Crystal structures of copper(II) complexes with methyliminodiacetate ions and 1,10-phenanthroline or imidazole [Cu(Phen)H<Subscript>2</Subscript>O][Cu(Mida)<Subscript>2</Subscript>]·2H<Subscript>2</Subscript>O and [Cu(Mida)Im]

Methyliminodiacetic acid (H₂Mida) and imidazole react with copper(II) to form crystals of the square pyramidal complex [Cu(Mida)Im]. One N and two O atoms of the Mida ligand (Cu-N 2.010(1) Å, Cu-O 1.955(1) Å, and 1.978(1) Å) and the imidazole N atom (1.950(1) Å) lie at the base of the pyramid. The carboxyl O atom of the neighboring complex lies at the apical position (2.411(1) Å); in this way the individual complexes are linked into infinite zigzag chains. Substitution of imidazole by 1,10-phenanthroline gave [Cu₂(Mida)₂(Phen)H₂O]·2H₂O crystals with two nonequivalent centrosymmetric octahedral anions [Cu(Mida)₂]^2? of face type (Cu-N 2.023 Å and 2.028(2) Å, Cu-O_ax 2.579 Å and 2.530(2) Å, Cu-O_bas 1.952 Å and 1.936(2) Å). The anions serve as bridges in chains between the [Cu(Phen)H₂O]²⁺ cation fragments to which they are bonded by their axial carboxyl groups. The Cu atom of the cation has a [4+1] environment (with the H₂O molecule lying on the axis of the pyramid, and with two N atoms of the ligand and two O atoms of the anions lying at the base).     

A new binuclear germanium(IV) and copper(II) complex with 1,3-diamino-2-propanoltetraacetic acid: Crystal and molecular structure of [(H2O)(OH)Ge(μ-Hpdta)Cu(H2O)] · 3H2O

A heteronuclear germanium(IV) and copper(II) complex with 1,3-diamino-2-propanoltetraacetic acid (H₅Hpdta) has been synthesized for the first time. The compound has been characterized by elemental analysis, X-ray diffraction, thermogravimetry, and IR spectroscopy. The structure of the complex [(H₂O)(OH)Ge(μ-Hpdta)Cu(H₂O)] · 3H₂O (I) has been determined by single-crystal X-ray diffraction. The crystals of I are monoclinic, a = 1 5.327(4) Å, b = 11.626(3) Å, c =21.058(3) Å, β = 96.35(2)°, V = 3729.2(2) ų, Z = 8, space group C2/c, R1 = 0.0551 on 3090 reflections with I > 2σ(I). The structural units of the crystal of I are binuclear complex molecules [(H₂O)(OH)Ge(μ-Hpdta)Cu(H₂O)] and crystal water molecules. The germanium and copper atoms are linked by the bridging oxygen atom of the deprotonated isopropanol group of the Hpdta^5? ligand (Ge-O, 1.843(3) Å; Cu-O, 2.221(3) Å). The coordination spheres of the Ge and Cu atoms contain each one nitrogen atom (Ge-N, 2.090(4) Å; Cu-N, 2.000(4) Å) and two carboxyl oxygen atoms from four acetate arms of the heptadentate Hpdta^5? ligand (av. Ge-O, 1.909(3) Å; Cu-O, 1.948(3) Å). The coordination polyhedron of the Ge atom is completed to a distorted octahedron by the oxygen atoms of the terminal hydroxy group (Ge-O, 1.786(3) Å) and a water molecule (Ge-O, 1.904(3)Å). The coordination polyhedron of the copper atom is completed to a prolate tetragonal pyramid (4 + 1) by the oxygen atom of a water molecule in the equatorial position (Cu-O, 1.955(4) Å) and the bridging O(11) atom (Hpdta^5?) in the apical position. Binuclear molecules are linked pairwise in a head-to-head manner via double Cu-O(2) bridges to form the centrosymmetric tetranuclear supramolecule {[(H₂O)(OH)Ge(μ-Hpdta)Cu(H₂O)]}₂. The coordination of the Cu atom is completed by the weak Cu-O(2A) contact (3.303 Å) to an asymmetrically elongated tetragonal bipyramid (4 + 1 +1). In the crystal, the complex molecules and crystal water molecules are combined by a system of hydrogen bonds into a three-dimensional framework.     

Complex [MoO2(L)(CH3OH)] (L2- = 3-methoxysalicylidenemonoethanolimine anion): Synthesis,crystal and molecular structures

The complex [MoO₂(L)(CH₃OH)] (where L^2- is 3-methoxysalicylidenemonoethanolimine anion) has been prepared and structurally characterized by X-ray diffraction. The molybdenum atom has an octahedral coordination to two ligands in cis-positions to each other, two oxygen atoms, the nitrogen atom of the tridentate bis(chelate) L^2- ligand, and also the oxygen atom of methanol. Strong O-H?O hydrogen bonds (O?O, 2.598 Å) link pairs of molecules into centrosymmetric pseudo-dimers.     

STEREOCHEMISTRY OF COMPLEXES WITH N-ALKYLATED AMINO ACIDS. VIII. CRYSTAL STRUCTURE AND CONFORMATIONAL ANALYSIS OF AQUABIS(L-N,N-DIMETHYLTHREONINATO)COPPER(II) DIHYDRATE

Abstract

The structure of blue, monoclinic (space group P2₁) crystals of aquabis(L-N,N-dimethylthreoninato)copper(II) dihydrate was determined by X-ray diffraction and refined to R = 0.030. The coordination around the copper(II) atom is distorted square-pyramidal with threonine N and O atoms in trans orientations (Cu-O 1.930(3) and 1.926(3)Å, Cu-N 2.042(3) and 2.055(3)Å, O-Cu-O 163.9, N-Cu-N 164.0°) and apical water (Cu-O(W) 2.206 Å). The shape of the coordination polyhedron was reasonably well reproduced with molecular mechanics calculations, yielding root-mean-square deviations of ten valence angles around copper to 4.5°. The calculated strain energy of the crystal conformation is about 21 kJ mol^? higher than the energy of the most stable conformer. This was tentatively attributed to the additional stabilization of molecular conformation by intermolecular hydrogen bonds in the solid state.     

Crystal and molecular structures of triaquabis(5-nitro-2-acetamidobenzoato)copper(II) dihydrate

A new copper(II) complex [Cu(5-NO₂-2-CH₃CONHC₆H₃COO)₂(H₂O)₃] · 2H₂O was synthesized by the reaction of sodium 5-nitro-5-acetamidobenzoate with CuSO₄ · 5H₂O (2: 1), and its structure was determined by X-ray diffraction. Crystals are monoclinic: a = 11.7146(7) Å, b = 16.8463(10) Å, c = 13.2408(9) Å, β = 113.896(5)°, Z = 4, ρ_calc = 1.668 g/cm³, space group P2₁/c, R = 0.0338. In the monomer complex, the copper atom has an elongated square-pyramidal coordination (4 + 1); the coordination sphere is formed by two oxygen atoms of the carboxylate groups of two monodentate organic ligands and the three oxygen atoms O(w) of the water molecules (the O(3w) atom is in the axial position). In the structure, the complex molecules are linked by hydrogen bonds involving two uncoordinated water molecules.     

New examples of mixed-ligand bis(hexafluoroacetylacenonato)copper(II) complexes with 3-imidazoline nitroxide radicals at a Cu(C5HF6O2)2∶L=3∶2 ratio (L2=C14H19N2O,L3=C13H17N2O3)

The crystal structures of two (hexafluoroacetylacetonato)copper(II) complexes with 3-imidazoline nitroxide radicals, [Cu(C₅HF₆O₂)₂]₃ (C₁₄H₁₉N₂O)₂ (I) and [Cu(C₅HF₆O₂)₂]₃ (C₁₃H₁₇N₂O₃)₂ (II), have been determined. The compounds are triclinic (PI, Z=1) with a=8.730(2), b=10.357(2), c=21.996(5) Å, α=103.24(2), β=94.03(2), γ=95.04(2)⁰, V=1920(1) ų for I and a=8.679(2), b=14.769(4), c=15.368(4) Å, α=85.58(2), β=96.25(1), γ=104.60(1)⁰, V=1893(1) ų for II. Complexes I and II are molecular. The trinuclear molecules are centrosymmetric relative to the Cu(1) atom. The coordination polyhedron of Cu(1) is a square bipyramid formed by the O atoms of the hfac anions and nitroxide radicals (average Cu?O_hfac 1.92(1) for I and 1.93(1) Å for II; Cu?O_N?O 2.47(1) for I and 2.56(1) Å for II). The coordination polyhedron of Cu(2) is a trigonal bipyramid formed by the O atoms of the hfac anions (Cu?O_hfac 1.91(1)–2.12(1) for I and 1.91(1)–2.09(1) Å for II) and an imine N atom of the radical (Cu(2)?N(2) 2.00(1) for I and 2.03(1) Å for II). The molecules are linked by van der Waals forces.     

Synthesis and crystal structures of two Schiff base copper(II) complexes derived from 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol

A centrosymmetric mononuclear copper(II) complex, [Cu(L¹)₂] (I), and a phenolate oxygen-bridged dinuclear copper(II) complex, [Cu₂(L²)₄] (II) (HL¹ = 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol, HL² = 4-chloro-2-(cyclohexylimino-methyl)phenol), were synthesized and characterized by elemental analyses, IR, and single crystal X-ray diffraction. The crystal of I is monoclinic: space group {ITP}2₁/n, a = 13.396(3), b = 5.339(1), c = 19.740(4) Å, β = 108.64(3), V = 1337.8(5) ų, {ITZ} = 2. The crystal of II is monoclinic: space group P2₁, a = 9.157(2), b = 22.715(4), c = 12.169(2) Å, = 95.28(3), {ITV} = 2520.4(8) Å3, {ITZ}= 2. The Cu atom in I, lying on the inversion center, is four-coordinate in a square planar geometry with two phenolate oxygen and two imine nitrogen atoms. Each Cu atom in II is five-coordinate in a square pyramidal geometry with two phenolate oxygen and two imine nitrogen atoms from two L² ligands defining the basal plane and with one phenolate oxygen atom of another L² ligand occupying the apical position.     

Structure and EPR spectra of binuclear copper(II) complexes with acyldihydrazones of benzenedicarboxylic acids and 5-substituted 2-hydroxyacetophenones

Binuclear copper(II) complexes with acyldihydrazones of 1,3- or 1,4 benzenedicarboxylic acid and 5-methyl- or 5-bromo-2-hydroxyacetophenone in which coordination polyhedra are connected by an aromatic bridge have been synthesized and studied. The structure of the copper(II) complex with diacylhydrazone of isophthalic acid and 2-hydroxy-5-methylacetophenone (H₄L) of composition [Cu₂L · 3Py] was studied by X-ray diffraction. The crystals are monoclinic: a = 12.1996(12) Å, b = 17.7295(17) Å, c = 17.9339(17) Å, β = 109.7450(10)°, space group P2₁/n, Z = 4. The complex is of the “dimer of dimers” type and contains two binuclear subunits that bind together into a centrosymmetric dimer owing to the coordination of the copper cation to the phenoxyl oxygen atom of a neighboring binuclear molecule to form the Cu₂O₂ moiety, in which the copper atoms are 3.409 Å apart. The distance between the copper(II) cations in the binuclear subunit is 8.56 atoms (2N + O) of the doubly deprotonated acylhydrazone moiety and the nitrogen atom of the pyridine molecule. One of the copper cation is additionally coordinated to an extra pyridine molecule so that its coordination sphere is completed to a tetragonal pyramid. The second copper atom is involved in additional interaction with the phenoxyl oxygen atom of the neighboring molecule. The EPR spectra of solutions of the binuclear complexes show an isotropic signal of four HFS lines (g _o = 2.065–2.143, a _Cu = 52.1–66.5 × 10^?4 cm^?1) typical of mononuclear copper(II) complexes.     

Crystal and molecular structures of bis(2,2,6,6-tetramethyl-3-methylaminoheptan-5-onate) copper(II) and nickel(II)

Two bis-chelates M(tmih)₂ (M = Cu(II), Ni(II), tmih = (CH₃)₃C(NCH₃)CHCOC(CH₃)₃)^? are synthesized and their crystal structures are determined using XRD (Bruker APEX-II diffractometer with a CCD detector, λMoK _α, λCuK _α, graphite monochromator, T = 240(2) K and 296(2) K): Cu(tmih)₂ (I) (space group P2₁/c, a = 12.9670(8) Å, b = 18.4921(9) Å, c = 11.0422(6) Å, β = 93.408(4)°, V = 2643.1(3) ų, Z = 4) and Ni(tmih)₂ (II) (space group P2₁/c, a = 12.810(2) Å, b = 18.529(2) Å, c = 11.243(2) Å, β = 91.959(7)°, V = 2667.1(6) ų, Z = 4). The complexes are isostructural; the coordination polyhedron of metal atoms is a flattened tetrahedron formed from two O atoms (Cu-O of 1.901(2) Å, 1.892(2) Å, Ni-O of 1.845(2) Å, 1.833(2) Å) and two N atoms (Cu-N of 1.976(3) Å, 1.972(3) Å, Ni-N of 1.911(2) Å, 1.920(2) Å) of the ligand; the chelate OMN angles (M = Cu(II), Ni(II)) are in the 87.4–93.1° range; the OMO and NMN angles are 162.2° and 167.2° in I, 171.1° and 173.2° in II. The complexes have the molecular structures formed from isolated molecules bonded by van der Waals interactions. Using a quantum chemical hybrid M06 method, the structures of copper(II) chelates with the H, CH₃, CH₂CH₃, CH(CH₃)₂, and C(CH₃)₃ substituents at the nitrogen atom are calculated. Found that with a bulky substituent at the nitrogen atom, the formation of chelates is hindered due to the intraligand repulsion between the atoms of this substituent and the tert-butyl group.     

SYNTHESIS AND CHARACTERIZATION OF DIAQUA(3-pTOLYLIMINO-2-BUTANONE OXIMATO)(3-p-TOLYLIMINO-2-BUTANONE OXIME)NICKEL(II) PERCHLORATE

Abstract

[Ni(L^?1)(HL)(H₂O)₂].ClO₄ with a Schiff base ligand L (HL = 3-p-tolylimino-2-butanone oxime) was prepared and structurally characterized by IR, cyclic voltammetry and X-ray diffraction methods. The nickel atom has distorted octahedral coordination consisting of four nitrogen atoms and two oxygen atoms. The equatorial plane is formed by two oxime nitrogen atoms and two imine nitrogen atoms of two Schiff base ligand (L^?1 and HL) with Ni‐ N bond distances between 2.01(1) and 2.11(1)Å. Water oxygen atoms occupy axial positions with Ni‐ O bond distances of 2.06(1) and 2.15(1) Å. The oxime groups in the Schiff base ligands are coordinated to Ni atom through their nitrogen atoms. One asymmetric intramolecular hydrogen bridge between the two oxime groups is found in the title complex.     

(2‐Methyl­quinolin‐8‐olato)­iron(III) and ‐copper(II) complexes

The crystal structures of tris(2‐methyl­quinolin‐8‐olato‐N,O)­iron(III), [Fe­(C₁₀­H₈­NO)₃], (I), and aqua­bis(2‐methyl­quinolin‐8‐olato‐N,O)­copper(II), [Cu­(C₁₀­H₈NO)₂­(H₂O)], (II), have been determined. Compound (I) has a distorted octahedral configuration, in which the central Fe atom is coordinated by three N atoms and three O atoms from three 2‐methylquinolin‐8‐olate ligands. The three Fe—O bond distances are in the range 1.934 (2)–1.947 (2) Å, while the three Fe—N bond distances range from 2.204 (2) to 2.405 (2) Å. In compound (II), the central Cu^II atom and H₂O group lie on the crystallographic twofold axis and the coordination geometry of the Cu^II atom is close to trigonal bipyramidal, with the three O atoms in the basal plane and the two N atoms in apical positions. The Cu—N bond length is 2.018 (5) Å. The Cu—O bond length in the basal positions is 1.991 (4) Å, while the Cu—O bond length in the apical position is 2.273 (6) Å. There is an intermolecular OW—H?O hydrogen bond which links the mol­ecules into a linear chain along the b axis.     

THE POLYMERIC COPPER COMPLEX 2,2′-BIPYRIDINE-N,N′-(μ-MALEATO-O,O′:O″)COPPER(II) DIHYDRATE

Abstract

Preparation and isolation of the polynuclear copper(II) complex, {[Cu(bipy)(maleato)] · 2H₂O} _n , was accomplished by reaction of an aqueous solution containing sodium maleate and an ethanolic solution of Cu(NO₃)₂·4H₂O and bipy. The crystal structure of the title complex was determined by single-crystal X-ray methods. The structure consists of one-dimensional infinite chains. The copper atom is five-coordinate and presents a square-pyramidal coordination sphere, which consists of the two imine N atoms of bipy and two terminal carboxylate O atoms of a maleate^2- ligand in the basal plane with Cu-N bond distances of 2.016(3) and 1.987(3) A and Cu-O distances of 1.909(2) and 1.947(2) Å, respectively. In the apical site an O atom of the maleate^2- ligand from an adjacent complex coordinates to copper (2.264(2) Å). The coordination fashion of the maleato ligand is also confirmed by the IR spectrum.     

Crystal structure oftrans-bis-(2,2,6-trimethyl-6-methoxy-5-iminoheptan-3-onato)copper(II)

A new volatile N,O-chelate complex of Cu(II) containing a methoxy group was studied by X-ray diffractometry (KUMA automatic diffractometer, MoK_a radiation for single crystals and DRON-UM1, CuK_a radiation for polycrystals). The structure is molecular and consists of transcomplexes of bis-(2,2,6-trimethyl-6-methoxy-5-iminoheptan-3-onato)copper(II). The structure was refined in an anisotropic approximation using 2426 independent reflections to R = 0.048. Crystal data: a = 13.426(2), b = 9.566(2), c = 19.562(4) Å, Β = 90.72?, space group F2₁ /n, V = 2512.2(8) ų, Z = 4, d_calc = 1216 g/cm³. The squareplanar environment of the copper atom with distances Cu-O = 1.938 and Cu-N = 1.912 Å is completed to pyramidal by interaction with the oxygen atom of one methoxy group of the neighboring molecule at a distance of Cu...O = 2.81 Å.     

Synthesis and Crystal Structures of Nickel(II) and Copper(II) Complexes of Meso-3,6,6,9-Tetramethyl-4,8-Diazaundecane-2,10-Dione Dioxime

The nickel(II) and copper(II) complexes of meso-3,6,6,9-tetramethyl-4,8-diazaundecane-2,10-dione dioxime (meso-HM-PAO) have an intramolecular hydrogen bond between cis oxime groups. [Cu(meso-HM-PAO-H)(H₂O)](NCS) crystallizes in space group P2₁/n with a = 7.692(1), b = 12.028(2), c=20.235(3) Å, β=93.03(1)°, Z = 4 and Dc=1.46 g/cm³. The final R value for this complex was 0.034 for 2223 observed reflections with I ≥ 2.5σ (I). The Cu(II) coordination is a distorted square pyramid. The Cu(II) ion is five-coorinated with the diazadioxime N atoms equatorial and water O atom axial. The Cu(II) is 0.12 Å from the equatorial plane towards the hydrate. The equatorial Cu-N distances span a narrow range, 1.953(3)-1.999(3) Å. The axial Cu-O distance is 2.314(3) Å. The thiocyanate group is almost linear. The intramolecular O ?O hydrogen bond length is 2.479(4) Å. [Ni(meso-HM-PAO-H)](ClO₄) crystallizes in space group P2₁/c with a = 14.774(3), b = 12.752(3), c = 20.035(4) Å, β = 92.94(3)°, Z = 8 and Dc = 1.51 g/cm³. The final R value for the complex was 0.053 for 4794 observed reflections with F ≥ 4σ (F). The coordination about Ni(II) is a slightly distorted square plane. The Ni(II) ion is 0.0673(7) Å from the best plane of the four donor nitrogen atoms away from the perchlorate ion. The Ni-N distances span a narrow range 1.863(4)-1.927(4) Å. There are two molecules per asymmetrical unit resulting in eight molecules being packed in an unit cell; they are bound together by van der Waals interactions. The O-H ?O bonds of these complexes give characteristic infrared absorptions as well as chemical shift of the ¹H NMR signal (Ni complex).     

Synthesis and Characterization of [Hg(sulfamethoxazolato)2]·2DMSO and[Cu2(μ‐CH3CO2)4(sulfamethoxazole)2]

[Hg(sulfamethoxazolato)₂]·2DMSO ( 1 ) and [Cu₂(CH₃COO)₄(sulfa‐methoxazole)₂] ( 2 ) can be obtained by the reaction of sulfamethoxazole with mercury acetate or copper acetate in methanol. The structures of the two complexes were characterized by single crystal X—ray diffractometry. Compound 1 consists of sulfamethoxazolato ligands bridging the metal ions building an unidimensional chain. Two solvent dimethylsulfoxide molecules are involved via N‐H···O hydrogen bridges. The mercury atom shows a linear primary coordination arrangement formed by two trans deprotonated sulfonamidic nitrogen atoms. The overall coordination around the metal atom may be regarded as a strongly distorted octahedron when the interactions of mercury with four sulfonamidic oxygen atoms [bond distances of 2.761(4) Å—2.971(4) Å] are also considered to build an equatorial plane and the N1 and N1′ atoms [bond distance of 2.037(5) Å] occupy the apical positions. Compound 2 is a dinuclear complex in which the copper ions are bridged by four syn‐syn acetate ligands which are related by a symmetry centre located in the centre of the complex. Each copper atom presents a nearly octahedral coordination where the equatorial plane is formed by four oxygen atoms and an isoxazolic nitrogen atom and the second copper atom occupy the apical positions.     

CRYSTAL STRUCTURE,SPECTRAL AND MAGNETIC BEHAVIOR OF COPPER(II)(5-CHLOROSALICYLATO)2 (AQUA)2

Abstract

The synthesis and characterization of Cu(5-Clsal)₂(H₂O)₂ (5-Clsal = 5-chlorosalicylate) are reported. Characterization of the compound was based on elemental analysis, electronic and EPR spectra, and magnetic susceptibility measurement over a temperature range 93–239 K.

An X-ray analysis of Cu(5-Clsal)₂(H₂O)₂ was carried out, showing a polymeric chain of copper(II) atoms bridged by pairs of water molecules with Cu-O(bridge) bond lengths of 1.970(2) and 2.718(2)Å. The coordination sphere about each copper(II) atom is completed (on the X-axis) by a trans-pair of unidentate 5-chlorosalicylate anions. The bridging oxygen atoms arrange a planar Cu₂O₂ rhombus. The relationship between degree of distortion and g-values from EPR spectra is also discussed.     

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.     

Synthesis,Spectral, Thermal Studies of Co(II), Ni(II), Cu(II) and Zn(II)‐arginato Complexes. Crystal Structure of Monoaquabis(arginato‐κO,κN)copper(II). [Cu(arg)2(H2O)].NaNO3

Transition metal complexes of arginine (using Co(II), Ni(II), Cu(II) and Zn(II) cations separately) were synthesized and characterized by FTIR, TG/DTA‐DrTG, UV‐Vis spectroscopy and elemental analysis methods. Cu(II)‐Arg complex crystals was found suitable for x‐ray diffraction studies. It was contained, one mole Cu^II and Na⁺ ions, two arginate ligands, one coordinated aqua ligand and one solvent NO₃^? group in the asymmetric unit. The principle coordination sites of metal atom have been occupied by two N atoms of arginate ligands, two carboxylate O atoms, while the apical site was occupied by one O atom for Cu^II cation and two O atoms for Co^II, Ni^II, Zn^II atoms of aqua ligands. Although Cu^II ion adopts a square pyramidal geometry of the structure. Co^II, Ni^II, Zn^II cations have octahedral due to coordination number of these metals. Neighbouring chains were linked together to form a three‐dimensional network via hydrogen‐bonding between coordinated water molecule, amino atoms and O atoms of the bridging carboxylate groups. Cu^II complex was crystallized in the monoclinic space group P2₁, a = 8.4407(5) Å, b = 12.0976(5) Å, c = 10.2448(6) Å, V = 1041.03(10) ų, Z = 2. Structures of the other metal complexes were similar to CuII complex, because of their spectroscopic studies have in agreement with each other. Copper complex has shown DNA like helix chain structure. Lastly, anti‐bacterial, anti‐microbial and anti‐fungal biological activities of complexes were investigated.     

A novel copper(II) complex with schiff base derived from o-vanillin and L-methionine: Syntheses and crystal structures

A new Schiff base copper(II) complex, {[CuL(H₂O)₂][CuL(H₂O)]₃ · 4H₂O · C₃H₇NO} _n (H₂L = (Z)-2-(2-hydroxy-3-methoxybenzylideneamino)-4-(methylthio)butanoic acid), was synthesized and characterized by IR, UV, and X-ray diffraction single-crystal analysis. The crystal belongs to the triclinic crystal system, space group with cell parameters a = 5.2027(5) Å, b = 16.6916(16) Å, c = 20.237(2) Å, α = 88.895(10)°, β = 84.127(1)°, γ = 83.577(10)°, V = 1737.2(3) ų, Z = 1, F(000) = 848, S = 1.042, ρ_calcd = 1.561 g cm^?3, μ = 1.411 mm^?1, the final R ₁ = 0.0760 and wR ₂ = 0.2318 for 6030 observed reflections (I > 2σ(I)). The crystal structure of the complex contains two independent units with different coordination environments. In independent unit 1, the Cu(1) is five-coordinated by one nitrogen atom and two oxygen atoms from the Schiff base ligand and two oxygen atoms from two water molecules to form a distorted square pyramid geometry. On the other hand, in independent unit 2, the Cu(2) is five-coordinated and possesses a slightly distorted square-pyramidal coordination geometry, defined by one nitrogen atom, one hydroxyl oxygen atom, two carboxylate oxygen atoms in two different ligands, and one oxygen atom of the water molecule. The complex forms a one-dimensional chain polymer in the xy plane through carboxyl oxygen atoms in the Schiff base ligands.     

Crystal structure of bis(semicarbazido)copper(II) nitrate [Cu(NH<Subscript>2</Subscript>NHC(O)NH<Subscript>2</Subscript>)<Subscript>2</Subscript>](NO<Subscript>3</Subscript>)<Subscript>2</Subscript>

The crystal structure of bis(semicarbazido)copper(II) nitrate [Cu(NH₂NHC(O)NH₂)₂](NO₃)₂ has been studied by X-ray diffraction. Monoclinic crystals, a = 6.835(2) Å, b = 7.733(2) Å, c = 10.320(3) Å, β = 105.701(3)°, V = 525.1(2) ų, space group P2₁/c, Z = 2, d _msd = 2.136 g/cm³, μ(MoK _α) = 2.143 mm⁻¹. The structure was solved with the program for automatic analysis of Patterson’s function and refined by full-matrix least squares in an anisotropic approximation for all non-hydrogen atoms using 753 independent reflections; R ₁ = 0.0203. The square environment of the Cu atom is formed from the amino nitrogen atoms of the hydrazine fragments and the C=O oxygen atoms of the two semicarbazide bidentate molecules (Cu-N 1.928 Å, Cu-O 1.999 Å). The axial positions are occupied by the O atoms of the NO ₃ ⁻ outer-spheric anions (Cu-O 2.505 Å). In the structure, the complex cations and the NO ₃ ⁻ anions are linked into a framework by N-H...O type hydrogen bonds. Original Russian Text Copyright ? 2007 by G. V. Romanenko, Z. A. Savelieva, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No. 2, pp. 370–373, March–April, 2007.