Copper Ions In Compound Research Articles

One-dimensional coordination polymers constructed from copper(II) ions and chromato bridges: Synthesis, crystal structures and thermal analysis

Three 1D coordination polymers, 1∞[Cu(NH3)4CrO4] (1) and 1∞[CuL(H2O)(CrO4)](H2O)(C2H5OH)0.5 with L = bipy (2) and phen (3), have been assembled using chromate(VI) ions as spacers (μ-ĸO:ĸO’ bridging mode). Their crystal structures have been solved. The copper ions in compound 1, whose structure consists of linear chains, show an elongated octahedral geometry, with four ammonia molecules, forming the equatorial plane, and two oxygen atoms arising from two chromato bridges into the apical positions. The ammonia ligands are involved in intramolecular hydrogen bonds with two chromate oxygen atoms, and intermolecular hydrogen bonds with two chromato oxygen atoms from another chain. The crystal structures of compounds 2 and 3 consist of helicoidal chains and solvent molecules. The copper(II) ions in 2 and 3 are five-coordinated (square-pyramidal geometry), with the apical positions occupied by the oxygen atoms from the chromato bridges. Helicoidal chains with opposite chirality are interconnected by π-π stacking interactions established between the organic ligands, resulting in supramolecular layers. The X-band and Q-band EPR spectra of compounds 1–3 are discussed. The total thermal decomposition of these complexes leads to a mixture of CuCr2O4 and CuO, for 1, and of CuCrO2, CuO and Cr2O3, for 2 and 3.

Crystal structures of μ-oxalato-bis-[azido-(hista-mine)-copper(II)] and μ-oxalato-bis-[(dicyan-amido)(hista-mine)-copper(II)

The title compounds, μ-oxalato-κ(4) O (1),O (2):O (1'),O (2')-bis-[[4-(2-amino-eth-yl)-1H-imid-azole-κ(2) N (3),N (4)](azido-κN (1))copper(II)], [Cu2(C2O4)(N3)2(C5H9N3)2], (I), and μ-ox-al-ato-κ(4) O (1),O (2):O (1'),O (2')-bis-[[4-(2-amino-eth-yl)-1H-imidazole-κ(2) N (3),N (4)](dicyanamido-κN (1))copper(II)], [Cu2(C2O4)(C2N3)2(C5H9N3)2], (II), are two oxalate-bridged dinuclear copper complexes. Each Cu(II) ion adopts a five-coordinate square-pyramidal coordination sphere where the basal N2O2 plane is formed by two O atoms of the oxalate ligand and two N atoms of a bidentate chelating histamine mol-ecule. The apical coordination site in compound (I) is occupied by a monodentate azide anion through one of its terminal N atoms. The apical coordination site in compound (II) is occupied by a monodentate dicyanamide anion through one of its terminal N atoms. The mol-ecules in both structures are centrosymmetric. In the crystals of compounds (I) and (II), the dinuclear complexes are linked through N-H⋯X and C-H⋯X (X = N, O) hydrogen bonds where the donors are provided by the histamine ligand and the acceptor atoms are provided by the azide, dicyanamide, and oxalate ligands. In compound (I), the coordinatively unsaturated copper ions inter-act with the histamine ligand via a C-H⋯Cu inter-action. The coordinatively unsaturated copper ions in compound (II) inter-act via a weak N⋯Cu inter-action with the dicyanamide ligand of a neighboring mol-ecule. The side chain of the histamine ligand is disordered over three sets of sites in (II).

Synthesis, characterization and bioactivity of two novel trinuclear Cu(II)/Ni(II) complexes with pentadentate ligand N-2-methyl-acryloyl-salicylhydrazide

Two new trinuclear complexes, Cu 3L 2(py) 2 ( 1) and Ni 3L 2(py) 4 ( 2), have been synthesized and characterized, where L 3− is N-2-methyl-acryloyl-salicylhydrazidate. Central metal ion and two terminal metal ions in the two complexes are combined by two bridging deprotonated L 3− ligands, forming a bent trinuclear structure unit with an M–N–N–M–N–N–M core. The bent angles in complexes 1 and 2 are 167.6(1)° and 75.4(1)°, respectively. Three nickel ions in compound 2 exhibit alternating square-planar and octahedral geometries, while three copper ions in compound 1 follow square-planar mode. The studies in solution integrity and stability of compounds 1 and 2 show they are soluble and stable in DMF. UV–Vis titrations demonstrate compound 1 is stable in DMF even in the presence of excess metal ions. Antibacterial screening data indicate the two compounds all have stronger antimicrobial activities against the tested microorganisms than ligand. The trinuclear copper compound 1 is more active than monocopper compounds in the previous study, and the trinuclear nickel compound 2 is less active than tetranuclear nickel compound in the previous study.

The effect of small ions on transition metal complex configurations. Synthesis, crystal structures and properties of two new copper(II) complexes containing a tripodal ligand

The monomeric CuII complex, [Cu(TLA)C2O4].2O (1), and dimeric CuII complex, [Cu2(TLA)2(C4O4)](ClO4)2(1), where TLA=[tris(6-methyl-2-pyridyl)methyl]amine, have been synthesized and characterized. Both complexes have been obtained as single crystals and their structures were determined by X-ray diffraction analysis. The configuration of (1) is pseudo-octahedral owing to the fact that one of the Cu-Npyridyl bonds is much longer than the others. Two molecules of (1) link via hydrogen bonding to the oxalic oxygen in the unit cell. The copper complex (2) dimer is obtained, using the squarate ion as a bridging ligand, from a monomer copper complex, [Cu(TLA)N3].4ClO4(3). By comparison of the configurations of (1), (2) with that of (3), the copper center is coordinated with TLA first, and then with secondary ligands, such as the azido group, squaric acid, or oxalate ion. The configurations of the transition metal complexes are affected by the smaller ions, as is further discussed below. The variable temperature magnetic susceptibilities of (2) have been studied, and the exchange integral is J=−2.5474 cm-, g=2.061, indicating the existence of a weaker anti-ferromagnetic interaction between the two copper ions in compound (2). The spectral behavior of the title complexes in solution has been studied by u.v.–vis. and i.r. techniques, and the results are discussed.

New One-dimensional Chain Compounds of [M (pdz) Cl 2 ] n (M=Cu(II), Fe(II), Mn(II); pdz = pyridazine and Their Magnetic Properties

Three novel one-dimensional coordination polymers with pyridazine (pdz),[M (pdz) Cl 2 ] n (M = Cu (II) ( 1 ), Fe (II) ( 2 ), Mn (II) ( 3 )), were synthesized and characterized. All the compounds have one-dimensional zigzag chain structures. The copper ion in compound 1 has a planer coordination sphere with two bridging pdz ligands and two C1 − anions, while the metal ions in the other compounds have a distorted octahedral environment with pdz and Cl − groups both acting as bridges. The magnetic data of these compounds show antiferromagnetic interaction between the magnetic centers within the chains.

Synthesis and spectroscopic studies on transition-metal nitrates and thiocyanates of a chelating imidazole-thioether ligand. The crystal structures of diaquabis[5-methyl-4-(ethyl-mercaptomethyl)imidazole]nickel(II) dinitrate, diaquabis[5-methyl-4-(ethyl-mercaptomethyl)imidazole] copper(II) dinitrate and bis[5-methyl-4-(ethyl-mercaptomethyl)imidazole] bis(thiocyanato- N)cobalt(II)

The synthesis and characterization of some monomeric transition-metal coordination compounds with the novel bidentate ligand 5-methyl-4-(ethyl- mercaptomethyl)imidazole (abbreviated memi) are described, viz. [M(memi) 2(H 2O) 2](NO 3) 2 and M(memi) 2(NCS) 2 with M = Co, Ni, Cu. Single crystals of [Ni(memi) 2(H 2O) 2](NO 3) 2 ( A), [Cu(memi) 2(H 2O) 2](NO 3) 2 ( B) and Co(memi) 2(NCS) 2 ( C) were used in structure determinations. The three compounds all crystallize in the monoclinic space group P2 1/ n with Z = 2. The cell dimensions for compound A are a = 10.402(2), b = 13.589(4), c = 8.476(3) Å, β = 108.35(2)°, V = 1137.21 Å 3 and D x = 1.551 g cm −3. The cell dimensions of compound B are a = 10.451(3), b = 13.430(5), c = 8.757(4) Å, β = 109.24(3)°, V = 1160.35 Å 3 and D x = 1.53 g cm −3. The cell dimensions for compound C are a = 12.147(7), b = 9.096(4), c = 10.363(4) Å, β = 102.14(4)°, V = 1119.27 Å 3, and D x = 1.447 g cm −3. The structures were solved by heavy-atom techniques and refined by least-squares methods to residual R w values of 0.032 ( A), 0.033 ( B) and 0.046 ( C). The coordination geometry of the metal ion in all compounds is distorted octahedral. In compounds A and B the metal ion is lying on a centre of symmetry and is surrounded by two thioether sulfur atoms, two imidazole nitrogen atoms and two oxygen atoms from water molecules. In contrast to the nickel ion in structure A the copper ion in compound B has a significantly elongated octahedral geometry in the direction of the oxygen molecules. The compound with the much stronger coordinating anion, NCS (compound C) resembles the structures of A and B in having the same coordination geometry with the thiocyanate anions coordinating instead of the water molecules.

Metal chloride compounds of chelating imidazolethioether ligands. Crystal structures of dichloro-(1,6-bis(5-methyl-4-imidazolyl)-2,5-dithiahexane)copper(II) and {chloro-(1,6-bis(5-methyl-4-imidazolyl)-2,5-dithiahexane)copper(II)} chloride dihydrate

The synthesis and spectroscopic properties of the cobalt, nickel, copper and zinc chlorides of the ligands 1,6-bis(5-methyl-4-imidazolyl)-2,5-dithia-hexane (abbreviated bidhx) and 1,6-bis(4(5)-imidazolyl)-2,5-dithiahexane (abbreviated bdhdhx) are described. The compound Cu(bidhx)Cl 2 (A) crystallizes in the orthorhombic space group Pbca with a = 17.917(2), b = 14.502(4), c = 12.905(2) Å, V = 33536.15 Å 3, D x = 1.651 g cm 3 for Z = 8. The compound [Cu(bidhx)Cl]Cl · 2H 2O (B) crystallizes in the triclinic space group P-1 with a = 8.270(5), b = 10.890(5), c = 11.478(5) Å, α = 87.52(4)°, β = 76.93(5)°, γ = 71.52(4)°, V = 954.5 Å 3, D x = 1.576 g cm 3 for Z = 2. Both structures were solved by heavy atom techniques and refined by least-squares methods to residual R w values of 0.037 (A) and 0.034 (B). The coordination geometry of the copper ion in compound (A) is a compressed octahedron with the two imidazole nitrogens along the main axis at 1.94 and 1.95 Å, and both chloride anions and the two thioether sulfur atoms at relatively large distances in the equatorial plane (CuCl 2.39 and 2.56 Å, CuS 2.62 and 2.81 Å). The copper ion in compound (B) is in a distorted trigonal bipyramid, formed by the two imidazole nitrogen atoms in the axial position (1.94 and 1.95 Å), and the two thioether sulfurs and one chloride ion in the equatorial plane (CuS 2.53 and 2.46 Å, CuCl 2.29 Å). The nickel and cobalt bidhx chlorides and the copper and nickel bhdhx chlorides are isostructural with compound A.