Synthesis, structure and magnetism of a novel carboxylate bridged manganese(II) sheet structure containing the first unsupported aqua bridge

The structural characterisation of a 2D sheet complex [[Mn2(Hetheidi)2(mu-H2O)(H2O)].3H2O]n 1 [Hetheidi =DL-N-(1-hydroxymethylpropyl)iminodiacetic acid] assembled from the tetradentate ligand Hetheidi and MnCl2 reveals the presence of rare unsupported mu-aqua bridges and novel hydrogen-bonded water channels, which bind the sheets together.     

Synthesis and structure of tetranuclear copper(Ⅱ) complex containing μ4-oxo bridge

A new dinucleating Schiff base ligand HL(L=C13H17N2O3) has been synthesised and characterized.The single crystal structure of its complex [L2Cu4O(AcO4)]·2H2O has beendetermined by X-ray diffraction methods.The result indicates that every Cu atom has its square pyramidal coordination polyhedron and there is a tetrahedral Cu4O core in the complex molecule.Its active sites where catalytic oxidation of dioxygen occurs have been inferred.     

Synthesis and thermal characterization of sulfur containing methionine bridged cobalt(III) and copper(II) complex

The sulfur containing amino acid bridging polynuclear transition metal complex has been synthesized and characterized by different measurements such as UV?CVis, FT?CIR, C?CH?CN?CS, TG?CDTA, ICP-AES, differential scanning calorimeter (DSC), and XRD. DSC has showed negative specific heat of this polynuclear system and has used to evaluate some thermodynamic constants like activation energy (E _a), frequency factor (A), enthalpy, and entropy of that system. The specific heat capacity is measured at heating rate of 10?°C?min^?1 in room atmosphere of this polynuclear complex. The characterization of this complex has showed five Co(III) and four Cu(II) atoms and this complex contained ten sulfur containing methionine amino acid units.     

Synthesis,crystal structure and magnetic characterization of a novel linear trinuclear copper(II) complex bridged by phenoxy and benzyloxy oxygen atoms

A novel linear trinuclear copper(II) complex bridged by phenoxy and benzyloxy oxygen atoms ([Cu₃L₂](ClO₄)₂ · (CH₃CN)₂, L = C₁₁H₁₃BrN₂O₂ ²⁻) was synthesized and the crystal structure of the complex was determined by X-ray diffraction technique. The crystal structure of the complex contains a linear trinuclear array of copper(II) ions in which the central copper(II) ion is in an octahedron coordination sphere and lies on an inversion center of the molecule, the terminal ones are in an identical square pyramid structure. Variable-temperature magnetic data indicate that the complex displays a strong antiferromagnetic coupling with J = −270(8) cm⁻¹ between the metal ions.     

Synthesis and characterisation of phenoxo bridged dinuclear complexes of copper(II)

A series of model complexes for the type III site, in oxidised hemocyanin, containing Cu₂(μ-0Ph)³⁺ core have been synthesised using a heptadentate ligand (H₃L) formed from the Schiff base condensation of triethylenetetramine and salicylaldehyde. The ligand provides one imine and one inbuilt imidazole nitrogen and two phenolic oxygen donors with both five- and six-membered chelate rings to each metal centre. In the pentacoordinated complexes [Cu₂(L)X]·nH₂O, a third exogenous bridging ligand is present. The TG curve indicates the loss of lattice water molecules between 70 and 125°C. The residue after decomposition is CuO above 550°C. Theg values of theX-band EPR spectrum of [Cu₂L(μ-OAc)]·2H₂O in methanol glass (77 K) are typical of a variety of bridged copper(II) dimers. The copper-copper magnetic interaction is dependent on the presence and nature of X in these complexes.     

Synthesis and magneto-structural correlation of a new maleato bridged copper(II) coordination polymer

A one-dimensional (1-D) copper(II) coordination polymer [Cu(maleate)(2,2′-bipyridyl)] _n ·2H₂O has been synthesised. Single crystal X-ray diffraction study reveals that maleate ion bridges two adjacent copper(II) centres along the chain in a syn–anti fashion. A complete cryomagnetic investigation of the title complex correlates well with the distorted square pyramidal geometry of the central copper(II) ion and bridging nature of the maleate. A τ value of 0.26 indicates the distortion towards tbp coordination allowing the magnetic orbital to acquire some character leading to a weak antiferromagnetic interaction having J = −0.26 cm⁻¹. The complex has also been firmly established from several other instrumental techniques like Fourier transform infrared (FT-IR) and EPR spectroscopies.     

Synthesis, characterization, crystal structure and antitumor activities of a novel demethylcantharidato bridged copper(II) phenanthroline complex

A new polymeric demethylcantharidato (DCA) bridged copper(Ⅱ) phenanthroline (phen) complex ([Cu(DCA)(phen)] n ·nH2O) has been synthesized and characterized by elemental analysis, IR and electronic spectra studies, molar conductivity measurement, and single crystal X-ray diffraction. The complex crystallizes in the orthorhombic space group Pbca with crystallographic data: a = 12.4537(4), b = 9.3897(5), c = 30.1264(10), and Z = 8. In the crystal structure, the octahedral coordinated copper(Ⅱ) ions are bridged by demethylcantharidate ligands into a one-dimensional zigzag-like structure with the Cu···Cu separation of 6.1719, along with phen ligands attached to both sides of the chain alternatively. Interdigitation of the chelating phen ligands of two neighboring chains via hydrophobic interaction and van der Waals forces along ac plane forms two-dimensional polymeric bilayers with discrete water sandwich layer between the adjacent polymeric bilayers. The evaluation of the cytotoxic activity of the copper(Ⅱ) complex against HCT-8 (colorectal carcinoma), A549 (pulmonary carcinoma), HeLa (cervical cancer), HepG2 (hepatocarcinoma), BGC-823 (gastric carcinoma), and MCF-7 (breast adenocarcinoma) cell lines revealed that it is a potent cytotoxic agent, superior to Na2DCA and phen against HeLa, HepG2 and BGC-823 cells.     

Crystal structure of new melamine bridged polymeric complex of copper(II)

The new co-crystal copper(II) melamine complex poly[bis(μ-methacrylato)μ-(1,3,5-triazine-2,4,6-triamine)], C₁₉H₂₆Cu₂N₆O₈ (1) crystallizes in the triclinic P-1 space group with a = 8.9670(2) Å, b = 9.4108(2) Å, c = 15.4476(3) Å, α = 96.6090(10)°, β = 100.6270(9)°, γ = 95.5950(10)°. Each Cu(II) exhibits a pseudooctahedral geometry. Four coplanar carboxylate oxygen atoms coordinated to the Cu(II) ion define the basal plane, whereas the apical position is occupied by one nitrogen atom from the melamine ligand. Here, the carboxylato-bridged two dinuclear copper(II) complexes are linked through melamine giving a 1D alternating chain. The structure of 1 consists of a two-dimensional supramolecular layer constructed by intermolecular N-H...N hydrogen bonds of the melamine ligands from adjacent one-dimensional [Cu₂(C₄H₅O₂)₄(C₃H₆N₆)] chains.     

A mixed bridged trinuclear copper(II)–1,10‐phenanthroline complex with a linear structure

The title compound, diaqua‐1κO,3κO‐di‐μ‐hydroxido‐1:2κ²O:O,2:3κ²O:O‐di‐μ‐methacrylato‐1:2κ²O:O′,2:3κ²O:O′‐bis(1,10‐phenanthroline)‐1κ²N,N′;3κ²N,N′‐tricopper(II) dinitrate dihydrate, [Cu₃(C₄H₅O₂)₂(OH)₂(C₁₂H₈N₂)₂(H₂O)₂](NO₃)₂·2H₂O, has the central Cu atom on an inversion centre. The three Cu^II atoms are in a linear arrangement linked by methacrylate and hydroxide groups. The coordination environments of the Cu^II ions are five‐coordinated distorted square‐pyramidal for the outer Cu atoms and four‐coordinated square‐planar for the central Cu atom. All nitrate ions, hydroxide groups and water molecules are linked by hydrogen bonds, forming a linear structure. The complex exhibits ferromagnetic exchange coupling, which is helpful in elucidating magnetic interactions between copper ions and other metallic ions in heteronuclear complexes.     

弱桥联二聚体氯代二苄基锡二甲基氨荒酸酯的合成、 表征及晶体结构

利用二苄基二氯化锡和二甲基氨荒酸盐反应,合成了氯代二苄基锡二甲基氨荒酸酯。通过元素分析、红外光谱和核磁共振氢谱对其结构进行了表征。用X-射线单晶衍射测定了该化合物的晶体结构。它属于三斜晶系,空间群为P1,a=0.75750(15),b=1.0615(2),c=1.2059(2)nm,α=95.053(3)°,β=95.539(4)°,Υ=99.113(4)°,Z=2,V=0.9476(3)nm^3,Dx=1.600g/cm^3,μ=1.705mm^-^1,F(000)=456,R1=0.0409,wR2=0.1194[I≥2σ(I)]。分子中锡原子的配位数为5,形成一个严重扭曲的三角双锥构型,并且化合物以弱桥联二聚体存在。     

Synthesis,spectral and magnetic properties of binuclear copper(II)/nickel(II) and copper(II) complexes bridged by glyoximate groups

Three new dinuclear complexes, [(tmen) (H2O)2Ni (Hdmg)(dmg)Cu]·ClO4, [(dien)(H2O)Ni (Hdmg)(dmg) Cu]·ClO4 and [(tmen)Cu(Hdmg)(dmg) Cu] ClO4·H2O (H2dmg=dimethylglyoxime, tmen=tetramethylene diamine), have been prepared. Variable-temperature- magnetic susceptibility measurements (75–300K) on the complexes reveal the presence of intramolecular antiferromagnetic interactions through the oximate bridges. The formation of mononuclear, dinuclear complexes has been confirmed by spectrophotometry.     

Synthesis and crystal structure of a new copper(II) binuclear complex bridged by the reduced derivative of a nitronyl nitroxide biradical

A new copper(II) binuclear complex, [Cu(hfac)₂]₂(IMH)₂Ph(OMe)₂ ((IMH)₂Ph(OMe)₂?=?2,5-dimethoxyl-1,4-bis(4′,4′,5′,5′-tetramethylimidazoline-3′-oxide)benzene, hfac?=?hexafluoroacetonate), bridged by a reduced derivative of a nitronyl nitroxide biradical has been synthesized and characterized by X-ray crystallography. The complex crystallizes in the monoclinic space group P2₁/n, with a?=?10.002(14), b?=?19.950(3), c?= 14.504(2) Å, β?=?108.842(3)° and Z?=?2. The structure refined to a final R value of 0.0644. The complex contains two copper(II) ions bridged by a reduced derivative of a nitronyl nitroxide biradical with a Cu?···?Cu separation of 8.430(2) Å.     

Synthesis and structure of an asymmetric copper(I) dimer with two-coordinate and four-coordinate copper(I) sites

An asymmetric copper(I) dimer Cu(1)2(pip)2 [pip = (2-picolyliminomethyl)pyrrole anion] with both two-coordinate and four-coordinate copper(I) sites was synthesized and studied by X-ray diffraction and DFT calculations.     

Synthesis,crystal structure and properties of a 1D copper(II) complex with 1,5,9-triazacyclododecane bridged by p -benzenebicarboxylate

A 1D complex [{[Cu₂([12]aneN₃)₂(p-paa)(H₂O)₂](ClO₄)₂}[Cu₂([12]aneN₃)₂(p-paa)₂]] _n ([12]aneN₃ = 1,5,9-triazacyclododecane, p-paa = p-benzenebicarboxylate) has been synthesized and structurally characterized. The complex contains two different binuclear copper(II) moieties. One part includes a binuclear copper(II) unit and non-coordinated perchlorate anions. A neutral binuclear copper(II) part which forms a zigzag chain structure via the bridging p-paa ligand completes the unit-cell. Elemental analysis, IR, UV-Vis spectra and magnetic properties for the complex have also been determined. Magnetic susceptibilities in the solid state are measured over the temperature range from 77 to 300 K, showing a weak antiferromagnetic coupling with a best fit J ₁ = ?3.09 cm^?1, J ₂ = ?5.279 cm^?1, g = 2.099 and R = 1.226 × 10^?5.     

Synthesis and magnetic properties of trinuclear copper(II) complexes bridged by dimethylglyoximate groups

Summary New three Cu^II-Cu^II-Cu^II homotrinuclear complexes have been synthesized, namely [Cu(dmg)₂{CuL}₂](ClO₄)₂ [L = 5-nitro-1,10-phenanthroline (5-NO₂-phen), 4,4-dimethyl-2,2-bipyridiine (DMbpy), tetramethylenediamine (TMDA) and dimethylglyoximate ion (dmg)^2-]. The magnetic susceptibilities of complexes (1) (L = 5-NO₂-phen) and (2) (L = DMbpy) were measured in the 4.2–300 K range, giving the parameters,J = -335cm^-1 (1) andJ= -327.5cm^-1 (2). The results demonstrate a very strong antiferromagnetic exchange interaction between the adjacent copper(II) ions.     

Synthesis,crystal structure,and DNA-binding studies of a one-dimensional copper(II) polymer bridged both by oxamidate and thiocyanato ligands

A new one-dimensional copper(II) polymer, [Cu₄(dmapox)₂(SCN)₄(CH₃OH)₂] _n , where dmapox is the dianion of N,N′-bis[3-(dimethylamino)propyl]oxamide, was synthesized and characterized by elemental analysis, conductivity measurement, IR, and electronic spectral studies. The crystal structure of the copper(II) complex has been determined by X-ray single-crystal diffraction. The complex crystallizes in triclinic, space group P ? 1 and exhibits infinite one-dimensional copper(II) polymeric chain bridged both by bis-tridentate μ-trans-dmapox and μ-1,3-thiocyanato ligand. The environment around the copper(II) atom can be described as distorted square-pyramid. The Cu···Cu separations through the oxamidate and thiocyanato bridges are 5.246(2) Å (Cu1–Cu1ⁱ), 5.2649(14) Å (Cu2–Cu2ⁱⁱ), and 5.8169(15) Å (Cu1–Cu2), respectively. The interaction of the copper(II) complex with herring sperm DNA (HS-DNA) has been investigated by using absorption and emission spectral and electrochemical techniques and viscometry. The results reveal that the copper(II) complex may interact with DNA in the mode of groove binding with the intrinsic binding constant of 2.56 × 10⁵ M^?1.     

Synthesis,spectral and ferromagnetic interactions in isophthalato bridged binuclear copper(II) complexes

Transition Metal Chemistry - Four novel copper(II) binuclear complexes have been synthesized and characterized, namely [Cu2(IPHTA)( L)2](ClO4)2 (L denotes 2,2′-bipyridine (bpy); 1,10-...     

Synthesis and magnetic properties of binuclear cobalt(Ⅱ), nickel(Ⅱ) and copper(Ⅱ) complexes bridged by oxamidate group

Four binuclear Co(Ⅱ), Ni(Ⅱ) and Cu(Ⅱ) complexes bridged by oxamidate (oxd) group have been synthesized, namely Co2(byp)2(oxd)(ClO4)2 (1), Co2(Me2bpy)2(oxd)(ClO4)2.H2O (2), Ni2(bpy)2(oxd)(ClO4)2.2H2O (3) and Cu2(Me2bpy)2(oxd)(NO3)2 (4). (bpy=2,2'-bipyridyl, Me2-bpy=4,4'-dimethylbipyridyl, oxd=oxamidate) The complexes are characterized by IR, UV spectra, EPR and variable-temperature magnetic susceptibility (4-300 K). The susceptibility data for. complexes 1 and 3 were least-squares fit to the susceptibility equation derived from the spin Hamiltonian H=-2J . S1 . S2. The exchange integral, J, was found to be equal to -3.62 cm-1 in 1 and -1.82 cm-1 in 3. This indicates a weak antiferromagnetic spin exchange interaction between the metal ions.