Electrocatalytic oxidation of methanol at platinum electrode modified with Eu-Fe cyanide-bridged binuclear complexes

The electrocatalytic oxidation of methanol at the platinum electrode modified with Eu-Fe cyanide-bridged binuclear complexes (Eu-Fe film) was investigated for the first time by cyclic voltammetry.Compared with the bare platinum electrode,the results showed that the modified electrode had excellent electrocatalytic activity for the oxidation of methanol;the oxidation peak potential shifted more negatively and the peak current increased about twenty times.The electrooxidation of methanol at the modified elect...

ORGANOMETALLIC FERROELECTRIC LIQUID CRYSTALS Ⅰ. LIQUID CRYSTAL PROPERTIES OF ORTHO—PALLADATED BINUCLEAR COMPLEXES OF AZINE, IMINE AND AZO DERIVATIVES

The mesomorphie properties of title complexes are investigated by means of DSC and polarizing microscopy. The mesophase temperature ranges of complexes are wider than that of corresponding organic ligands. The bridging groups of the complexes have profoand effects on the mesomorphic behavior, When the bridging groups are opticallhy active. the compleve show chiral smectic

TRIPLY BRIDGED BINUCLEAR COMPLEX OF OXOMOLYBDENUM(Ⅴ)WITH MERCAPTOPHENOLATE LIGANDS

Reaction of(n-Bu_4N)_xNa_(4-x)[a-Mo_8O_(26)](x=1-4)and mpH_2(mpH_2=o-mercaptophenol) leads to the formation of compound(n-Bu_4N)[Mo_2O_3(mp)_3Na(EtOH)_2(MeOH)],It crystallizes in the space group P2_1/n with four molecules per unit cell.The cell dimension is a=12.776(3),b=14.154(5),c=26.281(7)(?)=95.50(2)°,V=4730.5 (?),d_c=1.407 g/cm^3.Full-matrix refinement of 496 parameters on 3348 reflection data gave final R(R_w) value of 0.072(0.072).The two oxomolybdenum-mercaptophenolate,units are triply bridged by an inorganic oxygen atom and a doubly bridging mp^(2-)ligand.

Synthesis and Magnetism of μ-IsophthalatoOxovanadium(Ⅱ) Binuclear Complexes

Two μ-isophthalato oxovanadium(Ⅱ) binuclear complexes, [(VO)2-(IPHTA) (phen)2] SO4 (1) and [(VO)2 (IPHTA) (NO2-phen)2 ]SO4 (2) were syn thesized and characterized. The magnetism of complex (1) was studied

SYNTHESES AND CHARACTERIZATION OF A SERIES OF RARE EARTH BINUCLEAR COMPLEXES

A direct method of obtaining complexes of cobalt with respect to rare earth elements is reported. The total of 14 new compounds which are insoluble in water and general organic media have been synthesized by the reaction of RE（Ac）3·XH2O （RE=rare earth elements except for Ce, Pm; X=2, 5, 8） with [H6CO2（Gc）5CS2] （Gc=-S2CNHCH2CO2-） in acetone/ water at room temperature. The complexes having the general formula, [RE2Co2（Gc）5HAcCS2·XH2O], were characterized by elemental analyses, infrared spectra, DSC and TGA.

Synthesis, structures, and properties of two new binuclear complexes based on carboxyl-substituted nitronyl nitroxide: [M₂(NITpBA)₄(H₂O)₂] (M = Zn and Cu)

Two new binuclear complexes, [M2(μ-NITpBA)4(H2O)2] (M = Zn 1 and Cu 2) [where NIpBA =?2-(4-carboxyl-phenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxyl-3-oxide], were stylized and characterized. Magnetic susceptibility measurements revealed antiferromagnetic exchange interactions in two complexes.

Synthesis and Crystal Structure of a Novel Binuclear Copper(Ⅱ) Complex, [Cu(paba)Cl]

A novel binuclear Cu（Ⅱ） complex [Cu（paba）Cl] （pabaH = 2-（2-pyridylmethylimine）benzenesulfonic acid） has been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal of the title complex crystallizes in a monoclinic system, space group P21/n, with a = 6.8165（7）, b = 15.3073（16）, c = 12.3795（13） A^°, β= 95.0160（10）°, V= 1286.8（2） A^°^3, Mr = 360.26, Dc= 1.860 g/cm^3,μ = 2.074 mm^-1, F（000） = 724, Z = 4, the final R = 0.0252 and wR = 0.0675 for 2395 observed reflections with I 〉 20（I）. The title complex is centrosymmetric and a pair of chlorides act as μ2-bridges to link two Cu（Ⅱ） ions forming a binuclear complex. Every Cu（Ⅱ） ion is five-coordinated by pyridyl N, imine N and sulfonate O atoms of the tridentate paba ligand as well as two bridging Cl^-, constructing the distorted square-pyramidal geometry. In the structure extensive hydrogen bonds and weak π-π stacking stabilize the solid structures, through which the complex builds its 3-dimensional supramolecular structure.

Synthesis and magnetism of rare earth (Nd,Gd,Dy,Ho,Er,Y) pentafluoropropionate binuclear complexes with 2-(4'-methoxy-phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide

Six compounds of the general formula [Ln(pfpr)3]2(NITPhOMe).nH2O, where Ln=Nd, Gd, Dy, Ho, Er, Y, pfpr=pentafluoropropionate, NITPhOMe=2-(4'-methoxyphenyl)-4,4,5, 5-tetra-methylimidazoline-1-oxyl-3-oxide, and n=4 (for Nd, Dy, Er); 3 (for Gd); 6 (for Ho); 5 (for Y), have been synthesized. These complexes were characterized by elemental analyses, IR, electronic spectra and molar conductances. The variable temperature (4-300 K) magnetic susceptibility of the complex [Gd(pfpr)3]2(NITPhOMe).3H2O was determined. The observed susceptibility data were fit to those from theoretical magnetic equation by least-squares method. The exchange integral, J, was found to be equal to 2.14 cm-1. This indicates a weak ferromagnetic spin-exchange interaction between the radical and the gadolinium(III) ion.

Synthesis and Crystal Structure of Binuclear Copper (Ⅱ) Complex Containing (Dimethylaminomethyl)ferrocene

A binuclear complex including ferrocenyl, Cu2{Fe(C5H5)[C5H4CH2N(CH3)2]}2 (CH3COO)4, was synthesized and characterized by X-ray diffraction. The title complex crystallizes in triclinic, space group P with a = 8.2779(8), b = 9.4830(8), c = 12.262(1) ? = 81.079(5), b = 80.620(4), g = 78.960(4), V = 924.4(1) 3, Z = 1, C34H46Cu2Fe2N2O8, Mr = 849.51, Dc = 1.526 g/cm3, l(MoK) = 0.71073 ? ?= 1.954 mm-1, F(000) = 438, R = 0.0297 and wR = 0.0901. Both cyclopentadienyl rings in each dmaf (dmaf = (dimethylaminomethyl)ferrocene, Fe(C5H5)- [C5H4CH2N(CH3)2]) have an eclipsed conformation. The binuclear molecule has a crystallographic centrosymmetry; four acetates and two Cu atoms form a cage structure with the distance between two neighboring Cu atoms of 2.655(1) .

Synthesis and magnetic properties of copper(Ⅱ)-lanthanoid(Ⅲ) binuclear complexes with N,N'-bis(3-aminopropyl) oxamido ligand

Six novel u-oxamido binuclear complexes, namely Cu(oxpn)Ln(L)2(ClO4)3 (Ln: Eu, Gd, Tb, Nd, Ho, Er), where oxpn is N,N'-bis(3-aminopropyl) oxamido, L denotes 5-nitro-1,10-phenanthroline (abbreviated as NO2-phen), have been synthesized and characterized. The magnetic susceptibility of complexes Cu(oxpn)Gd(NO2-phen)2(ClO4)3.2H2O was measured over the 4-300 K and the observed data were successfully simulated by equation based on spin Hamil-tonian operator (H = -2JS1.S2), giving the exchange integral J(Cu-Gd)=-1.62 cm-1. This indicates a weak antiferromagnetic interaction between the Cu(Ⅱ) and Gd(Ⅲ) ions.

Synthesis and magnetic properties of μ-phenolato copper (Ⅱ) binuclear complexes with different exogenous bridges

The syntheses and magnetic properties are reported for a series of copper(Ⅱ) complexes prepared from a pentadentate binucleating ligand 2,6-diformyl-4-methylphenol di(benzoyl-hydrazone) (H3L). These complexes incorporate different exogenous ions (X-) into a bridging position to form copper(Ⅱ) binuclear complexes of the formula [Cu2(H2L)X]2+, where X-= Br-(1), Cl-(2), HO-(3), C2H5O-(4) and C3H3N2- (5). The complexes have been characterized with variable temperature magnetic susceptibility (4.2-300 K) and the observed data were fit to those from a modified Bleaney-Bowers equation by least-squares method, giving the exchange integral 2J = -6.2 cm-1 for 1, -76.4 cm-1 for 2, -241.9 cm-1 for 3, -231.1 cm-1 for 4 and -343.8 cm-1 for 5. This suggested that there is an antiferromagnetic interaction between the Cu(Ⅱ) ions and the sequence of the effect of some exogenous bridging ligands on magnetic coupling is corresponding to that in spectrochemical series.

Crystal Structure of Binuclear Manganese(Ⅲ) Complex with Schiff-base Ligand,〔Mn_2(C_(22)H_(22)N_2O_2)_2(EtOH)_2 (bipy)〕(ClO_4)_2

The title complex, [Mn2L2(EtOH)2 (bipy )](ClO4)2 (L=N,N'-ethylenebis (1-phenyl-3-imino-1-butanonato), bipy = 4, 4'-bipyridine] crystallizes inmonoclinic system, space group P21/c with a= 12. 63O(5), b=13- 151 (2), c=18. 3773001 reflections The two [MnL(EtOH)]+ units are joined by one 4, 4'-bipyridine molecule to form a centrosymmetric binuclear complex cation [Mn2L2(EtOH)2 (bipy]2+. The coordination geometry around Mn atoms is a distorted octahe-dron with equatorial plane N2O2 from the Schiff base ligand L.

Synthesis and Characterization of Binuclear Lanthanide Complexes with Macrocyclic Schiff Base Derived From 2,6-Diacetylpyridine and 1,3-Diamino-2-hydroxypropane

Nine homobinuclear lanthanide complexes with macrocyclic Schiff base were prepared by condensing 2, 6-diacetylpyridine and 1, 3-diamino-2-hydroxypropane in the presence of template lanthanide metal ions. These complexes were characterized by elemental analysis, IR, molar conductance and magnetic susceptibility. The variable-temperature magnetic susceptibility (4-300 K) of complexes of Gd( Ⅲ ) and Dy( Ⅲ ) was determined. A satisfactory fit to theoretical curve derived from spin Hamiltonian operator was obtained using least-squares method. The exchange interaction parameters are J=-0.26 cm-1, g=1.98 and △=0.06 cm-1, Z.J'=-0. 21 cm-1,g'=1.33 for Gd( Ⅲ ) and Dy( Ⅲ ), respectively. The results indicate a very week antiferromagnetic interaction between Gd( Ⅲ )-Gd( Ⅲ ) and Dy( Ⅲ )-Dy( Ⅲ ) ions.

Hydrothermal Synthesis and Crystal Structure of Binuclear Copper(Ⅱ) Complex Bridged by 1,2,4,5- Benzenetetracarboxylato Trivalent Anion

The title complex [(phen) 2Cu(Htcb)Cu(phen) 2]H 3tcb(tcb=1,2,4,5-benzenetetracarboxylato tetravalent anion; phen=1,10-phenanthroline) was synthesized by the hydrothermal synthesis method. The crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic system with space group P1, a=1.04174(8) nm, b=1.07119(8) nm, c=1.26360(10) nm, α=98.169(2)°, β=99.679(10)°, γ=93.658(10)°, V=1.37031(18) nm3, Z=1. The two copper(Ⅱ) cations are bridged by Htcb in the monodentate fashion, and have the same five-coordinated environment completed by the four N atoms from the two phen molecules and one O atom from the carboxylic group of Htcb respectively, which can be best described as distorted trigonal-bipyramid geometry. Moreover, the three dimensional network is formed by H-bonding interactions [O…O distance from 0.2506(10) nm to 0.3176(11) nm] and π-π stacking interactions between the phen rings of adjacent binuclear entities with a face-to-face separation of ca. 0.354 nm.

Ab Initio Molecular Orbital Calculation on Dinuclear Gold(Ⅰ) Complexes──Metal-Metal Interaction and Electronic Structure of Binuclear Gold(Ⅰ) Complexes with Bridging Bidentate Ligands

The electronic structure and electronic absorption spectra of binuclear Au(Ⅰ) complexes with bidentate phophines and a bidentate ylid ligand have been studied using quasirelativistic pseudopotential ab initio calculations at the HF and MP2 levels by the LANL2DZ basis sets. The electronic properties of the spectral transition and Au(Ⅰ)—Au(Ⅰ) interaction were also discussed.

Synthesis, Properties and Structureof a Novel Unsymmetrical Bis (phenoxo) BridgedBinuclear Copper (Ⅱ) Complex

A novel bis (phenoxo) bridged binuclear copper ( II) complex with dissimilar coordination environments was synthesized and characterized by spectroscopies and X-ray crystallography. It crystallized in the monoclinic system with space group C2/c, a=2. 241 1(2) nm, b=1. 834 2 (2) nm, c=1.877 9(2) nm, β=122.861(2)°, V=6.484 3(11) nm3, Z=8. Itconsistsof two unsymmetrical Cu (Ⅱ ) centers bridged by two phenolic oxygen atoms to yield a Cu2O2 core with the Cu-Cu separation of 0. 310 2 nm, in which Cul and Cu2 ions exhibit distorted N2O3 and N3O2 square pyramidal geometries, respectively.

Synthesis and Crystal Structure of Binuclear Complex of Copper(Ⅱ)Chloroacetate with Acetamine

The title complex, Cu 2(O 2CCH 2Cl) 4 OC(NH 2)CH 3 2, crystallizes in space group P2 1/a with a=7.616(4), b=18.665(5), c=7.949(5) , β=106.29(5)°. V=1084(1) 3, Z=2, M r=619.19, D c =1.896 g/cm 3; μ =25.05 cm -1 and F(000)=620.00, R =0.045 and R w =0.054 for 1807 observable reflections. X ray crystal structure analysis revealed that two Cu atoms are bridged by four chloroacetate groups, and the acetamine ligands are bonded by O(carboxide) to the terminal Cu atoms of each dimeric unit. The coordination geometry of Cu atom is a distorted octahedral configuration. The distance between the two Cu atoms is 2.648(1) .

Synthesis, Characterization and Biological Activities of Binuclear Metal Complexes of 2-Benzoylpyridine and Phenyl(Pyridin-2-yl) Methanediol Derived from 1-Phenyl-1-(Pyridin-2-yl)-N-(Pyrimidin-2-yl) Methanimine Dihydrate Schiff Base

The Schiff base, 1-phenyl-1-(pyridin-2-yl)-N-(pyrimidin-2-yl)methanimine dihydrate (L1) has been synthesized by the condensation reaction between 2-aminopyrimidine and 2-benzoylpyridine and characterized using 13C-NMR, 1H-NMR, microanalysis, FT-IR, DEPT-135, HSQC, HMBC, COZY, NOESY. The reaction of 1-phenyl-1-(pyridin-2-yl)-N-(pyrimidin-2-yl)methanimine dihydrate (L1) with salts of V(IV), Co(II) and Cu(II), however, resulted in the hydrolysis of L1 to give binuclear metal complexes of 2-benzoylpyridine (L2) and phenyl(pyridin-2-yl)methanediol (L3) which were characterized using UV-visible spectroscopy, and TGA. The single crystal x-ray structure determined for the Copper(II) complex revealed that we obtained a compound previously obtained using a different method of synthesis. The Schiff base ligand (L1) is soluble in methanol, ethanol, DMSO, acetone and DMF. Microanalysis and Spectroscopic studies indicated that binuclear metal complexes were obtained by the coordination of metal ion to 2-benzoylpyridine (L2) and phenyl(pyridin-2-yl)methanediol (L3) from the hydrolysis of L1. Spectroscopic and elemental analysis reveal the formation of square pyramidal complexes of Co(II) and Cu(II) and a square planar complex of V(IV). In vitro antibacterial and antifungal activity against three bacterial strains (Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus) and three fungal stains (Candida albicans, Candida glabrata and Candida parapsilosis) showed moderate biological activity. Antioxidant studies reveal that only the binuclear Co(II) and oxovanadium(II) complexes are potent to eliminate free radicals.

Synthesis,structure and properties of an imidazolate bridged copper,zinc binuclear complex

A new imidazolate bridged Cu^(2+),Zn^(2+)binuclear complex[(dtma) CulmZn (dtma)]ClO_4· 2.5H_2O taken as active site model for Cu,Zn-SOD has been synthesized and its crystal structure determined.All the bond lengths, bond angles and the distance between Cu and Zn atoms in Cu-Im- Zn core of the model complex are close to those in Cu,Zn-SOD.ESR parameters of the model complex as a function of pH show that the imidazolate bridge is stable in pH range 10—12,and is broken on Zn side at pH～9.With decreasing pH,the imidazole is released at pH～4 and the dtma ligand dissociates from the Cu containing fragment at pH～2.4.

Synthesis and Crystal Structure of a Binuclear Gadolinium（Ⅲ） Complex Bridged by Cucurbit[6]uril

A new cucurbit[6]uril bridsed binuclear complex {[Gd（H2O）6]2[Q6（H2O）]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows that the complex has an extended cucurbit[6]uril-bridged structure consisting of two gadolinium（Ⅲ） ions, in which each gadolinium（Ⅲ） ion is coordinated with two neighboring carbonylic oxygen atoms of Q6 and six oxygen atoms of water molecules that leans toward one side of the portal. One disordered guest water molecule resides in the Q6 molecule cavity and occupies two different positions. Hydrogen bonds assemble the complcx to threedimensional supramolecular structure.