oblique activity was about 1. However, during the unilateral bridging exercise, the ipsilateral internal/external abdominal oblique activity ratio was 2.79 as a consequence of the significant higher relative activity of the internal oblique compared to the external oblique. The relative muscle activity and the ratios of the back muscles demonstrated similar activity levels for all back muscles, resulting in ratios about 1. Conclusion Both the minimal relative activity of the rectus abdominis and the high internal oblique to the rectus abdominis activity ratio reported in the present study are in accordance with results of other trunk stabilization exercises. The relative muscle activity and the ratio of the abdominal obliques seem to alter depending on the task and the presumable need for stability. The findings concerning the relative muscle activity and

  11. Crystal structures of a copper(II and the isotypic nickel(II and palladium(II complexes of the ligand (E-1-[(2,4,6-tribromophenyldiazenyl]naphthalen-2-ol

    Directory of Open Access Journals (Sweden)

    Souheyla Chetioui

    2016-08-01

    Full Text Available In the copper(II complex, bis{(E-1-[(2,4,6-tribromophenyldiazenyl]naphthalen-2-olato}copper(II, [Cu(C16H8Br3N2O2], (I, the metal cation is coordinated by two N atoms and two O atoms from two bidentate (E-1-[(2,4,6-tribromophenyldiazenyl]naphthalen-2-olate ligands, forming a slightly distorted square-planar environment. In one of the ligands, the tribromobenzene ring is inclined to the naphthalene ring system by 37.4 (5°, creating a weak intramolecular Cu...Br interaction [3.134 (2 Å], while in the other ligand, the tribromobenzene ring is inclined to the naphthalene ring system by 72.1 (6°. In the isotypic nickel(II and palladium(II complexes, namely bis{(E-1-[(2,4,6-tribromophenyldiazenyl]naphthalen-2-olato}nickel(II, [Ni(C16H8Br3N2O2], (II, and bis{(E-1-[(2,4,6-tribromophenyldiazenyl]naphthalen-2-olato}palladium(II, [Pd(C16H8Br3N2O2], (III, respectively, the metal atoms are located on centres of inversion, hence the metal coordination spheres have perfect square-planar geometries. The tribromobenzene rings are inclined to the naphthalene ring systems by 80.79 (18° in (II and by 80.8 (3° in (III. In the crystal of (I, molecules are linked by C—H...Br hydrogen bonds, forming chains along [010]. The chains are linked by C—H...π interactions, forming sheets parallel to (011. In the crystals of (II and (III, molecules are linked by C—H...π interactions, forming slabs parallel to (10-1. For the copper(II complex (I, a region of disordered electron density was corrected for using the SQUEEZE routine in PLATON [Spek (2015. Acta Cryst. C71, 9–18]. The formula mass and unit-cell characteristics of the disordered solvent molecules were not taken into account during refinement.

  12. Application of modern timber structure in short and medium span bridges in China

    Directory of Open Access Journals (Sweden)

    Meizhen Fu

    2014-02-01

    Full Text Available A series of problems about Chinese bridges with short and medium span recent years were analyzed in this paper. The necessity and feasibility of modern timber structure applied in short and medium span bridges in China were also put forward. The results showed that the short and medium span bridges had many problems, such as monotonous structural forms, serious environmental pollution, multiple bridge defects and difficulty in maintenance. With the development of connection and maintenance technology of modern timber structure and its advantages of light self-weight, environmental coordination, high carrying capacity, excellent durability and abundant structural forms, it was necessary and feasible to apply modern timber structure in short and medium span bridges in China. More emphasis on the construction of modern timber structure should be conducted to expand its application scopes and improve the construction proportion of short and medium span timber bridges.

  13. BUILDING "BRIDGES" WITH QUALITY ASSURANCE

    Science.gov (United States)

    The papr describes how, rather than building "bridges" across centuries, quality assurance (QA) personnel have the opportunity to build bridges across technical disciplines, between public and private organizations, and between different QA groups. As reviewers and auditors of a...

  14. Public response to bridge colors.

    Science.gov (United States)

    1973-01-01

    To determine people's reactions to bridges painted in colors as white, yellow, green, blue, red, brown, black, and aluminum, two test bridges were selected in Charlottesville, Virginia. One was painted a different color each month and the other was k...

  15. Bridge-Vehicle Impact Assessment

    Science.gov (United States)

    2011-08-01

    Bridges in New York State have been experiencing close to 200 bridge hits a year. These : accidents are attributed to numerous factors including: improperly stored equipment on trucks; : violation of vehicle posting signs; illegal commercial vehicles...

  16. Colorado statewide historic bridge inventory.

    Science.gov (United States)

    2011-05-01

    The purpose of the Colorado statewide historic bridge inventory was to document and evaluate the National : Register of Historic Places eligibility all on-system highway bridges and grade separation structures built in : Colorado between 1959 and 196...

  17. Virginia Bridge Information Systems Laboratory.

    Science.gov (United States)

    2014-06-01

    This report presents the results of applied data mining of legacy bridge databases, focusing on the Pontis and : National Bridge Inventory databases maintained by the Virginia Department of Transportation (VDOT). Data : analysis was performed using a...

  18. Synthesis and characterization of mononuclear copper(II complex of tetradentate N2S2 donor set and the study of DNA and bovine serum albumin binding

    Directory of Open Access Journals (Sweden)

    Sandipan Sarkar

    2014-12-01

    Full Text Available One mononuclear copper(II complex, containing neutral tetradentate NSSN-type ligands, of formulation [Cu II(L 1Cl]ClO 4 (1, was synthesized and isolated in pure form [where L 1˭ 1,3-bis(3-pyridylmethylthiopropane]. Green-colored copper(II complex was characterized by physicochemical, spectroscopic methods and conductivity measurement. These experimental data matched well with the proposed structure of the complex. Biological activity of the complex (1 toward calf thymus DNA and bovine serum albumin has been examined systematically and groove-binding behavior of the Copper(II complex 1 with calf thymus DNA has been observed from the spectral study.

  19. Looking Beyond the Bridge

    DEFF Research Database (Denmark)

    Jahn, Elke; Rosholm, Michael

    We perform a comprehensive analysis of the stepping-stone effect of temporary agency employment on unemployed workers. Using the timing-of-events approach, we not only investigate whether agency employment is a bridge into regular employment but also analyze its effect on post-unemployment wages...

  20. Bridging the Gap?

    Science.gov (United States)

    Salter, Colin

    2009-01-01

    The political context of the conversion of the Historic Tramway Bridge, adjacent to Sandon Point in Bulli (NSW, Australia), and how this was exploited to serve predetermined ends, illustrates that technologies can be designed to have particular social (and political) effects. Through reflection on this relatively small engineering project, this…

  1. Building a Straw Bridge

    Science.gov (United States)

    Teaching Science, 2015

    2015-01-01

    This project is for a team of students (groups of two or three are ideal) to design and construct a model of a single-span bridge, using plastic drinking straws as the building material. All steps of the design, construction, testing and critiquing stages should be recorded by students in a journal. Students may like to include labelled diagrams,…

  2. Bridge over troubled water?

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Nannestad, Peter; Svendsen, Gert Tinggaard

    2008-01-01

    The problem of integrating non-Western immigrants into Western welfare states is the focus of this paper. To address this issue, we suggest a social capital approach in which we apply the conceptual pair of bridging social capital (BR), which connects an individual to the broader social structure...

  3. Quantum Bidding in Bridge

    Science.gov (United States)

    Muhammad, Sadiq; Tavakoli, Armin; Kurant, Maciej; Pawłowski, Marcin; Żukowski, Marek; Bourennane, Mohamed

    2014-04-01

    Quantum methods allow us to reduce communication complexity of some computational tasks, with several separated partners, beyond classical constraints. Nevertheless, experimental demonstrations of this have thus far been limited to some abstract problems, far away from real-life tasks. We show here, and demonstrate experimentally, that the power of reduction of communication complexity can be harnessed to gain an advantage in a famous, immensely popular, card game—bridge. The essence of a winning strategy in bridge is efficient communication between the partners. The rules of the game allow only a specific form of communication, of very low complexity (effectively, one has strong limitations on the number of exchanged bits). Surprisingly, our quantum technique does not violate the existing rules of the game (as there is no increase in information flow). We show that our quantum bridge auction corresponds to a biased nonlocal Clauser-Horne-Shimony-Holt game, which is equivalent to a 2→1 quantum random access code. Thus, our experiment is also a realization of such protocols. However, this correspondence is not complete, which enables the bridge players to have efficient strategies regardless of the quality of their detectors.

  4. Bridging a Cultural Gap

    Science.gov (United States)

    Leviatan, Talma

    2008-01-01

    There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes--aimed at bridging the gap between high-school mathematics and tertiary mathematics--is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a…

  5. DOE Information Bridge

    CERN Document Server

    United States. Department of Energy. Office of Scientific and Technical Information

    DOE Information Bridge, a component of EnergyFiles, provides free, convenient, and quick access to full-text DOE research and development reports in physics, chemistry, materials, biology, environmental sciences, energy technologies, engineering, computer and information science, renewable energy, and other topics. This vast collection includes over 43,000 reports that have been received and processed by OSTI since January 1995.

  6. Revised Rules for Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Jensen, F. M.; Middleton, C.

    This paper is based on research performed for the Highway Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: Concrete Bridges" It contains details of a methodology which can be used to generate Whole Life (WL) reliability profiles....... These WL reliability profiles may be used to establish revised rules for Concrete Bridges....

  7. Simple and mixed complexes of copper(II) with 8-hydroxyquinoline derivatives and amino acids: Characterization in solution and potential biological implications.

    Science.gov (United States)

    Sgarlata, Carmelo; Arena, Giuseppe; Bonomo, Raffaele P; Giuffrida, Alessandro; Tabbì, Giovanni

    2018-03-01

    Copper(II) complexes with 8-hydroxyquinoline (8-HQ) and two 8-HQ derivatives, namely clioquinol (CQ) and 5,7-dichloro-2-[(dimethylamino)methyl]quinolin-8-ol (PBT2), were investigated in organic and, where feasible, in aqueous solutions. This class of compounds is of particular interest in neurological disorders since they may act as metal-protein attenuating compounds and may help redistributing metal ions and restoring intracellular metal reserves, which are often perturbed in neurological patients. Several techniques, like potentiometry, UV-Vis absorption, electron paramagnetic resonance (EPR), cyclic voltammetry and electrospray ionisation-mass spectrometry (ESI-MS), were used to obtain information on both the formation of copper(II) complexes in solution as well as on the structure of their species. Multi-wavelength treatment of UV-Vis data clearly indicated the formation of both [Cu(PBT2)] + and [Cu(PBT2) 2 ] species; the speciation was also supported by ESI-MS data. The EPR results showed that the mono- and bis-copper(II) complexes with PBT2 have square-based pyramidal structures while the bis-copper (II) complexes with CQ or 8-HQ have square-planar o pseudo-octahedral geometries. The formation of copper(II) ternary complexes with 8-HQ, CQ and PBT2 and some selected neurotransmitters (glycine, glutamate and histidine) is also reported. Except for the copper(II) ternary complex with PBT2 and His, almost all ternary complexes have molecular geometries, which are not different from those of the bis-complexes. Interestingly the ternary copper(II) complexes, containing CQ, 8-HQ and PBT2 and glycine, glutamate or histidine turned out to be more soluble in aqueous solution than their binary complexes with parent 8-HQ derivatives; the copper(II) complexes can also be reduced more easily than their parent bis-complexes. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Antimicrobial Activity and Urease Inhibition of Schiff Bases Derived from Isoniazid and Fluorinated Benzaldehydes and of Their Copper(II Complexes

    Directory of Open Access Journals (Sweden)

    Ladislav Habala

    2016-12-01

    Full Text Available In order to evaluate the influence of substitution on biological properties of Schiff bases and their metal complexes, a series of differently substituted fluorine-containing Schiff bases starting from the drug isoniazid (isonicotinylhydrazide were prepared and their structures were established by single-crystal X-ray diffraction. Also, four copper(II complexes of these Schiff bases were synthesized. The prepared compounds were evaluated for their antimicrobial activity and urease inhibition. Two of the Schiff bases exerted activity against C. albicans. All copper(II complexes showed excellent inhibitory properties against jack bean urease, considerably better than that of the standard inhibitor acetohydroxamic acid.

  9. Synthesis and characterization of mononuclear copper(II) complex of tetradentate N2S2 donor set and the study of DNA and bovine serum albumin binding

    OpenAIRE

    Sandipan Sarkar; Biswajit Das

    2014-01-01

    One mononuclear copper(II) complex, containing neutral tetradentate NSSN-type ligands, of formulation [Cu II(L 1)Cl]ClO 4 (1), was synthesized and isolated in pure form [where L 1˭ 1,3-bis(3-pyridylmethylthio)propane]. Green-colored copper(II) complex was characterized by physicochemical, spectroscopic methods and conductivity measurement. These experimental data matched well with the proposed structure of the complex. Biological activity of the complex (1) toward calf thymus DNA and bovine s...

  10. DNA binding affinity of a macrocyclic copper(II) complex: Spectroscopic and molecular docking studies.

    Science.gov (United States)

    Shahabadi, Nahid; Hakimi, Mohammad; Morovati, Teimoor; Fatahi, Navid

    2017-08-03

    The interaction of a novel macrocyclic copper(II) complex, ([CuL(ClO 4 ) 2 ] that L is 1,3,6,10,12,15-hexaazatricyclo[13.3.1.1 6,10 ]eicosane) with calf thymus DNA (ct-DNA) was investigated by various physicochemical techniques and molecular docking at simulated physiological conditions (pH = 7.4). The absorption spectra of the Cu(II) complex with ct-DNA showed a marked hyperchroism with 10 nm blue shift. The intrinsic binding constant (K b ) was determined as 1.25 × 10 4 M -1 , which is more in keeping with the groove binding with DNA. Furthermore, competitive fluorimetric studies with Hoechst33258 have shown that Cu(II) complex exhibits the ability to displace the ct-DNA-bound Hoechst33258 indicating that it binds to ct-DNA in strong competition with Hoechst33258 for the groove binding. Also, no change in the relative viscosity of ct-DNA and fluorescence intensity of ct-DNA-MB complex in the present of Cu(II) complex is another evidence to groove binding. The thermodynamic parameters are calculated by van't Hoff equation, which demonstrated that hydrogen bonds and van der Waals interactions played major roles in the binding reaction. The experimental results were in agreement with the results obtained via molecular docking study.

  11. Solid Phase Extraction of Trace Copper(II Using Modified Nano Polyacrylonitrile Fiber

    Directory of Open Access Journals (Sweden)

    A. Moghimi

    2012-07-01

    Full Text Available A simple method has been developed for the preconcentration of copper(II based on the adsorption of its Modified nano polyacrylonitrile fiber. Modified nano polyacrylonitrile fiber (PANF was prepared by adding of acrylic fibers to mSethanolamine (MMA with different concentration solutions. The stability of a chemically Modified nano polyacrylonitrile fiber especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of modified nano polyacrylonitrile fiber. The application of this Modified nano polyacrylonitrile fiber for sorption of a series of metal ions was performed by using different controlling factors such as the pH of metal ion solution and the equilibration shaking time by the static technique. Cu (II was found to exhibit the highest affinity towards extraction by these Modified nano polyacrylonitrile fiber phases. The pronounced selectivity was also confirmed from the determined distribution coefficient (Kd of all the metal ions, showing the highest value reported for Cu (II to occur by Modified nano polyacrylonitrile fiber. The potential applications ofModified nano polyacrylonitrile fiber for selective extraction of Cu(II to occur from aqueous solution were successfully accomplished as well as pre- concentration of low concentration of Cu(II (60 pg ml-1 from natural tap water with a pre-concentration factor of 100 for Cu(II off-line analysis by flame atomic absorption analysis.

  12. The Necessity of Having a Tetradentate Ligand to Extract Copper(II) Ions from Amyloids.

    Science.gov (United States)

    Nguyen, Michel; Rechignat, Lionel; Robert, Anne; Meunier, Bernard

    2015-02-01

    The accumulation of redox-active metal ions, in particular copper, in amyloid plaques is considered to the cause of the intensive oxidation damage to the brain of patients with Alzheimers disease (AD). Drug candidates based on a bis(8-aminoquinoline) tetradentate ligand are able to efficiently extract Cu(2+) from copper-loaded amyloids (Cu-Aβ). Contrarily, in the presence of a bidentate hydroxyquinoline, such as clioquinol, the copper is not released from Aβ, but remains sequestrated within a Aβ-Cu-clioquinol ternary complex that has been characterized by mass spectrometry. Facile extraction of copper(II) at a low amyloid/ligand ratio is essential for the re-introduction of copper in regular metal circulation in the brain. As, upon reduction, the Cu(+) is easily released from the bis(8-aminoquinoline) ligand unable to accommodate Cu(I), it should be taken by proteins with an affinity for copper. So, the tetradentate bis(8-aminoquinoline) described here might act as a regulator of copper homeostasis.

  13. Synthesis, characterization and biological studies of copper(II) complexes with 2-aminobenzimidazole derivatives

    Science.gov (United States)

    Joseph, J.; Suman, A.; Nagashri, K.; Joseyphus, R. Selwin; Balakrishnan, Nisha

    2017-06-01

    Novel series of four copper(II) complexes with 2-aminobenzimidazole derivatives (obtained from the Knoevenagel condensate of acetylacetone (obtained from acetylacetone and halogen substituted benzaldehydes) and 2-aminobenzimidazole) were synthesized. They were structurally characterized using elemental analysis, molar conductance, FAB mass, FT- IR, 1H &13C-NMR, UV-Vis., and EPR techniques. On the basis of analytical and spectral studies, the distorted square planar geometry was assigned for all the complexes. The antibacterial screening of the ligands and their copper complexes indicated that all the complexes showed higher anti microbial activities than the free ligands. Superoxide dismutase and antioxidant activities of the copper complexes have also been performed. In the electrochemical technique, the shift in ΔEp, E1/2 and Ipc values were explored for the interaction of the complexes with CT-DNA. During the electrolysis process, the present ligand system stabilizes unusual oxidation state of copper in the complexes. It is believed that the copper complexes with curcumin analogs may enhance chemotherapeutic behavior.

  14. Chiral copper(II) complex based on natural product rosin derivative as promising antitumour agent.

    Science.gov (United States)

    Fei, Bao-Li; Huang, Zhi-Xiang; Xu, Wu-Shuang; Li, Dong-Dong; Lu, Yang; Gao, Wei-Lin; Zhao, Yue; Zhang, Yu; Liu, Qing-Bo

    2016-07-01

    To evaluate the biological preference of chiral drug candidates for molecular target DNA, the synthesis and characterization of a chiral copper(II) complex (2) of a chiral ligand N,N'-(pyridin-2-ylmethylene) dehydroabietylamine (1) was carried out. The interactions of 1 and 2 with salmon sperm DNA were investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. Absorption spectral, emission spectral and viscosity analysis reveal that 1 and 2 interacted with DNA through intercalation and 2 exhibited a higher DNA binding ability. In the absence/presence of ascorbic acid, 1 and 2 cleaved supercoiled pBR322 DNA by single-strand and 2 displayed stronger DNA cleavage ability. In addition, in vitro cytotoxicity of 1 and 2 against HeLa, SiHa, HepG-2 and A431 cancer cell lines study show that they exhibited effective cytotoxicity against the tested cell lines, notably, 2 showed a superior cytotoxicity than the widely used drug cisplatin under identical conditions, indicating it has the potential to act as effective anticancer drug. Flow cytometry analysis indicates 2 produced death of HeLa cancer cells through an apoptotic pathway. Cell cycle analysis demonstrates that 2 mainly arrested HeLa cells at the S phase. The study represents the first step towards understanding the mode of the promising chiral rosin-derivative based copper complexes as chemotherapeutics. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Synthesis and magnetism of μ-oxamido-bridged Cu2IILnIII - type heterotrinuclear complexes (Ln = Ce, Nd, Sm, Eu, Gd, Tb, Dy, Er)

    International Nuclear Information System (INIS)

    Li, Y.T.; Yan, C.W.

    2001-01-01

    Eight new Cu 2 II Ln III - type (Ln = Ce, Nd, Sm, Eu, Gd, Tb, Dy, Er) heterotrinuclear complexes bridged by N,N'-bis (2-aminopropyl)oxamidocopper(II) [Cu(oxdn)], namely Cu 2 (oxdn)Ln(NO 3 ) 3 , have been synthesized and characterized by elemental analyses, molar conductivity measurements and spectroscopic (IR, UV, ESR) studies. Magnetic susceptibility measurements (4.2 ∼300 K) and studies of Cu 2 (oxdn)Gd(NO 3 ) 3 complex have revealed that the central gadolinium(III) and terminal copper(II) ions are ferromagnetically coupled with the exchange integral J (Cu-Gd) = +2.98 cm -1 , while an antiferromagnetic coupling is detected between the terminal copper(II) metal ions with the exchange integral J' (Cu-Gd) = -0.75 cm -1 , on the basis of the spin Hamiltonian operator [H -2J(S Cu1 -S Gd +S Cu2 +S Gd )-2J'(S Cu1 S Cu2 )]. (author)

  16. Polymeric coordination compounds

    Indian Academy of Sciences (India)

    Administrator

    Ce(dipic)3Sr(dipicH2)(OH2)3·5H2O (4) (dipicH2 – dipicolinic acid) exhibits 1-D polymeric chain structure, built up of alternating nine coordinate Ce and eight coordinate. Sr polyhedra. The analogous Ce–Ba compound (5) exhibits a polymeric chain built up of nine coordinate Ba units only, arranged in a hexagonal lattice.

  17. BALKANS: Building bridges

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    At a time when upheaval and political unrest in some Balkan countries gives cause for concern, it is good to know that physics, once again, is building bridges between nations. The new international mobility in the region was marked by a major activity of the Balkan Physical Union - the first Balkan School of Physics, held on the banks of the Bosphorus during the first two weeks of September

  18. Novel Silver Cobaltacarborane Complexes with a Linearly Bridging Halide

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun Seo; Bae, Hye Jin; Do, Youngkyu [KAIST, Daejeon (Korea, Republic of); Park, Youngwhan [LG Chem/Research Park, Daejeon (Korea, Republic of); Go, Min Jeong; Lee, Junseong [Chonnam National Univ., Gwangju (Korea, Republic of)

    2013-10-15

    The structural versatility of halides mainly originates from their coordinating abilities of adopting a bridging bond between two or more metal atoms, as well as a terminal bond. Moreover, a halide bridging bond angle is so flexible that thermodynamic stability can be endowed with proper geometry, which conceptually varies from acute to right, obtuse, and linear. In spite of innumerable reports on molecular metal halides, examples of the linearly bridging fashion are very scarce. The reason for the rarity of the linear M. X. M arrangement can be easily explained by the VSEPR (Valence Shell Electron Pair Repulsion) concept. The linear M. X. M formation has only been achieved by adopting a macrocyclic chelate ligand, which is structurally demanding, so that the VSEPR repulsions among lone-pair electrons on the halide atom could be overcome.

  19. Green and selective synthesis of N-substituted amides using water soluble porphyrazinato copper(II) catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Ghodsinia, Sara S.E.; Akhlaghinia, Batool; Eshghi, Hossein, E-mail: akhlaghinia@um.ac.ir [Ferdowsi University of Mashhad (Iran, Islamic Republic of). Faculty of Sciences. Department of Chemistry; Safaei, Elham [Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan (Iran, Islamic Republic of). Department of Chemistry

    2013-06-15

    N, N',N{sup ,} N{sup '}-Tetramethyl tetra-2,3-pyridinoporphyrazinato copper(II) methyl sulfate ([Cu(2,3-tmtppa)](MeSO{sub 4}){sub 4}) efficiently catalyzed the direct conversion of nitriles to N-substituted amides. The one pot selective synthesis of the N-substituted amides from nitriles and primary amines was performed in refluxing H{sub 2}O. The catalyst was recovered and reused at least four times, maintaining its efficiency. (author)

  20. Preparation and thermal decomposition of copper(II, zinc(II and cadmium(II chelates with 8-hydroxyquinoline

    Directory of Open Access Journals (Sweden)

    Marisa S. Crespi

    1999-02-01

    Full Text Available When the compounds are heated in an inert atmosphere it can be verified the consecutive partial sublimation, fusion, partial volatilization and partial thermal decomposition of the anhydrous complexes. When in an oxidating atmosphere the above process is only verified to Cu(II chelates. Anhydrous copper(II complexes present a monoclinic structure in the b form and the volatilized compound in a a form. Zinc(II and cadmium(II hydrated complexes are isomorphous and they present different cell dimensions from those reported previously.

  1. Kinetics of the oxidative hydroxylation of tetraphosphorus in the presence of copper(II) chloride modified by humic (fulvo-) acid

    OpenAIRE

    Zhaksyntay Kairbekov; Dina Akbayeva; Zh. Eshova

    2012-01-01

    It was established that in mild conditions (50-70 oC, РО2= 1 atm) white phosphorus effectively is oxidized by oxygen in water-toluene solutions of copper(II) chloride modified by humic (fulvo-) acid to give mainly phosphoric acid. Humic (fulvo-) acid was extracted from brown coal of domestic deposit Kiyakty. For determination of optimum parameters of fulvo-acid extraction the laboratory experiments were carried out using the method of experiment planning. The kinetics, intermediate and final ...

  2. Structure-antiproliferative activity studies on l-proline- and homoproline-4-N-pyrrolidine-3-thiosemicarbazone hybrids and their nickel(ii), palladium(ii) and copper(ii) complexes.

    Science.gov (United States)

    Dobrova, Aliona; Platzer, Sonja; Bacher, Felix; Milunovic, Miljan N M; Dobrov, Anatolie; Spengler, Gabriella; Enyedy, Éva A; Novitchi, Ghenadie; Arion, Vladimir B

    2016-09-14

    Two water-soluble thiosemicarbazone-proline (H2L(1)) and thiosemicarbazone-homoproline hybrids (H2L(2)) were synthesised. By reaction of H2L(1) with NiCl2·6H2O, PdCl2 and CuCl2·2H2O in ethanol, the series of square-planar complexes [Ni(H2L(1))Cl]Cl·1.3H2O (1·1.3H2O), [Pd(H2L(1))Cl]Cl·H2O (2·H2O) and [Cu(H2L(1))Cl]Cl·0.7H2O (3·0.7H2O) was prepared, and starting from H2L(2) and CuCl2·2H2O in methanol, the complex [Cu(H2L(2))Cl2]·H2O (4·H2O) was obtained. The compounds have been characterised by elemental analysis, spectroscopic methods (IR, UV-vis and NMR spectroscopy), ESI mass spectrometry and single crystal X-ray crystallography (H2L(1), 1, 2 and 4). As a solid, 1 is diamagnetic, while it is paramagnetic in methanolic solution. The effective magnetic moment of 3.26 B.M. at room temperature indicates the change in coordination geometry from square-planar to octahedral upon dissolution. The in vitro anticancer potency of ligand precursors H2L(1) and H2L(2) and metal complexes 1-4 was studied in three human cancer cell lines (A549, CH1 and SW480) and in noncancerous murine embryonal fibroblasts (NIH/3T3), and the mechanism of cell death was also assayed by flow cytometry. Clear-cut structure-activity relationships have been established. The metal ions exert marked effects in a divergent manner: copper(ii) increases, whereas nickel(ii) and palladium(ii) decrease the cytotoxicity of the hybrids. The antiproliferative activity of H2L(1) and metal complexes 1-3 decreases in all three tumour cell lines in the following rank order: 3 > H2L(1) > 1 > 2. The role of square-planar geometry in the underlying mechanism of cytotoxicity of the metal complexes studied seems to be negligible, while structural modifications at the terminal amino group of thiosemicarbazide and proline moieties are significant for enhancing the antiproliferative activity of both hybrids and copper(ii) complexes.

  3. Antioxidant, DNA interaction, VEGFR2 kinase, topoisomerase I and in vitro cytotoxic activities of heteroleptic copper(II) complexes of tetrazolo[1,5-a]pyrimidines and diimines.

    Science.gov (United States)

    Haleel, A; Mahendiran, D; Veena, V; Sakthivel, N; Rahiman, A Kalilur

    2016-11-01

    A series of heteroleptic mononuclear copper(II) complexes of the type [Cu(L(1-3))(diimine)]ClO4 (1-6) containing three tetrazolo[1,5-a]pyrimidine core ligands, ethyl 5-methyl-7-(2-hydroxyphenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (HL(1)), ethyl 5-methyl-7-(4-diethylamino-2-hydroxyphenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (HL(2)) or ethyl 5-methyl-7-(2-hydroxy-4-nitrophenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (HL(3)), and two diimine coligands, 2,2'-bipyridyl (bpy) or 1,10-phenanthroline (phen) have been synthesized and characterized by spectral methods. The geometry of complexes have been determined with the help of electronic absorption and EPR splitting patterns, which suggest four coordinated square planar geometry around copper(II) ion. The lowering of HOMO-LUMO band gap value of complex 4 implies its higher biological activity compared to other complexes. Antioxidant studies revealed that the complexes possess considerable radical scavenging potency against DPPH. The binding studies of the complexes with calf thymus DNA (CT-DNA) revealed groove mode of binding, which was further supported by docking simulation. The complexes 3 and 4 strongly inhibit the topoisomerase I, and also strongly interact with VEGFR2 kinase receptor via π-π, σ-π and hydrogen bonding interaction. Gel electrophoresis experiments demonstrated the ability of the complexes to cleave plasmid DNA in the absence of activators. In vitro cytotoxic activities of the complexes were examined on three cancerous cell lines such as human lung (A549), cervical (HeLa) and colon (HCT-15), and two normal cells such as human embryonic kidney (HEK) and peripheral blood mononuclear cells (PBMCs). The live cell and fluorescent imaging of cancer cells were observed with acridine orange/ethidium bromide staining assay. All encouraging chemical and biological findings indicate that the complex 4 is a suitable candidate for drug target. Copyright © 2016

  4. Coordination failure caused by sunspots

    DEFF Research Database (Denmark)

    Beugnot, Julie; Gürgüç, Zeynep; Øvlisen, Frederik Roose

    2012-01-01

    In a coordination game with Pareto-ranked equilibria, we study whether a sunspot can lead to either coordination on an inferior equilibrium (mis-coordination) or to out-of equilibrium behavior (dis-coordination). While much of the literature searches for mechanisms to attain coordination on the e......In a coordination game with Pareto-ranked equilibria, we study whether a sunspot can lead to either coordination on an inferior equilibrium (mis-coordination) or to out-of equilibrium behavior (dis-coordination). While much of the literature searches for mechanisms to attain coordination...

  5. Coordinate measuring machines

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo

    This document is used in connection with three exercises of 2 hours duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercises concern three aspects of coordinate measuring: 1) Measuring and verification of tolerances on coordinate measuring machines, 2) Traceability...

  6. Cyclam Derivatives with a Bis(phosphinate) or a Phosphinato-Phosphonate Pendant Arm: Ligands for Fast and Efficient Copper(II) Complexation for Nuclear Medical Applications

    Czech Academy of Sciences Publication Activity Database

    David, T.; Kubíček, V.; Gutten, Ondrej; Lubal, P.; Kotek, J.; Pietzsch, H.-J.; Rulíšek, Lubomír; Hermann, P.

    2015-01-01

    Roč. 54, č. 24 (2015), s. 11751-11766 ISSN 0020-1669 R&D Projects: GA ČR(CZ) GA14-31419S Grant - others:COST(XE) TD1004 Institutional support: RVO:61388963 Keywords : cyclam derivatives * radiolabelling * quantum chemical calculations * copper(II) chelation Subject RIV: CA - Inorganic Chemistry Impact factor: 4.820, year: 2015

  7. Characterisation of spin-waves in copper(II) deuteroformate tetradeuterate: A square ¤S¤=1/2 Heisenberg antiferromagnet

    DEFF Research Database (Denmark)

    Clarke, S.J.; Harrison, A.; Mason, T.E.

    1999-01-01

    Copper(II) formate tetrahydrate (CFTH) is a model square S = 1/2 Heisenberg antiferromagnet with T-N = 16.54 +/- 0.05 K. The dispersion of spin-waves in the magnetic layers of a fully deuterated sample of this material has been mapped at 4.3 K by inelastic neutron scattering from the zone centre...

  8. Novel homo- and hetero-nuclear copper(II) complexes of tetradentate Schiff bases: synthesis, characterization, solvent-extraction and catalase-like activity studies.

    Science.gov (United States)

    Dede, Bülent; Karipcin, Fatma; Cengiz, Mustafa

    2009-04-30

    Twelve homo- and hetero-nuclear copper(II) complexes of tetradentate Schiff base ligands containing N(4) donor sets have been prepared by employing several steps. The characterization and nature of bonding of the complexes have been deduced from elemental analysis, FT-IR, molar conductivity, magnetic moment measurements and thermal analysis. The three Schiff base ligands were further identified using (1)H and (13)C NMR spectra. All copper(II) complexes are 1:2 electrolytes as shown by their molar conductivities (Lambda(M)) in DMF and paramagnetic. The subnormal magnetic moment values of the di- and tri-nuclear complexes explained by a very strong anti-ferromagnetic interaction. The extraction ability of the ligands has been examined by the liquid-liquid extraction of selected transition metal (Mn(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Pb(2+), Cd(2+), Hg(2+)) cations. The ligands show strong binding ability toward copper(II) ion. Furthermore the homo- and hetero-nuclear copper(II) complexes were each tested for their ability to catalyse the disproportionation of hydrogen peroxide in the presence of the added base imidazole.

  9. Characterisation of the interactions between substrate, copper(II) complex and DNA and their role in rate acceleration in DNA-based asymmetric catalysis.

    Science.gov (United States)

    Draksharapu, Apparao; Boersma, Arnold J; Browne, Wesley R; Roelfes, Gerard

    2015-02-28

    Interactions of the azachalcone derived substrate Aza with copper(II) complexes in the presence and absence of st-DNA were studied in detail by UV/Vis absorption, EPR and Raman and (UV and vis) resonance Raman spectroscopies. The binding of Aza to the Lewis acidic copper(II) complexes, which results in activation of the substrate, was established spectroscopically. It was shown that the binding of Aza differs between Cu(II)dmbpy and Cu(II)terpy, consistent with the observed differences in catalytic asymmetric Diels-Alder reactions with regard to both the rate and enantiomeric preference. Finally, it was shown that DNA has a major beneficial effect on the binding of Aza to the copper(II) complex due to the fact that both bind to the DNA. The result is a high effective molarity of both the copper complexes and the Aza substrate, which leads to a significant increase in binding of Aza to the copper(II) complex. This effect is a key reason for the observed rate acceleration in the catalyzed reactions brought about by the presence of DNA.

  10. Synthesis of mononuclear copper(II) complexes of acyclic Schiff's base ligands: Spectral, structural, electrochemical, antibacterial, DNA binding and cleavage activity

    Science.gov (United States)

    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.

  11. Potentiometric determination of stability constants of cyanoacetato complexes of cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II) and lead(II).

    Science.gov (United States)

    Matusinović, T; Filipović, I

    1981-03-01

    Stability constants of cyanoacetato complexes of cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II) and lead(II) were determined potentiometrically at 25.0 +/- 0.1 degrees and ionic strength 2M (sodium perchlorate). The stability constants were evaluated by a weighted least-squares method.

  12. Simulation of multivariate diffusion bridges

    DEFF Research Database (Denmark)

    Bladt, Mogens; Finch, Samuel; Sørensen, Michael

    We propose simple methods for multivariate diffusion bridge simulation, which plays a fundamental role in simulation-based likelihood and Bayesian inference for stochastic differential equations. By a novel application of classical coupling methods, the new approach generalizes a previously...... proposed simulation method for one-dimensional bridges to the mulit-variate setting. First a method of simulating approzimate, but often very accurate, diffusion bridges is proposed. These approximate bridges are used as proposal for easily implementable MCMC algorithms that produce exact diffusion bridges....... The new method is much more generally applicable than previous methods. Another advantage is that the new method works well for diffusion bridges in long intervals because the computational complexity of the method is linear in the length of the interval. In a simulation study the new method performs well...

  13. Morphological aspects of myocardial bridges.

    Science.gov (United States)

    Lujinović, Almira; Kulenović, Amela; Kapur, Eldan; Gojak, Refet

    2013-11-01

    Although some myocardial bridges can be asymptomatic, their presence often causes coronary disease either through direct compression of the "tunnel" segment or through stimulation and accelerated development of atherosclerosis in the segment proximally to the myocardial bridge. The studied material contained 30 human hearts received from the Department of Anatomy. The hearts were preserved 3 to 5 days in 10% formalin solution. Thereafter, the fatty tissue was removed and arterial blood vessels prepared by careful dissection with special reference to the presence of the myocardial bridges. Length and thickness of the bridges were measured by the precise electronic caliper. The angle between the myocardial bridge fibre axis and other axis of the crossed blood vessel was measured by a goniometer. The presence of the bridges was confirmed in 53.33% of the researched material, most frequently (43.33%) above the anterior interventricular branch. The mean length of the bridges was 14.64 ± 9.03 mm and the mean thickness was 1.23 ± 1.32 mm. Myocardial bridge fibres pass over the descending blood vessel at the angle of 10-90 degrees. The results obtained on a limited sample suggest that the muscular index of myocardial bridge is the highest for bridges located on RIA, but that the difference is not significant in relation to bridges located on other branches. The results obtained suggest that bridges located on other branches, not only those on RIA, could have a great contractive power and, consequently, a great compressive force, which would be exerted on the wall of a crossed blood vessel.

  14. Bridge Aesthetics and Structural Honesty

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    In bridges the overall form must be chosen with due respect to the transmission of forces if efficient structures shall be created, The design must therefore be governed by experienced structural engineers - in some cases assisted by aesthetic advisers on specific issues. Some basic requirements...... decisive for choosing the form of trusses, arches and cable-stayed bridges are outlined, and several examples show bridges designed without giving priority to the structural aspects....

  15. Morphological aspects of myocardial bridges

    Directory of Open Access Journals (Sweden)

    Almira Lujinović

    2013-11-01

    Full Text Available Although some myocardial bridges can be asymptomatic, their presence often causes coronary disease either through direct compression of the “tunnel” segment or through stimulation and accelerated development of atherosclerosis in the segment proximally to the myocardial bridge. The studied material contained 30 human hearts received from the Department of Anatomy. The hearts were preserved 3 to 5 days in 10% formalin solution. Thereafter, the fatty tissue was removed and arterial blood vessels prepared by careful dissection with special reference to the presence of the myocardial bridges. Length and thickness of the bridges were measured by the precise electronic caliper. The angle between the myocardial bridge fibre axis and other axis of the crossed blood vessel was measured by a goniometer. The presence of the bridges was confirmed in 53.33% of the researched material, most frequently (43.33% above the anterior interventricular branch. The mean length of the bridges was 14.64±9.03 mm and the mean thickness was 1.23±1.32 mm. Myocardial bridge fibres pass over the descending blood vessel at the angle of 10-90 degrees. The results obtained on a limited sample suggest that the muscular index of myocardial bridge is the highest for bridges located on RIA, but that the difference is not significant in relation to bridges located on other branches. The results obtained suggest that bridges located on other branches, not only those on RIA, could have a great contractive power and, consequently, a great compressive force, which would be exerted on the wall of a crossed blood vessel.

  16. Synthesis, characterization, DNA-binding and cleavage studies of polypyridyl copper(II) complexes

    Science.gov (United States)

    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.

  17. Comprehensive evaluation of fracture critical bridges.

    Science.gov (United States)

    2014-02-01

    Two-girder steel bridges are classified as fracture critical bridges based on the definition given in the AASHTO LRFD Bridge Design Specifications. In a fracture critical bridge a failure of a tension member leads to collapse of the bridge. However, ...

  18. 75 FR 41281 - Bridge Safety Standards

    Science.gov (United States)

    2010-07-15

    ... bridges. The structural integrity of bridges that carry railroad tracks is important to the safety of... the structural failure of a railroad bridge. Train accidents caused by the structural failure of... inspection and analysis of the bridge. In general, timber bridges continue to function safely, and masonry...

  19. 33 CFR 115.40 - Bridge repairs.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which do...

  20. Coordinating Interactions: The Event Coordination Notation

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    on a much more technical level. The Event Coordination Notation (ECNO) allows modelling the behaviour of an application on a high level of abstraction that is closer to the application’s domain than to the software realizing it. Still, these models contain all necessary details for actually executing...... the models and for generating code from them. In order to be able to model the behaviour of a domain, the ECNO makes the events in which the different elements of the domain could engage explicit. The local behaviour of an element defines at which time an element can engage or participate in an event....... The global behaviour of the application results from different elements jointly engaging in such events, which is called an interaction. Which events are supposed to be jointly executed and which elements need to join in is defined by so-called coordination diagrams of the ECNO. Together, the models...

  1. Copper(II Thiosemicarbazone Complexes and Their Proligands upon UVA Irradiation: An EPR and Spectrophotometric Steady-State Study

    Directory of Open Access Journals (Sweden)

    Michal Hricovíni

    2018-03-01

    Full Text Available X- and Q-band electron paramagnetic resonance (EPR spectroscopy was used to characterize polycrystalline Cu(II complexes that contained sodium 5-sulfonate salicylaldehyde thiosemicarbazones possessing a hydrogen, methyl, ethyl, or phenyl substituent at the terminal nitrogen. The ability of thiosemicarbazone proligands to generate superoxide radical anions and hydroxyl radicals upon their exposure to UVA irradiation in aerated aqueous solutions was evidenced by the EPR spin trapping technique. The UVA irradiation of proligands in neutral or alkaline solutions and dimethylsulfoxide (DMSO caused a significant decrease in the absorption bands of aldimine and phenolic chromophores. Mixing of proligand solutions with the equimolar amount of copper(II ions resulted in the formation of 1:1 Cu(II-to-ligand complex, with the EPR and UV-Vis spectra fully compatible with those obtained for the dissolved Cu(II thiosemicarbazone complexes. The formation of the complexes fully inhibited the photoinduced generation of reactive oxygen species, and only subtle changes were found in the electronic absorption spectra of the complexes in aqueous and DMSO solutions upon UVA steady-state irradiation. The dark redox activity of copper(II complexes and proligand/Cu(II aqueous solutions towards hydrogen peroxide which resulted in the generation of hydroxyl radicals, was confirmed by spin trapping experiments.

  2. Inhibition of the hemolytic activity caused by Staphylococcus aureus alpha-hemolysin through isatin-Schiff copper(II) complexes.

    Science.gov (United States)

    Melo, Maria C A; Teixeira, Luciana R; Pol-Fachin, Laercio; Rodrigues, Claudio G

    2016-01-01

    A great number of pathogens secrete pore-forming proteins during infection. Such molecules, from either bacterial or viral origin, are considered important virulence factors, which makes them attractive targets in the study of new therapeutic agents. Thus, the inhibitory activity of isatin-Schiff base copper(II) complexes was evaluated against membrane damage activity of Staphylococcus aureus α-hemolysin (α-HL). For this purpose, a standard hemolysis assay with rabbit erythrocytes and micromolar concentrations of the compounds was employed. Additionally, planar artificial lipid membranes with a single α-HL ion channel and molecular docking studies were used to elucidate the molecular mechanism of the complexes. Accordingly, the compounds were observed to possess a significant anti-hemolytic activity, capable of interacting with the constriction region of α-HL channel and blocking it in a potential dependent manner. Based on these results, it is expected that such isatin-Schiff base Copper(II) complexes may be employed as cotherapeutic agents for the treatment of staphylococcal infections. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Intercalative interaction of asymmetric copper(II) complex with DNA: experimental, molecular docking, molecular dynamics and TDDFT studies.

    Science.gov (United States)

    Hu, Wei; Deng, Suwen; Huang, Jianyin; Lu, Yanmei; Le, Xueyi; Zheng, Wenxu

    2013-10-01

    The intercalative interactions of small molecules with DNA are important in a variety of biological processes including mutagenesis, carcinogenesis, and chemotherapy. A comprehensive research protocol including experiments and calculations was employed to investigate the intercalative interaction between metallointercalator copper(II) complex and DNA. The intercalative binding mode has been validated by UV spectra, fluorescence spectra, CD spectra and viscosity measurements. The classical molecular dynamics simulation was carried out to investigate the intercalative interaction between asymmetric copper(II) complex and DNA. An analytical method was proposed to simulate the dynamically changing absorption spectra of intercalator/DNA system. According to the established model, the changing process of the electronic absorption spectra for intercalator/DNA system can be predicted accurately. A rational explanation for the change law of absorption spectra has been proposed. Moreover, the analyses of the frontier orbital reveal that the red shift of the absorption spectra is due to the increase of π orbital energy caused by the coupling of the π orbital of the intercalated ligand with the π orbital of DNA. This cause of red shift of spectra is completely different from the previous inference. All these insights are of crucial importance for correctly analyzing the absorption spectra of intercalative interaction, as well as for explaining the macroscopic phenomena observed in experiments at the molecular level. © 2013.

  4. Synthesis, characterization and DNA interaction of new copper(II) complexes of Schiff base-aroylhydrazones bearing naphthalene ring.

    Science.gov (United States)

    Gökçe, Cansu; Gup, Ramazan

    2013-05-05

    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. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Synthesis, crystal structures and antitumor activities of copper(II) complexes with a 2-acetylpyrazine isonicotinoyl hydrazone ligand

    Science.gov (United States)

    Xu, Jun; Zhou, Tao; Xu, Zhou-Qing; Gu, Xin-Nan; Wu, Wei-Na; Chen, Hong; Wang, Yuan; Jia, Lei; Zhu, Tao-Feng; Chen, Ru-Hua

    2017-01-01

    Five complexes, [Cu(L)2]·4.5H2O (1), [Cu(HL)2](NO3)2·CH3OH (2) {[Cu2(L)2(NO3)(H2O)2]·(NO3)}n (3), [Cu2(HL)2(SO4)2]·2CH3OH (4) and [Cu4(L)4Cl4]·5H2O (5) based on HL (where HL = 2-acetylpyrazine isonicotinoyl hydrazone) have been synthesized and characterized by X-ray diffraction analyses. The counter anion and organic base during the synthesis procedure influence the structures of the complexes efficiently, which generate five complexes as mono-, bi-, tetra-nuclear and one-dimensional structures. The antitumor activities of the complexes 1-5 (except for complex 3 with the poor solubility) against the Patu8988 human pancreatic cancer, ECA109 human esophagus cancer and SGC7901 human gastric cancer cell lines are screened by MTT assay. The results indicate that the chelation of Cu(II) with the ligand is responsible for the observed high cytotoxicity of the copper(II) complexes and the 1:2 copper species 1 and 2 demonstrate lower antitumor activities than that of the 1:1 copper species 4 and 5. In addition, the in vitro apoptosis inducing activity of the copper(II) complex 5 against SGC7901 cell line is determined. And the results show that the complex can bring about apoptosis of the cancerous cells in vitro.

  6. Removal of Copper(II and Zinc(II Ions From Aqueous Solution by Chemical Treatment of Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Eleonora Sočo

    2015-12-01

    Full Text Available The aim of this study was to investigate the chemical modifications of coal fly ash (CFA treated with HNO3 or ammonium acetate (AcNH4 or NaOH or sodium diethyldithiocarbamate (NaDDTC as an adsorbent for the removal of copper(II and zinc(II ions from aqueous solution. The morphology of fly ash grains before and after modification was examined via X-ray diffraction (XRD and images of scanning electron microscope (SEM. Adsorption of copper(II and zinc(II ions was conducted under batch process at different duration, concentrations and temperature of the suspension. Equilibrium experiments shows that the selectivity of CFA-NaOH nanoparticles towards Cu(II ions is greater than that of Zn(II ions, which is related to their hydrated ionic radius and first hydrolysis equilibrium constant. The adsorption isotherms were described by Langmuir and Freundlich models. Kinetic data revealed that the adsorption fits well by the pseudo-second-order rate model with high regression coefficients. Thermodynamic parameters suggested that the immobilization Cu(II and Zn(II ions onto CFA-NaOH is a spontaneous process. Results demonstrated that the treating coal fly ash with alkaline solution was a promising way to enhance Cu(II and Zn(II ions adsorption.

  7. Field performance of timber bridges. 7, Connell Lake stress-laminated deck bridge

    Science.gov (United States)

    L. E. Hislop; M. A. Ritter

    The Connell Lake bridge was constructed in early 1991 on the Tongass National Forest, Alaska, as a demonstration bridge under the Timber Bridge Initiative. The bridge is a stress-laminated deck structure with an approximate 36-ft length and 18-ft width and is the first known stress-laminated timber bridge constructed in Alaska. Performance of the bridge was monitored...

  8. 47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Operator requirements of the Bridge-to-Bridge... Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the Bridge-to-Bridge Act must have on board a radio operator who holds a restricted radiotelephone operator permit or...

  9. Synthesis, Crystal Structure, and Electroconducting Properties of a 1D Mixed-Valence Cu(I–Cu(II Coordination Polymer with a Dicyclohexyl Dithiocarbamate Ligand

    Directory of Open Access Journals (Sweden)

    Kenji Nakatani

    2015-04-01

    Full Text Available A new mixed-valence Cu(I–Cu(II 1D coordination polymer, [CuI4CuIIBr4(Cy2dtc2]n, with an infinite chain structure is synthesized by the reaction of Cu(Cy2dtc2 (Cy2dtc− = dicyclohexyl dithiocarbamate, C13H22NS2 with CuBr·S(CH32. The as-synthesized polymer consists of mononuclear copper(II units of CuII(Cy2dtc2 and tetranuclear copper(I cluster units, CuI4Br4. In the cluster unit, all the CuI ions have distorted trigonal pyramidal coordination geometries, and the CuI–CuI or CuI–CuII distances between the nearest copper ions are shorter than the sum of van der Waals radii for Cu–Cu.

  10. Cobalt(II), nickel(II), copper(II), and zinc(II) complexes with [3(5)]adamanzane, 1,5,9,13-tetraazabicyclo[7.7.3]nonadecane and [(2.3)(2).2(1)]adamanzane, 1,5,9,12-tetraazabicyclo[7.5.2]hexadecane

    DEFF Research Database (Denmark)

    Broge, Louise; Pretzmann, Ulla; Jensen, Nicolai

    2001-01-01

    ) and of three cobalt(II), four nickel(II), one copper(II), and two zinc(II) complexes with [3(5)]adamanzane. For nine of these compounds (2-8, 10b, and 12) the single-crystal X-ray structures were determined. The coordination geometry around the metal ion is square pyramidal in [Cu([(2.3)(2).2(1)]adz)Br]ClO4 (2......) and trigonal bipyramidal in the isostructural structures [Cu([3(5)]adz)Br]Br (3), [Ni-([3(5)]adz)Cl]Cl (5), [Ni([3(5)]adz)Br]Br (6), and [Co([3(5)]adz)Cl]Cl (8). In [Ni([3(5)]adz)(NO3)]NO3 (4) and [Ni([3(5)]-adz)(ClO4)]ClO4 (7) the coordination geometry around nickel(II) is a distorted octahedron...... with the inorganic ligands at cis positions. The coordination polyhedron around the metal ion in [Co([3(5)]adz)][ZnCl4] (10b) and [Zn([3(5)]adz)][ZnCl4] (12) is a slightly distorted tetrahedron. Anation equilibrium constants were determined spectrophotometrically for complexes 2-6 at 25 and 40 degreesC and fall...

  11. Developing deterioration models for Nebraska bridges.

    Science.gov (United States)

    2011-07-01

    Nebraska Bridge Management System (NBMS) was developed in 1999 to assist in optimizing budget allocation for : the maintenance, rehabilitation and replacement needs of highway bridges. This requires the prediction of bridge : deterioration to calcula...

  12. Faster bridge construction using precast substructures : brief.

    Science.gov (United States)

    2011-07-01

    Bridge replacement often requires road closures and detours that frustrate road users. It remains a key goal of Wisconsin DOT to reduce construction-related road use interruptions. This will be a challenge with bridges: Bridge inspections in 2007 ide...

  13. Key Royale bridge five year evaluation : [summary].

    Science.gov (United States)

    2013-06-01

    The Florida Department of Transportation (FDOT) : maintains more than 6,500 bridges. Considering : the expense of repair and replacement of bridges, : extending their durability and service life is : important. Of special concern for bridges in : mar...

  14. Monitoring bridge scour using fiber optic sensors.

    Science.gov (United States)

    2015-04-01

    The scouring process excavates and carries away materials from the bed and banks of streams, and from : around the piers and abutments of bridges. Scour undermines bridges and may cause bridge failures due to : structural instability. In the last 30 ...

  15. Lean Construction Applications for Bridge Inspection

    Science.gov (United States)

    2017-10-01

    Lean philosophy was used to analyze the efficiency of bridge inspection. Emphasis was put on identifying activities that add value to the final output, an owner approved bridge inspection report. 26 bridge inspections were shadowed. Time spent on bri...

  16. Developmental coordination disorder

    Science.gov (United States)

    Developmental coordination disorder can lead to: Learning problems Low self-esteem resulting from poor ability at sports and teasing by other children Repeated injuries Weight gain as a result of not wanting to participate ...

  17. Supercritical Airfoil Coordinates

    Data.gov (United States)

    National Aeronautics and Space Administration — Rectangular Supercritical Wing (Ricketts) - design and measured locations are provided in an Excel file RSW_airfoil_coordinates_ricketts.xls . One sheet is with Non...

  18. Regional transit coordination guidebook.

    Science.gov (United States)

    2009-01-01

    Constant growth in rural areas and extensive suburban development have contributed to increasingly more people needing seamless and adequate public transportation into and from nearby cities. Coordinating existing services or determining the need for...

  19. Environmental Compliance Issue Coordination

    Science.gov (United States)

    An order to establish the Department of Energy (DOE) requirements for coordination of significant environmental compliance issues to ensure timely development and consistent application of Departmental environmental policy and guidance

  20. Haskell_#: Coordinating Functional Processes

    OpenAIRE

    Junior, Francisco Heron de Carvalho; Lins, Rafael Dueire

    2012-01-01

    This paper presents Haskell#, a coordination language targeted at the efficient implementation of parallel scientific applications on loosely coupled parallel architectures, using the functional language Haskell. Examples of applications, their implementation details and performance figures are presented.

  1. Understanding social motor coordination.

    Science.gov (United States)

    Schmidt, R C; Fitzpatrick, Paula; Caron, Robert; Mergeche, Joanna

    2011-10-01

    Recently there has been much interest in social coordination of motor movements, or as it is referred to by some researchers, joint action. This paper reviews the cognitive perspective's common coding/mirror neuron theory of joint action, describes some of its limitations and then presents the behavioral dynamics perspective as an alternative way of understanding social motor coordination. In particular, behavioral dynamics' ability to explain the temporal coordination of interacting individuals is detailed. Two experiments are then described that demonstrate how dynamical processes of synchronization are apparent in the coordination underlying everyday joint actions such as martial art exercises, hand-clapping games, and conversations. The import of this evidence is that emergent dynamic patterns such as synchronization are the behavioral order that any neural substrate supporting joint action (e.g., mirror systems) would have to sustain. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Steel-soil composite bridge

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2017-01-01

    viability, while their environmental performance is overlooked. Today’s designers are urged to seek new design options to reduce the environmental burdens. Sweden owns more than 24574 bridges and most of them are short spans. Among them, the slab frame bridge (CFB) is a common solution. Soil steel composite...

  3. Crossing borders via mental bridges

    DEFF Research Database (Denmark)

    Keil, Dirk

    administration, and in specific on the attempt to initiate and promote cross-border regional integration via the building of mental bridges between Danish and German parts of the Femern Belt Region. Here one of the first projects aiming primarily at building mental bridges in the Femern Belt Region...

  4. The violin bridge as filter.

    Science.gov (United States)

    Bissinger, George

    2006-07-01

    The violin bridge filter role was investigated using modal and acoustic measurements on 12 quality-rated violins combined with systematic bridge rocking frequency f(rock) and wing mass decrements deltam on four bridges for two other violins. No isolated bridge resonances were observed; bridge motions were complex (including a "squat" mode near 0.8 kHz) except for low frequency rigid body pivot motions, all more or less resembling rocking motion at higher frequencies. A conspicuous broad peak near 2.3 kHz in bridge driving point mobility (labeled BH) was seen for good and bad violins. Similar structure was seen in averaged bridge, bridge feet, corpus mobilities and averaged radiativity. No correlation between violin quality and BH driving point, averaged corpus mobility magnitude, or radiativity was found. Increasing averaged-over-f(rock) deltam(g) from 0 to 0.12 generally increased radiativity across the spectrum. Decreasing averaged-over-deltam f(rock) from 3.6 to 2.6 kHz produced consistent decreases in radiativity between 3 and 4.2 kHz, but only few-percent decreases in BH frequency. The lowest f(rock) values were accompanied by significantly reduced radiation from the Helmholtz A0 mode near 280 Hz; this, combined with reduced high frequency output, created overall radiativity profiles quite similar to "bad" violins among the quality-rated violins.

  5. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Straalen, IJ.J. van

    2004-01-01

    Traffic bridges are subjected to variable loads and should therefore be checked on fatigue. Especially low weight materials, like aluminium, are sensitive to fatigue, because the variable load is a substantial part of the total load. This paper shows the structural design of an aluminium bridge

  6. Synthesis and characterization of a chiral dimeric copper(II) complex ...

    Indian Academy of Sciences (India)

    Unknown

    midal geometry. Generally, the dichloro-bridged square- pyramidal copper complexes with square pyramid geometry exhibit three different geometries with re- gard to the relative arrangement of square pyramids, viz. perpendicular bases (type I), parallel bases (type. II) and coplanar bases (type III).12 The asymmetric.

  7. Majorana entanglement bridge

    Science.gov (United States)

    Plugge, Stephan; Zazunov, Alex; Sodano, Pasquale; Egger, Reinhold

    2015-06-01

    We study the concurrence of entanglement between two quantum dots in contact to Majorana bound states on a floating superconducting island. The distance between the Majorana states, the charging energy of the island, and the average island charge are shown to be decisive parameters for the efficiency of entanglement generation. We find that long-range entanglement with basically distance-independent concurrence is possible over wide parameter regions, where the proposed setup realizes a "Majorana entanglement bridge." We also study the time-dependent concurrence obtained after one of the tunnel couplings is suddenly switched on, which reveals the time scales for generating entanglement. Accurate analytical expressions for the concurrence are derived both for the static and the time-dependent cases. Our results indicate that entanglement formation in interacting Majorana devices can be fully understood in terms of an interplay of elastic cotunneling (also referred to as "teleportation") and crossed Andreev reflection processes.

  8. Bridging the Evaluation Gap

    Directory of Open Access Journals (Sweden)

    Paul Wouters

    2017-02-01

    Full Text Available Paul Wouters’ essay is concerned with bridging the gap between what we value in our academic work and how we are assessed in formal evaluation exercises. He reflects on the recent evaluation of his own center, and reminds us that it is productive to see evaluations not as the (obviously impossible attempt to produce a true representation of past work, but rather as the exploration and performance of “who one wants to be.” Reflecting on why STS should do more than just play along to survive in the indicator game, he suggests that our field should contribute to changing its very rules. In this endeavor, the attitude and sensibilities developed in our field may be more important than any specific theoretical concepts or methodologies.

  9. Electrothermally Tunable Bridge Resonator

    KAUST Repository

    Hajjaj, Amal Z.

    2016-12-05

    This paper demonstrates experimentally, theoretically, and numerically a wide-range tunability of an in-plane clamped-clamped microbeam, bridge, and resonator compressed by a force due to electrothermal actuation. We demonstrate that a single resonator can be operated at a wide range of frequencies. The microbeam is actuated electrothermally, by passing a DC current through it. We show that when increasing the electrothermal voltage, the compressive stress inside the microbeam increases, which leads eventually to its buckling. Before buckling, the fundamental frequency decreases until it drops to very low values, almost to zero. After buckling, the fundamental frequency increases, which is shown to be as high as twice the original resonance frequency. Analytical results based on the Galerkin discretization of the Euler Bernoulli beam theory are generated and compared to the experimental data and to simulation results of a multi-physics finite-element model. A good agreement is found among all the results.

  10. Half Bridge Inductive Heater

    Directory of Open Access Journals (Sweden)

    Zoltán GERMÁN-SALLÓ

    2015-12-01

    Full Text Available Induction heating performs contactless, efficient and fast heating of conductive materials, therefore became one of the preferred heating procedure in industrial, domestic and medical applications. During induction heating the high-frequency alternating currents that heat the material are induced by means of electromagnetic induction. The material to be heated is placed inside the time-varying magnetic field generated by applying a highfrequency alternating current to an induction coil. The alternating electromagnetic field induces eddy currents in the workpiece, resulting resistive losses, which then heat the material. This paper describes the design of a power electronic converter circuit for induction heating equipment and presents the obtained results. The realized circuit is a low power half bridge resonant inverter which uses power MOS transistors and adequate driver circuits.

  11. Encoding of coordination complexes with XML.

    Science.gov (United States)

    Vinoth, P; Sankar, P

    2017-09-01

    An in-silico system to encode structure, bonding and properties of coordination complexes is developed. The encoding is achieved through a semantic XML markup frame. Composition of the coordination complexes is captured in terms of central atom and ligands. Structural information of central atom is detailed in terms of electron status of valence electron orbitals. The ligands are encoded with specific reference to the electron environment of ligand centre atoms. Behaviour of ligands to form low or high spin complexes is accomplished by assigning a Ligand Centre Value to every ligand based on the electronic environment of ligand centre atom. Chemical ontologies are used for categorization purpose and to control different hybridization schemes. Complexes formed by the central atoms of transition metal, non-transition elements belonging to s-block, p-block and f-block are encoded with a generic encoding platform. Complexes of homoleptic, heteroleptic and bridged types are also covered by this encoding system. Utility of the encoded system to predict redox electron transfer reaction in the coordination complexes is demonstrated with a simple application. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Bridging Organizations Drive Effective Governance Outcomes for Conservation of Indonesia's Marine Systems.

    Science.gov (United States)

    Berdej, Samantha M; Armitage, Derek R

    2016-01-01

    This study empirically investigates the influence of bridging organizations on governance outcomes for marine conservation in Indonesia. Conservation challenges require ways of governing that are collaborative and adaptive across boundaries, and where conservation actions are better coordinated, information flows improved, and knowledge better integrated and mobilized. We combine quantitative social network analysis and qualitative data to analyze bridging organizations and their networks, and to understand their contributions and constraints in two case studies in Bali, Indonesia. The analysis shows 1) bridging organizations help to navigate the 'messiness' inherent in conservation settings by compensating for sparse linkages, 2) the particular structure and function of bridging organizations influence governing processes (i.e., collaboration, knowledge sharing) and subsequent conservation outcomes, 3) 'bridging' is accomplished using different strategies and platforms for collaboration and social learning, and 4) bridging organizations enhance flexibility to adjust to changing marine conservation contexts and needs. Understanding the organizations that occupy bridging positions, and how they utilize their positionality in a governance network is emerging as an important determinant of successful conservation outcomes. Our findings contribute to a relatively new body of literature on bridging organizations in marine conservation contexts, and add needed empirical investigation into their value to governance and conservation in Coral Triangle nations and beyond.

  13. Novel Viologen Derivative Based Uranyl Coordination Polymers Featuring Photochromic Behaviors.

    Science.gov (United States)

    Hu, Kong-Qiu; Wu, Qun-Yan; Mei, Lei; Zhang, Xiao-Lin; Ma, Lei; Song, Gang; Chen, Di-Yun; Wang, Yi-Tong; Chai, Zhi-Fang; Shi, Wei-Qun

    2017-12-19

    A series of novel uranyl coordination polymers have been synthesized by hydrothermal reactions. Both complexes 1 and 2 prosess two ipbp - ligands (H 2 ipbpCl=1-(3,5-dicarboxyphenyl)-4,4'-bipyridinium chloride), one uranyl cation, and two coordination water molecules, which can further extend to 2D networks through hydrogen bonding. In complex 1, two sets of equivalent nets are entangled together, resulting in a 2D + 2D → 3D polycatenated framework. In complex 2, the neighbouring equivalent nets interpenetrate each other, forming a twofold interpenetrated network. Complexes 3 and 4 are isomers, and both of them are constructed from (UO 2 ) 2 (OH) 2 dinuclear units, which are connected with four ipbp - ligands. The 3D structures of complexes 3 and 4 are similar along the b axis. Similar to other viologen-based coordination polymers, complexes 3 and 4 exhibit photochromic and thermochromic properties, which are rarely observed in actinide coordination polymers. Unlike the monotonous coordination mode in complexes 1-4, the ipbp - ligands feature a μ 3 -bridge through two kinds of coordination modes in complex 5. Notably, complex 5 presents a unique example in which terminal pyridine nitrogen atom is involved in the coordination. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Wright-Fisher diffusion bridges.

    Science.gov (United States)

    Griffiths, Robert C; Jenkins, Paul A; Spanò, Dario

    2017-10-06

    The trajectory of the frequency of an allele which begins at x at time 0 and is known to have frequency z at time T can be modelled by the bridge process of the Wright-Fisher diffusion. Bridges when x=z=0 are particularly interesting because they model the trajectory of the frequency of an allele which appears at a time, then is lost by random drift or mutation after a time T. The coalescent genealogy back in time of a population in a neutral Wright-Fisher diffusion process is well understood. In this paper we obtain a new interpretation of the coalescent genealogy of the population in a bridge from a time t∈(0,T). In a bridge with allele frequencies of 0 at times 0 and T the coalescence structure is that the population coalesces in two directions from t to 0 and t to T such that there is just one lineage of the allele under consideration at times 0 and T. The genealogy in Wright-Fisher diffusion bridges with selection is more complex than in the neutral model, but still with the property of the population branching and coalescing in two directions from time t∈(0,T). The density of the frequency of an allele at time t is expressed in a way that shows coalescence in the two directions. A new algorithm for exact simulation of a neutral Wright-Fisher bridge is derived. This follows from knowing the density of the frequency in a bridge and exact simulation from the Wright-Fisher diffusion. The genealogy of the neutral Wright-Fisher bridge is also modelled by branching Pólya urns, extending a representation in a Wright-Fisher diffusion. This is a new very interesting representation that relates Wright-Fisher bridges to classical urn models in a Bayesian setting. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Compilation of accelerated bridge construction (ABC) bridges : final report.

    Science.gov (United States)

    2016-01-01

    Development of accelerated bridge construction (ABC) technologies has been occurring across the country, many times in : isolation. Although FHWA and others have worked to facilitate communication between these efforts, there was not a : comprehensiv...

  16. Bridge Creek IMW database - Bridge Creek Restoration and Monitoring Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The incised and degraded habitat of Bridge Creek is thought to be limiting a population of ESA-listed steelhead (Oncorhynchus mykiss). A logical restoration approach...

  17. Reliability Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Middleton, C. R.

    This paper is partly based on research performed for the Highways Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: concrete bridges". It contains the details of a methodology which can be used to generate Whole Life (WL) reliability...... profiles. These WL reliability profiles may be used to establish revised rules for concrete bridges. This paper is to some extend based on Thoft-Christensen et. al. [1996], Thoft-Christensen [1996] et. al. and Thoft-Christensen [1996]....

  18. Vulnerability of bridges to fire

    DEFF Research Database (Denmark)

    Giuliani, Luisa; Crosti, C.; Gentili, F.

    2012-01-01

    Even if recent effort in developing methodology and measures for design structures against fire and explosions has been mostly focused on buildings, bridges can also be very sensitive to those actions, as witnesses by some recent bridge accidents, which caused major economic losses and also......, considering both the costs deriving by structural damages and by limited serviceability and other indirect societal aspects. Few cases of recent bridge fire are reviewed in detail and structural consequences are highlighted, distinguishing between damages directly induced by fire and damages induced by local...

  19. [Binocular coordination during reading].

    Science.gov (United States)

    Bassou, L; Granié, M; Pugh, A K; Morucci, J P

    1992-01-01

    Is there an effect on binocular coordination during reading of oculomotor imbalance (heterophoria, strabismus and inadequate convergence) and of functional lateral characteristics (eye preference and perceptually privileged visual laterality)? Recordings of the binocular eye-movements of ten-year-old children show that oculomotor imbalances occur most often among children whose left visual perceptual channel is privileged, and that these subjects can present optomotor dissociation and manifest lack of motor coordination. Close binocular motor coordination is far from being the norm in reading. The faster reader displays saccades of differing spatial amplitude and the slower reader an oculomotor hyperactivity, especially during fixations. The recording of binocular movements in reading appears to be an excellent means of diagnosing difficulties related to visual laterality and to problems associated with oculomotor imbalance.

  20. Kinetics of the oxidative hydroxylation of tetraphosphorus in the presence of copper(II chloride modified by humic (fulvo- acid

    Directory of Open Access Journals (Sweden)

    Zhaksyntay Kairbekov

    2012-12-01

    Full Text Available It was established that in mild conditions (50-70 oC, РО2= 1 atm white phosphorus effectively is oxidized by oxygen in water-toluene solutions of copper(II chloride modified by humic (fulvo- acid to give mainly phosphoric acid. Humic (fulvo- acid was extracted from brown coal of domestic deposit Kiyakty. For determination of optimum parameters of fulvo-acid extraction the laboratory experiments were carried out using the method of experiment planning. The kinetics, intermediate and final products, optimum conditions of new catalytic reaction of P4 oxidation by oxygen in water medium were defined by kinetics, volumometry, redox-potentiometry, 31Р{1Н} NMR spectroscopy and  titration. 

  1. COMPOSITIONS BASED ON PALLADIUM(II AND COPPER(II COMPOUNDS, HALIDE IONS, AND BENTONITE FOR OZONE DECOMPOSITION

    Directory of Open Access Journals (Sweden)

    T. L. Rakitskaya

    2017-05-01

    bromide ion. For Cu(II-KBr/N-Bent composition, kinetic and calculation data show that, in the presence of bromide ions, copper(II inhibits the ozone decomposition. For Pd(II-KBr/NBent composition, it has been found that the maximum activity is attained at СPd(II = 1.02·10-5 mol/g. For bimetallic Pd(II- Cu(II-KBr/N-Bent composition, changes in τ0, τ1/2, k1/2, and Q1/2 parameters depending on a Pd(II content are similar to those for monometallic Pd(II-KBr/NBent composition; however, values of the parameters are higher for the monometallic system. Thus, the inhibiting effect of Cu(II is observed even in the presence of palladium(II.

  2. Copper(II), cobalt(II) and nickel(II) complexes of lapachol: synthesis, DNA interaction, and cytotoxicity.

    Science.gov (United States)

    Tabrizi, Leila; Talaie, Faranak; Chiniforoshan, Hossein

    2017-11-01

    Three novel copper(II), cobalt(II), and nickel(II) complexes of lapachol (Lap) containing 110-phenanthroline (phen) ligand, [M(Lap) 2 (phen)] (M=Cu(II), 1, Co(II), 2, and Ni(II), 3), have been synthesized and characterized using, elemental analysis and spectroscopic studies. Their interactions with calf thymus DNA (CT DNA) were investigated using viscosity, thermal denaturation, circular dichorism, fluorescence quenching, and electronic absorption spectroscopy. The DNA cleavage abilities of 1-3 have been studied, where cleavage activity of copper complex 1 is more than the complexes 2 and 3. The in vitro cytotoxic potential of the complexes 1-3 against human cervical carcinoma (HeLa), human liver hepatocellular carcinoma (HepG-2), and human colorectal adenocarcinoma (HT-29) cells indicated their promising antitumor activity with quite low IC 50 values in the range of .15-2.41 μM, which are lower than those of cisplatin.

  3. Introduction to Coordination Chemistry

    CERN Document Server

    Lawrance, Geoffrey Alan

    2010-01-01

    Introduction to Coordination Chemistry examines and explains how metals and molecules that bind as ligands interact, and the consequences of this assembly process. This book describes the chemical and physical properties and behavior of the complex assemblies that form, and applications that may arise as a result of these properties. Coordination complexes are an important but often hidden part of our world?even part of us?and what they do is probed in this book. This book distills the essence of this topic for undergraduate students and for research scientists.

  4. Quantifying linguistic coordination

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Tylén, Kristian

    task (Bahrami et al 2010, Fusaroli et al. 2012) we extend to linguistic coordination dynamical measures of recurrence employed in the analysis of sensorimotor coordination (such as heart-rate (Konvalinka et al 2011), postural sway (Shockley 2005) and eye-movements (Dale, Richardson and Kirkham 2012......). We employ nominal recurrence analysis (Orsucci et al 2005, Dale et al 2011) on the decision-making conversations between the participants. We report strong correlations between various indexes of recurrence and collective performance. We argue this method allows us to quantify the qualities...

  5. Coordinate Standard Measurement Development

    Energy Technology Data Exchange (ETDEWEB)

    Hanshaw, R.A.

    2000-02-18

    A Shelton Precision Interferometer Base, which is used for calibration of coordinate standards, was improved through hardware replacement, software geometry error correction, and reduction of vibration effects. Substantial increases in resolution and reliability, as well as reduction in sampling time, were achieved through hardware replacement; vibration effects were reduced substantially through modification of the machine component dampening and software routines; and the majority of the machine's geometry error was corrected through software geometry error correction. Because of these modifications, the uncertainty of coordinate standards calibrated on this device has been reduced dramatically.

  6. Recursive Advice for Coordination

    DEFF Research Database (Denmark)

    Terepeta, Michal Tomasz; Nielson, Hanne Riis; Nielson, Flemming

    2012-01-01

    Aspect-oriented programming is a programming paradigm that is often praised for the ability to create modular software and separate cross-cutting concerns. Recently aspects have been also considered in the context of coordination languages, offering similar advantages. However, introducing aspect...... systems. Even though primarily used for analysis of recursive programs, we are able to adapt them to fit this new context.......Aspect-oriented programming is a programming paradigm that is often praised for the ability to create modular software and separate cross-cutting concerns. Recently aspects have been also considered in the context of coordination languages, offering similar advantages. However, introducing aspects...

  7. A unique discrete tetranuclear Cu'-Cu(N-N)2Cu-Cu' copper(II) complex, built from a μ3-1,2,4-triazolato-μ-carboxylato ligand, as an effective DNA cleavage agent.

    Science.gov (United States)

    Hernández-Gil, Javier; Ferrer, Sacramento; Castiñeiras, Alfonso; Lloret, Francesc

    2012-09-17

    The title compound, characterized by means of an X-ray structure analysis, represents an easy example of a noncatena "1 + 2 + 1" tetranuclear copper(II) μ(3)-triazolate compound. [Cu(4)(atc)(2)(dien)(4)(ClO(4))(2)](ClO(4))(2)·2H(2)O (1), where H(2)atc = 5-amino-l,2,4-triazole-3-carboxylic acid and dien = diethylenetriamine = 1,4,7-triazaheptane, contains two copper atoms linked by a double diazinic bridge, each of which is further connected to a third and fourth copper atom (Cu') through the triply bridging triazolato ring and the bidentate carboxylato group of the atc(2-) ligands. The copper-copper distances within the tetranuclear unit are Cu-Cu = 4.059 Å, Cu-Cu' = 5.686 and 6.370 Å, and Cu'-Cu' = 11.373 Å. The compound self-assembles into a tridimensional hydrogen-bonded network to generate a MOF. 1 exhibits antiferromagnetic behavior with g = 2.10(1), J = -34.1(2) cm(-1) and j = -5.50(3) cm(-1), where J is the coupling constant of the central Cu-Cu pair and j the coupling constant of the two Cu-Cu' (Cu(central)-Cu(pheripheral)) pairs, as defined by H = -JS(2)S(2a) - j (S(1)S(2) + S(2a)S(1a)). Complex 1 has been tested as nuclease mimic. It shows good binding propensity to calf thymus DNA, with a binding constant value of 6.20 × 10(6) M(-1) (K(app)) and ΔT(m) = 18.3 °C. Moreover, the compound displays efficient oxidative cleavage of pUC18 DNA, even at low concentration, in the presence of a mild reducing agent (ascorbate), with a rate constant for the conversion of supercoiled to nicked DNA (k(obs)) of ~0.126 min(-1). The good reactivity of 1 toward DNA is explained from the electrostatic interactions of the cationic species produced in solution.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, M.T.S.D.; Azenha, M.A.O. [Laquipai, Porto (Portugal). Faculdade de Ciencias do Porto; Cabral, J.P.S. [Inst. de Botanica e Centro de Citologia Experimental U.P., Porto (Portugal)

    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.

  9. Anti-cancer activity and mutagenic potential of novel copper(II) quinolinone Schiff base complexes in hepatocarcinoma cells.

    Science.gov (United States)

    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. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Conjugation of a new series of dithiocarbazate Schiff base Copper(II) complexes with vectors selected to enhance antibacterial activity.

    Science.gov (United States)

    Low, May Lee; Maigre, Laure; Dorlet, Pierre; Guillot, Régis; Pagès, Jean-Marie; Crouse, Karen A; Policar, Clotilde; Delsuc, Nicolas

    2014-12-17

    A new series of six Schiff bases derived from S-methyldithiocarbazate (SMDTC) and S-benzyldithiocarbazate (SBDTC) with methyl levulinate (SMML, SBML), levulinic acid (SMLA, SBLA), and 4-carboxybenzaldehyde (SM4CB, SB4CB) were reacted with copper(II), producing complexes of general formula ML2 (M = Cu(II), L = ligand). All compounds were characterized using established physicochemical and spectroscopic methods. Crystal structures were determined for three Schiff bases (SMML, SBML, SBLA) and two Cu(II) complexes (Cu(SMML)2 and Cu(SMLA)2). In order to provide more insight into the behavior of the complexes in solution, electron paramagnetic resonance (EPR) and electrochemical experiments were performed. The parent ligands and their respective copper(II) complexes exhibited moderate antibacterial activity against both Gram-negative and Gram-positive bacteria. The most active ligand (SB4CB) and its analogous S-methyl derivative (SM4CB) were conjugated with various vector moieties: polyarginines (R1, R4, R9, and RW9), oligoethylene glycol (OEG), and an efflux pump blocker, phenylalanine-arginine-β-naphthylamide (PAβN). Nonaarginine (R9) derivatives showed the most encouraging synergistic effects upon conjugation and complexation with copper ion including enhanced water solubility, bacteria cell membrane permeability, and bioactivity. These Cu(II)-R9 derivatives display remarkable antibacterial activity against a wide spectrum of bacteria and, in particular, are highly efficacious against Staphylococcus aureus with minimum inhibitory concentration (MIC) values of 0.5-1 μM. This pioneer study clearly indicates that the conjugation of cell-penetrating peptides (CPPs) to dithiocarbazate compounds greatly enhances their therapeutic potential.

  11. Mixed-ligand copper(II) phenolate complexes: Synthesis, spectral characterization, phosphate-hydrolysis, antioxidant, DNA interaction and cytotoxic studies

    Science.gov (United States)

    Gurumoorthy, Perumal; Mahendiran, Dharmasivam; Prabhu, Durai; Arulvasu, Chinnasamy; Rahiman, Aziz Kalilur

    2015-01-01

    A series of phenol-based mixed-ligand copper(II) complexes of the type [CuL1-4(diimine)] (1-8), where L1-4 = N1,N2-bis(5-substituted-2-hydroxybenzylidene)-1,2-ethylene/phenylenediimine and diimine = 2,2‧-bipyridyl (bpy) or 1,10-phenanthroline (phen), have been isolated and fully characterized by analytical and spectral techniques. Electronic spectra of complexes suggest Cu(II) cation has a d9 electronic configuration, adopting distorted octahedral geometry with axial elongation, due to Jahn-Teller effect. Electrochemical studies of complexes evidenced one-electron irreversible reduction wave in the cathodic region. The observed rate constant (k) values for the hydrolysis of 4-nitrophenylphosphate (4-NPP) are in the range of 0.25-3.82 × 10-2 min-1. The obtained room temperature magnetic moment values (1.79-1.90 BM) lies within the range observed for octahedral copper(II) complexes. Antioxidant studies revealed that these complexes possess considerable radical scavenging potency against DPPH. The binding studies of complexes with calf thymus DNA (CT-DNA) revealed intercalation with minor-groove binding, and the complex 4 exhibits highest binding activity than the other complexes. The cleavage activity on supercoiled pBR322 DNA revealed the involvement of hydroxyl radical and singlet-oxygen as reactive oxygen species, and complexes encourage binding to minor-groove. Further, the cytotoxicity of complex 4 on human hepatocellular liver carcinoma HepG2 cell line implies the cell death through apoptosis.

  12. DNA condensation by copper(II) complexes and their anti-proliferative effect on cancerous and normal fibroblast cells.

    Science.gov (United States)

    Rajalakshmi, Subramaniyam; Kiran, Manikantan Syamala; Nair, Balachandran Unni

    2014-06-10

    In our search towards copper(II) based anticancer compounds, copper(II) complexes [Cu(bitpy)2](ClO4)21, [Cu(bitpy)(phen)](NO3)22 and [Cu(bitpy)(NO3)](NO3) 3 were synthesized and characterized. All the three complexes contain the tridentate ligand bitpy, which bears biologically relevant benzimidazolyl head group, as one of the ligands. Because of the presence of the planar benzimidazolyl group in the bitpy ligand, the complexes exhibited intercalative mode of binding with DNA. The DNA binding constant, K(b), for complexes 1, 2 and 3 were determined to be (1.84 ± 0.32) × 10(4), (1.83 ± 0.57) × 10(4) and (1.87 ± 0.21) × 10(4) M(-1) respectively. All the three complexes possessed DNA condensing ability. The DNA condensing ability of the complexes was in the order 2 > 1 > 3. The DNA condensation induced by these three complexes was found to be reversed in the presence of 1 M NaCl. In vitro cytotoxicity of three complexes was tested against osteosarcoma MG63 cell line as well as normal fibroblast NIH3T3 cell line by MTT reduction assay. Complexes 1 and 2 were found to be highly toxic towards MG63 than NIH3T3 cell line and both these complexes brought about cell death in the MG-63 cell line due to apoptosis. Whereas, complex 3 exhibited almost equal toxic effect towards both MG63 and NIH3T3 cell lines. Based on the fact that both complexes 1 and 2 brought about reversible condensation of DNA and induced apoptosis in osteosarcoma MG-63 cell line, it is hypothesized that they might possess potential pharmaceutical applications. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  13. Effects of Electrolyte on Floating Water Bridge

    Directory of Open Access Journals (Sweden)

    Hideo Nishiumi

    2009-01-01

    spontaneously. In this paper, we examined flow direction of water bridge and what effects the addition of electrolytes such as NaCl, NaOH, and NH4Cl to the floating water bridge would give. We found that ionization degree reduced the length of water bridge though insoluble electrolyte Al2O3 had no effect on the length of water bridge.

  14. The stories of two bridges in Ghana

    DEFF Research Database (Denmark)

    Andreasen, Jørgen

    2004-01-01

    Public participation in bridge building was promoted by un habitat in the village of Mankrong. The neighbouring village did not participate in the construction of their bridge. The first flooding washed the second bridge down while the "participative bridge" stood up....

  15. Caltrans bridge inspection aerial robot.

    Science.gov (United States)

    2008-10-01

    The California Department of Transportation (Caltrans) project resulted in the development of a twin-motor, : single duct, electric-powered Aerobot designed of carrying video cameras up to 200 feet in elevation to enable : close inspection of bridges...

  16. Energy harvesting on highway bridges.

    Science.gov (United States)

    2011-01-01

    A concept for harvesting energy from the traffic-induced loadings on a highway bridge using piezoelectric : materials to generate electricity was explored through the prototype stage. A total of sixteen lead-zirconate : titanate (PZT) Type 5A piezoel...

  17. Preventative maintenance program for bridges.

    Science.gov (United States)

    2015-07-01

    The Kentucky Transportation Cabinets (KYTC) bridge inventory is rapidly aging. As such, the Cabinet : needs to identify and implement relevant preventative maintenance (PM) actions to extend the useful : service lives of those structures. Maintena...

  18. Research notes : listening to bridges.

    Science.gov (United States)

    2008-09-01

    The Federal Highway Administration requires owners of structurally deficient bridges to repair, replace, restrict truck loads, or conduct analysis and testing to maintain a safe highway system. Past experiments on reinforced concrete beams showed aco...

  19. Corrosion inhibitors for concrete bridges.

    Science.gov (United States)

    2004-12-01

    Deicing salts and salt-water spray can cause serious corrosion problems for reinforced concrete bridge structures. : These problems can lead to costly and labor-intensive repair and even replacement of the structure. Surface applied : corrosion inhib...

  20. Linear Cracking in Bridge Decks

    Science.gov (United States)

    2018-03-01

    Concrete cracking in bridge decks remains an important issue relative to deck durability. Cracks can allow increased penetration of chlorides, which can result in premature corrosion of the reinforcing steel and subsequent spalling of the concrete de...

  1. Interstate-35 bridge instrumentation renaissance.

    Science.gov (United States)

    2012-09-01

    An updated, accelerometer-based, sensor and data acquisition system was installed and verified on the I-35 Walnut Creek Bridge in Purcell, Oklahoma. The data collection system also includes a microwave communication system to move sensor and video da...

  2. Coordination diversity of new mononucleating hydrazone in 3d metal complexes: Synthesis, characterization and structural studies

    Directory of Open Access Journals (Sweden)

    RAJESH S. BALIGAR

    2006-12-01

    Full Text Available The mononucleating hydrazone ligand LH3, a condensation product of salicyloylhydrazine and (2-formylphenoxyacetic acid, was synthesized and its coordination behavior with first row transition metal(II ions was investigated by isolating and elucidating the structure of the complexes using elemental analysis, conductivity and magnetic susceptibility measurements, as well as IR, 1H-NMR, electronic and EPR spectral techniques. The ligand forms mononuclear metal(II complexes of the type [CoLH(H2O2], [NiLH(H2O2, [CuLH] and [ZnLH]. The ligand field parameters, Dq, B and b values, in the case of the cobalt and nickel complexes support not only the octahedral geometry around the metal ion, but also imply the covalent nature of the bonding in the complexes. The EPR study revealed the presence of a spin exchange interaction in the solid copper complex and the covalent nature of the bonding. The 1H-NMR study of the zinc(II complex indicated the non-involvement of the COOH group in the coordination. The physico-chemical study supports for the presence of octahedral geometry around cobalt(II, nickel(II and tetrahedral geometry around copper(II and zinc(II ions.

  3. Fulltext PDF

    Indian Academy of Sciences (India)

    compound formed from μ1,1-azido clipping of two methoxido bridged [Cu2] complexes showing asymmetric coordination from benzophenone oxygen atoms and terminal azido groups. Keywords. Tetranuclear copper(II); azido; methoxido; phenoxido; X-ray structure; rhombiodal. 1. Introduction. In recent years, the utilization ...

  4. Synthesis, crystal structure and magnetic properties of [Cu(mal)(abpt ...

    African Journals Online (AJOL)

    Complex 1 consist of a neutral mononuclear [Cu(mal)(abpt)(H2O)] unit and water molecule of crystallization in a distorted square pyramidal coordination sphere, while complex 2 is viewed as being made up of [Cu(sq)(abpt)2] units with the squarato ligand bridging the two copper(II) cations. Variable temperature magnetic ...

  5. 77 FR 53251 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Science.gov (United States)

    2012-08-31

    ... describing construction materials used in new Federal-aid bridge construction and bridge rehabilitation... construction materials used in new bridge construction and bridge rehabilitation projects. Data on Federal-aid... the following tables: Construction Materials for New and Replaced Bridges, a summary report which...

  6. Coordination failure caused by sunspots

    DEFF Research Database (Denmark)

    Beugnot, Julie; Gürgüç, Zeynep; Øvlisen, Frederik Roose

    2012-01-01

    on the efficient equilibrium, we consider sunspots as a potential reason for coordination failure. We conduct an experiment with a three player 2x2x2 game in which coordination on the efficient equilibrium is easy and should normally occur. In the control session, we find almost perfect coordination on the payoff......-dominant equilibrium, but in the sunspot treatment, dis-coordination is frequent. Sunspots lead to significant inefficiency, and we conclude that sunspots can indeed cause coordination failure....

  7. Dinuclear 1,4,7-triazacyclononane (tacn) complexes of cobalt(III) with amido and tacn bridges. Synthesis, characterization and reversible acid-accelerated bridge cleavage

    DEFF Research Database (Denmark)

    Andersen, Peter; Glerup, Jørgen; Gumm, Andreas

    2004-01-01

    Amido-bridged dinuclear cobalt(III) complexes with 1,4,7-triazacyclononane (tacn) were synthesized from [Co(tacn)(O3SCF3)3] by treatment with potassium amide in liquid ammonia at 100 degrees C. Two isomeric triply bridged complexes, [(tacn)Co(mu-NH2)3Co(tacn)]3+ and [(tacn)Co(mu-NH2)2[mu-tacn(-H)......Amido-bridged dinuclear cobalt(III) complexes with 1,4,7-triazacyclononane (tacn) were synthesized from [Co(tacn)(O3SCF3)3] by treatment with potassium amide in liquid ammonia at 100 degrees C. Two isomeric triply bridged complexes, [(tacn)Co(mu-NH2)3Co(tacn)]3+ and [(tacn)Co(mu-NH2)2[mu......-tacn(-H)]Co(NH3)]3+, were isolated as perchlorates, and the crystal structure of the perrhenate of the latter complex was determined by X-ray diffraction. In this compound a nitrogen atom (deprotonated) from one of the tacn ligands forms a third bridge together with two amido bridges. In 1.0 M (Na,H)ClO4 ([H+] 0.......1-1.0 M) the two isomers undergo acid-accelerated amido bridge cleavage, as earlier found for chromium(III) analogues, in spite of the fact that such bridges are co-ordinatively saturated. The triamido-bridged isomer is in this acid medium in equilibrium with [(H2O)(tacn)Co(mu-NH2)2Co(tacn)(NH3...

  8. Coordination Compounds in Biology

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 6. Coordination Compounds in Biology - The Chemistry of Vitamin B12 and Model Compounds. K Hussian Reddy. General Article Volume 4 Issue 6 June 1999 pp 67-77 ...

  9. Coordination Compounds in Biology

    Indian Academy of Sciences (India)

    Coordination Compounds in Biology equatorial ligand, there are two axial ligands in most B. 12 derivatives. Derivatives of B12. The various derivatives of B. 12 result most commonly from changes in the axial ligands bound to cobalt. Often it is convenient to draw a greatly abbreviated structure for a B. 12 molecule using a ...

  10. Polymeric coordination compounds

    Indian Academy of Sciences (India)

    Administrator

    Metal coordination polymers with one- and two-dimensional structures are of current interest due to their possible relevance to material science 1. In continuation of our previous studies 2,3, several new polymeric compounds are reported here. Among the complexes of silver with aminomethyl pyridine (amp) ...

  11. Coordination of mobile labor

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    2008-01-01

    Roč. 139, č. 1 (2008), s. 25-46 ISSN 0022-0531 R&D Projects: GA MŠk LC542 Institutional research plan: CEZ:AV0Z70850503 Keywords : coordination * general equilibrium * global games Subject RIV: AH - Economics Impact factor: 1.224, year: 2008

  12. Block coordination copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Kyoung Moo; Wong-Foy, Antek G.; Matzger, Adam J.; Benin, Annabelle I.; Willis, Richard R.

    2012-12-04

    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  13. Block coordination copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R

    2014-11-11

    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  14. Block coordination copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R

    2012-11-13

    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  15. Reusability of coordination programs

    NARCIS (Netherlands)

    F. Arbab (Farhad); C.L. Blom (Kees); F.J. Burger (Freek); C.T.H. Everaars (Kees)

    1996-01-01

    textabstractIsolating computation and communication concerns into separate pure computation and pure coordination modules enhances modularity, understandability, and reusability of parallel and/or distributed software. This can be achieved by moving communication primitives (such as SendMessage and

  16. [Civilian-military coordination].

    Science.gov (United States)

    de Montravel, G

    2002-01-01

    Current humanitarian emergencies create complex, mutidimensional situations that stimulate simultaneous responses from a wide variety of sources including governments, non-governmental organizations (NGO), United Nations agencies, and private individuals. As a result, it has become essential to establish a coherent framework in which each actor can contribute promptly and effectively to the overall effort. This is the role of the United Nations Office for the Coordination of Humanitarian Affairs. Regardless of the circumstances and level of coordination, cooperation and collaboration between humanitarian and military personnel, it is necessary to bear in mind their objectives. The purpose of humanitarian action is to reduce human suffering. The purpose of military intervention is to stop warfare. The author of this article will discuss the three major obstacles to civilian-military coordination (strategic, tactical, and operational). Operations cannot be conducted smoothly and differences cannot be ironed out without mutual respect between the two parties, an explicit definition of their respective duties and responsibilities, a clear understanding of their cultural differences, and the presence of an organization and facilities for coordination and arbitrage by a neutral referee.

  17. Copper(II) complexes with naringenin and hesperetin : cytotoxic activity against A 549 human lung adenocarcinoma cells and investigation on the mode of action

    NARCIS (Netherlands)

    Tamayo, Lenka V.; Gouvea, Ligiane R.; Sousa, Anna C.; Albuquerque, Ronniel M.; Teixeira, Sarah Fernandes; de Azevedo, Ricardo Alexandre; Louro, Sonia R. W.; Ferreira, Adilson Kleber; Beraldo, Heloisa

    Copper(II) complexes [Cu(H (2) O) (2) (L1)(phen)](ClO (4) ) (1) and [Cu(H (2) O)(L2)(phen)](ClO (4) ) (2) (HL1 = naringenin; HL2 = hesperetin) were obtained, in which an anionic flavonoid ligand is attached to the metal center along with 1,10-phenanthroline (phen) as co-ligand. Complexes (1) and (2)

  18. Copper(II) and molybdenum(VI) complexes of a tridentate ONN donor isothiosemicarbazone: synthesis, characterization, X-ray, TGA and DFT

    Czech Academy of Sciences Publication Activity Database

    Fasihizad, A.; Akbari, A.; Ahmadi, M.; Dušek, Michal; Henriques, Margarida Isabel Sousa; Pojarová, Michaela

    2016-01-01

    Roč. 115, Sep (2016), s. 297-305 ISSN 0277-5387 R&D Projects: GA ČR(CZ) GA14-03276S; GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : isothiosemicarbazone * Copper(II) complex * molybdenum(VI) complex * crystal structure * DFT Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.926, year: 2016

  19. Reagents for selective extraction of nickel(II), cobalt(II) and copper(II) from highly acidic sulfate feeds containing iron

    OpenAIRE

    Roebuck, James William

    2015-01-01

    This thesis focuses on development of new regents which are suitable for recovering nickel, cobalt and copper from laterite leach solutions, specifically focusing on reagent requirements for novel base metal flowsheets developed by Anglo American. The work aims to design reagents which can extract nickel(II), cobalt(II) and copper(II) from a highly acidic aqueous sulfate solutions whilst showing selectivity over iron(II) and iron(III). Chapter 1 reviews current extractive metallur...

  20. New μ-OAC bridged dinuclear copper(II) complex with tridentate Schiff base ligand: synthesis, characterization, crystal structure, and CuO nano-particles formation

    Czech Academy of Sciences Publication Activity Database

    Grivani, G.; Eigner, Václav; Dušek, Michal; Sadeghi, B.; Khalaji, A.D.

    2015-01-01

    Roč. 41, č. 7 (2015), s. 456-461 ISSN 1070-3284 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : Schiff base * complex structure * x-ray crystallography * Jana2006 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.516, year: 2015

  1. Functionalization of a nanostructured hydroxyapatite with copper(II) compounds as pesticide: in situ TEM and ESEM observations of treated Vitis vinifera L. leaves.

    Science.gov (United States)

    Battiston, Enrico; Salvatici, Maria C; Lavacchi, Alessandro; Gatti, Antonietta; Di Marco, Stefano; Mugnai, Laura

    2018-02-19

    The present study evaluates a biocompatible material for plant protection to reduce the amount of active substance applied. We used a synthetic hydroxyapatite (HA) that has been studied extensively due its bioactivity and biocompatibility. Aggregation between HA nanoparticles and four copper(II) compounds applied in Vitis vinifera L. leaves as pesticide was studied. Formulations were characterised by XRD, DLS, electron microscopy and applied in planta to verify the particle aggregation and efficiency in controlling the pathogen, Plasmopara viticola. XRD showed a different interaction between HA and the copper(II) compounds, DLS showed a granular distribution ranging out of the nanometer range and in all formulations, TEM and ESEM microscopy showed large aggregates which were partially nanostructured and were recognised as stable in their micrometric dimension. Such particles did not show phytotoxic effects after their application in planta. A formulation based on HA and the soluble copper(II) compound showed promising results in the control of the fungal pathogen, confirming the potential role of HA an as innovative delivery system of Cu(II) ions. The present work indicates the possibility to improve the biological activity of a bioactive substance by modifying its structure through an achievable formulation with a biocompatible material. This article is protected by copyright. All rights reserved.

  2. Development of an extractive spectrophotometric method for the determination of copper(II) in leafy vegetable and pharmaceutical samples using pyridoxal-4-phenyl-3-thiosemicarbazone (PPT).

    Science.gov (United States)

    Sarma, L Subramanyam; Kumar, J Rajesh; Reddy, K Janardhan; Reddy, A Varada

    2005-07-13

    A highly sensitive extractive spectrophotometric method has been developed for the determination of copper(II) using pyridoxal-4-phenyl-3-thiosemicarbazone(PPT) as an analytical reagent. The PPT forms reddish brown species of copper(II) at a pH range of 3.0-5.5, and the complex was extracted into n-butanol. The Cu(II)-PPT complex shows maximum absorbance at 440 nm, with molar absorptivity and Sandell's sensitivity being 2.16 x 10(4) L mol(-1) cm(-1) and 2.94 x 10(-3) microg cm(-2), respectively. The system obeys Beer's law in the range of 0.2-5.0 mg/L. The regression coefficient of the Beer's law straight line is 0.338, and the correlation coefficient is 0.96. The detection limit of the method is 0.0065 microg mL(-1). Most of the common metal ions generally found associated with copper do not interfere. The repeatability of the method was checked by finding the relative standard deviation. The developed method has been successfully employed for the determination of copper(II) in leafy vegetable and pharmaceutical samples. The method is evaluated by analyzing samples from the Bureau of Analyzed Samples (BCS 233, 266, 216/1, 207, and 179) and by intercomparison of experimental values using AAS.

  3. cis-Aquadichlorido[pyrimidin-2(1H-one-κN3]copper(II

    Directory of Open Access Journals (Sweden)

    A. Guy Orpen

    2008-07-01

    Full Text Available In the title compound, [CuCl2(C4H4N2O(H2O], the CuII cation is coordinated by two chloride anions, one pyrimidin-2-one N atom and one water molecule, giving a slightly distorted square-planar geometry. In the crystal structure, the pyrimidin-2-one rings stack along the b axis, with an interplanar distance of 3.306 Å, as do the copper coordination planes (interplanar spacing = 2.998 Å. The coordination around the Jahn–Teller-distorted CuII ion is completed by long Cu...O [3.014 (5 Å] and Cu...Cl [3.0194 (15 Å] interactions with adjacent molecules involved in this stacking. Several N—H...Cl, O—H...Cl and O—H...O intermolecular hydrogen bonds form a polar three-dimensional network.

  4. Dynamic assessment of bridge deck performance considering realistic bridge-traffic interaction

    Science.gov (United States)

    2017-09-01

    Concrete bridge decks are directly exposed to daily traffic loads and may experience some surface cracking caused by excessive stress or fatigue accumulation, which requires repair or replacement. Among typical bridges in North America, bridge decks ...

  5. Bridging Organizations Drive Effective Governance Outcomes for Conservation of Indonesia’s Marine Systems

    Science.gov (United States)

    Berdej, Samantha M.; Armitage, Derek R.

    2016-01-01

    This study empirically investigates the influence of bridging organizations on governance outcomes for marine conservation in Indonesia. Conservation challenges require ways of governing that are collaborative and adaptive across boundaries, and where conservation actions are better coordinated, information flows improved, and knowledge better integrated and mobilized. We combine quantitative social network analysis and qualitative data to analyze bridging organizations and their networks, and to understand their contributions and constraints in two case studies in Bali, Indonesia. The analysis shows 1) bridging organizations help to navigate the ‘messiness’ inherent in conservation settings by compensating for sparse linkages, 2) the particular structure and function of bridging organizations influence governing processes (i.e., collaboration, knowledge sharing) and subsequent conservation outcomes, 3) ‘bridging’ is accomplished using different strategies and platforms for collaboration and social learning, and 4) bridging organizations enhance flexibility to adjust to changing marine conservation contexts and needs. Understanding the organizations that occupy bridging positions, and how they utilize their positionality in a governance network is emerging as an important determinant of successful conservation outcomes. Our findings contribute to a relatively new body of literature on bridging organizations in marine conservation contexts, and add needed empirical investigation into their value to governance and conservation in Coral Triangle nations and beyond. PMID:26794003

  6. 33 CFR 118.100 - Retroreflective panels on bridge piers.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Retroreflective panels on bridge... SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.100 Retroreflective panels on bridge piers. The... 12 inches square. (c) To mark bridge piers or channel sides on bridges not required to have bridge...

  7. The Akashi Kaikyo Bridge and the Storebælt Bridge

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    With the completion of the Akashi Kaikyo Bridge and the Storebælt East Bridge the development of the suspension bridge technology in the 20th century has manifested itself in two impressive structures. With the present echnology may bridges of similar (and also more modest) dimensions...... will undoubtedly be built far into the next century. For bridges going beyond the spans of existing bridges it is, however, likely that new concepts will be developed....

  8. Coordination chemistry of technetium

    International Nuclear Information System (INIS)

    Together with development of chemistry of radiopharmaceuticals, coordination chemistry of technetium has recently progressed. The synthetic procedures of technetium complexes have also been established in a various oxidation states. Especially, technetium(V) complexes which possess a Tc=0 or 0=Tc = 0 core are interested from a view point kinetic stability. In the present paper, substitution reaction mechanisms of Tc(V), Tc(IV) and Tc(III) complexes coordinated with a β-diketone as ligand are discussed in connection with the structural chemistry of technetium complexes. The base hydrolysis of halobis(β-diketonato)oxotechnetium(V) and dihalobis (β-diketonato)technetium(IV) complexes liberate halide ion by the attack of hydroxide ion, followed by the liberation of β-diketones. Technetium is found to be pertechnetate as a final product

  9. Coordinating Work with Groupware

    DEFF Research Database (Denmark)

    Pors, Jens Kaaber; Simonsen, Jesper

    2003-01-01

    One important goal of employing groupware is to make possible complex collaboration between geographically distributed groups. This requires a dual transformation of both technology and work practice. The challenge is to re­duce the complexity of the coordination work by successfully inte......­grating the protocol stipulating the collaboration and the ar­te­fact, in form of the groupware application, mediating the col­laboration. This paper analyses a generic groupware application that was deployed in a large financial organisation in order to support working groups distributed throughout four countries....... Using the CSCW frame­work of coordination mechanisms, we have elicited six general factors influencing the integration of the groupware application in two situations....

  10. Synthesis, characterization, and tyrosinase biomimetic catalytic activity of copper(II) complexes with schiff base ligands derived from α-diketones with 2-methyl-3-amino-(3 H)-quinazolin-4-one

    Science.gov (United States)

    Ramadan, Abd El-Motaleb M.; Ibrahim, Mohamed M.; Shaban, Shaban Y.

    2011-12-01

    A template condensation of α-diketones (biacetyl, benzile and 2,3-pentanedione) with 2-methyl-3-amino-(3 H)-quinazolin-4-one (AMQ) in the presence of CuX 2 (X = Cl -, Br -, NO3- or ClO4-) resulted in the formation of tetradentate Schiff base copper(II) complexes of the type [CuLX]X and [CuL]X 2. Structural characterization of the complex species was achieved by several physicochemical methods, namely elemental analysis, electronic spectra, IR, ESR, molar conductivity, thermal analysis (TAG & DTG), and magnetic moment measurements. The stereochemistry, the nature of the metal chelates, and the catalytic reactivity are markedly dependent upon the type of counter anions and the ligand substituent within the carbonyl moiety. A square planar monomeric structure is proposed for the perchlorate, nitrate, and bromide complexes, in which the counter anions are loosely bonded to copper(II) ion. For the chloride complexes, the molar conductivities and the spectral data indicated that they have square-pyramidal environments around copper(II) center. The reported copper(II) complexes exhibit promising tyrosinase catalytic activity towards the hydroxylation of phenol followed by the aerobic oxidation of the resulting catechol. A linear correlation almost exists between the catalytic reactivity and the Lewis-acidity of the central copper(II) ion created by the donating properties of the parent ligand. The steric considerations could be accounted to clarify the difference in the catalytic activity of these functional models.

  11. m-Carboranylphosphinate as Versatile Building Blocks To Design all Inorganic Coordination Polymers.

    Science.gov (United States)

    Oleshkevich, Elena; Viñas, Clara; Romero, Isabel; Choquesillo-Lazarte, Duane; Haukka, Matti; Teixidor, Francesc

    2017-05-15

    The first examples of coordination polymers of manganese(II) and a nickel(II) complex with a purely inorganic carboranylphosphinate ligand are reported, together with its exhaustive characterization. X-ray analysis revealed 1D polymeric chains with carboranylphosphinate ligands bridging two manganese(II) centers. The reactivity of polymer 1 with water and Lewis bases has also been studied.

  12. Variable coordinating activity of sulfur in silver(I) complexes with ...

    Indian Academy of Sciences (India)

    Variable coordinating activity of sulfur in silver(I) complexes with thiophene based N. 1. -substituted thiosemicarbazones: First case of thiopheneyl-thione sulfur bridging in a dinuclear complex. REKHA SHARMAa,b, TARLOK S LOBANAa,∗, MANVIR KAURa, NEERAJ THATHAIa,. GEETA HUNDALa, JERRY P JASINSKIc ...

  13. Improving Project Manufacturing Coordination

    Directory of Open Access Journals (Sweden)

    Korpivaara Ville

    2014-09-01

    Full Text Available The objective of this research is to develop firms’ project manufacturing coordination. The development will be made by centralizing the manufacturing information flows in one system. To be able to centralize information, a deep user need assessment is required. After user needs have been identified, the existing system will be developed to match these needs. The theoretical background is achieved through exploring the literature of project manufacturing, development project success factors and different frameworks and tools for development project execution. The focus of this research is rather in customer need assessment than in system’s technical expertise. To ensure the deep understanding of customer needs this study is executed by action research method. As a result of this research the information system for project manufacturing coordination was developed to respond revealed needs of the stakeholders. The new system improves the quality of the manufacturing information, eliminates waste in manufacturing coordination processes and offers a better visibility to the project manufacturing. Hence it provides a solid base for the further development of project manufacturing.

  14. Universal mechatronics coordinator

    Science.gov (United States)

    Muir, Patrick F.

    1999-11-01

    Mechatronic systems incorporate multiple actuators and sensor which must be properly coordinated to achieve the desired system functionality. Many mechatronic systems are designed as one-of-a-kind custom projects without consideration for facilitating future system or alterations and extensions to the current syste. Thus, subsequent changes to the system are slow, different, and costly. It has become apparent that manufacturing processes, and thus the mechatronics which embody them, need to be agile in order to more quickly and easily respond to changing customer demands or market pressures. To achieve agility, both the hardware and software of the system need to be designed such that the creation of new system and the alteration and extension of current system is fast and easy. This paper describes the design of a Universal Mechatronics Coordinator (UMC) which facilitates agile setup and changeover of coordination software for mechatronic systems. The UMC is capable of sequencing continuous and discrete actions that are programmed as stimulus-response pairs, as state machines, or a combination of the two. It facilitates the modular, reusable programing of continuous actions such as servo control algorithms, data collection code, and safety checking routines; and discrete actions such as reporting achieved states, and turning on/off binary devices. The UMC has been applied to the control of a z- theta assembly robot for the Minifactory project and is applicable to a spectrum of widely differing mechatronic systems.

  15. Coordinating Shared Activities

    Science.gov (United States)

    Clement, Bradley

    2004-01-01

    Shared Activity Coordination (ShAC) is a computer program for planning and scheduling the activities of an autonomous team of interacting spacecraft and exploratory robots. ShAC could also be adapted to such terrestrial uses as helping multiple factory managers work toward competing goals while sharing such common resources as floor space, raw materials, and transports. ShAC iteratively invokes the Continuous Activity Scheduling Planning Execution and Replanning (CASPER) program to replan and propagate changes to other planning programs in an effort to resolve conflicts. A domain-expert specifies which activities and parameters thereof are shared and reports the expected conditions and effects of these activities on the environment. By specifying these conditions and effects differently for each planning program, the domain-expert subprogram defines roles that each spacecraft plays in a coordinated activity. The domain-expert subprogram also specifies which planning program has scheduling control over each shared activity. ShAC enables sharing of information, consensus over the scheduling of collaborative activities, and distributed conflict resolution. As the other planning programs incorporate new goals and alter their schedules in the changing environment, ShAC continually coordinates to respond to unexpected events.

  16. Global coordination: weighted voting

    Directory of Open Access Journals (Sweden)

    Jan-Erik Lane

    2014-03-01

    Full Text Available In order to halt the depletion of global ecological capital, a number of different kinds of meetings between Governments of countries in the world has been scheduled. The need for global coordination of environmental policies has become ever more obvious, supported by more and more evidence of the running down of ecological capital. But there are no formal or binding arrangements in sight, as global environmental coordination suffers from high transaction costs (qualitative voting. The CO2 equivalent emissions, resulting in global warming, are driven by the unstoppable economic expansion in the global market economy, employing mainly fossil fuel generated energy, although at the same time lifting sharply the GDP per capita of several emerging countries. Only global environmental coordination on the successful model of the World Band and the IMF (quantitative voting can stem the rising emissions numbers and stop further environmental degradation. However, the system of weighted voting in the WB and the IMF must be reformed by reducing the excessive voting power disparities, for instance by reducing all member country votes by the cube root expression.

  17. 2-Organoselenomethyl-1H-benzimidazole Complexes of Copper(II) and Copper(I)

    Czech Academy of Sciences Publication Activity Database

    Leboschka, M.; Sieger, M.; Sarkar, B.; Heck, J.; Niemeyer, M.; Bubrin, D.; Lissner, F.; Schleid, T.; Záliš, Stanislav; Su, Ch. Y.; Kaim, W.

    2009-01-01

    Roč. 635, 13-14 (2009), s. 2177-2184 ISSN 0044-2313 R&D Projects: GA MŠk OC 139; GA AV ČR KAN100400702 Institutional research plan: CEZ:AV0Z40400503 Keywords : coordination models * copper * imidazole ligands * selenoether ligands Subject RIV: CG - Electrochemistry Impact factor: 1.226, year: 2009

  18. Structures of the two new compounds distrontium copper(II) triselenite(IV) and distrontium copper(II) bis[hydrogenselenite(IV)] bisselenite(IV)

    International Nuclear Information System (INIS)

    Effenberger, H.

    1988-01-01

    Sr 2 Cu(SeO 3 ) 3 , M r =619.68, triclinic, Panti 1, a=7.229(3), b=7.710(3), c=8.656(3) A, α=102.68(3), β=105.31(3), γ=96.12(3) 0 , V=447.0 A 3 , Z=2, D x =4.60 Mg m -3 , λ(MoKα)=0.71073 A, μ=26.0 mm -1 , F(000)=558, room temperature, R=0.033 for 3330 reflections up to 2θ=70 0 . Sr 2 Cu(SeO 2 OH) 2 (SeO 3 ) 2 , M r =748.65, triclinic, Panti 1, a=5.260(1), b=6.961(1), c=9.052(2) A, α=67.86(1), β=75.40(1), γ=80.41(1) 0 , V=296.6A 3 , Z=1, D x =4.19 Mg m -3 , λ(MoKα)=0.71073 A, μ=22.6 mm -1 , F(000)=339, room temperature, R=0.036 for 2362 reflections up to 2θ=70 0 . In the two compounds the Sr atoms are [8] and [9] coordinated (Sr-O=2.52 to 2.93 A), the Cu atoms have a tetragonal-pyramidal [4+1] and a square-planar [4] coordination, respectively. The distance Se-O h (1.80 A) is significantly longer than the other Se-O bonds (1.66 to 1.73 A). In Sr 2 Cu(SeO 3 ) 3 , the SrO 8 polyhedra form a three-dimensional network; in Sr 2 Cu(SeO 2 OH) 2 (SeO 3 ) 2 , the SrO 9 polyhedra are edge-linked to form sheets which are connected by CuO 4 squares, SeO 3 groups and the hydrogen bond (O-H...O=2.88 A). (orig.)

  19. Floating liquid bridge charge dynamics

    Science.gov (United States)

    Teschke, Omar; Soares, David Mendez; Gomes, Whyllerson Evaristo; Valente Filho, Juracyr Ferraz

    2016-01-01

    The interaction of liquid with electric fields is investigated in a configuration where up to 13 kV are applied between electrodes resulting in a 106 V/m electric field in the capillaries and where there is the formation of a free-standing fluid bridge in the interelectrode gap. The Mott-Gurney equation was fitted to the measured ionization current vs applied voltage curve which indicates that the ionization rate at the high-voltage anode electrode dimethylsulfoxide (DMSO) interface and space charging in the interelectrode gap determine the floating liquid bridge current for a given cathode-to-anode voltage. Space charge effects were measured in the cathode becker and also at the liquid bridge since the ionized charges at the anode migrate to the bridge outer surface and decrease the interfacial tension from 43 mJ/m2 to 29 mJ/m2. Two distinct structural regions then form the bridge, a charged plastic (bulk modulus ˜100 MPa) conducting outer layer with a surface conductivity of ˜10-9 Ω-1, which shapes and supports the floating fluid structure, and an inner liquid cylinder, where DMSO molecules flow.

  20. Thermal bridges of modern windows

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Møller, Eva B.; Nielsen, Anker

    2013-01-01

    With its focus on reduced energy consumption, contemporary housing construction requires a highly insulated and airtight building envelope with as few thermal bridges as possible.Windows must be carefully designed, as thermal bridges can lead to surface condensation or mold growth, even if the wi......With its focus on reduced energy consumption, contemporary housing construction requires a highly insulated and airtight building envelope with as few thermal bridges as possible.Windows must be carefully designed, as thermal bridges can lead to surface condensation or mold growth, even...... if the window has an U-factor of 1 W/(m2·K) or lower. This paper describes the development of modern, energy efficient Danish windows with reduced thermal bridges. It focuses on materials, geometry, and sealing of window panes based on a literature review. Examples of modern windows are presented. Experience...... been an important driver for the development of new window solutions in Denmark, increasing the inner-surface temperature at the sealing of window panes. However, it will not stop complaints fromconsumers, as this temperature is calculated under standardized conditions. Increasing requirements...

  1. A tutorial on bridge sampling.

    Science.gov (United States)

    Gronau, Quentin F; Sarafoglou, Alexandra; Matzke, Dora; Ly, Alexander; Boehm, Udo; Marsman, Maarten; Leslie, David S; Forster, Jonathan J; Wagenmakers, Eric-Jan; Steingroever, Helen

    2017-12-01

    The marginal likelihood plays an important role in many areas of Bayesian statistics such as parameter estimation, model comparison, and model averaging. In most applications, however, the marginal likelihood is not analytically tractable and must be approximated using numerical methods. Here we provide a tutorial on bridge sampling (Bennett, 1976; Meng & Wong, 1996), a reliable and relatively straightforward sampling method that allows researchers to obtain the marginal likelihood for models of varying complexity. First, we introduce bridge sampling and three related sampling methods using the beta-binomial model as a running example. We then apply bridge sampling to estimate the marginal likelihood for the Expectancy Valence (EV) model-a popular model for reinforcement learning. Our results indicate that bridge sampling provides accurate estimates for both a single participant and a hierarchical version of the EV model. We conclude that bridge sampling is an attractive method for mathematical psychologists who typically aim to approximate the marginal likelihood for a limited set of possibly high-dimensional models.

  2. Bridging nations through muons

    CERN Document Server

    2006-01-01

    From America to Israel and Japan, a team of international technicians and scientists are working together to build the ATLAS endcap muon chambers. The Israeli and Pakistani teams stand in front of part of the ATLAS endcap muon spectrometer. They are working on the project along with...... a team from American universities and research institutions. It's a small world; at least you might think so after a visit to Building 180. Inside, about 30 engineers and physicists weld, measure and hammer away, many of whom are miles from their homes and families. They hail from Pakistan, Israel, Japan, China, Russia and the United States. Coordinated by a group of CERN engineers, the team represents an international collaboration in every sense. Whether they've been here for years or months, CERN is their temporary home as they work toward one common goal: the completion of the ATLAS muon chamber endcaps. When finished, the ATLAS muon spectrometer will include four moving 'big wheel'structures on each end of the detecto...

  3. An Expert System for Concrete Bridge Management

    DEFF Research Database (Denmark)

    Brito, J. de; Branco, F. A.; Thoft-Christensen, Palle

    1997-01-01

    management systems are presently being implemented by bridge authorities in several countries. The prototype of an expert system for concrete bridge management is presented in this paper, with its functionality relying on two modules. The inspection module relies on a periodic acquisition of field......The importance of bridge repair versus new bridge construction has risen in recent decades due to high deterioration rates that have been observed in these structures. Budgets both for building new bridges and keeping the existing ones are always limited. To help rational decision-making, bridge...

  4. Symmetric two-coordinate photodiode

    Directory of Open Access Journals (Sweden)

    Dobrovolskiy Yu. G.

    2008-12-01

    Full Text Available The two-coordinate photodiode is developed and explored on the longitudinal photoeffect, which allows to get the coordinate descriptions symmetric on the steepness and longitudinal resistance great exactness. It was shown, that the best type of the coordinate description is observed in the case of scanning by the optical probe on the central part of the photosensitive element. The ways of improvement of steepness and linear of its coordinate description were analyzed.

  5. Precast concrete elements for accelerated bridge construction : laboratory testing, field testing, evaluation of a precast concrete bridge, Madison County bridge.

    Science.gov (United States)

    2009-01-01

    The importance of rapid construction technologies has been recognized by the Federal Highway Administration (FHWA) and the Iowa : DOT Office of Bridges and Structures. Recognizing this a two-lane single-span precast box girder bridge was constructed ...

  6. Nanostructured lipid carriers for incorporation of copper(II) complexes to be used againstMycobacterium tuberculosis.

    Science.gov (United States)

    Sato, Mariana R; Oshiro Junior, João A; Machado, Rachel Ta; de Souza, Paula C; Campos, Débora L; Pavan, Fernando R; da Silva, Patricia B; Chorilli, Marlus

    2017-01-01

    Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis . Cessation of treatment before the recommended conclusion may lead to the emergence of multidrug-resistant strains. The aim of this study was to develop nanostructured lipid carriers (NLCs) for use in the treatment of M. tuberculosis . The NLCs comprised the following lipid phase: 2.07% polyoxyethylene 40 stearate, 2.05% caprylic/capric triglyceride, and 0.88% polyoxyl 40 hydrogenated castor oil; the following aqueous phase: 3.50% poloxamer 407 (F1-F6), and 0.50% cetyltrimethylammonium bromide (F7-F12); and incorporated the copper(II) complexes [CuCl 2 (INH) 2 ]·H 2 O (1), [Cu(NCS) 2 (INH) 2 ]·5H 2 O (2), and [Cu(NCO) 2 (INH) 2 ]·4H 2 O (3) to form compounds F11.1, F11.2, and F11.3, respectively. The mean diameter of F11, F11.1, F11.2, and F11.3 ranged from 111.27±21.86 to 134.25±22.72 nm, 90.27±12.97 to 116.46±9.17 nm, 112.4±10.22 to 149.3±15.82 nm, and 78.65±6.00 to 122.00±8.70 nm, respectively. The polydispersity index values for the NLCs ranged from 0.13±0.01 to 0.30±0.09. The NLCs showed significant changes in zeta potential, except for F11.2, with F11, F11.1, F11.2, and F11.3 ranging from 18.87±4.04 to 23.25±1.13 mV, 17.03±1.77 to 21.42±1.87 mV, 20.51±1.88 to 22.60±3.44 mV, and 17.80±1.96 to 25.25±7.78 mV, respectively. Atomic force microscopy confirmed the formation of nanoscale spherical particle dispersions by the NLCs. Differential scanning calorimetry determined the melting points of the constituents of the NLCs. The in vitro activity of copper(II) complex-loaded NLCs against M. tuberculosis H 37 R v showed an improvement in the anti-TB activity of 55.4, 27.1, and 41.1 times the activity for complexes 1, 2, and 3, respectively. An in vivo acute toxicity study of complex-loaded NLCs demonstrated their reduced toxicity. The results suggest that NLCs may be a powerful tool to optimize the activity of copper(II) complexes against M. tuberculosis .

  7. Excitation Methods for Bridge Structures

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, C.R.; Duffy, T.A.; Cornwell, P.J.; Doebling, S.W.

    1999-02-08

    This paper summarizes the various methods that have been used to excited bridge structures during dynamic testing. The excitation methods fall into the general categories of ambient excitation methods and measured-input excitation methods. During ambient excitation the input to the bridge is not directly measured. In contrast, as the category label implies, measured-input excitations are usually applied at a single location where the force input to the structure can be monitored. Issues associated with using these various types of measurements are discussed along with a general description of the various excitation methods.

  8. Synthesis and characterization of a multifunctional inorganic-organic hybrid mixed-valence copper(I/II) coordination polymer: {[CuCN][Cu(isonic)2]}n

    Science.gov (United States)

    Liu, Dong-Sheng; Chen, Wen-Tong; Ye, Guang-Ming; Zhang, Jing; Sui, Yan

    2017-12-01

    A new multifunctional mixed-valence copper(I/II) coordination polymer, {[CuCN][Cu(isonic)2]}n(1) (Hisonic = isonicotinic acid), was synthesized by treating isonicotinic acid and 5-amino-tetrazolate (Hatz = 5-amino-tetrazolate) with copper(II) salts under hydrothermal conditions, and characterized by elemental analysis, infrared spectroscopy, and single crystal X-ray diffraction, respectively. The X-ray diffraction analysis reveals that compound exhibit noncentrosymmetric polar packing arrangement. It is three-dimensional (3D) framework with (3,5)-connected 'seh-3' topological network constructed from metal organic framework {[Cu(isonic)2]}n and the inorganic linear chain{Cu(CN)}n subunits. A remarkable feature of 1 is the rhombic open channels that are occupied by a linear chain of {Cu(CN)}n. Impressively compound 1 displays not only a second harmonic generation (SHG) response, but also a ferroelectric behavior and magnetic properties.

  9. Work Coordination Engine

    Science.gov (United States)

    Zendejas, Silvino; Bui, Tung; Bui, Bach; Malhotra, Shantanu; Chen, Fannie; Kim, Rachel; Allen, Christopher; Luong, Ivy; Chang, George; Sadaqathulla, Syed

    2009-01-01

    The Work Coordination Engine (WCE) is a Java application integrated into the Service Management Database (SMDB), which coordinates the dispatching and monitoring of a work order system. WCE de-queues work orders from SMDB and orchestrates the dispatching of work to a registered set of software worker applications distributed over a set of local, or remote, heterogeneous computing systems. WCE monitors the execution of work orders once dispatched, and accepts the results of the work order by storing to the SMDB persistent store. The software leverages the use of a relational database, Java Messaging System (JMS), and Web Services using Simple Object Access Protocol (SOAP) technologies to implement an efficient work-order dispatching mechanism capable of coordinating the work of multiple computer servers on various platforms working concurrently on different, or similar, types of data or algorithmic processing. Existing (legacy) applications can be wrapped with a proxy object so that no changes to the application are needed to make them available for integration into the work order system as "workers." WCE automatically reschedules work orders that fail to be executed by one server to a different server if available. From initiation to completion, the system manages the execution state of work orders and workers via a well-defined set of events, states, and actions. It allows for configurable work-order execution timeouts by work-order type. This innovation eliminates a current processing bottleneck by providing a highly scalable, distributed work-order system used to quickly generate products needed by the Deep Space Network (DSN) to support space flight operations. WCE is driven by asynchronous messages delivered via JMS indicating the availability of new work or workers. It runs completely unattended in support of the lights-out operations concept in the DSN.

  10. Morphometry of the osteodural bridge and the myodural bridge of ...

    African Journals Online (AJOL)

    The osteodural bridge, the connective tissue between the axis and dura can be measured radiographically. The aim of the study was therefore to determine if there is a relationship between their lengths. Thirty formalin fixed cadavers were meticulously dissected at the department of Human Anatomy, University of Nairobi, ...

  11. Synthesis, micellization behavior, antimicrobial and intercalative DNA binding of some novel surfactant copper(II) complexes containing modified phenanthroline ligands.

    Science.gov (United States)

    Nagaraj, Karuppiah; Ambika, Subramanian; Rajasri, Shanmugasundaram; Sakthinathan, Subramanian; Arunachalam, Sankaralingam

    2014-10-01

    The novel surfactant copper(II) complexes, [Cu(ip)2DA](ClO4)21, [Cu(dpqc)2DA](ClO4)22, [Cu(dppn)2DA](ClO4)23, where ip=imidazo[4,5-f][1,10]phenanthroline, dpqc=dipyrido[3,2-a:2',4'-c](6,7,8,9-tetrahydro)phenazine, dppn=benzo[1]dipyrido[3,2-a':2',3'-c]phenazine and DA-dodecylamine, were synthesized and characterized by physico-chemical and spectroscopic methods. In these complexes 1-3, the geometry of copper metal ions was described as square pyramidal. The critical micelle concentration (CMC) value of these surfactant copper(II) complexes in aqueous solution was found out from conductance measurements. Specific conductivity data at different temperatures served for the evaluation of the temperature-dependent CMC and the thermodynamics of micellization (ΔGm°, ΔHm° and ΔSm°). The binding interaction of these complexes with DNA (calf thymus DNA) in Tris buffer was studied by physico-chemical techniques. In the presence of the DNA UV-vis spectrum of complexes showed red shift of the absorption band along with significant hypochromicity indicating intercalation of our complexes with nucleic acids. Competitive binding study with ethidium bromide (EB) shows that the complexes exhibit the ability to displace the nucleic acid-bound EB indicating that the complexes bind to nucleic acids in strong competition with EB for the intercalative binding site. Observed changes in the circular dichoric spectra of DNA in the presence of surfactant complexes support the strong binding of complexes with DNA. CV results also confirm this mode of binding. Some significant thermodynamic parameters of the binding of the titled complexes to DNA have also been determined. The results reveal that the extent of DNA binding of 3 was greater than that of 1 and 2. The antibacterial and antifungal screening tests of these complexes have shown good results compared to its precursor chloride complexes. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Laboratory and field testing of an accelerated bridge construction demonstration bridge : US Highway 6 bridge over Keg Creek.

    Science.gov (United States)

    2013-04-01

    The US Highway 6 Bridge over Keg Creek outside of Council Bluffs, Iowa is a demonstration bridge site chosen to put into practice : newly-developed Accelerated Bridge Construction (ABC) concepts. One of these new concepts is the use of prefabricated ...

  13. Fiber reinforced polymer bridge decks : [technical summary].

    Science.gov (United States)

    2011-01-01

    A number of researchers have addressed the use of Fiber Reinforced Polymer (FRP) deck as a replacement solution for deteriorated bridge decks made of traditional materials. The use of new, advanced materials such as FRP is advantageous when the bridg...

  14. Developing county bridge repair and retrofit techniques.

    Science.gov (United States)

    2013-08-01

    Oklahoma rated first in the Nation in the percentage of bridges that are structurally deficient or : functionally obsolete. According to Federal Highway Administration data, Oklahoma uses : approximately 23,250 bridges maintained by state, County, Ci...

  15. Risk Mitigation for Highway and Railway Bridges

    Science.gov (United States)

    2009-02-01

    Performance of the transportation network strongly depends on the performance of bridges. Bridges constitute a vital part of the transportation infrastructure system and they are vulnerable to extreme events such as natural disasters (i.e., hurricane...

  16. Performance monitoring of jointless bridges : phase III.

    Science.gov (United States)

    2014-05-01

    Part I: : The third phase of a research project investigating the field performance of jointless bridges is reported. Three : integral abutment bridges in Vermont, US have been instrumented and monitored as part of this research. : General descriptio...

  17. IceBridge Mission Flight Reports

    Data.gov (United States)

    National Aeronautics and Space Administration — The IceBridge Mission Flight Reports data set contains flight reports from NASA Operation IceBridge Greenland, Arctic, Antarctic, and Alaska missions. Flight reports...

  18. Meeting Environmental Requirements after a Bridge Collapse

    Science.gov (United States)

    2008-08-01

    This report is intended to assist transportation and environmental professionals in the event of a bridge collapse or similar emergency. It analyzes the environmental review process in five cases of bridge reconstruction following collapse in Florida...

  19. Forensic testing of a double tee bridge.

    Science.gov (United States)

    2014-12-01

    This report describes an investigation to quantify the behavior of precast, prestressed concrete double-tee bridge : girders made with lightweight concrete. As part of the investigation, three bridge girders were salvaged from a : decommissioned brid...

  20. Microfluidic Wheatstone bridge for rapid sample analysis.

    Science.gov (United States)

    Tanyeri, Melikhan; Ranka, Mikhil; Sittipolkul, Natawan; Schroeder, Charles M

    2011-12-21

    We developed a microfluidic analogue of the classic Wheatstone bridge circuit for automated, real-time sampling of solutions in a flow-through device format. We demonstrate precise control of flow rate and flow direction in the "bridge" microchannel using an on-chip membrane valve, which functions as an integrated "variable resistor". We implement an automated feedback control mechanism in order to dynamically adjust valve opening, thereby manipulating the pressure drop across the bridge and precisely controlling fluid flow in the bridge channel. At a critical valve opening, the flow in the bridge channel can be completely stopped by balancing the flow resistances in the Wheatstone bridge device, which facilitates rapid, on-demand fluid sampling in the bridge channel. In this article, we present the underlying mechanism for device operation and report key design parameters that determine device performance. Overall, the microfluidic Wheatstone bridge represents a new and versatile method for on-chip flow control and sample manipulation.

  1. Characterization of bridge foundations workshop report.

    Science.gov (United States)

    2013-11-01

    "In 2013, the Federal Highway Administration proposed a new research program for the characterization of bridge foundations. To narrow the focus and develop a research roadmap for the program, a workshop on Characterization of Bridge Foundations...

  2. Phase and widening construction of steel bridges : [summary].

    Science.gov (United States)

    2014-03-01

    Maintaining traffic flow for bridge widening and replacement projects often requires bridges to be constructed in phases so that traffic can travel on one : portion of the bridge while another portion is being : constructed. The bridge portions are t...

  3. A comprehensive study on removal and recovery of copper(II) from aqueous solutions by NaOH-pretreated Marrubium globosum ssp. globosum leaves powder: potential for utilizing the copper(II) condensed desorption solutions in agricultural applications.

    Science.gov (United States)

    Kililç, Mehmet; Yazilcil, Hüseyin; Solak, Murat

    2009-04-01

    This paper reports on removal and recovery of copper(II) ions from aqueous solutions under batch experimental conditions using NaOH-pretreated powdered leaves of Marrubium globosum ssp. globosum plant. Experimental results showed that pH was optimized at the value of 5.5 by 16.23 mg/g. The increasing metal concentration and temperature caused an increase in biosorption capacity and the process reached its equilibrium in 60 min. The result obtained from kinetic and isotherm studies resulted in better agreement with pseudo second-order kinetic and Langmuir isotherm models. Thermodynamic parameters revealed that the Cu(2+) biosorption by the biomass was an endothermic process. The higher desorption efficiency above 90% was obtained in case of using Na(2)EDTA, K(4)O(7)P(2), HNO(3), HCl, and (NH(4))(2)C(2)O(4) x H(2)O solutions, individually. Reusability of the biomass was examined under consecutive biosorption-desorption cycles repeating five times. The most interesting finding of the study is the idea of utilizing the EDTA-Cu complex, which can be qualified as a residual from desorption processes, as a liquid chemical fertilizer in agricultural applications.

  4. Bridge Design to Eurocodes – Worked examples

    OpenAIRE

    BOUASSIDA Yorsa; BOUCHON Emmanuel; CRESPO Pilar; CROCE Pietro; DAVAINE Laurence; DENTON Steve; FELDMANN Markus; FRANK Roger; HANSWILLE Gerhard; HENSEN Wolfang; KOLIAS Basil; MALAKATAS Nikolaos; MANCINI Giuseppe; ORTEGA CORNEJO Miguel; SEDLACEK Gerhard

    2011-01-01

    This document is a Technical Report with worked examples for a bridge structure designed following the Eurocodes. It summarizes important points of the Eurocodes for the design of concrete, steel and composite road bridges, including foundations and seismic design, utilizing a common bridge project as a basis. The geometry and materials of the example bridge as well as the main assumptions and the detailed structural calculations are presented in the first chapter of the report. Each of ...

  5. Field performance of timber bridges. 5, Little Salmon Creek stress-laminated deck bridge

    Science.gov (United States)

    M. A. Ritter; J. A. Kainz; G. J. Porter

    The Little Salmon Creek bridge was constructed in November 1988 on the Allegheny National Forest in Pennsylvania. The bridge is a simple span, single-lane, stress-laminated deck superstructure that is approximately 26-ft long and 16-ft wide. The bridge is unique in that it is the first known stress-laminated timber bridge to be constructed of hardwood lumber. The...

  6. Field performance of timber bridges. 6, Hoffman Run stress-laminated deck bridge

    Science.gov (United States)

    M. A. Ritter; P. D. Hilbrich Lee; G. J. Porter

    The Hoffman Run bridge, located just outside Dahoga, Pennsylvania, was constructed in October 1990. The bridge is a simple-span, single-lane, stress-laminated deck superstructure that is approximately 26 ft long and 16 ft wide. It is the second stress-laminated timber bridge to be constructed of hardwood lumber in Pennsylvania. The performance of the bridge was...

  7. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Bridge-to-bridge communication procedure. 80.331 Section 80.331 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL..., Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a) Vessels...

  8. Bridge Programs in Illinois: Results of the 2010 Illinois Bridge Status Survey

    Science.gov (United States)

    Taylor, J. L.; Harmon, T.

    2010-01-01

    This report provides a summary of major results of the Illinois Bridge Status Survey, administered online between April and June 2010. The purpose of the survey was to understand the extent to which bridge programs are being implemented in Illinois, as well as to build an online directory of bridge programs. Bridge programs are an emerging…

  9. 75 FR 62181 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Science.gov (United States)

    2010-10-07

    ... describing construction materials used in new Federal-aid bridge construction and bridge rehabilitation...), the FHWA has produced a report that summarizes the types of construction materials used in new bridge....fhwa.dot.gov/bridge/brdgtabs.cfm , consists of the following tables: Construction Materials for New and...

  10. 76 FR 55160 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Science.gov (United States)

    2011-09-06

    ... describing construction materials used in new Federal-aid bridge construction and bridge rehabilitation... FHWA has produced a report that summarizes the types of construction materials used in new bridge....fhwa.dot.gov/bridge/brdgtabs.cfm , consists of the following tables: Construction Materials for New and...

  11. Project LOCAL - Bridging The Gap

    Science.gov (United States)

    Haven, Robert N.

    1975-01-01

    Project LOCAL, a not-for-profit regional consortium, offers a broad spectrum of in-service training courses tailored to meet the needs of educators in various disciplines and levels of experience. The purpose of these offerings is to bridge the communication gap between innovative centers in computer-oriented education and staff members in Boston…

  12. The Wien Bridge Oscillator Family

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2006-01-01

    A tutorial in which the Wien bridge family of oscillators is defined and investigated. Oscillators which do not fit into the Barkhausen criterion topology may be designed. A design procedure based on initial complex pole quality factor is reported. The dynamic transfer characteristic...

  13. Talent Management: Bridging the Gap

    Science.gov (United States)

    2015-06-12

    culling continues at each grade. By this process, the model proposes to raise the talent distribution and level. Professional sports use this method... TALENT MANAGEMENT: BRIDGING THE GAP A thesis presented to the Faculty of the U.S. Army Command and General Staff College in...

  14. Evaluation of Summer Bridge Programs

    Science.gov (United States)

    Garcia, Lisa D.; Paz, Chiara C.

    2009-01-01

    Many colleges and universities in the United States offer summer programs for their incoming students. While programs are structured and administered in a variety of ways and target various student populations, the most common type of summer bridge program aims to serve historically underrepresented students and students of low socioeconomic…

  15. Optimizing Tailored Bus Bridging Paths

    NARCIS (Netherlands)

    Gu, Wei; Yu, Jie; Ji, Yuxiong; van der Gun, J.P.T.; Pel, A.J.; Zhang, H. Michael; van Arem, B.

    2017-01-01

    Metro disruptions due to unexpected events reduce transit system reliability, resulting in significant productivity loss and long passenger delays. Bus bridging strategy is often used to connect stations affected by metro disruptions such that passengers could continue their journey. The literature

  16. Accelerated bridge paint test program.

    Science.gov (United States)

    2011-07-06

    The accelerated bridge paint (AB-Paint) program evaluated a new Sherwin-Williams two-coat, : fast-curing paint system. The system is comprised of an organic zinc-rich primer (SW Corothane I : Galvapac One-Pack Zinc-Rich Primer B65 G11) and a polyurea...

  17. Detection of Ultrafine Anaphase Bridges

    DEFF Research Database (Denmark)

    Bizard, Anna H; Nielsen, Christian F; Hickson, Ian D

    2018-01-01

    Ultrafine anaphase bridges (UFBs) are thin DNA threads linking the separating sister chromatids in the anaphase of mitosis. UFBs are thought to form when topological DNA entanglements between two chromatids are not resolved prior to anaphase onset. In contrast to other markers of defective...

  18. Intercellular bridges in vertebrate gastrulation.

    Directory of Open Access Journals (Sweden)

    Luca Caneparo

    Full Text Available The developing zebrafish embryo has been the subject of many studies of regional patterning, stereotypical cell movements and changes in cell shape. To better study the morphological features of cells during gastrulation, we generated mosaic embryos expressing membrane attached Dendra2 to highlight cellular boundaries. We find that intercellular bridges join a significant fraction of epiblast cells in the zebrafish embryo, reaching several cell diameters in length and spanning across different regions of the developing embryos. These intercellular bridges are distinct from the cellular protrusions previously reported as extending from hypoblast cells (1-2 cellular diameters in length or epiblast cells (which were shorter. Most of the intercellular bridges were formed at pre-gastrula stages by the daughters of a dividing cell maintaining a membrane tether as they move apart after mitosis. These intercellular bridges persist during gastrulation and can mediate the transfer of proteins between distant cells. These findings reveal a surprising feature of the cellular landscape in zebrafish embryos and open new possibilities for cell-cell communication during gastrulation, with implications for modeling, cellular mechanics, and morphogenetic signaling.

  19. Nonlinear models of suspension bridges

    Czech Academy of Sciences Publication Activity Database

    Malík, Josef

    2006-01-01

    Roč. 321, č. 2 (2006), s. 828-850 ISSN 0022-247X Institutional research plan: CEZ:AV0Z30860518 Keywords : suspension bridges * principle of minimum energy Subject RIV: BA - General Mathematics Impact factor: 0.758, year: 2006

  20. Exodermic bridge deck performance evaluation.

    Science.gov (United States)

    2010-07-01

    In 1998, the Wisconsin DOT completed a two"leaf bascule bridge in Green Bay with an exodermic deck system. The exodermic deck consisted of 4.5"in thick cast"in"place reinforced concrete supported by a 5.19"in tall unfilled steel grid. The concrete an...

  1. 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

    Science.gov (United States)

    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.

  2. Building Bridges One Line at a Time

    Science.gov (United States)

    Grigsby, Cathy Murray

    2012-01-01

    In this article, first-grade students were taught the different kinds of lines that were part of the construction of various bridges--the curved lines of the arches of stone bridges, straight lines connecting the cables of a suspension bridge, vertical lines, horizontal lines, and so on. They gained practice in drawing structures and in fine brush…

  3. Hydrodynamic forces on inundated bridge decks

    Science.gov (United States)

    2009-05-01

    The hydrodynamic forces experienced by an inundated bridge deck have great importance in the design of bridges. Specifically, the drag force, lift force, and the moment acting on the bridge deck under various levels of inundation and a range of flow ...

  4. Hydraulic forces on submerged bridge decks.

    Science.gov (United States)

    2008-09-01

    Bridge decks can be subjected to large horizontal forces when overtopping occurs. These forces may result in the displacement of bridge decks from the bents. This paper reports on the results of a laboratory study of horizontal forces on bridge decks...

  5. BRIDGES for Young Adolescents in North Dakota.

    Science.gov (United States)

    Harris, Mary McDonnell

    The BRIDGES Project was initiated to explore ways for North Dakota to provide young people with stronger bridges from childhood to adulthood. This report summarizes recommendations of the 1990-91 Governor's Task Force on Early Adolescence. The recommendations concern practical actions for the building of bridges by the following groups: (1)…

  6. Spread prestressed concrete slab beam bridges.

    Science.gov (United States)

    2015-04-01

    TxDOT uses prestressed slab beam bridges for short-span bridges ranging from approximately 3050 ft in : length. These bridges have precast, pretensioned slab beams placed immediately adjacent to one another : with a cast-in-place slab made composi...

  7. A multi-functional coordination polymer coexisting spontaneous chirality resolution and weak ferromagnetism

    International Nuclear Information System (INIS)

    Li, Xiu-Hua; Zhang, Qi; Hu, Ping

    2014-01-01

    A multifunctional homochiral coordination polymer, [Co(H 2 O)(BDC)(4,4′-BPY)]∙3H 2 O (1) (H 2 BDC=1,2-benzenedicarboxylate and 4,4′-BPY=4,4′-bipyridine), has been successfully isolated from Co(II) ions and mixed ligands (1,2-benzenedicarboxylate and 4,4′-bipyridine). Complex 1, which exhibits spontaneous chirality resolution and weak ferromagnetism, is built by chiral helices interconnected via end-to-end 4,4′-BPY bridges into a two-dimensional (2D) layer structure. - Graphical abstract: A 2D cobalt coordination polymer compound showing spontaneous chirality resolution and weak ferromagnetism. - Highlights: • A new 2D cobalt mix-ligand coordination polymer complex has been synthesized. • The cobalt coordination polymer complex shows spontaneous chirality resolution in solid state. • The cobalt coordination polymer complex displays dominant and weak intrachain ferromagnetic interactions

  8. 33 CFR 115.70 - Advance approval of bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Advance approval of bridges. 115... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.70 Advance approval of bridges. (a) The General Bridge Act of 1946 requires the approval of the location and plans of bridges prior...

  9. Selective adsorption of silver(I) ions over copper(II) ions on a sulfoethyl derivative of chitosan.

    Science.gov (United States)

    Petrova, Yulia S; Pestov, Alexandr V; Usoltseva, Maria K; Neudachina, Ludmila K

    2015-12-15

    This study presents a simple and effective method of preparation of N-(2-sulfoethyl) chitosan (NSE-chitosan) that allows obtaining a product with a degree of modification up to 1.0. The chemical structure of the obtained polymers was confirmed by FT-IR and 1H NMR spectroscopies. Cross-linking of N-(2-sulfoethyl) chitosans by glutaraldehyde allows preparation of sorbents for removal and concentration of metal ions. Capacity of sorbents towards hydroxide ions was determined depending on the degree of sulfoethylation under static and dynamic conditions. Dissociation constants of functional amino groups of the analyzed sorbents were determined by potentiometric titration. It was shown that basicity of the amino groups decreased (wherein pKa decreased from 6.53 to 5.67) with increase in degree of sulfoethylation. It explains the significant influence of sulfo groups on selectivity of sorption of metal ions on N-(2-sulfoethyl) chitosan-based sorbents. The investigated substances selectively remove copper(II) and silver(I) ions from solutions of complex composition. Wherein the selectivity coefficient KAg/Cu increased to 20 (pH 6.5, ammonium acetate buffer solution) with increase in degree of sulfoethylation of the sorbent up to 1.0. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Specificity of the ion exchange/atomic absorption method for free copper(II) species determination in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Sweileh, J.A.; Lucyk, D.; Kratochvil, B.; Cantwell, F.F.

    1987-02-15

    Concentrations of the free copper(II) species (Cu/sup 2 +/) measured by the ion exchange/atomic absorption (IEX) method in the presence of various concentrations of the ligands citrate, glycinate, phthalate, salicylate, chloride, and fulvate are compared to concentrations measured with a cupric ion selective electrode (ISE) and/or to concentrations calculated from known metal-ligand formation constants. The IEX method is considerably more sensitive for Cu/sup 2 +/ than the ISE method but is subject to interference from cationic and neutral copper complexes as well as from filterable colloids copper-hydroxo species at higher pH values. Accurate values of Cu/sup 2 +/ concentration are obtained by both methods in the presence of anionic copper-ligand complexes. Since fulvate, which is the principal ligand present in natural freshwaters, forms anionic copper complexes, the IEX method possesses adequate selectivity for measuring Cu/sup 2 +/ at trace levels in such waters. The complexing capacity of an acidic lake water with a very low dissolved organic carbon content was measured as 3.0 x 10/sup -8/ M by monitoring Cu/sup 2 +/ concentration by the IEX method during titration with copper nitrate.

  11. Geochemical characterization of organic ligands for copper(II) in different molecular size fractions in Lake Biwa, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fengchang Wu [Chinese Academy of Science, Guiyang (China). Inst. of Geochemistry; Eiichiro Tanoue [Nagoya University, Nagoya (Japan). Graduate School of Environmental Studies

    2001-07-01

    In a previous study, we reported the isolation of organic ligands for copper(II), their mass distribution and fluorescence properties in different molecular size fractions of the waters in Lake Biwa by immobilized metal ion affinity chromatography (IMAC) and three dimensional excitation/emission matrix spectroscopy (3DEEM) (Wu, F., Tanoue, E., 2001. Molecular mass distributions and fluorescence characteristics of organic ligands for copper (II) in Lake Biwa, Japan. Org. Geochem. 32, 11-20). In this continuous study, geochemical properties of these isolated ligand fractions were characterized in terms of binding complexation, functional groups and amino acid composition. The results show that two ligand classes (L{sub 1} and L{sub 2}) were recovered from all molecular size ligand fractions, L{sub 1} with a conditional stability constant (LogK'{sub CuL}) of 7.82-9.56, and L{sub 2} with a LogK'{sub CuL} value of 7.05-8.78. The stronger ligands with protein-like fluorescence were of recent biogenic origin, and the weaker ligands with humic-like fluorescence were related to refractory humic substances. Functional groups responsible for the fluorescence in the ligand fractions are also discussed. The results presented here would have significance for understanding the nature of natural organic ligands and their biogeochemical role in aquatic systems. (author)

  12. Copper(II), cobalt(II) and nickel(II) complexes of juglone: synthesis, structure, DNA interaction and enhanced cytotoxicity.

    Science.gov (United States)

    Tabrizi, Leila; Fooladivanda, Mahrokh; Chiniforoshan, Hossein

    2016-12-01

    Three novel copper(II), cobalt(II), and nickel(II) complexes of juglone (Jug) containing 1,10-phenanthroline (phen) ligand, [M(Jug) 2 (phen)] (M = Cu(II), 1, Co(II), 2, and Ni(II), 3), have been synthesized and characterized using, elemental analysis and spectroscopic studies. Their interactions with calf thymus DNA were investigated using viscosity measurements, UV-visible and fluorescence spectrophotometric methods. The catalytic activities on DNA cleavage of the complexes 1-3 were studied, which copper complex 1 showed better catalyst activity in the DNA cleavage process than complexes 2 and 3. The in vitro cytotoxic potential of the complexes 1-3 against human cervical carcinoma (HeLa), human liver hepatocellular carcinoma (HepG-2), and human colorectal adenocarcinoma (HT-29) cells indicated their promising antitumor activity with quite low IC 50 values in the range of 0.09-1.89 μM, which are 75 times lower than those of cisplatin.

  13. Disperse dyeing and antibacterial properties of nylon and wool fibers using two novel nanosized copper(II complexes bearing phosphoramide

    Directory of Open Access Journals (Sweden)

    Zahra Shariatinia

    2017-11-01

    Full Text Available Disperse dyeing of nylon and wool fibers with two new nanosized copper(II complexes including phosphoric triamide ligands with formula Cu(NO32L2 (1 and Cu(CH3COO2L2 (2 where L = 4-NO2C6H4NHP(O(NC4H8O2 (A was performed successfully. Both complexes 1 and 2 produced yellow and green colored nylon and wool fabrics, respectively. The complexes were synthesized by ultrasonic method and characterized by 1H, 13C, 31P NMR, Fourier-transform infrared, photoluminescence, ultraviolet–visible spectroscopy, X-ray diffraction, field-emission microscopy and elemental analysis. The FE-SEM micrographs revealed that the nanoparticles of these compounds are spherical in morphology and ∼17–20 nm in size. Very appropriate washfastness while poor lightfastness results were deduced for the dyed fibers. The in vitro antibacterial activities of the dyes 1, 2 and dyed wool/nylon fibers against the Gram-positive Bacillus subtilis bacterium illustrated increasing in the antibacterial effect by increasing the dye concentration from 0.1% to 0.5% o.w.f. on both wool and nylon dyed fibers.

  14. Trapping of muscle relaxant methocarbamol degradation product by complexation with copper(II) ion: spectroscopic and quantum chemical studies.

    Science.gov (United States)

    Mansour, Ahmed M; Shehab, Ola R

    2014-07-15

    Structural properties of methocarbamol (Mcm) were extensively studied both experimentally and theoretically using FT IR, (1)H NMR, UV-Vis., geometry optimization, Mulliken charge, and molecular electrostatic potential. Stability arises from hyper-conjugative interactions, charge delocalization and H-bonding was analyzed using natural bond orbital (NBO) analysis. Mcm was decomposed in ethanol/water mixture at 80°C to guaifenesin [(RS)-3-(2-methoxyphenoxy)propane-1,2-diol] and carbamate ion [NH2COO(-)], where the degradation mechanism was explained by trapping the carbamate ion via the complexation with copper(II) ion. The structure of the isolated complex ([Cu(NH2COO)2(H2O)]⋅4H2O) was elucidated by spectral, thermal, and magnetic tools. Electronic spectra were discussed by TD-DFT and the descriptions of frontier molecular orbitals and the relocations of the electron density were determined. Calculated g-tensor values showed best agreement with experimental values from EPR when carried out using both the B3LYP and B3PW91 functional. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Selective determination of trace copper(II) by cathodic adsorptive stripping voltammetry with a naphthol-derivative Schiff's base.

    Science.gov (United States)

    Shamsipur, Mojtaba; Saeidi, Mahboubeh; Sharghi, Hashem; Naeimi, Hossein

    2003-01-01

    A selective and sensitive stripping voltammetric method for the determination of trace amounts of copper(II) with a recently synthesized naphthol-derivative Schiff's base (2,2'-[1,2-ethanediylbis(nitriloethylidyne)]bis(1-naphthalene)) is presented. The method is based on adsorptive accumulation of the resulting copper-Schiff's base complex on a hanging mercury drop electrode, followed by the stripping voltammetric measurement at the reduction current of adsorbed complex at -0.15 V (vs. Ag/AgCl). The optimal conditions for the stripping analysis of copper include pH 5.5 to 6.5, 8 microM Schiff's base and an accumulation potential of -0.05 V (vs. Ag/AgCI). The peak current is linearly proportional to the copper concentration over a range 2.3-50.8 ng ml(-1) with a limit of detection of 1.9 ng ml(-1). The accumulation time and RSD are 90 s and (3.2-3.5)%, respectively. The method was applied to the determination of copper in some analytical grade salts, tap water, human serum and sheep's liver.

  16. Field performance of timber bridges. 4, Graves Crossing stress-laminated deck bridge

    Science.gov (United States)

    J. P. Wacker; M. A. Ritter

    The Graves Crossing bridge was constructed October 1991 in Antrim County, Michigan, as part of the demonstration timber bridge program sponsored by the USDA Forest Service. The bridge is a two-span continuous, stress-laminated deck superstructure and it is 36-ft long and 26-ft wide. The bridge is one of the first stress-laminated deck bridges to be built of sawn lumber...

  17. Coordinating Group report

    International Nuclear Information System (INIS)

    1994-01-01

    In December 1992, western governors and four federal agencies established a Federal Advisory Committee to Develop On-site Innovative Technologies for Environmental Restoration and Waste Management (the DOIT Committee). The purpose of the Committee is to advise the federal government on ways to improve waste cleanup technology development and the cleanup of federal sites in the West. The Committee directed in January 1993 that information be collected from a wide range of potential stakeholders and that innovative technology candidate projects be identified, organized, set in motion, and evaluated to test new partnerships, regulatory approaches, and technologies which will lead to improve site cleanup. Five working groups were organized, one to develop broad project selection and evaluation criteria and four to focus on specific contaminant problems. A Coordinating Group comprised of working group spokesmen and federal and state representatives, was set up to plan and organize the routine functioning of these working groups. The working groups were charged with defining particular contaminant problems; identifying shortcomings in technology development, stakeholder involvement, regulatory review, and commercialization which impede the resolution of these problems; and identifying candidate sites or technologies which could serve as regional innovative demonstration projects to test new approaches to overcome the shortcomings. This report from the Coordinating Group to the DOIT Committee highlights the key findings and opportunities uncovered by these fact-finding working groups. It provides a basis from which recommendations from the DOIT Committee to the federal government can be made. It also includes observations from two public roundtables, one on commercialization and another on regulatory and institutional barriers impeding technology development and cleanup

  18. Numerical Hybrid Simulation Modeling Verification for a Curved 3-Pier Bridge (Investigation of Combined Actions on Reinforced Concrete Bridge Piers (CABER Project

    Directory of Open Access Journals (Sweden)

    Adel Abdelnaby

    2013-06-01

    Full Text Available Reinforced concrete bridge piers are subjected to complex loading conditions under earthquake ground motions. Bridge geometric irregularities and asymmetries result in combined actions imposed on the piers as a combination of displacements and rotations in all six degrees of freedom at the pier-deck juncture. Existing analytical tools have proven their inadequacy in representing the actual behavior of piers under these combined actions, particularly in their inelastic range. The objective of this investigation is to develop a fundamental understanding of the effects of these combined actions on the performance of RC piers and the resulting system response. This paper describes a part of the CABER project that verifies the numerical hybrid simulation of the curved bridge. In this part two models were introduced, a whole model and a sub-structured hybrid model. The whole model was established using the Zeus-NL analysis platform, which is capable of performing inelastic nonlinear response history analysis of the whole curved bridge. The hybrid model was divided into three modules which comprised the deck, left and right piers, and the middle pier of the bridge. The three modules were modeled by Zeus-NL as a static analysis module interface. The simulation coordinator (SimCor software was utilized to communicate between these modules using a Pseudo-Dynamic time integration scheme. Results obtained from both models were compared and conclusions were drawn.

  19. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Enevoldsen, I.

    Vibration of a bridge structure due to the passage of vehicles is an important consideration in the design of bridges. Further, a common problem in bridge engineering practice in these years is the upgrading of minor highway bridges (=5-20 m) to carry heavier loads partly due to a tendency...... of heavier trucks moving at larger speeds, and partly because the authorities want to permit transportation of special heavy goods at a larger part of the road net. These needs will in many cases cause the strengthening of the bridges becomes necessary. In order to keep the expenses of such strengthening....... Each axle is suspended on two elastic supports modelling the wheels....

  20. Effects of Electrolyte on Floating Water Bridge

    OpenAIRE

    Hideo Nishiumi; Fumitaka Honda

    2009-01-01

    Fuchs found phenomena that when high voltage is applied to deionized water filled in two contacted beakers, a floating water bridge forms spontaneously. In this paper, we examined flow direction of water bridge and what effects the addition of electrolytes such as NaCl, NaOH, and N H 4 C l to the floating water bridge would give. We found that ionization degree reduced the length of water bridge though insoluble electrolyte A l 2 O 3 had no effect on the length of water bridge.