Synthesis,Crystal Structure and Characterization of Polynuclear Potassium(I), Copper(II) and Cobalt(II) Complex with Acetylacetonethylenediamine

The title complex [K{Cu(acen)}₃]₂[Co(NCS)₄]·1/4CH₃OH (acen = acetylacetonethylenediamine anion) has been prepared and characterized. Single-crystal x-ray analysis reveals that the complex crystallizes in space group P I with a = 11.442(2), b = 15.098(3), c = 28.500(4) Å, α = 82.77(1), β = 83.58(1), γ = 85.07(1)°. The crystal consists of the complex [K{Cu(acen)}₃]⁺ cations, [Co(NCS)₄]^2? anions and methanol molecules. Three [Cu(acen)] molecules function as bridging ligands through phenolic O atoms to one K⁺ to give the tetranuclear [K{Cu(acen)}₃]⁺ cation. Each copper(II) atom in the cation is in a square-planar geometry, being coordinated by two oxygen atoms and two nitrogen atoms from a quadridentate acen ligand. The cobalt(II) atom is coordinated by four nitrogen atoms of thiocyanate ligands, forming a deformed tetrahedral environment. The IR and UV-Vis spectra have also been investigated.     

Synthesis,Characterization and Crystal Structure of a Ternary Cu(II) Complex with 1,10-Phenanthroline and l-Leucinate

The complex [Cu(l-Leu)(phen)(H₂O)]NO₃ has been synthesized and characterized by elemental analysis, molar conductivity, spectroscopic and X-ray diffraction methods, where phen = 1,10-phenanthroline and l-Leu = l-leucinate. The complex crystallizes in the triclinic space group Pī with two molecules in a unit cell of dimensions a = 7.288(4) Å, b = 11.588(7) Å, c = 12.349(3) Å, α = 86.388(10)^o, β = 76.175(11)°, γ = 72.132(3)°, V = 963.8(10) ų, Z = 2, D _c = 1.564 g/cm³, μ = 1.177 mm^?1, F(000) = 470, R ₁ = 0.0611, and wR ₂ = 0.0711. The copper(II) is ligated in a distorted square-pyramidal geometry by the two nitrogen atoms of phen and the amino nitrogen atom and one carboxylate oxygen atom from each independent l-Leu moiety in the basal plane, and one water oxygen at the apical position. A supramolecular configuration is formed from strong phen-phen stacking interactions between neighboring [Cu(l-leu)(phen)(H₂O)]⁺cations in the crystal.     

Synthesis and Crystal Structure of a Fumaratocopper(II) Complex with Bipyridine

The title complex [Cu₂(C₄H₂O₄)₂(bipy)₂(H₂O)₃] · 3H₂O (bipy = 2,2'-bipyridine) was prepared and its crystal structure determined by X-ray diffraction methods. Both Cu(II) atoms of the binuclear complex assume square pyramidal coordination. The fumarate groups display different coordination modes. One fumarate group bridges two Cu(II) ions to form a binuclear complex while another fumarate group terminally coordinates to a Cu(II) atom with one carboxyl group free from coordination. The terminally coordinated fumarate showed unusual disorder, which may be due to an intermolecular H-bonding interaction. Close stacking of bipy rings is observed as verified by the distance of 3.46 Å between parallel ring planes. IR spectra were assigned based on the molecular structure.     

Crystal Structure and Magnetic Properties of a Copper(II) Chloride Complex with Nitronyl Nitroxide

A new compound [Cu(NITPhCH₃)₂Cl₂] (NITPhCH₃ 2-(4-methyl-phenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide) has been characterized spectroscopically. A crystal structure analysis has shown the copper ion to be planar, coordinated by two chlorine atoms and two oxygen (nitroxyl) atoms. Based on magnetic susceptibility measurements the compound was found to exhibit a moderately strong antiferromagnetic interaction (J= m 107.44 cm_-1) between copper(II) and the radical.     

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.     

Synthesis,Characterization and Crystal Structures of Four Dinuclear Schiff Base Nickel(II) and Copper(II) Complexes with Versatile Bridging Groups

Four novel Schiff base nickel(II) and copper(II) complexes, derived from the end‐on (μ_1,1‐N₃) azide, end‐to‐end (μ_1,3‐NCS) thiocyanate, or phenolate oxygen bridges, have been synthesized and their crystal structures determined by X‐ray diffraction methods. They are the dinuclear double end‐on azide‐bridged [Ni₂(L1)₂(MeCN)₂(μ_1,1‐N₃)₂]·MeOH ( 1 ), the dinuclear double end‐on azide‐bridged [Ni₂(L2)₂(MeOH)₂(μ_1,1‐N₃)₂][Ni₂(L2)₂(OH₂)₂(μ_1,1‐N₃)₂]·MeOH ( 2 ), the dinuclear double end‐to‐end thiocyanate‐bridged [Cu₂(L3)₂(μ_1,3‐NCS)₂] ( 3 ), and the dinuclear double phenolate O‐bridged [Cu₂(L4)₂(NCS)₂] ( 4 ), where HL1, HL2, HL3 and HL4 are four tridentate Schiff bases obtained by the condensation of 3,5‐dibromosalicylaldehyde with N‐ethylethane‐1,2‐diamine, of 3,5‐dichlorosalicylaldehyde with N‐methylpropane‐1,3‐diamine, of 3‐bromo‐5‐chlorosalicylaldehyde with 2‐aminomethylpyridine, and of 5‐nitrosalicylaldehyde with 2‐aminomethylpyridine, respectively. Each nickel(II) atom in 1 and 2 is in an octahedral coordination, while each copper(II) atom in 3 and 4 is in a square pyramidal coordination. There exists crystallographic inversion centre symmetry in each of the complexes.     

Structural Relationships obtained from the Coordination of α‐Picolinamide to the (Iminodiacetato)copper(II) Chelate: Synthesis,Crystal Structure,and Properties of (α‐Picolinamide)(iminodiacetato)copper(II) Dihydrate

The stoichiometric reaction of copper(II) hydroxycarbonate, iminodiacetic acid (H₂IDA = HN(CH₂CO₂H)₂) and α‐picolinamide (pya) in water yields crystalline samples of (α‐picolinamide)(iminodiacetato)copper(II) dihydrate, [Cu(IDA)(pya)] · 2 H₂O ( 1 ). The compound was characterised by thermal (TG analysis with FT‐IR study of the evolved gasses), spectral (IR, electronic and ESR spectra), magnetic and single crystal X‐ray diffraction methods. It crystallises in the triclinic system, space group P1, a = 8.8737(4), b = 10.23203(5), c = 15.7167(11) Å, α = 77.61(1)°, β = 103.89(1)°, γ = 80.32(1)°, Z = 4, final R1 = 0.056. The asymmetric unit contains two crystallographic independent molecules but chemically very similar ones. The Cu^II atom exhibits a square base pyramidal coordination (type 4 + 1). pya acts as N,O‐bidentate ligand supplying two among the four closest donor atoms of the metal [averaged bond distances (Å): Cu–N = 1.982(2), Cu–O(amide) = 1.972(2)]. IDA plays a N,O,O′‐terdentate chelating role [averaged bond distances (Å): Cu–N = 2.004(3), Cu–O = 1.941(2) and Cu–O = 2.242(2)]. The coordinating behaviour of pya in 1 is discussed on the basis of its N,O‐bidentate chelating role and the preference of the ‘Cu‐iminodiacetato' moiety [Cu(IDA)] to link the N‐heterocyclic donor of pya in trans versus the Cu–N(IDA) bond. Consistently the ligand pya is able to impose a fac‐chelating configuration to IDA one around the copper(II) as previously has been reported to mixed‐ligand complexes having a 1/1/2 Cu^II/IDA/N(heterocyclic) donor ratio or a closely related 1/1/1/1 Cu^II/IDA/N(heterocyclic)/N(aliphatic) one.     

Synthesis and magnetic properties of copper (II)-lanthanoid (III) binuclear complexes with N,N′-bis(3-aminopropyl) oxamido ligand

Six novel μ-oxamido binuclear complexes, namely Cu(axpn)Ln(L)₂(ClO₄)₃ (Ln: Eu, Gd, Tb, Nd, Ho, Er), where oxpn is N,N'-bis(3-aminopropyl) oxamido, L denotes 5-nitro,10-phenanthroline (abbreviated as NO₂-phen), have been synthesized and characterised. The magnetic susceptibility of complexes Cu(oxpn)Gd(NO₂-phen)2(ClO₄)₃.2H₂O was measured over the 4–300 K and the observed data were successfully simulated by equation based on spin Hamiltonian operator (H = -2J₁ · S₂), giving the exchange integral J(Cu-Gd)=-1.62 cm^?1. This indicates a weak antiferromagnetic interaction between the Cu(II) and Gd(III) ions.     

Copper(II) coordination compounds with ferulic acid

The first two molecular structures of the ferulic acid (3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid, C₁₀H₁₀O₄) coordination compounds are presented, namely, [Cu₂(C₁₀H₉O₄)₄(CH₃CN)₂] 1 and [Cu₂(C₁₀H₉O₄)₄(C₆H₆N₂O)₂]·4CH₃CN (C₆H₆N₂O = nicotinamide) 2. Both compounds were synthesised from the starting mixture of Cu₂O and CuCl upon copper oxidation in the acetonitrile solution. The single-crystal X-ray diffraction analysis of 1 and 2 reveals the binuclear structure of the ‘paddle–wheel’ type for both complexes. 1 and 2 are unstable outside mother liquid due to loosely bound acetonitrile molecules. The final products of decomposition are [Cu₂(C₁₀H₉O₄)₄] 1a and [Cu₂(C₁₀H₉O₄)₄(C₆H₆N₂O)₂] 2a, which were characterized by several physico-chemical methods. The triplet X-band EPR spectra of 1a and 2a, showing signals B_Z1  15 mT, B₂  460 mT and B_Z2  580 mT, are in agreement with the expected data for the binuclear tetracarboxylate units, found in the structures of the parent complexes 1 and 2. Together with the room temperature magnetic susceptibility data, μ_eff/B.M. 1.40 (1a), 1.48 (2a), the EPR spectra analysis confirm the antiferromagnetic interaction in 1a and 2a. This is suggesting preservation and stability of the paddle–wheel structures in 1a and 2a.     

Syntheses,crystal structures,and antibacterial activities of manganese(III), nickel(II), and copper(II) complexes containing a tetradentate Schiff base

Three new mononuclear Schiff-base complexes, namely [Mn(L)Cl] (1), [Ni(L)] (2), and [Cu(L)] (3), where L?=?anion of [N,N′-bis(2-hydroxybenzophenylidene)]propane-1,2-diamine, have been synthesized by reacting equimolar amounts of the respective metal chloride and the tetradentate Schiff base, H₂L, in methanol. The complexes have been characterized by microanalytical, spectroscopic, single-crystal X-ray diffraction, and other physicochemical studies. Structural studies reveal that 1 adopts a distorted square-pyramidal geometry whereas 2 and 3 are isotypic with distorted square-planar geometries. The antibacterial activities of 1–3 along with their Schiff base have been tested against some Gram(+) and Gram(?) bacteria.     

Synthesis and Crystal Structure of a Novel Polymeric Thiocyanato-Bridged Heteronuclear Complex of Copper(II) and Cadmium(II)

The title polymeric complex of Cu(II) and Cd(II) bridged by thiocyanate, Cu(en)₂[Cd(SCN)₃]₂, has been prepared and its structure determined by X-ray diffraction (XRD) methods. The crystal structure reveals that the Cu(II) atom is in an elongated octahedral coordination formed by two SCN^– anions and two en molecules. The Cd(II) atom is in a distorted octahedral coordination formed by six bridging SCN^– anions. Two different bridging thiocyanate anions exist in the complex. Both 1,1--SCN^– and 1,3--SCN^– anion act a role of bridge ligand and link Cu(II), Cd(II) atoms, and adjacent Cd(II). Cd(II) atoms form the three-dimensional (3-D) network polymeric structure. The IR and UV-Vis spectra have also been investigated.     

Synthesis,Crystal Structure and Magnetic Properties of Diaqua(1,10-Phenanthroline-N,N')-Hydrogenmaleatocopper(Ii) Hydrogenmaleate Monohydrate

Reaction of freshly-prepared CuCO₃, phenanthroline monohydrate and maleic acid in CH₃OH/H₂O(1 : 1 v/v) at pH=2.13 yielded diaqua(1,10-phenanthroline-N,N')hydrogenmaleatocopper(II) hydrogenmaleate monohydrate, [Cu(phen)(H₂O)₂(C₄H₃O₄)](C₄H₃O₄)(H₂O), which consists of [Cu(phen)(H₂O)₂(C₄H₃O₄)]⁺ complex cations, hydrogenmaleate anions and lattice H₂O molecules. Within the complex cations, the Cu atoms are each square-pyramidally coordinated by two N atoms of one chelating phen ligand and three O atoms of two H₂O molecules and one hydrogenmaleato ligand with one H₂O molecule at the apical position (d(Cu-N) = 2.001, 2.009 Å, equatorial d(Cu-O) = 1.966 Å and axial d(Cu-O) = 2.235 Å). Through hydrogen bonding, the complex cations, hydrogenmaleate anions and lattice H₂O molecules are assembled into 1D chains, which are held together by weak Cu···O interactions (3.139 Å) to form corrugated 2D layers. Significant π-π stacking interactions between neighboring phen ligands leads to supramolecular assembly of the 2D layers. Over the temperature range 5-300 K, the complex obeys the Currie-Weiss law with an effective magnetic moment of 1.78 BM at room temperature.     

Study of the Interaction of Bis(4‐pyridylthio)methane with Copper(II) Chloride and Bromide

The new ligand bis(4‐pyridylthio)methane (4‐bpytm) ( 1 ) and its complexes [CuX₂(4‐bpytm)] and [CuX₂(4‐bpytm)₂] (X = Cl and Br) ( 2 – 5 ) have been prepared and characterized by elemental analysis, IR‐Raman, UV/Vis spectroscopy. The structures of (4‐bpytm) ( 1 ), [CuCl₂(4‐bpytm)₂] ( 3 ) and [CuBr₂(4‐bpytm)₂] ( 4 ) were determined by single‐crystal X‐ray diffraction analysis. X‐ray analysis of the 1:2 derivatives reveals that the copper atom has a distorted (4 + 2) octahedral environment. The copper atom is coordinated by four nitrogen atoms from four bridging 4‐bpytm ligands and two halogen atoms. The axial Cu–N bonds are considerably longer than the equatorial Cu–N bonds owing to JahñTeller distortion. CuX₂ units are linked to each other through bridging 4‐bpytm ligands to form a 2D interpenetrated coordination polymer. The structural parameters of the 4‐bpytm ligand in these complexes were compared with those of the free ligand.     

Synthesis and Characterization of Ni(II), Cu(II), Zn(II) and Cd(II) Complexes of a New Vic-Dioxime Ligand

In this study, 1,2-dihydroxyimino-3,7-di-aza-9,10-O-α-methyl benzal decane (LH₂) was synthesized starting from 1,2-O-α-methyl benzal-4-aza-7-amino heptane (RNH₂) and antichloroglyoxime. With this ligand, complexes were synthesized using Ni(II) and Cu(II) salts with a metal:ligand ratio of 1:2. However, the reaction of the ligand with salts of Zn(II) and Cd(II) gave products with metal:ligand ratio of 1:1. Structures of the ligand and its complexes are proposed based on elemental analyses, IR, ¹³C- and ¹H-NMR spectra, magnetic susceptibility measurements and thermogravimetric analyses (TGA).     

Simple,Selective, and Sensitive Spectrophotometric Method for Determination of Trace Amounts of Nickel（Ⅱ）, Copper （Ⅱ）, Cobalt （Ⅱ）, and Iron （Ⅲ） with a Novel Reagent 2-Pyridine Carboxaldehyde Isonicotinyl Hydrazone

A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.     

Synthesis and Structure of Copper(II) Nitrate Complexes with 2, 6‐Bis(pyrazolyl)pyridine

Three mononuclear copper(II) complexes of copper nitrate with 2, 6‐bis(pyrazol‐1‐yl)pyridine ( bPzPy ) and 2, 6‐bis(3′,5′‐dimethylpyrazol‐1‐yl)pyridine ( bdmPzPy ), [Cu(bPzPy)(NO₃)₂] ( 1 ), [Cu(bPzPy)(H₂O)(NO₃)₂] ( 2 ) and [Cu(bdmPzPy)(NO₃)₂] ( 3 ) were synthesized by the reaction of copper nitrate with the ligand in ethanol solution. The complexes have been characterized through analytical, spectroscopic and EPR measurements. Single crystal X‐ray structure analysis of complexes 1 and 2 revealed a five‐coordinate copper atom in 1 , whereas 2 contains a six‐coordinate (4+2) Cu^II ion with molecular units acting as supramolecular nodes. These neutral nodes are connected through O–H ··· O(nitrate) hydrogen bonds to give couples of parallel linear strips assembled in 1D‐chains in a zipper‐like motif.     

Synthesis,characterization and magnetism of copper(II)‐lanthanide(III) heterobimetalic complexes with N,N'‐oxamidobis‐(benzoato)cuprate (II)

Seven new μ‐oxamido copper(II)‐lanthanide(III) heterobimetalic complexes described by the formula Cu(obbz) Ln‐(Ph‐phen)₂NO₃(Ln = La, Nd, Eu, Gd, Tb, Ho, Er), where obbz denotes the oxamidobis(benzoato) and Ph‐phen represents 5‐phenyl‐1, 10‐phenanthroline, have been synthesized and characterized by the elemental analyses, spectroscopic (IR, UV, ESR) studies, magnetic moments (at room temperature) and molar conductivity measurement. The temperature dependence of the magnetic susceptibility of Cu(obbz)Gd(Ph‐phen)₂NO₃ complex has been measured over the range 4.2–300 K. The least‐squares fit of the experimental susceptibilities based on the spin Hamiltonian operator, ? = ?2 J?₁·?₂, yielded J= +1.28 cm^?1, a weak ferromagnetic coupling, A plausible mechanism for a ferromagnetic coupling between Gd(III)‐Cu(II) is discussed in terms of spin‐polarization.     

Synthesis,crystal structure,and antibacterial activity of mononuclear nickel(II) and cobalt(III) Schiff-base complexes

Four new mononuclear complexes, [Ni(L¹)(NCS)₂] (1), [Ni(L²)(NCS)₂] (2), [Co(L¹)(N₃)₂]ClO₄ (3), and [Co(L²)(N₃)₂]ClO₄ (4), where L¹ and L² are N,N′-bis[(pyridin-2-yl)methylidene]butane-1,4-diamine and N,N′-bis[(pyridin-2-yl)benzylidene]butane-1,4-diamine, respectively, have been prepared. The syntheses have been achieved by reaction of the respective metal perchlorate with the tetradentate Schiff bases, L¹ and L², in presence of thiocyanate (for 1 and 2) or azide (for 3 and 4). The complexes have been characterized by microanalytical, spectroscopic, single crystal X-ray diffraction and other physicochemical studies. Structural studies reveal that 1–4 are distorted octahedral geometries. The antibacterial activity of all the complexes and their constituent Schiff bases have been tested against Gram-positive and Gram-negative bacteria.     

Synthesis and Physicochemical Characteristics of New Tetrachloroferrates(III) with Dimethylammonium Cation: X‐ray Crystal Structure of Bis(dimethylammonium) Chloride Tetrachloroferrate(III)

Two new tetrachloroferrates(III) have been synthesized of molecular formulas [(CH₃)₂NH₂][FeCl₄] and [(CH₃)₂NH₂]₂FeCl₅. The differences in their physicochemical properties have been highlighted using thermal analysis (TG‐MS) and differential scanning calorimetry (DSC). The crystal and molecular structure of [(CH₃)₂NH]₂FeCl₅ was determined. The iron(III) cation is four coordinated by chloride ions, and it adopts a slightly distorted tetrahedral coordination with three angles smaller and three larger than the tetrahedral one. In the structure four intermolecular N‐H···Cl hydrogen bonds link the [(CH₃)₂NH₂]⁺ cations to dimers via a Cl^? bridge.     

Hg(II), Tl(III), Cu(I), and Pd(II) Complexes with 2,2'-Diphenyl-4,4'-Bithiazole (DPBTZ), Syntheses and X-Ray Crystal Structure of [Hg(DPBTZ)(SCN)2]

Reaction of the ligand 2,2′-diphenyl-4,4′-bithiazole (DPBTZ) with Hg(SCN)₂, Tl(NO₃)₃, CuCl, and PdCl₂ gives complexes with stoichiometry [Hg(DPBTZ)(SCN)₂], [Tl(DPBTZ)(NO₃)₃], [Cu(DPBTZ)(H₂O)Cl]_, and [Pd(DPBTZ)Cl₂]. The new complexes were characterized by elemental analyses and infrared spectroscopy. The crystal structure of [Hg(DPBTZ)(SCN)₂] determined by X-ray crystallography. The Hg atom in the title monomeric complex, (2,2′-diphenyl-4,4′-bithiazole)mercury(II)bisthiocyanate, [Hg(C₁₈H₁₂N₂S₂)(SCN)₂], is four-coordinate having an irregular tetrahedral geometry composed of two S atoms of thiocyanate ions [Hg-S 2.4025(15) and 2.4073(15) Å] and two N atoms of 2,2′-diphenyl-4,4′-bithiazole ligand [Hg-N 2.411(4) and 2.459(4) Å]. The bond angle S(3)-Hg(1)-S(4) of 147.46(5)° has the greatest derivation from ideal tetrahedral geometry. Intermolecular interaction between Hg(1) and two S atoms of two neighboring molecules, 3.9318(15) and 3.9640(18) Å, make the Hg(1) distort from a tetrahedron to a disordered octahedron. The attempts for preparation complexes of Tl(I), Pb(II), Bi(III), Cd(II) ions with 2,2′-diphenyl-4,4′-bithiazole ligand were not successful and also the attempts for preparation complexes of 4,4′,5,5′-tetraphenyl-2,2′-bithizole ligand with Cu(II), Ni(II), Co(II), Co(III), Mn(II), Mn(III), Fe(II), Fe(III), Cr(III), Zn(II), Tl(III), Pb(II), Hg(II), Cu(I), Pd(II) were not successful. This point can be regarded as the initial electron withdrawing of phenyl rings and also their spatial steric effects.