Synthesis, Crystal Structure and Properties of a Novel Tetranuclear Nickel（II） Complex with Azo-enolic-2-hydroxybenzamide

A novel tetranuclear nickel(Ⅱ) complex [Ni4L2(DMF)2(H2O)2·2DMF] (1,H4L=azo-enolic-2-hydroxybenzamide, DMF=N,N-dimethyl-formamide) has been synthesized and characterized by elemental analysis, UV, IR and X-ray single-crystal diffraction characterization. Complex 1 crystallizes in the monoclinic system, space group P21/n with a=8.8944(11), b=14.4583(18), c=18.097(2) , β=90.00(2)o, Z=2 , V=2327.2(5)3 , C40H48N12Ni4O14 , Mr=1155.66, Dc=1.649g/cm 3 , μ=1.672 mm-1 , F(000)=1192, R=0.0392 and wR=0.0958. The local coordination environment around the nickel ions exist a distorted octahedral and quadrangle geometry in the molecular structure. Complex 1 exhibits strong photoluminescent emission in the ultraviolet region at room temperature. The electrochemical studies reveal that redox of Ni 3+ /Ni 2+ in the complex is a quasi-reversible process.     

Synthesis,Crystal Structures and Electrochemical Properties of Complexes [M(ImH)4(tfbdc)(H2O)] (M=Co,Ni)

The title complexes [M(ImH)₄(tfbdc)(H₂O)] ( 1 : M=Co; 2 : M=Ni) (ImH=imidazole, tfbdc=2,3,5,6‐tetrafluoroterephthalate) were synthesized by the reaction of M(OAc)₂·4H₂O, H₂tfbdc and ImH in water solution. The complexes were characterized by elemental analysis, IR spectra, thermogravimetric analysis, cyclic voltammetry and X‐ray single crystal structure analysis. Structural analysis reveals that 1 and 2 possess isostructure: monoclinic, P2₁/c, Z=4. M(II) ion in complexes 1 and 2 has a distorted octahedral geometry coordinated by one oxygen atom from water, one oxygen atom from tfbdc^2? and four nitrogen atoms from ImHs. They are discrete zero‐dimensional molecular complexes. And the adjacent monomeric components are connected by hydrogen bonds to form a supramolecule. Electrochemical properties of the complexes 1 and 2 show that electron transfer of M(II) between M(III) in electrolysis is a quasi‐reversible process.     

Complexes of Co(II) and Zn(II) with N-(Thio)phosphorylthioureas AdNHC(S)NHP(O)(OiPr)2 and MeNHC(S)NHP(S)(OiPr)2

The reaction of the potassium salt of the N-(thio)phosphorylated thioureas AdNHC(S)NHP(O)(OiPr)₂ (HL^I , Ad = Adamantyl) and MeNHC(S)NHP(S)(OiPr)₂ (HL^II ) with Co(II) and Zn(II) in aqueous EtOH leads to [ML^I,II ₂] chelate complexes. They were investigated by UV-vis, ¹H and ³¹P NMR spectroscopy, and microanalysis. The molecular structures of [ML^I ₂] were elucidated by single crystal X-ray diffraction analysis. The metal centers in both complexes are found to be in a distorted-tetrahedral O₂S₂ environment formed by the C=S sulfur atoms and the P=O oxygen atoms of two deprotonated L^I ligands. The photoluminescence properties of [ZnL^II ₂] are also reported.     

Synthesis, Crystal Structure and Electrochemical Studies of Two Novel Zn(II) Complexes of Phthalic Acid and Imidazole Derivatives

Two novel coordination polymers [Zn(pa)(vim)2]n (1) and [Zn(pa)(eim)2]n (2) (pa＝phthalic acid dianion, vim＝1-vinyl-1H-imidazole, eim＝1-ethyl-1H-imidazole) have been synthesized and their structures characterized by X-ray single crystal diffractometry and elemental analysis. Both of the complexes consist of [Zn(L)2] (L＝vim for 1; eim for 2) entities linked into polymeric zigzag chains along the crystallographic c-axis by bridging phthalate anions in the μ2-1,2 coordination mode. The coordination around each Zn(II) atom is tetrahedral. There are only van der Waals interactions between the chains in 1, while the three-dimensional network in 2 is assembled by C—H…O contacts. The electrochemical studies reveal that redoxes of Zn2+/Zn in complexes 1 and 2 are irreversible processes.     

[Co(mim)_6]Br_2·2H_2O的离子热合成、晶体结构及电化学性质

以N-甲基咪唑(min)为配体,采用离子热方法在离子液体(1-乙基-3-甲基咪唑溴盐)中合成了Co(Ⅱ)配合物{[Co(mim)6]Br2·2H2O, 1},其结构经IR和元素分析表征.X-射线单晶衍射分析表明:1属单斜晶系,P21/c空间群,晶胞参数:a＝0.818 2(2) nm, b＝1.357 3(2) nm, c＝1.623 4(19) nm, β＝111.12(4)°, V＝1.682(5) nm3, Dc＝1.476 g·cm-3, F(000)＝762, Z＝2, μ(MoKα)＝2.927 mm-1, R1＝0.036 8, R2＝0.098 9.在1的晶体结构中,钴(Ⅱ)与配位原子形成畸变的八面体结构.采用循环伏安法研究了1在水溶液中的电化学性质,结果表明1中存在一对可逆的氧化还原峰,其峰值分别为0.51 V和0.25 V,为Co(Ⅱ)/Co(Ⅲ)间的相互转化.     

Synthesis, Crystal Structure and Electrochemical Properties of Complex[Ni(2,2''-bipy)2(ClC6H4COO)(H2O)](ClO4)

A new nickel(Ⅱ) coordination complex [Ni(2,2'-bipy)2(ClC6H4COO)(H2O)](ClO4) was synthesized by self-assembly reaction of m-chlorobenzoic acid, 2,2'-bipy and Ni(ClO4)2(6H2O. The crystal of the title compound belongs to monoclinic system, space group P21/n with a = 0.77764(14), b = 2.6572(5), c = 1.3637(2) nm, β = 96.456(3)°, V = 2.8000(9) nm3, Dc = 1.528 g/cm3, Z = 4, Mr = 644.10, μ(MoKα) = 0.937 mm-1, F(000) =1320, R = 0.0549 and wR = 0.1164. Structure analysis shows that the nickel(Ⅱ) ion is coordinated with four nitrogen atoms from two bipys as well as two oxygen atoms from m-chlorobenzoic acid and water, respectively, giving a distorted octahedral coordination geometry. The cyclic voltametric behavior of the complex is also presented.     

Complexes of Co(II), Ni(II) and Cu(II) with lapachol

Complexes of naturally occurring hydroxynaphtho-quinone, lapachol (2-hydroxy-3(3-methyl-2-buthenyl)-1,4-naphthoquinone = HL) with Co(II), Ni(II) and Cu(II) have been prepared by reaction of the corresponding acetates with the ligand (HL) in ethanol. The molecular and crystal structures were determined for [CoL₂(EtOH)₂] (1), [NiL₂(EtOH)₂] (2), and [CuL₂(py)₂] (3). In all cases the deprotonated lapachol behaves as chelating bidentate ligand. The complexes were also characterized by elemental analyses, cyclic voltammetry, and FAB-MS.     

A Novel Adipate Bridged Supramolecular Layer: Crystal Structure of the Cobalt(II) Complex [(μ‐C6H8O4)4/2Co(μ‐H2O)2Co(H2O)4] · 4 H2O

The pale‐rose compound [(μ‐C₆H₈O₄)_4/2Co(μ‐H₂O)₂Co(H₂O)₄] · 4 H₂O was prepared from adipic acid and CoCO₃ in aqueous solution. The crystal structure (monoclinic, P2₁/n (no. 14), a = 8.061(1), b = 15.160(2), c = 9.708(2) Å, β = 90.939(7)°, Z = 2, R = 0.0405, wR² = 0.0971) consists of adipate bridged supramolecular [(μ‐C₆H₈O₄)_4/2Co(μ‐H₂O)₂Co(H₂O)₄] layers and hydrogen bonded H₂O molecules. The cobalt atoms Co1 and Co2 are distorted octahedrally coordinated by the O atoms of two bridging trans‐H₂O molecules and four bidentate adipate anions (Co1) and by the O atoms of two bridging trans‐H₂O molecules and four monodentate H₂O molecules (Co2), respectively. Equatorial bonds: d(Co1–O) = 2.048 Å (2 × ), 2.060 Å (2 × ); d(Co2–O) = 2.057 Å (2 × ), 2.072 Å (2 × ). Axial bonds: d(Co1–O) = 2.235 Å (2 × ); d(Co2–O) = 2.156 Å (2 × ).     

[Cu(PTA)(Phen)2](p-MBA)(H6O)配合物的合成、晶体结构及电化学分析

The crystal structure of the title complex with the stoichiometric formula [Cu(PTA)(Phen)₂](p-MBA)(H₆O) (Phen=1,10-phenanthroline, PTA=terephthalic acid, p-MBA=p-toluic acid) has been determined by single-crystal X-ray diffraction. The crystal (C₄₈H₄₀CuN₄O₁₀, M_r=896.38) belongs to the monoclinic space group C2/c, with the following crystallographic parameters: a=1.778 6(3) nm, b=1.912 5(3) nm, c=1.389 9(2) nm, β=114.686(2)°, V=4.295 7(12) nm³, D_c=1.386 g·cm^-3, Z=4, μ(Mo Kα)=0.574 mm^-1, F(000)=1 860, final GooF=1.019, R=0.054 0, wR=0.148 3 for 2 644 observed reflections (I>2σ(I)). The crystal structure shows that the copper(Ⅱ) ion is coordinated with two oxygen atoms from one terephthalic acid molecule and four nitrogen atoms from two 1,10-phenanthroline molecules, forming a distorted octahedral coordination geometry. The cyclic voltametric behavior of the complex is also reported. CCDC: 298809.     

Novel Isatin-Schiff Base Cu (II) and Ni(II) Complexes. X-ray Crystal Structure of Bis[3-(4-hexylphenylimino)-1H-indol-2(3H)-one]-dichlorocopper(II) Complex

Schiff bases of isatin were reported to possess antibacterial, antifungal, antiviral, anti-HIV, antiprotozoal, and anthelmintic activities1. They also exhibit significantanticonvulsant activity, apart from other pharmacological properties2. Conductingsubs…     

1,3-Disubstitutedpyrazole-4-caboxaldehyde in Heterocyclic Synthesis: A Novel Synthesis of Pyridine-2(1H)-thione and Fused Nitrogen and/or Sulfur Heterocyclic Derivatives

Pyridine-2(1H)-thione 5 was synthesized from the reaction of 3-[3-(4-chlorophenyl)-1-phenyl-1H-pyrazol-4-yl]-1-phenylpropenone (3) and cynothioacetamide (4). Compound 5 reacted with halogented compounds 6a–e to give 2-S-alkylpyridine derivatives 7a–e, which could be in turn cyclized into the corresponding thieno[2,3-b]-pyridine derivatives 8a–e. Compound 8a reacted with hydrazine hydrate to give 9. The latter compound reacted with acetic anhydride (10a), formic acid (10b), acetic acid, ethyl acetoacetate, and pentane-2,4-dione to give the corresponding pyrido[3′,2′:4,5]thieno-[3,2-d]pyrimidine 13a,b, pyrazolo[3′,4′:4,5]thieno[3,2-d]pyridine 14 and thieno[2,3-b]-pyridine derivatives 18 and 20, respectively. Alternatively, 8c reacted with 10a,b and nitrous acid to afford the corresponding pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine 24a,b and pyrido[3′,2′:4,5]thieno[3,2-d][1,2,3]triazine 26 derivatives, respectively. Finally compound 5 reacted with methyl iodide to give 2-methylthiopyridine derivative 27, which could be reacted with hydrazine hydrate to yield the corresponding pyrazolo[3,4-b]-pyridine derivative 29.     

3-(2-吡啶基)-1,2,4-三唑配体Co(II)Cu(II)和Cd(II)配合物的合成、结构及荧光性质

利用3-（2-吡啶基）-1,2,4-三唑配体（HL）和不同的金属盐设计合成了5个配合物[Co（HL）₂（H₂O）₂]（NO₃）₂（1）、[Cu₂（L）₂（NO₃）₂（H₂O）₄] （2）、[Cu₂（L）₂（AcO）₂（H₂O）₂]·6H₂O （3）、[Cu₂（L）₂（HL）₂（ClO₄）₂]·2CH₃CN （4）和[Cd₂（L）₂（HL）₂（NO₃）₂]·2H₂O （5）,并通过X射线单晶衍射、红外、元素分析、X射线粉末衍射和热重对配合物结构进行了表征。测试结果表明配合物1具有单核结构,并且可以通过氢键的相互作用形成二维超分子结构。配合物2~5为双核结构。配合物2和5可以通过氢键的相互作用形成二维超分子结构。配合物3通过氢键的相互作用形成三维超分子结构。研究了配合物中HL配体的配位模式。此外,研究了配体HL和配合物1和5的固态荧光性质及荧光寿命。     

Co2SnO4/Carbon Nanotubes Composites: A Novel Approach for Electrochemical Sensing of Hydrogen Peroxide

For the first time Co₂SnO₄ (CTO)/Carbon nanotubes (CNT) composites were prepared and used to modify glassy carbon electrodes for the amperometric determination of hydrogen peroxide. The catalytic activity of composites towards the oxidation of hydrogen peroxide was dependent on the quantity of CNT present in the composite and to the pH of the medium. The pure cobalt stannate phase with a ratio of 3 : 1 (CTO:CNT) exhibited the best catalytic activity towards hydrogen peroxide oxidation at low potentials (0.200 and 0.500 V). A linear relationship between current and hydrogen peroxide concentration was obtained with a sensitivity of 95 and 258 μA mM⁻¹ and a detection limit of 0.130 and 0.08 μM respectively.     

三维超分子配合物[Co2(Dpq)2(btec)(H2O)6]•2H2O的水热合成、晶体结构和电化学性质

以1,2,4,5-均苯四羧酸(btec)和二-吡啶-(3,2-d:2,3'-f)-二氮萘(Dpq)为混合配体,水热合成了一种三维超分子配合物: [Co2(Dpq)2(btec)(H2O)6]•2H2O (1), 并通过元素分析、红外光谱、热重分析和X-射线衍射法对其结构进行了表征。晶体结构解析结果表明,该配合物属单斜晶系,P21/c 空间群,晶胞参数为：a=0.8978(5)nm, b= 2.9822(16)nm, c= 0.7058(4)nm, β= 94.199(6)º, V= 1.8848(18)nm3, Z= 2, R1= 0.0350, wR2= 0.0796。该化合物由1,2,4,5-均苯四羧酸中羧基氧原子、二-吡啶-(3,2-d:2,3'-f)-二氮萘的螯合氮原子及水分子中氧原子与中心Co(II)离子配位, 形成六配位的扭曲八面体几何构型。羧酸作为桥连配体连接两个相邻的中心Co(II)离子形成钴配合物的双核单元,双核单元之间通过氢键及π-π堆积作用相互连接构成三维超分子网状结构。电化学实验结果表明,钴配合物修饰碳糊电极(1-CPE)在0.1 M 乙酸-乙酸钠缓冲溶液中电位范围+600 – –300 mV内有一对归属于Co(II)/Co(III) 的氧化还原峰,而且此修饰电极对亚硝酸根的氧化有很好的电催化效果。     

Preparation,Properties and Thermal Decompositions of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) Complexes of 2,5-dichlorobenzoic Acid

Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 2,5-dichlorobenzoates were prepared and their compositions and solubilities in water at 295 K were determined. The IR spectra and X-ray diffractograms of the obtained complexes were recorded. The complexes of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) were obtained as solids with a 1:2 molar ratio of metal to organic ligand and different degrees of hydration. When heated at a heating rate of 10 K min^-1, the hydrated complexes lose some (Co, Zn) or all (Ni, Cu, Cd) of the crystallization water molecules and then decompose to oxide MO (Co, Ni) or gaseous products (Cu, Zn, Cd). When heated at a heating rate of 5 K min^-1, the complexes of Ni(II) and Cu(II) lose some (Ni) or all (Cu) of the crystallization water molecules and then decompose directly to MO. This revised version was published online in July 2006 with corrections to the Cover Date.     

Electrochemical and Spectroscopic Studies of Co(CREATININE)2Cl2

The electrochemical behavior of Co(creatinine)₂Cl₂ was investigated by cyclic voltammetry in organic solvents (DMSO and DMF) and in aqueous solution. Analysis of the results indicates that the electroactive species depend on the nature of the solvent. In DMF a single reduction process Co(II)/Co(I) is observed. In DMSO the redox behavior of the complex changes with the scan rate and a two-electron transfer process can be eventually observed. In aqueous solution the complex immediately decomposes giving rise to the aquo-cation. The characteristic peak of the redox couple Cl₂/Cl^? is observed as a consequence of the chloride released from the coordination sphere. Analysis of the electronic spectra gave additional support to the proposed mechanisms. The Co-Cl and Co-N stretching bands were clearly identified in the low frequency region of the IR spectrum.     

配合物EuxM1-x(TTA)3(H2O)2(M=La,Gd)光致发光特性

合成了一系列组成为EuxM1－x(TTA)3(H2O)2(M=La,Gd)的固体配合物,利用红外光谱和荧光光谱研究了配合物结构和发光性质随Eu3＋浓度的变化规律.红外光谱的结果表明,配合物的成份为Eu(TTA)3(H2O)2和M(TTA)3(H2O)2,没有新化合物生成.而荧光光谱的结果显示配合物的发光强度与Eu3＋浓度不成线性关系,其中不发光的M(TTA)3组分对发光有增益作用.对其可能的发光机制进行了探讨.     

[Co(N-(3-Aminopropyl)-1,3-propanediamine)(2-(Aminomethyl)pyridine) Cl][ZnCl_4]的一对差向异构体的合成及晶体结构

用过氧化物法合成了 [Co(3,3-tri)(amp)Cl][ZnCl4]的两个经式异构体,晶体结构解析表明两者互为差向异构体。其中反式异构体 (仲氢相对于 Cl)晶体属单斜晶系,空间群 C2/c, a=2.7663(7)nm, b=0.9505(1)nm, c=1.8288(4)nm,β =105.57(2)°, V=4.632(1)nm3, Dc=1.706g· cm-3, Z=8, F000=2432.00,μ (MoKα )=23.51cm-1, R=0.033, Rw=0.041;顺式异构体 (仲氢相对于 Cl)晶体属三斜晶系,空间群, a=1.0790(2)nm, b=1.1749(1)nm, c=0.8920(1)nm,α =90.73(1)°,β =109.573(9)°,γ =80.60(1)°, V=1.0500(2)nm3, Dc=1.71g· cm-3, Z=2, F000=548.00,μ (MoKα )=25.73cm-1, R=0.022, Rw=0.030。两异构体中 Co3＋为六配位,其差异仅表现在 3,3-tri仲胺上氢的取向不同。     

Physico-Chemical Characteristics and Formation Constants of Mono- and Binuclear Co(II), Ni(II) and Cu(II) Chelates with Phthaleincomplexone

A series of Co(II), Ni(II) and Cu(II) complexes of the type [M(PC)]2H₂O and [M₂(PC)]4H₂O, where PC is phthaleincomplexone (metalphthalein), are synthesized. It is attempted to throw some light on (heir stoichiometry, structure and stability. The formation of 1:1 and 2:1 (M:L) complexes is confirmed by their elemental microanalysis. The compounds are characterized by IR, electronic absorption spectra, X-band ESR spectra, magnetic moments and TGA measurements. The conditional stability constants are also determined.