Synthesis and Structure of Acetonitrile Solvates of Copper(II) Monofluoroacetate and Silver(I) Trifluoroacetate, [Cu2(CH2FCOO)4· 2CH3CN](CH3CN) and Ag3(CF3COO)3(CH3CN)2

Compounds [Cu₂(CH₂FCOO)₄· 2CH₃CN](CH₃CN) (I) and Ag₃(CF₃COO)₃(CH₃CN)₂(II) were synthesized and studied by X-ray structural analysis. Crystals Iare monoclinic, space group C2/c, a= 27.854(6), b= 8.286(2), c= 19.428(4) Å, = 106.82(3)°, V= 4292(2) ų, Z= 8, R ₁= 0.0426; crystals IIare triclinic, space group , a= 8.676(2), b= 9.819(2), c= 11.961(2) Å, = 95.27(3), = 109.59(3)°, = 104.60(3)°, V= 911.4(3) ų, Z= 2, R ₁= 0.0252. Structure Iis composed of the structural units (lanterns) typical of copper(II) carboxylates. The presence of an additional acetonitrile molecule noncoordinated by the copper atoms makes it possible to consider compound Ias a lattice clathrate. Structure IIhas no analogs among the silver carboxylates. It simultaneously contains silver atoms with coordination numbers varying from 2 to 4.     

Synthesis and structure of tetranuclear copper(Ⅱ) complex containing μ4-oxo bridge

A new dinucleating Schiff base ligand HL(L=C13H17N2O3) has been synthesised and characterized.The single crystal structure of its complex [L2Cu4O(AcO4)]·2H2O has beendetermined by X-ray diffraction methods.The result indicates that every Cu atom has its square pyramidal coordination polyhedron and there is a tetrahedral Cu4O core in the complex molecule.Its active sites where catalytic oxidation of dioxygen occurs have been inferred.     

Synthesis, characterization and crystal structure of tetranuclear copper(II) complex [Cu4(μ-Salophen)2(μ1,1-N3)2(N3)2] with alternating μ1,1-azido and phenoxo bridges

Tetranuclear copper(II) complex [Cu₄(??-Salophen)₂(??_1,1-N₃)₂(N₃)₂] (I) has been synthesized from the reaction of Cu(NO₃)₂ · 3H₂O with the Schiff-base ligand salophen condensed from salicylaldehyde and 1,2-phenylenediamine at the presence of a large excess of NaN₃, which has been characterized by elemental analyses, FT-IR spectroscopy, and single-crystal X-ray diffraction. X-ray diffraction studies show that I is a tetranuclear Cu(II) complex with a pair of end-on (EO) azido ions bridging the copper(II) ions in a central Cu(??_1,1-N₃)₂Cu core and one phenoxo bridging the copper(II) ions in a Cu(??-Salophen)Cu core. All copper(II) ions in I are four coordinated and adopt approximate square planar coordination geometry.     

Synthesis,characterization and crystal structure determination of mononuclear and dinuclear copper(II) carboxylates: [Cu(Hdpa)2(en)] and [{Cu2(μ-na)4(CH3OH)2}·2CH3OH]

Two new copper complexes [Cu(Hdpa)₂(en)] (1) and [{Cu₂(μ-na)₄(CH₃OH)₂}·2CH₃OH] (2) (where en is ethylene diamine, Hdpa is 2′-carboxy-[1,10-biphenyl]-2-carboxylate anion and na is 1-naphtalenecarboxylate) have been synthesized and their crystal structures were determined by X-ray crystallography. Complex 1 was prepared from the reaction of Cu(NO₃)₂·3H₂O with ethylene diamine and 2,2′-biphenyldicarboxylic acid in a mixture of water and methanol and complex 2 was prepared from the reaction of CuSO₄·5H₂O with 1-naphtalenecarboxylic acid in methanol. The two complexes were characterized by IR, UV–vis, luminescence and elemental analysis. Moreover, complex 2 was characterized by EPR spectroscopy and thermogravimetric analysis. Complex 1 is a monomer and complex 2 is a dimer with a paddle-wheel structure; both structures are without precedent in the literature.     

Synthesis and crystal structure of a novel trinuclear Schiff base cadmium(II) complex [Cd3L4] · 2ClO4 · 2CH3OH with antimicrobial activity

The Schiff base 2-ethoxysalicylaldehydethiosemicarbazone (HL) derived from 3-ethoxysalicylaldehyde and thiosemicarbazide and its centrosymmetric trinuclear cadmium(II) complex [Cd₃L₄] · 2ClO₄ · 2CH₃OH (I), have been successfully prepared. The structure of complex I was characterized by elemental analysis, IR spectrum, and single crystal X-ray crystallographic determination. The complex crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 15.584(2), b = 19.540(2), c = 20.994(3) Å, β = 106.632(2)°, V = 6125.2(13) ų, Z = 4, R ₁ = 0.0558, and wR ₂ = 0.1696. The Schiff base coordinates to the Cd atoms through the phenolate O, ether O, imino N, and S atoms. The central Cd atom of complex I is coordinated by eight O atoms from four Schiff base ligands. The terminal Cd atoms of the complex are coordinated by six donor atoms from two Schiff base ligands. The effect of the complex on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans were studied.     

Synthesis,crystal structure,and magnetism of a dinuclear nickel(II) complex [Ni2(MOBPT)2(N3)4] · 2H2O

A dinuclear nickel(II) complex, [Ni₂(MOBPT)₂(N₃)₄] · 2H₂O (MOBPT = 4-(p-methoxyphenyl)-3,5-bis(pyridine-2-yl)-1,2,4-triazole), has been synthesized and characterized by elemental analysis, UV, IR, ESI-MS, and single crystal X-ray crystallography. The complex crystallizes in triclinic system, space group P 1 with a = 9.877(2) Å, b = 10.396(2) Å, c = 11.975(3) Å, α = 71.638(3)°, β = 74.968(3)°, γ = 64.747(3)°, V = 1044.2(4) ų, Z = 1, R = 0.0371 for 5774 observed reflections. The crystal structure determination shows that the dinuclear Ni₂N₈ unit is almost planar with each Ni²⁺ coordinated by four nitrogens from two MOBPT ligands and two axial azides in a distorted octahedral geometry. Magnetic measurements reveal weak antiferromagnetic exchange in the complex.     

Synthesis and Structure of [HOCH2CH2N（CH3）3]4[Cu4OCl10]

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Structure of a new binuclear complex of tungsten [W2S4Cl2(dppe)2]·2CH3CN

Journal of Structural Chemistry - In the reaction of (Et4N)2[W2S4Cl4] with 1,2-bis(diphenylphosphino)ethane in acetonitrile a new binuclear complex of tungsten(V) [W2S4Cl2(dppe)2]·2CH3CN is...     

Synthesis,crystal structure and magnetic properties of the first dinuclear copper(II)–iron(II) complex [Cu(L)Fe(CN)5NO] based on nitroprusside

The nitrosyl cyanide [Cu(L)Fe(CN)₅NO] was prepared by the reaction of [Cu(L)]Cl₂ [L = 3, 10-bis(2-hydroxymethyl)-1,3,5,8,10,12-hexaazacyclotetradecane] with Na₂[Fe(CN)₅NO]·2H₂O in aqueous solution. Single-crystal analysis revealed that the title complex is the first structurally characterized dinuclear copper(II)–iron(II) complex based on the nitroprusside. Variable temperature magnetic susceptibility measurements (4.0–180.0 K) show the occurrence of very weak antiferromagnetic interactions between the copper(II) ions with zJ = –0.410 cm^–1.     

Synthesis,structure, and DNA-binding of a new binuclear copper(II) complex: [Cu2(heap)(H2O)2](pic)2 · 2H2O

In this study, a new μ-oxamido-bridged binuclear copper(II) complex [Cu₂(heap)(H₂O)₂](pic)₂ ? 2H₂O, where heap and pic stand for the anion of N,N′-bis(N-hydroxyethylaminopropyl)oxamide and 2,4,6-trinitrophenol, respectively, has been synthesized and characterized by elemental analyses, IR, UV, molar conductance, and single-crystal X-ray diffraction. The complex has an embedded inversion center at the middle of the C–C bond of the oxamido group. Each copper(II) is in a square-pyramidal coordination geometry. The bridging ligand (heap) adopts a bis-tetradentate trans conformation and the oxamido group is in an imidic acid configuration. Hydrogen bonds contribute to a 3-D supramolecular structure in the crystal. The interaction of the binuclear complex with herring sperm deoxyribonucleic acid (HS-DNA) has been investigated by using absorption and emission spectra, electrochemical techniques, and viscometry. The results suggest that the binuclear copper(II) complex interacts with HS-DNA by electrostatic interaction with intrinsic binding constant of 2.67 × 10⁴ (mol L^?1)^?1. The influence of anions on the structure and the interaction of the binuclear complex with HS-DNA were preliminarily discussed.     

Bonding properties of copper(II)—N chromophores: Preparation,structure, and spectroscopic properties of ethylenediaminecopper(II) complexes. Molecular structure of [Cu(ethylenediamine)(pyridine)2(ClO4)2]

Summary Ethylenediaminecopper(II) perchlorate complexes of the [Cu(ethylenediamine)L₂(ClO₄)₂] type, where L = imidazole, N-methylimidazole, 2-methylimidazole, 4-methylimidazole, and pyridine, have been prepared and characterized by elemental analyses, and electronic, vibrational, and e.p.r. spectroscopic measurements. The molecular structure of [Cu(ethylenediamine)(pyridine)₂(ClO₄)₂] has been determined by three-dimensional X-ray diffraction data. The Cu^II ion is coordinated by one ethylenediamine and two pyridine ligands forming an equatorial plane, and by two perchlorate anions located on the z axis. The pyridine ligands incline at 54.9 ° to the CuN₄ plane suggesting virtually no -interaction in the complex. Similar structures with a CuN₄ coordination plane are proposed for other complexes based on the spectroscopic data. The bonding properties of these complexes are elucidated and discussed with reference to the electronic structures deduced from Gaussian analyses of their LF spectra.     

Crystal Structures of 1,3-Calix[4]-bis-crown-6·3CH3CN and 1,3-Calix[4]-bis-(benzo-crown-6)·3 CH3CN

The crystal structures of a new solvate of the ditopic receptor 1,3-calix[4]-bis-crown-6, Bis-C6, and of 1,3-calix[4]-bis-(benzo-crown-6), Bis-benzoC6, are reported. Bis-C6.3 CH3CN (1) crystallizes in the monoclinic space group P21/n, a = 14.388(3), b = 26.947(8), c = 14.707(4) Å, = 113.19(3)°, V = 5241(5) Å3, Z = 4. Refinement led to a final conventional R value of 0.092 for 2723 reflections. The structure of (1) differs from the previously reported structure of Bis-C6.4 CH3CN by the conformation of one crown either chain. Two acetonitrile molecules are in the close neighbourhood of the crown ether cavities. Bis-benzoC6.3 CH3CN (2) crystallizes in the monoclinic space group P21/c, a = 10.391(4), b = 17.264(11), c = 30.426(9) Å, = 94.62(3)°, V = 5440(7) Å3, Z = 4. Refinement led to a final conventional R value of 0.106 for 2965 reflections. Two acetonitrile molecules are located near the crown ether cavities, as in (1). One of the crown ether conformations is the same as in the binuclear caesium complex of Bis-benzoC6, supporting the hypothesis of a preorganization of this ligand towards the complexation of this ion; the second crown ether chain is partially disordered.     

Synthesis,crystal structure and properties of the dimeric copper(II) complex, [Cu2(Hboa)2(H2O)2] · (ClO4)2 (H2boa = biacetyl oxime azine)

The crystal structure of the polyhydrazone dioxime-containing dimeric copper(II) (polyhydrazone dioxime: HON=CMe[CMe=NN=CMe] _n CMe=NOH) complex, [Cu₂(Hboa)₂(H₂O)₂] · (ClO₄)₂ (1) (H₂boa = biacetyl oxime azine) has been determined. Complex (1) contains an unusual six-membered ring, which is composed of two oxime groups and two Cu^II ions. The variable temperature magnetic susceptibility of (1) in the 5–300 K range has been interpreted in terms of a Cu^II dimer. The magnetic behavior shows that the bridging six-membered ring mediates very strongly in the antiferromagnetic exchange interaction, with the fitting value J = –361(1) cm^–1 and the e.p.r. g-value of 2.193.     

Synthesis,characterization, and crystal structure of a 2-D metal diphosphonate: Cu3(H2O)2[HO3PCH2N(CH3)CH2PO3]2 · 2H2O

Hydrothermal reaction of N-methyl-iminobis(methylenephosphonic acid), CH₃N(CH₂PO₃H₂)₂, (H₄L) with copper(II) acetate afforded a new layered Cu(II) amino diphosphonate, Cu₃(H₂O)₂(HL)₂?·?2H₂O (1). Compound 1 was studied by IR spectroscopy, TGA/DTA data, and X-ray diffraction (XRD) techniques. The XRD patterns are the same for the hydrated and the dehydrated complexes. A single-crystal X-ray crystallographic determination reveals copper in two different coordination environments. Cu1 has a distorted elongated tetragonal octahedral geometry, whereas Cu2 has a square-pyramidal distorted geometry. The HL trianion is a pentadentate ligand with a deprotonated nitrogen atom and two oxygen atoms of each phosphonate binding to copper. Hydrogen bonds between lattice water molecules in interlayer spaces and the non-coordinated phosphonate oxygen atoms as well as water ligands leads to a 3-D supramolecular network structure.     

Tetranuclear azido-bridged copper(II) complex [Cu4(μ-salpn)2(μ1,1-N3)2(N3)2(H2O)2]: Synthesis,characterization and crystal structure

The reaction of salpnH₂ Schiff-base ligand (salpnH₂ = N,N′-bis(salicylidene)-1,3-propylenediamine) with Cu(NO₃)₂·3H₂O and a large excess of NaN₃ (1:2:8 molar ration), lead to the formation of [Cu₄(μ-salpn)₂(μ_1,1-N₃)₂(N₃)₂(H₂O)₂] (1), which has been successfully obtained and characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction. The strong absorption band at about 2000–2100 cm^?1 and at 1597 cm^?1 regions of the IR spectrum of 1 clearly proves the presence of the both end-on (EO) bridging and terminal azido ions and CN (azomethine) groups, respectively. Single-crystal X-ray analyses revealed that the copper atoms are bridged alternately by end-to-on (EO) azido and phenoxo-salpn ligands in the prepared tetranuclear copper(II) complex [Cu₄(μ-salpn)₂(μ_1,1-N₃)₂(N₃)₂(H₂O)₂] (1).     

Self assembled tetranuclear Cu4(II), Ni4(II) [2 × 2] square grids and a dicopper(II) complex of heterocycle based polytopic ligands - Magnetic studies

The ditopic ligand PyPzOAP (N-[(Z)-amino(pyridin-2-yl)methylidene]-5-methyl-1-(pyridin-2-yl)-1H-pyrazole-3-carbohydrazonic acid) and the polytopic ligand 2-PzCAP (N'(3),N'(5)-bis[(1E)-1-(pyridin-2-yl)ethylidene]-1H-pyrazole-3,5-dicarbohydrazide) were synthesized in situ by condensation of methyl imino picolinate with 5-methyl-1-(2-pyridyl) pyrazole-3-carbohydrazide and 2-acetyl pyridine with pyrazole-3,5-dicarbohydrazide respectively. The ligands PyPzOAP and PzOAP (reported earlier, Dalton Trans., 2007, 1229) self-assemble to form homoleptic [2 × 2] tetranuclear M(4) (M = Cu(II) and Ni(II)) square grids structures [Cu(4)(PyPzOAP)(4)](NO(3))(4) (1), [Cu(4)(PzOAP)(4)](ClO(4))(4) (2) and [Ni(4)(PyPzOAP)(4)](NO(3))(4)·8H(2)O·2CH(3)CN (3). While the ligand 2-PzCAP forms a dicopper(II) complex [Cu(2)(2-PzCAP)(OH)(NO(3))(H(2)O)](NO(3))·2H(2)O (4). The complex 1 is a perfect square grid (a = 4.201 ?), whereas, 2 and 3 are almost square grids. All these compounds have been characterized by X-ray structural analyses and variable temperature magnetic susceptibility measurements. EPR studies have also been carried out for complexes 1, 2 and 4. In the Cu(4) grid (1), all the Cu(II) centers are in a distorted octahedral environment with N(4)O(2) chromophore, while, in complex 2, all four Cu(II) centers have a square pyramidal environment with N(3)O(2) chromophore. In complex 3, all four Ni(II) centers have distorted octahedral geometry with N(4)O(2) chromophore. In compound 4, the Cu(II) centers are in square pyramidal environment with N(3)O(2) chromophore. The magnetic properties of compounds 1 and 2 show the presence of intramolecular ferromagnetic exchange interaction (J = 5.88 cm(-1) for 1 and 4.78 cm(-1) for 2). The complex 3 shows weak intramolecular antiferromagnetic interaction (J = -4.02 cm(-1)). While, complex 4, shows strong antiferromagnetic behavior (J = -443 cm(-1)).     

Synthesis, crystal structure, magnetic property and thermal studies of [Ni(CH(3)COO)2·(NH2CH2Ph)4

[Ni(CH(3)COO)(2)·(NH(2)CH(2)Ph)(4)] complex was synthesized using benzylamine and nickel acetate. The molecular structure of this complex was obtained by single crystal X-ray diffraction and characterized by elemental analysis, IR spectrometry and thermal analysis. The complex crystallized in the monoclinic space group P2(1)/n with cell parameters a=11.234(4)?, b=6.459(2)?, c=22.647(8)?, α=90.00, β=91.149(4)°, γ=90.00, V=1642.8(10)?(3), Z=2. The structure has been solved by direct methods and refined to R(1)=0.0876 for 6377 observed reflections I>2σ(I). Magnetic studies for complex show the data over the whole temperature range 5-300 K are well fitted to the Curie-Weiss law with C=1.03 cm(3) K mol(-1) and θ=-1.38 K. This fitting indicates antiferromagnetic interaction between the Ni ions and the metal center exhibits distorted octahedral coordination geometries. The thermal analysis was carried out to understand the thermal stability of the title complex.     

Synthesis and characterization of a tetranuclear copper(Ⅱ) complex with a chiral Schiff base ligand

The title complex l-[Cu^Ⅱ₄（Hvap）₂（vap）₂（MeOH）₂]（CIO₄）₂ 1 has been synthesized and characterized by EA. IR,TGA,solid-state CD spectra and X-ray single-crystal analyses（l-H₂vap’.a Schiff base ligand derived from the condensation of o-vanillin and l-2-amino-3-phenyl-l-propanol）.Complex 1 crystallizes in monoclinic system,chiral space group P2₁ with a =10.4257（18）.b = 21.695（4）,c = 15.721（3）A,β= 94.443（3）.V= 3545.1（11） ³,Z=2,Cu₄C₇₀H₇₈N₄O₂₂Cl₂.Mr= 1652.42,D_c= 1.548 g/cm³, F（000）= 1704 andμ（MoKα） = 1.338 mm^-1.The final R = 0.0682 and wR = 0.1420 for 6170 observed reflections with I > 2σ（I） and R = 0.1775 and wR = 0.1830 for all data.The structure of complex 1 contains a boat-shaped(Cu₄O₄} motif.The solid-state CD spectra confirm the chiral nature of complex 1.     

Crystal structure of [Cu4(pytp)2(SO4)2(H2O)10](SO4)2 · 4H2O. A tetranuclear copper(II) complex with a new asymmetric ligand,pytp*, as a bridge

A new asymmetric bridge ligand, pytp, was prepared and characterized systematically by f.t.i.r., u.v.–vis., ¹H-n.m.r. and by FAB-MS spectroscopy. A tetranuclear Cu^II complex [Cu₄(pytp)₂(SO₄)₂(H₂O)₁₀](SO₄)₂·4H₂O (1) was prepared and characterized by elemental analysis and u.v.–vis. spectroscopy. A crystal structure analysis indicates that there are two different coordination spheres in (1) and that two of the copper centers are bridged by two ₂-SO₄ entities, creating a most unusual sulphate bridge.