Synthesis and X-ray crystal structure of oxamido-bridged heterobinuclear Ni(Ⅱ)-Cu(Ⅱ) complexes

The two complexes [Ni(oxen)Cu(L)2](ClO4)2.xH2O (L=2,2'-bipyridyl(bpy), 1,10-phenanthroline(phen)) have been synthesized, where oxen is N,N'-bis(2-aminoethyl)oxamido di-anion. The crystal structure of [Ni(oxen)Cu(bpy)2](ClO4)2.CH3OH has been determined by X-ray diffraction method. The crystal is triclinic system, space group P1 with a=12.179(1),b=12.298(2), c=11.476(2) A, a=97.57(1), B=97.52(1), 7=80.29(2), V=1669.04(67) A3, Z=2, Dcalcd=1.667 g/cm3. The structure has been refined to final R of 0.076 and Rw of 0.080, respectively. The complexes have an extended oxamido-bridged structure and consist of Ni(Ⅱ) ion in a square planar environment and Cu(Ⅱ) ion in a distorted octahedral environment.     

Synthesis,crystal structure and spectral characterization of Co(II) complexes with acylpyrazolone ligands

The three new Cobalt(II) complexes [Co(L¹)₂(H₂O)₂] (1), [Co(L²)₂(H₂O)₂] (2), and [Co(L³)₂(H₂O)₂] (3) have been synthesized by interaction of acyl pyrazolone ligands, 4-(4-chlorobenzoyl)3-methyl1-phenyl1H-pyrazole5(4H)-one (HL¹), 4-(4-chlorobenzoyl)1-(3-chlorophenyl)3-methyl1H-pyrazole5(4H)-one (HL²) and 5-methyl4-(4-methylbenzoyl)2-phenyl2,4-dihydro3H-pyrazole3-one (HL³) with CoCl₂.6H₂O. The complexes were screened using FTIR, UV–Vis, TGA, and Single Crystal X-ray diffraction spectroscopic techniques. A relative study of the ligands’ FTIR spectra and their metal complexes reveal the formation, sifting, and disappearance of several bands during complexation. Other interpretations stipulated that these three complexes are mononuclear and exhibited octahedral geometry around Co²⁺.Triclinic crystal system, Distortion in Octahedral geometry, and Intermolecular hydrogen bonding confirmed by Single-crystal XRD analysis of [Co(L³)₂(EtOH)₂] complex.     

邻羟基苄基氨乙酸及其配合物的研究 VI: Cu(II)、Co(II)、Ni(II)配合物的合成、性质和结构

合成了邻羟基苄基氨乙酸与Cu(II)的双核配合物, 并得以了单晶; 同时合成了Cu(II)、Co(II)、Ni(II)与该配体的质子化配合物, 测定了它们的组成、溶解度和摩尔电导, 研究了它们的磁性、热谱、红外光谱及电子光谱. 用四圆衍射仪测定了单晶的结构. 讨论了这些配合物的配位情况以及结构与性能的关系.     

Synthesis, crystal structure, and magnetic properties of oxime-bridged polynuclear Ni(II) and Cu(II) complexes

Two new polynuclear complexes [Ni6(amox)6(mu6-O)(mu3-OH)2](Cl2).6H2O and [Cu3(amox)3(mu3-OH)(mu3-Cl)](ClO4).4H2O (amox- = anion of 4-amino-4-methyl-2-pentanone oxime) have been synthesized and characterized structurally and magnetically. The Ni(II) complex contains a novel Chinese-lantern-like Ni6 cage centered by an oxo ion. It contains the nearest octahedral Ni(II)...Ni(II) separation (<2.8 A) and exhibits strong antiferromagnetic properties. The Cu(II) complex has a cyclic trinuclear copper(II) core bridged by both mu3-OH(-) and mu3-Cl(-) ions. The magnetic susceptibilities of both antiferromagnetic complexes were fitted by using approximate models.     

Co(II), Ni(II) and Zn(II)-orotate complexes with N-methylimidazole: Synthesis, crystal structures and antimicrobial activities

Three Co(II), Ni(II) and Zn(II) complexes of orotate with the N-methylimidazole ligand were synthesized and characterized by means of elemental and thermal analysis, magnetic susceptibilities, IR, UV-Vis spectroscopic and antimicrobial activity studies. The crystal structures of [Co(HOr)(H₂O)₂(Nmeim)₂]₃·H₂O (1), [Ni(HOr)(H₂O)₂(Nmeim)₂] (2) and [Zn(HOr)(H₂O)(Nmeim)₂] (3) were determined by the single crystal X-ray diffraction technique (H₃Or = orotic acid and Nmeim = N-methylimidazole). In complexes 1 and 2, the Co(II) and Ni(II) ions have distorted octahedral geometries with two Nmeim, one orotate and two aqua ligands. Complex 3 has a distorted trigonal bipyramidal geometry with two N-methylimidazole, one orotate and one aqua ligands. In the complexes, the orotate is coordinated to the metal(II) ions through the deprotonated nitrogen atom of the pyrimidine ring and the oxygen atom of the carboxylate group as a bidentate ligand. The complexes form a three-dimensional framework by hydrogen bonding, C-H?π and π?π stacking interactions. The MIC values of the complexes against selected microorganisms were determined to be in range 300-2400 μg/mL.     

Synthesis, crystal structure, electrochemistry and studies on protein binding, antioxidant and biocidal activities of Ni(II) and Co(II) hydrazone complexes

Bivalent transition metal hydrazone complexes of the composition [Ni(L₁)₂] (1), [Co(L₁)₂] (2), [Ni(L₂)₂] (3) and [Co(L₂)₂] (4) have been synthesised from the reactions of [MCl₂(PPh₃)₂] (where M = Ni or Co) with hydrazones derived from 2-acetyl pyridine and carboxylic acid hydrazides of benzhydrazide (HL₁) or thiophene-2-carboxylic acid hydrazide (HL₂), respectively. Structure of the ligands HL₁ and HL₂ and their corresponding complexes with Ni(II) and Co(II) ions were proposed based on the elemental analysis, infrared and ¹H NMR spectral methods. Single crystal X-ray diffraction study of complex 1 revealed a distorted octahedral geometry around the metal ion provided by two units of the ligand. To explore the potential medicinal value of the new complexes, binding interaction of all the complexes with bovine serum albumin (BSA) was studied at normal physiological conditions using fluorescence and UV-Vis spectral techniques. The number of binding sites (n) and binding constant (K_a) were calculated according to the double logarithm regression equation. The results of synchronous fluorescence spectrum showed that binding of metal hydrazones with BSA induced conformational changes in BSA. The in vitro antioxidant and antimicrobial potentials of the new chelates were also carried out.     

Synthesis and characterization of Co(II), Ni(II), Zn(II) and Cu(II) complexes with a new tetraazamacrocyclic Schiff base ligand containing a piperazine moiety: X-ray crystal structure determination of the Co(II) complex

Two macrocyclic Schiff base ligands, L¹ [1+1] and L² [2+2], have been obtained in a one-pot cyclocondensation of 1,4-bis(2-formylphenyl)piperazine and 1,3-diaminopropane. Unfortunately, because of the low solubility of both ligands, their separation was unsuccessful. In the direct reaction of these mixed ligands (L¹ and L²) and the appropriate metal ions only [CoL¹(NO₃)]ClO₄, [NiL¹](ClO₄)₂, [CuL¹](ClO₄)₂ and [ZnL¹(NO₃)]ClO₄ complexes have been isolated. All the complexes were characterized by elemental analyses, IR, FAB-MS, conductivity measurements and in the case of the [ZnL¹(NO₃)]ClO₄ complex with NMR spectroscopy.     

Synthesis and crystal structure of thiolate-bridged dinuclear platinum(II) complexes

Russian Journal of General Chemistry - Reactions of 2,2′-bipyridine platinum(II) complexes with 2-aminoethanethiol or 2,2′-disulfanediyldi-(ethan-1-amine) afforded new complexes...     

Synthesis and structural studies of Co(II) and Ni(II) complexes of glutaric- and adipic dihydrazides

Glutaric dihydrazide (GDH) and adipic dihydrazide (ADH) have been found to react with Co(II) chloride and Ni(II) chloride and nitrate in ethanolic solution to form complexes of the general empirical compositionsMLCl₂,ML ₂Cl₂ and [NiL ₂(H₂O)₂] (NO₃)₂ whereM=Co(II), Ni(II) andL=GDH,ADH. Tetrahedral geometry has been proposed for 11 complexes of Co(II) and octahedral geometry for the remaining complexes based on measurements of molar conductance, magnetic susceptibility, electronic and ir spectra.

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Synthese und Struktur von Co(II)- und Ni(II)-Komplexen von Glutarsäure- und Adipinsäuredihydraziden

Zusammenfassung Glutarsäuredihydrazid (GDH) und Adipinsäuredihydrazid (ADH) bilden mit Co(II)-Chlorid und Ni(II)-Chlorid bzw.-Nitrat in ethanolischer Lösung Komplexe der generellen ZusammensetzungenMLCl₂,ML ₂Cl₂ und [NiL(H₂O)₂] (NO₃)₂, mitM=Co(II), Ni(II) undL=GDH,ADH. Für 11-Komplexe von Co(II) wird eine tetragonale Geometrie, für alle anderen Komplexe eine oktaedrische Geometrie vorgeschlagen. Die Basis dazu lieferten Messungen der molaren Leitfähigkeit, der magnetischen Suszeptibilität und der UV- bzw. IR-Spektren.

     

Oxamato-bridged trinuclear Ni(II)Cu(II)Ni(II) complexes with irregular spin state structures and a binuclear Ni(II)Cu(II) complex with an unusual supramolecular structure: crystal structure and magnetic properties

Four oxamato-bridged heterotrinuclear Ni(II)Cu(II)Ni(II) complexes of formula ([Ni(bispictn)](2)Cu(pba))(ClO(4))(2).2.5H(2)O (1), ([Ni(bispictn)](2)Cu(pbaOH))(ClO(4))(2).H(2)O (2), ([Ni(cth)](2)Cu(pba))(ClO(4))(2) (3), and ([Ni(cth)](2)Cu(opba))(ClO(4))(2).H(2)O (4) and a binuclear Ni(II)Cu(II) complex of formula [Cu(opba)Ni(cth)].CH(3)OH (5) have been synthesized and characterized by means of elemental analysis, IR, ESR, and electronic spectra, where pba = 1,3-propylenebis(oxamato), pbaOH = 2-hydroxyl-1,3-propylenebis(oxamato), opba = o-phenylenebis(oxamato), bispictn = N,N'-bis(2-pyridylmethyl)-1,3-propanediamine, and cth = rac-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane. The crystal structures of 1, 3, and 5 have been determined. The structures of complexes 1 and 3 consist of trinuclear cations and perchlorate anions, and that of 5 consists of neutral binuclear molecules which are connected by hydrogen bonds and pi-pi interactions to produce a unique supramolecular "double" sheet. In the three complexes, the copper atom in a square-planar or axially elongated octahedral environment and the nickel atom in a distorted octahedral environment are bridged by the oxamato groups, with Cu.Ni separations between 5.29 and 5.33 A. The magnetic properties of all five complexes have been investigated. The chi(M)T versus T plots for 1-4 exhibit the minimum characteristic of antiferromagnetically coupled NiCuNi species with an irregular spin state structure and a spin-quartet ground state. The chi(M)T versus T plot for 5 is typical of an antiferromagnetically coupled NiCu pair with a spin-doublet ground state. The Ni(II)-Cu(II) isotropic interaction parameters for the five complexes were evaluated and are between 102 and 108 cm(-)(1) (H = -JS(Cu).S(Ni)).     

Co(II) and Ni(II) complexes with imidazole-containing ligands: Synthesis,structural characterization,and magnetic property

Hydrothermal reaction of Co(II) salt with 1,4-di(1-imidazolyl)benzene (L¹) and 4,4’-oxydiphthalic acid (H₄OA) yields a new complex [Co₃(HOA)₂(L¹)₄(H₂O)₄] (I). [Ni(L²)₂SO₄] · 0.5H₂O (II) can be obtained via the hydrothermal reaction of NiSO₄ · 6H₂O with 1,3-di(1H-imidazol-4-yl)benzene (L²). Complexes I and II have been characterized by single-crystal and powder X-ray diffraction (CIF files CCDC nos. 1019291 (I) and 1019292 (II)), IR, elemental, and thermogravimetric analyses. Complex I exhibits the uninodal six-connected 3D pcu framework structure of I with (4¹² · 6³) topology; Complex II consists of the uninodal four-connected 2D sql (4⁴ · 6²) networks. In addition, magnetic property of I was investigated.     

Synthesis and structural studies of Co(II), Ni(II) and Cd(II) complexes with 2-acetylpyridine

Three new mononuclear complexes [Co(2-Acpy)₂(H₂O)₂](NO₃)₂ (1), [Ni(2-Acpy)₂(H₂O)₂](NO₃)₂ (2) and [Cd(2-Acpy)₂(NO₃)₂] (3) (2-Acpy = 2-acetylpyridine) have been synthesized and characterized by elemental analysis, IR and UV–Vis spectroscopy. The structures of 1 and 3 were accomplished by single crystal X-ray diffraction. Crystallographic investigation of 1 reveals monomeric, dicationic units in which the cobalt(II) ion is six-coordinate. The coordination sphere is formed by two N, O bidentate acetylpyridine ligands and two water molecules. The crystal structure of 3 consists of monomeric units in which the cadmium is eight-coordinate. Both the organic ligand and nitrate groups are bidentate chelators. The supramolecular solid-state architecture is sustained by π–π interactions.     

Co(II) and Ni(II) complexes with Schiff base ligands: Synthesis,characterization, and biological activity

The ligands, 1-acetylferrocenehydrazinecarboxamide (HL¹) and 1-acetylferrocenehydrazinecarbothioamide (HL²), and their Ni(II) and Co(II) complexes were synthesized. The properties of the synthesized compounds were determined by the elemental and spectroscopic analyses. Ni(II) and Co(II) acetates interact with the ligands at the molar ratios 1 : 1 and 1 : 2 to give coloured products. The complexes have octahedral geometry. The ligands are coordinated to Co(II) and Ni(II) centers via the azomethine nitrogen and thiolic sulfur /enolic oxygen atom. The ligands and their Co(II) and Ni(II) complexes were screened for antibacterial and antifungal activities. The Co(II) and Ni(II) complexes show enhanced inhibitory activity as compared to their parent ligands. The DNA cleavage activity of the Co(II) and Ni(II) complexes was determined by gel electrophoresis. It was shown that the complexes have better cleavage activity than the ligands. The antioxidant activity of the complexes was also evaluated and used to examine their scavenging ability on hydrogen peroxide.     

A new molecular building blocks: Synthesis,crystal structure,magnetic and spectroscopic properties of Cu(II) and Ni(II) macrocyclic complexes

New higly unsaturated macrocyclic building blocks [CuLSCN]·ClO₄ (1) (L = N-dl-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) and [NiL(SCN)₂] (2) (L = N-dl-5,12-dimethyl-7,14-diisopropyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) were synthesized and the crystal structures of both compounds were determined. Both complexes crystallizes in monoclinic, space group P2₁/n (1) and P2₁/c (2). Their magnetic properties were studied over the temperature range 1.8–300 K using a Quantum Design SQUID magnetometer (MPMSXL-5-type). The results indicate that both compounds behave as weakly interacting paramagnetic centers in the crystal lattice. The effects of hydrogen bond mediating the magnetic exchange interactions on the spin density have been evidenced by DFT calculations. The NIR–Vis–UV diffuse-reflectance electronic spectra confirm the square pyramidal and octahedral geometry around Cu²⁺ and Ni²⁺ metal ions.     

Synthesis,characterization and crystal structure of ruthenium(II) polypyridyl complexes

[Ru(bipy)2(5-R-phen)](ClO4)2 complexes have been prepared, where bipy=2,2- bipyridine, phen=1,10-phenanthroline, and R=H, Me, NO2 or NH2. The influence of the different 5- substituted phen on the electron delocalization and ligand-ligand interactions have been investigated by solution n.m.r.. The ligand- ligand interaction has also been observed in the solid state by determining the single crystal structure of [Ru(bipy)2(5- NO2-phen)](ClO4)2. The strong steric interaction between the polypyridyl ligands was relieved neither by the elongation of Ru–N bonds (2.055–2.086Å) nor by increase of N–Ru–N bite angles (77.8–79.4°), but rather by distortion of the coordination sphere by forming specific angles (=2.0, 3.2 and 4.2°) between the polypyridyl ligand planes and coordination planes (N–Ru–N), and larger torsion angles (5.8 and 8.2°) between the two pyridine rings for each bipy.     

Extended triple-bridged Ni(II)- and Co(II)-hydroxamate trinuclear complexes: synthesis, crystal structures, and magnetic properties

Crystal structures of new trinuclear complexes [Ni 3(mu-OAc F) 4(mu-AA) 2(tmen) 2], [Ni 3(mu-OAc F) 4(mu-BA) 2(tmen) 2], and [Co 3(mu-OAc F) 4(mu-BA) 2(tmen) 2] have been determined (OAc F = CF 3COO (-), AA = acetohydroxamate anion, BA = benzohydroxamate anion, tmen = N, N, N', N'-tetramethylethylenediamine). In each structure, the metal ions have distorted octahedral coordination and are triply bridged by one hydroxamate and two trifluoroacetate bridges. Magnetic properties of these compounds and of relative [Co 3(mu-OAc F) 4(mu-AA) 2(tmen) 2] were studied by susceptibility and magnetization measurements. It was shown that for nickel trimers the intramolecular magnetic coupling is weak ferromagnetic in the case of the complex with the AA group, and there is nearly no coupling in the case with BA group. Rather large zero field splitting was obtained for the distorted octahedral environments of the terminal nickel ions. The cobalt trimers were additionally studied by magnetic circular dichroism (MCD) measurements. The exchange interaction of the cobalt complexes is antiferromagnetic.