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,crystal structure and infrared spectra of Cu(II) and Co(II) complexes with 4,4′‐dichloro‐2,2′‐[ethylene dioxybis(nitrilomethylidyne)]diphenol

Novel 4,4′‐dichloro‐2,2′‐[ethylenedioxybis(nitrilomethylidyne)]diphenol (H₂L) and its complexes [CuL] and {[CoL(THF)]₂(OAc)₂Co} have been synthesized and characterized by elemental analyses, IR, ¹H‐NMR and X‐ray crystallography. [CuL] forms a mononuclear structure which may be stabilized by the intermolecular contacts between copper atom (Cu) and oxygen atom (O3) to form a head‐to‐tail dimer. In {[CoL(THF)]₂(OAc)₂Co}, two acetates coordinate to three cobalt ions through Co? O? C? O? Co bridges and four µ‐phenoxo oxygen atoms from two [CoL(THF)] units also coordinate to cobalt ions. Copyright © 2008 John Wiley & Sons, Ltd.     

Structurally characterized homotrinuclear Salamo‐type nickel(II) complexes: Synthesis,solvent effect and fluorescence properties

Four new solvent‐induced Ni(II) complexes with chemical formulae [{NiL(μ₂‐OAc)(MeOH)}₂Ni]·2MeOH ( 1 ), [{NiL(μ₂‐OAc)}₂(n‐PrOH)(H₂O)Ni]·n‐PrOH ( 2 ), [{NiL(μ₂‐OAc)(DMF)}₂Ni] ( 3 ) and [{NiL(μ₂‐OAc)(DMSO)}₂Ni]·2DMSO ( 4 ), (H₂L = 4‐Nitro‐4′‐chloro‐2,2′‐[(1,3‐propylene)dioxybis(nitrilomethylidyne)]diphenol) have been synthesized and characterized by elemental analyses, FT‐IR, UV–Vis spectra and X‐ray crystallography. X‐ray crystal structure determinations revealed that each of the Ni(II) complexes 1–4 consists of three Ni(II) atoms, two completely deprotonated (L)^2? units, two μ₂‐acetate ions and two coordinated solvent molecules (solvents are methanol, n‐propanol, water, N,N‐dimethylformamide and dimethyl sulphoxide, respectively). Although the four complexes 1–4 were synthesized in different solvents, it is worthwhile that the Ni(II) atoms in the four complexes 1–4 adopt hexa–coordinated with slightly distorted octahedral coordination geometries, and the ratios of the ligand H₂L to Ni(II) atoms are all 2: 3. The complexes 1–4 possess self‐assembled infinite 1D, 3D, 1D and 2D supramolecular structures via the intermolecular hydrogen bonds, respectively. In addition, fluorescence behaviors were investigated in the complexes 1–4 .     

Synthesis and characterization of potassium 1,3-bis(N-methylpiperazino)propan-2-O-xanthate and the complexes of Co(II), Ni(II) and Cu(I) ions

Potassium 1,3-bis(N-methyl piperazino)propan-2-O-xanthate (LK), and its complexes with Co(II), Ni(II) and Cu(I) ions have been prepared and characterized as [CoL₂(H₂O)₂], [NiL₂(H₂O)₂]·2H₂O and CuL·2H₂O by FT-IR, ¹H and ¹³C?NMR spectroscopies, elemental analyses, magnetic susceptibility and TGA techniques.     

Spectroscopic evaluation of Co(II), Ni(II) and Cu(II) complexes derived from thiosemicarbazone and semicarbazone

Co(II), Ni(II) and Cu(II) complexes were synthesized with thiosemicarbazone (L(1)) and semicarbazone (L(2)) derived from 2-acetyl furan. These complexes were characterized by elemental analysis, molar conductance, magnetic moment, mass, IR, electronic and EPR spectral studies. The molar conductance measurement of the complexes in DMSO corresponds to non-electrolytic nature. All the complexes are of high-spin type. On the basis of different spectral studies six coordinated geometry may be assigned for all the complexes except Co(L)(2)(SO(4)) and Cu(L)(2)(SO(4)) [where L=L(1) and L(2)] which are of five coordinated square pyramidal geometry.     

New Ni(II)Cu(II)Ni(II) trinuclear complexes with an 5=3/2 high-spin ground

Four new heterotrinuclear complexes have been synthesized and characterized, namely {[Ni(L)₂]₂[Cu(opba)]}(ClO₄)₂, where opba denotes o-phenylenebis(oxamato) and L stands for 1,10-phenanthroline(phen) (1), 5-nitro-l,10-phenanthroline(NO₂-phen) (2), 2,2′-bipyridyl(bpy) (S) and 4,4′-dimethyl-2,2′-bipyridyl(Me₂bpy) (4). The temperature dependence of the magnetic susceptibility of {[Ni(phen)₂]₂[Cu(opba)]}(ClO₄)₂3H₂O has been studied in the 4–300 K range, giving the exchange integral J—109 cm^?1. The HMT vs. T plot exhibits a minimum at about 100 K, characteristic of this kind of coupled polymetallic complex with an irregular spin-state structure.     

Salamo-type trinuclear and tetranuclear cobalt(II) complexes based on a new asymmetry Salamo-type ligand: syntheses,crystal structures,and fluorescence properties

Two multinuclear Co(II) complexes, [{Co(L)(i-PrOH)}₂Co(H₂O)]?2CH₃CN (1) and [{Co(L)(μ-OAc)Co(MeOH)₂}₂]?2CH₃COCH₃ (2), have been synthesized with a new asymmetric Salamo-type ligand (H₃L = 6-hydroxy-6′-ethoxy-2,2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol). The Co(II) complexes were obtained by different solvents, and the structures are completely different. In the Co(II) complex 1, the ratio of the ligand H₃L to Co(II) atom is 2 : 3 and the Co(II) ions are all five-coordinate with trigonal bipyramidal geometries. In the Co(II) complex 2, the ratio of the ligand H₃L to Co(II) atom is 2 : 4. Two central Co(II) ions are six coordinate with distorted octahedral geometries and two terminal Co(II) ions are five coordinate with distorted trigonal bipyramidal geometries. Self-assembling of an infinite 1-D supramolecular chain is formed by C–H?π interactions in 1. Interestingly, an infinite 2-D-layer plane structure is formed by the self-assembling array of 2 linked by C–H?π interactions. 1 and 2 exhibit blue emissions with the maximum emission wavelengths λ_max? = 403 and 395 nm when excited at 330 nm.     

Synthesis and Crystal Structure of a Dinuclear Cu(Ⅱ) Complex [Cu(C_(13)H_9N_2O)Cl]_2·(CH_3CN)_2 with Ligand 2-Benzimidazol

A new dinuclear copper complex, [Cu(C13H9N2O)Cl]2·(CH3CN)2 (C30H24Cl2Cu2N6O2), has been synthesized and characterized by X-ray structure determination. It crystallizes in the tricli- nic system, space group P1, with a = 7.6677(14), b = 9.2375(17), c = 11.227(2) , α = 81.338(3), β = 88.173(4), γ = 66.199(3)o, V = 718.9(2) 3, Z = 1, Mr = 698.53, F(000) = 354, Dc = 1.613 g/cm3, μ(MoKα) = 1.705 mm-1, the final R = 0.0645 and wR = 0.1364 for 2474 unique reflections with 1809 observed ones (I > 2σ(I)). In the title complex, each copper(II) atom is located at the center of a distorted tetrahedron consisting of four coordinate atoms (one nitrogen atom, two oxygen anions, and one chlorine atom). Two copper(II) atoms are bridged by two oxygen anions (O(1) and O(1a)) of two phenolates to form a Cu(II)–Cu(II) binuclear entity, and the distance between two copper(II) atoms is 3.0144(15) .     

配位聚合物{[Co(4,4''''-bpy)(H2O)4](Fum)·4H2O}n的合成和晶体结构

0引言近年来,利用晶体工程方法设计、裁剪和组装具有一维、二维和三维有序超分子结构的配位聚合物引起了人们极大的兴趣,并成为材料科学和化学学科中最活跃的研究领域之一[1~3]。在超分子结构设计方面,利用过渡金属借助配体配位作用引导的自组装已成为一个热点。其中多联吡啶类     

Synthesis,crystal structure,and magnetic properties of a linear trinuclear Cu(II) complex

A new linear trinuclear Cu(II) complex, [Cu₃(NTA)₂(4,4′-bpt)₄(H₂O)₂]?·?10H₂O (H₃NTA?=?nitrilotriacetic acid, 4,4′-bpt?=?4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole) (1), was obtained from evaporation of an aqueous solution containing Cu(NO₃)₂?·?6H₂O, 4,4′-bpt, nitrilotriacetic acid (H₃NTA), and NaOH. 1 was characterized using single-crystal X-ray diffraction, IR, and elemental analysis. In the trimer, the three linear copper ions are bridged by two NTA carboxylate groups in a syn–anti conformation and connected by 4,4′-bpt to produce a 1-D array. Temperature-dependent magnetic susceptibilities reveal the presence of weak antiferromagnetic exchange between metal centers.     

Synthesis,characterization, molecular modeling,and thermal analyses of bioactive Co(II) and Cu(II) complexes with diacetylmonoxime and different amines

Condensation of diacetylmonoxime with 2-amino-5-mercapto-1,3,4-thiadiazole, 2-amino-1,3,4-thiadiazole or 3-amino-5-methylisoxazole in the presence of Co(II) and Cu(II) salts with different anions produced nine complexes. The synthesized complexes have been characterized by elemental analyses, molar conductivities, thermal analyses, magnetic moments, IR, electron spin resonance, and UV-Vis spectral studies. The spectral data show that sulfur, oxygen, and nitrogen participate in chelation with the metal ions. The complexes are tetrahedral, octahedral, or square planar based on the amine used and the nature of anion. Molar conductance measurements of the complexes in DMF indicate non-electrolytes. CS Chem 3-D Ultra Molecular Modeling and Analysis Program has been used for optimization of the molecular structures of some complexes. In vitro cytotoxicities of the complexes were tested against different carcinoma cell lines. Antimicrobial activities of the complexes were screened against Gram-positive (Staphylococcus aureus), Gram negative bacteria (Escherichia coli), and fungal species (Aspergillus flavus, Candida albicans, and Microsporum canis).     

Synthesis and Crystal Structure of a Novel Co(II)-Nitronyl Complex [Co(IM2-Py)(PCA)(N_3)_2]

1 INTRODUCTION The design and synthesis of molecule-based mag-netic materials is one of the major subjects of mate-rials science. Nitronyl nitroxides acting as useful pa-ramagnetic building blocks have been extensively usedto assemble molecular magnetic materials in the pastfew years[1～5]. However, their weakly basic charac-ter strongly limits their coordination ability. Mean-while, the azide anion is a versatile ligand which canlink the transition metal atoms with different coor-dinatio…     

Synthesis and characterization of a new pyrrolidine containing sulfur ligand and the transition metal complexes of Co(II), Ni(II) and Cu(I)

Potassium 1,3-dipyrrolidinopropan-2-O-xanthate (LK), and its complexes with Co(II), Ni(II) and Cu(I) have been prepared and characterized as [CoL₂(H₂O)₂]?·?2H₂O, [NiL₂(H₂O)₂] and CuL?·?2H₂O by FT-IR, ¹H and ¹³C NMR spectroscopies, elemental analyses, magnetic susceptibility and TGA techniques.     

Preparation, Crystal Structure and Properties of a Pentametallic 3-Ferrocenyl-2-crotonic acid-Bridged Copper（Ⅱ） Complex

The synthesis and characterization of the copper (II) complex [Cu₂(OOCCH = C(CH₃)Fc)₃(phen)₂]CIO₄ · 2H₂O (1) are reported. The structure of the complex was determined by single‐crystal X‐ray analysis. The compound crystallizes in the monoclinic system, space group Pc, with Z =2, a = 1.2799(4) nm, b =0.9969 (4) nm, c = 2.5228 nm, and β = 91.576 (1) °. The cationic part of 1 indicates a penametallic core in which three 3‐ferrocenyl‐2‐crotonic acid salt (FCA) groups act as (O, O') bridging ligands between two copper (II) ions with a square‐pyramidal environment. Cyclic voltammetric experiments in acetonitrile have been performed mainly to examine the Fe(II) → Fe(III) one‐electron oxidation in FCA and its complex. The variable‐temperature magnetic susceptibility measurements revealed very weak intramolecular anti‐ferromagnetic coupling. Fitting parameters are 2J = ‐0.2 cm^?1, g = 2.114, and θ = 0K.     

Single crystal EPR of Cu(II) doped [Co(tbz)2(NO3)(H2O)]NO3: probe into copper-thiabendazole interaction

EPR of Cu(II) doped, low symmetry Co(II)-thiabendazole complex [Co(tbz)2(NO3)(H2O)](NO3) is investigated at 300 K. The spin Hamiltonian parameters are found to be orthorhombic with g33=2.305, g22=2.1351, g11=2.0626 and A33=147.0 x 10(-4), A22=33.5 x 10(-4) and A11=23.1 x 10(-4) cm(-1). Computer simulation of isofrequency plots reveal that the Cu(II) ions is substitutionally incorporated in the host lattice. Angular variation of the spectra shows the presence of two magnetic sites in the lattice. The low magnitude of A33 of the complex is rationalized in terms of admixture of d(x2-y2)/d(z2) ground state and delocalization of unpaired spin density onto the ligands.     

Coordination compounds of Co(II), Ni(II) and Cu(II) with capric acid hydrazide

The reaction of aquo-ethanolic solutions of Co(II), Ni(II) and Cu(II) salts and ethanolic solution of capric acid hydrazide (L) yielded paramagnetic, high-spin bis- and tris(ligand) chelate complexes. The tris(ligand) complexes, [ML ₃]X ₂·nH₂O [M=Co(II), Ni(II);X=NO ₃ ^– , ClO ₄ ^– , 1/2SO ₄ ^2– ], have an octahedral structure formed on account of the bidentate (NO) coordination of three neutral hydrazide molecules. In the bis(ligand) complexes,ML ₂(NCS)₂ [M=Co(II), Ni(II)] and CuL ₂ X ₂·nH₂O (X=NO ₃ ^– , ClO ₄ ^– and 1/2SO ₄ ^2– ), the oxoanions and NCS^– take also part in coordination. The complexes have been characterized by elemental analysis, IR spectra, magnetic measurements, molar conductivity and TG analysis.

---

Caprinsäurehydrazid-Komplexe von Co(II), Ni(II) und Cu(II)

Zusammenfassung Durch die Reaktion von wäßrig-ethanolischen Lösungen von Co(II)-, Ni(II)-und Cu(II)-Salzen mit einer ethanolischen Lösung von Caprinsäurehydrazid (L) wurden paramagnetische high-spin Bis- und Tris-Ligand-Chelatkomplexe erhalten. Tris-Ligand-Komplexe des Typs [ML ₃ X ₂·nH₂O [M=Co(II), Ni(II);X=NO ₃ ^– , ClO ₄ ^– , 1/2SO ₄ ^2– ], die eine oktaedrische Struktur besitzen, entstehen durch die Koordination von drei neutralen zweizähnigen (NO)-Hydrazidmolekülen. Bei den Bis-Ligand-KomplexenML ₂(NCS)₂ [M=Co(II), Ni(II)], sowie bei den Bis-Ligand-Komplexen CuL ₂ X ₂·nH₂O (X=NO ₃ ^– , ClO ₄ ^– , 1/2SO ₄ ^2– ) nehmen bei der Koordination außer Hydrazid auch die Säurereste teil. Die Komplexe wurden durch Elementaranalyse, IR-Spektren, magnetische Messungen, molare Leitfähigkeit und TG-Analysen charakterisiert.

     

Synthesis,characterization and antimicrobial activity of pentagonal-bipyramidal isothiocyanato Co(II) and Ni(II) complexes with 2,6-diacetylpyridine bis(trimethylammoniumacetohydrazone)

Pentagonal-bipyramidal isothiocyanato Co(II) and Ni(II) complexes with condensation product of 2,6-diacetylpyridine and trimethylammoniumacetohydrazide (Girard’s T reagent) were synthesized and characterized by elemental analyses, IR and UV–vis spectra, molar conductivity, and magnetic susceptibility. Crystal structures of the Co(II) and Ni(II) complexes were also determined. Antimicrobial activities of the ligand and metal complexes were examined.     

Syntheses,structures and catecholase activities of homo‐ and hetero‐trinuclear cobalt(II) complexes constructed from an acyclic naphthalenediol‐based bis(Salamo)‐type ligand

A series of homo‐ and hetero‐trinuclear cobalt(II) complexes [Co₃(L)(OAc)₂(CH₃CH₂OH)(H₂O)] ( 1 ), [Co₂Ba(L)(OAc)₂] ( 2 ) and [Co₂Ca(L)(OAc)₂]·CHCl₃ ( 3 ), containing an acyclic naphthalenediol‐based ligand H₄L were synthesized. All the three complexes were characterized by elemental analyses, IR, UV – vis spectra and single crystal X‐ray diffraction analyses. Comparative studies of the structures and spectroscopic properties are carried out on these complexes. All of the complexes show catechol oxidase activities in MeCN. Using UV – vis spectroscopy, we monitored the aerial oxidation of 3,5‐di‐tert ‐butylcatechol (3,5‐DTBCH₂) to 3,5‐di‐tert ‐butylquinone (3,5‐DTBQ), which confirms the essential role of these complexes in enhancing the catalytic reaction.     

Synthesis,characterization, and in vitro antiproliferative and antibacterial studies of tetraazamacrocyclic complexes of Co(II) and Cu(II) with pyromellitic acid

New cationic tetranuclear Co(II) and neutral binuclear Cu(II) complexes with tpmc (N,N′,N″,N″′-tetrakis-(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane) and bridging pyromellitate ligand pma (tetraanion 1,2,4,5-benzenetetracarboxylic acid) were isolated. The composition of the compounds is proposed based on elemental analyses (C, H, N, M=Cu, Co), molar conductivity determination, UV-Vis, FTIR, EPR, LC-MS and reflectance spectroscopy, magnetic measurements, cyclic voltammetry, as well as TG and DTA. It is proposed that in [Co₄(pma)(tpmc)₂](ClO₄)₄·6H₂O (1), cobalt(II) is six-coordinate out of cyclam rings and one OCO^? from pma participates in coordination with one Co(II). In the case of [Cu₂(pma)tpmc]?8H₂O (2), one OCO^? from pma bridges two Cu(II). The cytotoxic activity of 1 and 2 was tested against tumor cell lines human cervix adenocarcinoma (HeLa), estrogen-receptor-positive human breast cancer (MCF-7), human myelogenous leukemia (K562), and the human Caucasian Burkitt’s lymphoma (Ramos). The IC₅₀ values for 1 and 2 were within the range 44.66 ± 2.39 to 152.40 ± 2.28 μM, and from 140.88 ± 3.51 to 192.05 ± 2.09 μM, respectively. Both 1 and 2 were tested for antimicrobial activity. We determined that minimal inhibitory concentration for 1 against Staphylococcus aureus, Bacillus subtilis, and Klebsiella pneumoniae was 25 mM. Complex 2 did not express activity against tested microbial strains.     

Synthesis,Structure and Fluorescence of a Copper(II) Complex [Cu_2(bipy)_2(Hpht)_2Cl](Hpht)(bipy=2,2'-Bipyridine,H_2pht=o-Phthalic Acid)

1 INTRODUCTION o-Phthalic acid (H2pht) is a versatile ligand for co-ordinating to metal ions in various modes, such asmonodentate bonding through a carboxylic O atom[1],bidentate fashion via two carboxylic O atoms[2] andtriple coordination through its three carboxylic Oatoms[3], and bridging mode with two or four Oatoms of its carboxylate groups[4]. The coordinationproperties thus allow for the preparation of complex-es with a large variety of architectures, forming iso-lated mono-, di…