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Dinuclear Copper (dinuclear + copper)

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Chemistry100%

Selected Abstracts

Syntheses, Structures and Magnetic Properties of Dinuclear Copper(II),Lanthanide(III) Complexes Bridged by 2-Hydroxymethyl-1-methylimidazole

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 5 2008
Wei-Xiong Zhang
Abstract Three discrete dinuclear copper(II),lanthanide(III) complexes, namely, [CuLn(mmi)2(NO3)3(H2O)2] [Ln = La (1), Sm (2)] and [CuGd(mmi)2(NO3)2(H2O)3][NO3] (3) (Hmmi = 2-hydroxymethyl-1-methylimidazole) were synthesized and structurally characterized by X-ray diffraction analysis. In these complexes, dinuclear cores of CuII and LnIII are consolidated by a pair of ,-1,1- O bridges from mmi at a distance of 3.36,3.46 Å. The temperature dependence of the magnetic susceptibility and the field dependence of the magnetization indicate that 1, 2 and 3 exhibit paramagnetic, antiferromagnetic and ferromagnetic behaviours, respectively. The value of the JCu,Gd coupling constant of 3 [8.7(1) cm,1] is fairly large, which is probably related to the small dihedral angles, , (5.0°), between the two planes of O,Cu,O and O,Gd,O in the CuO2Gd core.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

ChemInform Abstract: Dinuclear Copper(I) Complexes as Precatalysts in Ullmann and Goldberg Coupling Reactions.

CHEMINFORM, Issue 49 2009
Estela Haldon
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Homo- and heteropolynuclear copper(II) complexes containing a new diimine,dioxime ligand and 1,10-phenanthroline: synthesis, characterization, solvent-extraction studies, catalase-like functions and DNA cleavage abilities

APPLIED ORGANOMETALLIC CHEMISTRY, Issue 12 2009
Bülent Dede
Abstract A series of homo-, heterodinuclear and homotrinuclear copper(II) complexes containing a new Schiff base ligand and 1,10-phenanthroline were synthesized. Based on results of elemental analyses, FTIR, 1H- and 13C-NMR spectra, conductivity measurements and magnetic susceptibility measurements, the complexes had general compositions {[Cu(L)(H2O)M(phen)2](ClO4)2 [M = Cu(II), Mn(II), Co(II)]} and {[Cu3(L)2(H2O)2](ClO4)2}. The metal:L:phen ratio is 2:1:2 for the dinuclear copper(II) complexes and the metal:L ratio was 3:2 for the trinuclear copper(II) complex. The liquid,liquid extraction of various transition metal cations [Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II), Hg(II)] from the aqueous phase to the organic phase was carried out using the diimine,dioxime ligand. It was concluded that the ligand can effectively be used in solvent extraction of copper(II) from the aqueous phase to the organic phase. Furthermore, catalytic activitiy of the complexes for the disproportionation of hydrogen peroxide was also investigated in the presence of imidazole. Dinuclear copper(II),manganese(II) complex has some similarity to manganese catalase in structure and activity. The interaction between these complexes and DNA has also been investigated by agarose gel electrophoresis; we found that the homo- and heterodinuclear copper complexes can cleave supercoiled pBR322 DNA to nicked and linear forms in the presence of H2O2. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Syntheses, Structures and Magnetic Properties of Dinuclear Copper(II),Lanthanide(III) Complexes Bridged by 2-Hydroxymethyl-1-methylimidazole

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 5 2008
Wei-Xiong Zhang
Abstract Three discrete dinuclear copper(II),lanthanide(III) complexes, namely, [CuLn(mmi)2(NO3)3(H2O)2] [Ln = La (1), Sm (2)] and [CuGd(mmi)2(NO3)2(H2O)3][NO3] (3) (Hmmi = 2-hydroxymethyl-1-methylimidazole) were synthesized and structurally characterized by X-ray diffraction analysis. In these complexes, dinuclear cores of CuII and LnIII are consolidated by a pair of ,-1,1- O bridges from mmi at a distance of 3.36,3.46 Å. The temperature dependence of the magnetic susceptibility and the field dependence of the magnetization indicate that 1, 2 and 3 exhibit paramagnetic, antiferromagnetic and ferromagnetic behaviours, respectively. The value of the JCu,Gd coupling constant of 3 [8.7(1) cm,1] is fairly large, which is probably related to the small dihedral angles, , (5.0°), between the two planes of O,Cu,O and O,Gd,O in the CuO2Gd core.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Syntheses, Structures, and Magnetic Properties of Copper(II) Complexes with 1,3-[Bis(2-pyridylmethyl)amino]benzene (1,3-tpbd) as Ligand

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2004
Simon P. Foxon
Abstract The dinuclear copper(II) complexes {[Cu2(1,3-tpbd)(H2O)(OAc)2](ClO4)2}0.23{[Cu2(1,3-tpbd)(H2O)2(OAc)](ClO4)3}0.77·0.77H2O (1), [Cu2(1,3-tpbd)(H2O)2(OAc)2](ClO4)2·2H2O (2), and the tetranuclear copper(II) complex [Cu4(1,3-tpbd)2(H2O)2(SO4)4]·8H2O (3) {1,3-tpbd = 1,3-bis[bis(2-pyridylmethyl)amino]benzene} were synthesised and structurally characterised by X-ray diffraction. Variable-temperature (2.0,290 K) magnetic susceptibility measurements on these complexes as well as on the dinuclear copper(II) complex [Cu2(1,3-tpbd)(H2O)2(ClO4)3]ClO4 (4) (whose structure was published earlier) were performed. In contrast to 2 and 3, significant ferromagnetic coupling with J = +9.3 cm,1 was observed for 4 (the Hamiltonian being defined as H, = ,J S,1·S,2). Density functional theory (DFT) calculations were used successfully for the interpretation of the ferromagnetic coupling observed in 4. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

The dinuclear copper(II) complexes di-,-chlorido-bis{[N,N,-bis(4-chlorobenzyl)propane-1,2-diamine]chloridocopper(II)} and di-,-chlorido-bis{[N,N,-bis(3,4-methylenedioxybenzyl)propane-1,2-diamine]chloridocopper(II)}

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2007
Shu-Ping Yang
The two title dinuclear copper(II) complexes, [Cu2Cl4(C17H20Cl2N2)2], (I), and [Cu2Cl4(C19H22N2O4)2], (II), have similar coordination environments. In each complex, the asymmetric unit consists of one half-molecule and the two copper centres are bridged by a pair of Cl atoms, resulting in complexes with centrosymmetric structures containing Cu(,-Cl)2Cu parallelogram cores; the Cu...Cu separations and Cu,Cl,Cu angles are 3.4285,(8),Å and 83.36,(3)°, respectively, for (I), and 3.565,(2),Å and 84.39,(7)° for (II). Each Cu atom is five-coordinated and the coordination geometry around the Cu atom is best described as a distorted square-pyramid with a , value of 0.155,(3) for (I) and 0.092,(7) for (II). The apical Cu,Cl bond length is 2.852,(1),Å for (I) and 2.971,(2),Å for (II). The basal Cu,Cl and Cu,N average bonds lengths are 2.2673,(9) and 2.030,(2),Å, respectively, for (I), and 2.280,(2) and 2.038,(6),Å for (II). The molecules of (I) are linked by one C,H...Cl hydrogen bond into a complex [10] sheet. The molecules of (II) are linked by one C,H...Cl and one N,H...O hydrogen bond into a complex [100] sheet. [source]

Homo- and heteropolynuclear copper(II) complexes containing a new diimine,dioxime ligand and 1,10-phenanthroline: synthesis, characterization, solvent-extraction studies, catalase-like functions and DNA cleavage abilities

APPLIED ORGANOMETALLIC CHEMISTRY, Issue 12 2009
Bülent Dede
Abstract A series of homo-, heterodinuclear and homotrinuclear copper(II) complexes containing a new Schiff base ligand and 1,10-phenanthroline were synthesized. Based on results of elemental analyses, FTIR, 1H- and 13C-NMR spectra, conductivity measurements and magnetic susceptibility measurements, the complexes had general compositions {[Cu(L)(H2O)M(phen)2](ClO4)2 [M = Cu(II), Mn(II), Co(II)]} and {[Cu3(L)2(H2O)2](ClO4)2}. The metal:L:phen ratio is 2:1:2 for the dinuclear copper(II) complexes and the metal:L ratio was 3:2 for the trinuclear copper(II) complex. The liquid,liquid extraction of various transition metal cations [Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II), Hg(II)] from the aqueous phase to the organic phase was carried out using the diimine,dioxime ligand. It was concluded that the ligand can effectively be used in solvent extraction of copper(II) from the aqueous phase to the organic phase. Furthermore, catalytic activitiy of the complexes for the disproportionation of hydrogen peroxide was also investigated in the presence of imidazole. Dinuclear copper(II),manganese(II) complex has some similarity to manganese catalase in structure and activity. The interaction between these complexes and DNA has also been investigated by agarose gel electrophoresis; we found that the homo- and heterodinuclear copper complexes can cleave supercoiled pBR322 DNA to nicked and linear forms in the presence of H2O2. Copyright © 2009 John Wiley & Sons, Ltd. [source]

The copper(II) complexes di-,-bromo-bis{[2,6-bis­(pyrazol-1-yl)­pyridine]­per­chlorato­copper(II)} and [2,6-bis(pyra­zol-1-yl)­pyridine]­di­bromo­copper(II)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2004
Surajit Chakrabarty
The two title compounds, di-,-bromo-bis{[2,6-bis­(pyrazol-1-yl-,N2)­pyridine-,N](perchlorato-,O)copper(II)}, [Cu2Br2(ClO4)2(C11H9N5)2], (I), and [2,6-bis­(pyrazol-1-yl)­pyridine]­dibromo­copper(II), [CuBr2(C11H9N5)], (II), were synthesized by only slight modifications of the same reaction; compound (II) was formed by adding one molar equivalent of pyrazole (C3N2H4) to the reaction mixture of (I). Compound (I) is a bromo-bridged dinuclear copper(II) compound stabilized by weak interactions with the perchlorate anions (ClO4,), while (II) is a related mononuclear species, which has a distorted square-pyramidal geometry. [source]

Enantiospecific Syntheses of Copper Cubanes, Double-Stranded Copper/Palladium Helicates, and a (Dilithium),Dinickel Coronate from Enantiomerically Pure Bis-1,3-diketones,Solid-State Self-Organization Towards Wirelike Copper/Palladium Strands,

CHEMISTRY - A EUROPEAN JOURNAL, Issue 5 2008

Abstract Enantiomerically pure, vicinal diols 1 afforded in a two-step synthesis (etherification and subsequent Claisen condensation) chiral bis-1,3-diketones H2L(S,S) (3,a,c) with different substitution patterns. Reaction of these C2 -symmetric ligands with various transition-metal acetates in the presence of alkali ions generated distinct polynuclear aggregates 4,8 by diastereoselective self-assembly. Starting from copper(II) acetate monohydrate and depending on the ratio of transition-metal ion to alkali ion to ligand, chiral tetranuclear copper(II) cubanes (C,C,C,C)-[Cu4(L(S,S))2(OMe)4] (4,a,c) or dinuclear copper(II) helicates (P)-[Cu2(L(S,S))2] (5) could be synthesized with square-pyramidal and square-planar coordination geometry at the metal center. In analogy to the last case, with palladium(II) acetate double-stranded helical systems (P)-[Pd2(L(S,S))2] (6,7) were accessible exhibiting a linear self-organization of ligand-isolated palladium filaments in the solid state with short inter- and intramolecular metal distances. Finally, the introduction of hexacoordinate nickel(II) in combination with lithium hydroxide monohydrate and chiral ligand H2L(S,S) (3,a) allowed the isolation of enantiomerically pure dinuclear nickel(II) coronate [(Li,MeOH)2,{(,,,)-Ni2(L(S,S))2(OMe)2}] (8) with two lithium ions in the voids, defined by the oxygen donors in the ligand backbone. The high diastereoselectivity, induced by the chiral ligands, during the self-assembly process in the systems 4,8 could be exemplarily proven by circular dichroism spectroscopy for the synthesized enantiomers of the chiral copper(II) cubane 4,a and palladium(II) helicate 6. [source]

CO2 Fixation and Transformation by a Dinuclear Copper Cryptate under Acidic Conditions

CHEMISTRY - AN ASIAN JOURNAL, Issue 6 2007
Jia-Mei Chen
Abstract CO2 fixation and transformation by metal complexes continuously receive attention from the viewpoint of carbon resources and environmental concerns. We found that the dinuclear copper(II) cryptate [Cu2L1](ClO4)4 (1; L1=N[(CH2)2NHCH2(m -C6H4)CH2NH-(CH2)2]3N) can easily take up atmospheric CO2 even under weakly acidic conditions at room temperature and convert it from bicarbonate into carbonate monoesters in alcohol solution. The compounds [Cu2L1(, - O2COH)](ClO4)3 (2), [Cu2L1(,-O2COR)](ClO4)3 (3: R=CH3; 4: R=C2H5; 5: R=C3H7; 6: R=C4H9; 7: R=C5H11; 8: R=CH2CH2OH), [Cu2L1(, - O2CCH3)](ClO4)3 (9), and [Cu2L1(OH2)(NO3)](NO3)3 (10) were characterized by IR spectroscopy and ESI-MS. The crystal structures of 2,6 and 10 were studied by single-crystal X-ray diffraction analysis. On the basis of the crystal structures, solution studies, and DFT calculations, a possible mechanism for CO2 fixation and transformation is given. [source]