Synthesis, characterisation and thermal analysis of copper (II) and chromium (II, III) hydrazine carboxylates

Copper(II) hydrazine carboxylate monohydrate, Cu(N₂H₃COO)₂·H₂O and chromium (II, III) hydrazine carboxylate hydrates, Cu(N₂H₃COO)₂·H₂O and Cu(N₂H₃COO)₂·3H₂O have been prepared and characterised by chemical analysis, IR, visible spectra and magnetic measurements. Thermal analysis of the copper complex yields a mixture of copper metal and copper oxide. Chromium complexes on thermal decomposition yield Cr₂O₃ as residue. Decomposition of chromium(HI) complex under hydrothermal conditions yield CrOOH, a precursor to CrO₂.     

Structure of Perchlorato(2,5,8,11-Tetraazadodecane)Copper (II) Perchlorate Monohydrate

[Cu(C₈H₂₂N₄)]·(ClO₄)₂.H₂O, M_r= 454.80, orthorhombic C222₁, a = 15.481(5), b = 7.404(1), c = 14.827(3)Å, V = 1699.5(8)ų, Z = 4, D_x = 1.78 g/cm³, λ(MoKα) = 0.71073Å, μ = 16.5 cm^?1. F(000) = 940, T = 22°C, R = 6.86%, R_w = 7.66% for 820 observed reflections (I > 2.5σ (I)). The coordination number for the copper(II) ion is five, and the coordination geometry about copper(II) ion is a buckled square pyramid with the tetraamine equatorial and a perchlorate ion axial. The tetraamine is coordinated in a square-plannar manner with slight tetrahedral distortions. The four Cu-N distances span a very narrow range, 1.990(10) ?1.994(14)Å.     

Complexation of copper(II) with 3-(2-hydroxyphenylazo)pentadione-2,4

It is shown that 3-(2-hydroxyphenylazo)pentadione-2,4 (H₂L) can exist in three tautomeric forms (enol-azo, keto-azo, and hydrazo). The effective atomic charges in the tautomeric forms of H₂L are calculated by the Hückel MO LCAO method. The molar fractions and molar absorptivities of the tautomers at different pH are found. The complexation of copper(II) with H₂L is studied by spectrophotometry. Beer’s law is obeyed for 0.51–5.12 μg/mL of copper. The assumed complex structure is given. The effect of foreign ions and masking agents on the complexation is studied. A procedure for the photometric determination of copper(II) in zinc-based alloys is proposed. Original Russian Text ? S.R. Gadzhieva, T.M. Mursalov, K.T. Makhmudov, F.G. Pashaev, F.M. Chyragov, 2006, published in Zhurnal Analiticheskoi Khimii, 2006, Vol. 61, No. 6, pp. 598–603.     

Synthese und Kristallstruktur von Ammin(μ3‐L‐glutamato)kupfer(II)

Synthesis and Crystal Structure of Ammine(μ₃‐L‐glutamato)copper(II) [Cu(L‐Glu)H₂O]·H₂O reacts with aqueous ammonia to give the ammine complex [Cu(L‐Glu)NH₃] ( 1 ). 1 forms orthorhombic crystals, space group P 2₁2₁2 with a = 1585,1(1) pm; b = 979,46(7) pm and c = 504,70(5) pm. In the crystal structure of 1 the copper atoms are linked by μ₃‐glutamate units to give a 2D layer structure. The copper atoms exhibit a square‐pyramidal coordination with two N atoms and two O atoms in the base plane and one O atom at the apex of the pyramid. The crystal structure is stabilized by a 3D network of N–H···O hydrogen bridges.     

A New Copper(II) Complex with the N,N′‐Tetra(antipyryl‐4‐methyl)‐1,2‐ethanediamine (TAMEN) Ligand: [Cu(TAMEN)](ClO4)2·H2O·DMF

The synthesis of the Mannich base N,N′‐tetra(antipyryl‐4‐methyl)‐1,2‐ethanediamine (TAMEN) ( 1 ), its crystal structure as well as the synthesis and the crystal structure of the copper complex [Cu(TAMEN)](ClO₄)₂·H₂O·DMF ( 2 ) are reported. C₅₀H₅₆N₁₀O₄·2C₂H₅OH (TAMEN·2EtOH) crystallizes with triclinic symmetry, space group , lattice parameters: a = 877.3(1), b = 1078.1(1), c = 1433.3(2) pm, α = 71.93(1), β = 82.16(1), γ = 84.54(1)° and Z = 1. The copper complex [Cu(TAMEN)](ClO₄)₂·H₂O·DMF also crystallizes with triclinic symmetry, space group , lattice parameters: a = 1279.2(2), b = 1485.6(2), c = 1513.6(2) pm, α = 98.04(1), β = 101.24(1), γ = 94.66(1)° and Z = 2. The copper(II) atom is six‐coordinate with an elongated pseudo‐octahedral geometry due to a strong Jahn‐Teller effect.     

Hydrazinium metal(II) and metal(III) ethylenediamine tetraacetate hydrates

Hydrazinium metal ethylenediaminetetraacetate complexes of molecular formula (N₂H₅)₂[Mg(edta)·H₂O], (N₂H₅)₃[Mn(edta)··H₂O](NO₃)·H₂O, N₂H₅[Fe(edta)·H₂O], N₂H₅[Cu(Hedta)·H₂O] and N₂H₅[Cd(Hedta)·H₂O]·H₂O have been synthesized and characterized by elemental and chemical analysis, conductivity and magnetic measurements and spectroscopic techniques. The thermal behaviour of these complexes has been studied by thermogravimetry and differential thermal analysis. The data set provided by the simultaneous TG-DTA curves of the complexes shows the occurrence of three or four consecutive steps such as dehydration, ligand pyrolysis and formation of metal oxides. X-ray powder diffraction patterns of copper and cadmium complexes show that they are not isomorphous. These studies suggest seven coordination for Mg,Mn, Fe complexes and six coordination for Cu and Cd derivatives.     

Nickel(II) and copper(II) complexes of aza macrocycles derived from trichloromethane

Syntheses of nickel(II) complexes of the tetraaza macrocycles 2,7-dichloro-1,3,6,8-tetraazacyclodecane (DCCD) and 2,8-dichloro-1,3,7,9-tetraazacyclododecane (DICD) and a copper(II) complex of 2,6,8,12,13,17-hexaazabicyclo[5.5.5]heptadecane (HBCH) are reported in the template condensation of trichloromethane with 1,2-diaminoethane or 1,3-diaminopropane. Formulation of the synthesized products [Ni(DCCD)(H₂O)₂]Cl₂, [Ni(DICD)(H₂O)₂]Cl₂?·?H₂O, and [Cu₃(HBCH)(H₂O)₆]Cl₆, and the metal-free ligand hydrochloride HBCH?·?6HCl has been confirmed by elemental analyses, conductivity measurements, and spectral studies. Potentiometric studies of nickel(II) and copper(II) complexes of HBCH and structurally similar 2,5,8,10,13,16,17,20,23-nonaazabicyclo[7.7.7]tricosane (NACT, earlier derived from trichloromethane and diethylenetriamine) have also been performed in the structural support of HBCH. In 1?:?1, metal?:?HBCH solution, copper(II) is coordinated to four N-donors of two-HN(CH₂)₃NH– groups of the ligand in a non-planar tetraaza cavity. The equilibrium constant value (log?K?=?15.41) for the reaction Cu^2+?+?A???CuA²⁺ (A?=?HBCH) is in favor of the cyclic structure of the ligand. A high value (log?K?=?23.27) for corresponding reaction in the NACT system is due to conformational change in the ligand, where copper(II) organizes the macrocycle to form a nearly planar cavity in which the cation fits well.     

Solvent extraction of copper(II) from sulfate medium with N -(2-hydroxybenzylidene)aniline

Solvent extraction of copper(II) from sulfate medium with N-(2-hydroxybenzylidene)aniline is studied with the following parameters: pH, concentration of the extractant, nature of diluent, and temperature. The extraction of copper(II) proceeds by a cation exchange mechanism and the extracted species are CuL₂ in cyclohexane and toluene and CuL₂ with some CuL₂HL in chloroform. The equilibrium constants have been calculated as well as thermodynamic parameters ΔH°, ΔS°, and ΔG°. The temperature effect on the solvent extraction of copper(II) with N-(2-hydroxybenzylidene)aniline in cyclohexane is discussed.     

A novel one-dimensional copper(II) imino nitroxide polymer

A copper(II) complex [Cu(im2-py)(4,4′-bipy)(NO₃)](NO₃)·1.5H₂O (im2-py?=?2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl; 4,4′-bipy?=?4,4′-bipyridyl) has been synthesized by reaction of Cu(NO₃)·3H₂O with im2py and 4,4-bipyridyl in methanol solution. Its crystal structure has been determined by X-ray diffraction. The structure shows that each copper ion is coordinated by a bidentate imino nitroxide radical, two 4,4′-bipyridyl ligands and a nitrate group to form a distorted square pyramidal environment. The crystal structure consists of chains of copper ions linked by 4,4′-bipyridyl.     

Complex formation of copper(II) with chrome azurol s

The complex formation of copper(II) with chrome azurol S (CAS) was studied by spectrophotometric and potentiometric methods. In the pH range 5–7, two complexes with the composition Cu(H₂O)₂HCAS- and (Cu(H₂O)₂)₂CAS were detected; the stability constants were calculated to be log K = 4.02 ±0.05 and log K = 13.7±0.1, respectively (at 25° and ionic strength 0.1 (KCl)). A comparison is made between the copper(II)-CAS and iron(III)-CAS systems.     

Three new binuclear copper(II) complexes with isonicotinic acid N-oxide: syntheses,crystal structures and properties

Three new copper(II) complexes with isonicotinic acid N-oxide (HL) and 1,10-phenanthroline (phen) as ligands, [Cu(L)(phen)(H₂O)]₂(NO₃)₂···2H₂O (1), [Cu(L)(phen)(H₂O)]₂(ClO₄)₂···2H₂O (2), and [Cu(L)(phen)Br]₂- [Cu(L)(phen)(H₂O)]₂Br₂···6H₂O (3) have been synthesized and structurally characterized. The structures of all three complexes feature a Cu₂ dimer formed by two Cu(II) ions interconnected by two bridging ligands. Each copper(II) ion has a distorted square pyramidal coordination geometry with elongated axial coordination by an aqua ligand or halogen anion. The isonicotinic acid N-oxide anion is bidentate, being coordinated to two Cu(II) ions through its N-O oxygen and one of its carboxylate oxygen atoms. Magnetic susceptibility measurements show a Curie–Weiss paramagnetic behavior characteristic of one unpaired electron for a copper(II) ion for all three complexes.     

Thermal behaviour of two new salts of malonic acid: Cu(C3H2O4)·4H2O and Cu(NH4)2(C3H2O4)2

Two new salts of malonic acid have been prepared: the copper(II) malonate tetrahydrate and the copper(II)-ammonium double malonate. Their study by thermal analysis (TG and DTA) leads to the following results:Cu(C₃H₂O₄)·4H₂O: the dehydration is rather complex and it is only under careful conditions that an intermediate hydrate Cu(C₃H₂O₄)·3H₂O could be traced. At about 170°C the dehydration is not ended (the salt holds yet about 0.15H₂O) and the anhydrous salt occurs only at about 240°C. It decomposes immediately leading to residues the composition of which depends upon the surrounding atmosphere; the part played by the gas given off is discussed.Cu(NH₄)₂(C₃H₂O₄)₂: this salt melts and decomposes simultaneously at about 190°C. During the decomposition the copper nitride Cu₃N forms as intermediate compound (as well as copper metal). Concerning the final residues of the decomposition the results and the conclusions are the same as the ones of the previous case.     

Synthesis, Structure and Characterization of Two-dimensional Network Copper Complex [Cu_3(nta)_2(azpy)_2(H_2O)_2]·6H_2O

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SYNTHESIS AND CRYSTAL STRUCTURE OF OXAMIDATO-BRIDGED BINUCLEAR COPPER(II) COMPLEXES

Abstract

The compounds [Cu(oxpn)] (1), [(bpy)(H₂O)Cu(μ-cis-oxpn)Cu(H₂O)] · 2NO₃ · 2H₂O (2) and [(Him)(NO₃)Cu(μ-trans-oxpn)Cu(Him)(NO₃)] (3), where oxpn is the dianion of N,N′-bis(3-aminopropyl)oxamide, bpy is bipyridine and Him is imidazole, were prepared and characterized by elemental analysis and IR spectra. Complex (2) was also studied by thermochemical analysis and its structure determined by X-ray crystallography. The structure of complex (2) consists of binuclear copper(II) molecules in which the copper(II) atoms are bridged by an oxamidato group in the cis conformation resulting a copper-copper distance of 5.21 Å. Both copper(II) ions are in square-pyramidal surroundings with almost coplanar basal planes and a water molecule occupying the apical positions. The N atoms of the oxamidato moiety are trigonal. Two lattice water molecules together with the two coordinated ones hydrogen bond with nitrate ions.     

Heptacopper(II) and dicopper(II)-adenine complexes: synthesis,structural characterization,and magnetic properties

The syntheses, crystal structures, and magnetic properties of two new copper(II) complexes with molecular formulas [Cu₇(μ₂-OH₂)₆(μ₃-O)₆(adenine)₆](NO₃)₂·6H₂O (1) and [Cu₂(μ₂-H₂O)₂(adenine)₂(H₂O)₄](NO₃)₄·2H₂O (2) are reported. The heptanuclear compound is composed of a central octahedral CuO₆ core sharing edges with six adjacent copper octahedra. In 2, the copper octahedra shares one equatorial edge. In both compounds, these basic copper cluster units are further linked by water bridges and bridging adenine ligands through N3 and N9 donors. All copper(II) centers exhibit Jahn–Teller distorted octahedral coordination characteristic of a d⁹ center. The study of the magnetic properties of the heptacopper complex revealed a dominant ferromagnetic intra-cluster interaction, while the dicopper complex exhibits antiferromagnetic intra-dimer interactions with weakly ferromagnetic inter-dimer interaction.     

Salze von Halogenophosphorsäuren. XIV. Darstellung und Kristallstruktur von Kalium-dikupferhydroxid-bis(monofluorophosphat)-Monohydrat Cu2K(OH)(PO3F)2 · H2O

Salts of Halogenophosphoric Acids. XIV. Preparation and Crystal Structure of Dicopper-potassium-hydroxide-bis(monofluorophosphate) Monohydrate Cu₂K(OH)(PO₃F)₂ · H₂O By the reaction of potassium monofluorophosphate and copper(II) salts in aqueous medium a crystalline, insoluble basic copper potassium monofluorophosphate Cu₂K(OH)(PO₃F)₂ · H₂O 1 is formed. The thermal decomposition of 1 has been studied. 1 crystallizes in the monoclinic space group B2/m with a = 9.094 Å, b = 7.755 Å, c = 6.333 Å, α = β = 90°; γ = 117.55°, and Z = 2.     

Copper(II) complex with 3-(2-hydroxy-3-sulfo-5-nitrophenylhydrazo)pentane-2,4-dione: Synthesis and structure

The copper(II) complex with 3-(2-hydroxy-3-sulfo-5-nitrophenylhydrazo)pentane-2,4-dione (H₃L) is studied, and its crystal structure is studied by X-ray diffraction analysis. The crystals of [Cu(H₂O)₂]₂(μ-L)₂[Cu(H₂O)₄] (I) are triclinic (space group P \(\bar 1\)) at 100 K, a = 7.085(3), b = 10.373(5), c = 12.265(6) Å, α = 0.842(5)°, β = 104.996(6)°, γ = 99.156(6)°, Z = 1). The C=O and NH groups of hydrazone and the OH and SO₃H groups from the aromatic moiety of the molecule are involved in coordination with the copper(II) atom. In the centrosymmetric trinuclear molecule the central Cu(2) atom has the coordination number six, and the terminal Cu(1) atoms have the coordination number five. The thermal properties of complex I are studied. The complex formation of copper(II) with the H₃L ligand in an aqueous solution at temperatures 298 ± 0.5, 308 ± 0.5, and 318 ± 0.5 K is studied by potentiometric titration. The standard thermodynamic functions of the complex formation are determined.     

Supramolecular Complexes Based on [M(CN)8]4– (M = Mo,W) and Aliphatic Amine CuII Tectons

Three heterometallic supramolecular complexes [Cu₂(pn)₄(Mo(CN)₈)·4H₂O] (pn = diaminopropane) ( 1 ), [Cu₂(pn)₄(W(CN)₈)·4H₂O] ( 2 ) and [Cu₂(1,2‐pn)₄(H₂O) (W(CN)₈)·3H₂O] ( 3 ) have been synthesized and structurally characterized by single‐crystal X‐ray diffraction studies. Complexes 1 – 3 exhibit three different networks. In 1 , the copper(II) ion is pentacoordinate with a distorted square‐pyramidal arrangement and the network is formed by the incorporation of coordinative linkage between the μ₂ bridge of [Mo(CN)₈]^4– and copper(II) ions and hydrogen‐bonding interactions. In 2 , the copper(II) ion exhibits a distorted square‐pyramidal arrangement and the network is formed by the hydrogen bonded trinuclear complexesof [Cu₂(pn)₂(W(CN)₈)]. In 3 , the copper(II) ions show twodifferent distorted octahedral arrangements. The network structure of 3 is formed by the hydrogen‐bonded complex chains of [Cu₂(1,2‐pn)₂(W(CN)₈)].     

Complexes of Cu2(μ‐OAc)4(H2O)2 with 1,10‐Phenanthroline and Comparison with those of 2,2′‐Bipyridine. Crystal Structure of the Dimer [Cu(OAc)2(phen)](μ‐H2O)

The two complexes of composition Cu₂(OAc)₄(phen)(H₂O)₂ ( 1 ) andCu₂(OAc)₄(phen)₂(H₂O) ( 2 ) have been synthesized and characterized by chemical analysis and IR and electronic spectroscopies. Compound 2 has the structure of a dimer with a phenanthroline molecule and two monodentate acetate groups coordinated to each copper atom and a water molecule as the only bridging ligand between them. Each copper atom has a distorted square‐planar pyramidal coordination, determined by two oxygen atoms at 1.94(3) and 1.959(3) Å, two nitrogen atoms at 2.023(4) Å and the oxygen atom of the bridging water molecule at 2.289(2) Å. The distance between the two copper atoms is of 4.29 Å and the angle Cu(1)‐O(3)‐Cu(1A) 139.2(2)°. The water molecule is involved in two intramolecular hydrogen bonds with non coordinated oxygen atoms. The distance between the molecules of phenanthroline is 3.75 Å. Magnetic and EPR results for Cu₂(OAc)₄(phen)(H₂O)₂ ( 1 ), Cu₂(OAc)₄(phen)₂(H₂O) ( 2 ), Cu₂(OAc)₄(bipy) ( 3 ) and Cu₂(OAc)₄(bipy)₂(H₂O)₂ ( 4 ) have been analysed and compared. For 1 and 3 an antiferromagnetic dimer unit [Cu₂(μ‐OAc)₄] with 2J = ?325 and ?292 cm^?1, respectively, and other two copper atoms without significant magnetic interaction are present. Triplet signals are detected in the EPR spectra. In 2 and 4 there is no practically magnetic exchange and the orthorhombic signals are observed in the EPR spectra.