Yao Xinkan

Crystal structure and magnetic properties of binuclear copper(II) complexes of 2,6-diformyl-4-tert-butylphenol di(benzoylhydrazone)

Abstract The crystal structure and magnetic properties of copper(II) binuclear complexes are reported. The binucleating ligand (L) is 2,6-diformyl-4-tert-butylphenol di(benzoyl-hydrazone). The small exogenous bridging anions are OR− and Br− for complexes 1 and 2, respectively. The magnetic coupling parameters are consistent with antiferromagnetic exchange between the two copper(II) centres and fits of the data with binuclear magnetic exchange models give antiferromagnetic coupling parameters of 2J = −309 and −47.8 cm−1 for complexes 1 and 2, respectively. Crystal data for complex 1 [Cu2L(C2H5O) (CH3OH)](ClO4)2, Mr = 844.59 g mol−1, space group P 1 , a = 10.552(1), b = 13.271(2), c = 14.4184(4) A, α = 72.53(1), β = 78.46(2), γ = 72.83(1)°, V = 1826.2 A3, Z = 2, Dx = 1.534 g cm−3 λ(Mo-Kα) = 0.71037 A, μ = 13.78 cm−1, F(000) = 864, R = 5.2%, Rw = 6.3% with 1992 observed unique reflections.

Synthesis and crystal structure of a binuclear zinc(II) complex of 2,6-diformylpyridine N--oxide bis(benzoylhydrazone)

Abstract The binuclear zinc(II) complex [Zn 2 L(O 2 CCH 3 ) 2 ] · CH 3 CCH 2 OOH was synthesized by a template reaction in alcohol. The crystal and molecular structure of this complex has been determined by X-ray analysis. The binucleating ligand L, 2,6-diformylpyridine TV-oxide bis(benzoylhydrazone), is in doubly deprotonated form. All the coordinated atoms in the bis-Schiff base ligand and two zinc atoms in the complex molecule are coplanar, and the N -oxide oxygen atom bridges two zinc atoms with the same bond length of 2.24(1) A. The two acetate ions act as bidentate ligands linking two zinc atoms, both being in a distorted trigonal-bipyramidal environment.

Crystal structure of the complex of dibenzo-30-crown-10 with dysprosium isothiocyanate

Crystalline [Dy(NCS)3(dibenzo-30-crown-10)(H2O)2]·H2O·MeCN can be obtained by slowly evaporating a reaction mixture of Dy(NCS)3·nH2O with dibenzo-30-crown-10 in a solution of acetonitrile. The material crystallizes in the monoclinic space groupP21/n, the cell parameters area=11.450(5),b=23.284(4),c=18.424(6)Å, β=106.28(4)°,V=4715Å3,M=968.47,Dx=1.36 g cm−1, μ=17.80 cm−1,F(000)=1972,Z=4.2740 independently observed [I≥3σI] reflections were used in the final least-squares refinement leading to an agreement index ofR=0.085. The Dy(III) ion coordination geometry approximates a square antiprism, involving two water oxygens and three dibenzo-30-crown-10 oxygen atoms and three isthiocyanate nitrogens. Hydrogen bonds are formed between the two water molecules and four uncoordinated crown ether oxygen atoms.

Crystal structure and ferromagnetic behavior of a μ-acetato-bridged one-dimensional linear-chain copper(II) complex

Abstract A μ-acetato-bridged copper(II) complex, CuBr(CH 3 COO)·2H 2 O, was synthesized and its structure refined by X-ray single crystal structure analysis to R = 0.071. The crystals are orthorhombic, of space group Pnma , with cell constants a = 8.980(2), b = 7.569(2), c = 10.393(3) A , and Z = 4 . The copper(II) ions are bridged by acetate ions to form a one-dimensional linear-chain structure. Magnetic measurements in the range 4–250 K and subsequent calculations based upon Bakers equation suggest intrachain ferromagnetic coupling between the copper(II) ions with J = 3.8 cm −1 .

Synthesis, structure, magnetic properties and molecular mechanics study on the dinuclear copper (II) with biradical

Dinuclear copper complex with biradicals [Cu(hfac)2]2PhBNM(PhBNM = 2,5-bimethyl-1,4-bis (4,4,5,5-tetramethyllimidazoline-1-oxyl-3-oxide)phenyl,hfac=hexafluoroacetylacetonate) has been synthesized and characterized. It crystallized in the monoclinic system, with space groupC2/c,a=1.9012(4),b=1.3718(3),c=2.1620(4) nm, s=97.55(3)°,Z=4. The X-ray structure analysis shows that the molecular structure consists of two kinds of conformations. The ratio of them is 7:3. The energy of two conformations, calculated with molecular mechanics, are different,E1=740 kJ/mol, andE2=771 kJ · mol−1. The CNDO/k results on the complex indicate that the orbital energy of low spin state is lower than that of high spin state, which correspond with the results of magnetic measurement.

Synthesis and properties of one-dimensional Ni(II) and Ni(II)Cu(II) complexes linked by hydrogen bond

Four dithiooxalato (Dto) bridged one-dimensional Ni(ll) and Ni(ll)Cu(ll) complexes (Me6[14]dieneN4)Ni2(Dto)2) (1), (Me6[14]dieneN4)CuNi(Dto)2 (2), (Me6[14]aneN4)Ni2(Dto)2 (3), and (Me6[14]aneN4)CuNi(Dto)2 (4), were synthesized. These complexes have been characterized by elemental analysis, IR, UV and ESR spectra. The crystal structure of complex3 was determined. It crystallizes in the monoclinic system, space group C2/c with a = 2. 2425(4) nm,b = 1.0088(2) nm,c= 1.4665(3) nm, β= 125.32(3)δ Z = 4;R = 0.076, Rw = 0.079. In the complex, Ni(1) coordinates four sulphur atoms of two Dto ligands in plane square environment. Ni(2) lies in the center of macrocyclic ligand. For Dto ligand, two sulphur atoms coordinate Ni(1), and O(1) coordinates Ni(2) and forms weak coordination bond. O(2) is linked to N(2) of macrocyclic ligand through hydrogen bond.

Preparation and Properties of FeNi-Mg/MgO Nanocomposite

The FeNi-Mg/MgO nanocomposite synthesized by spark erosion of pure Mg and Fe70Ni30 electrodes was investigated by X-ray diffraction, Mössbauer spectroscopy and magnetic measurements. From the X-ray diffraction measurements Mg, MgO, and α-FeNi were recognized. According to the Mössbauer spectra analysis, iron atoms were identified in α-FeNi, Fe1-xO, and FeNi in Mg/MgO phases. The FeNi in Mg/MgO phase consists of fcc γ-FeNi phase which is antiferromagnetic below TN ≈ 40 K and weakly ferromagnetic bcc α-FeNi clusters. The magnetic measurements confirmed the presence of the γ-FeNi phase and the composite model in the form of isolated magnetic particles in Mg/MgO matrix.

X-ray powder diffraction studies of multipyrazole series compounds

X-ray powder diffraction data are reported for a series of multipyrazole compounds in this paper. This work shows that the unit cell dimensions determined by single crystal agree well with those of powder diffraction analysis.

STUDIES ON ORGANOMETALLIC COMPOUNDS OF TITANIUM,ZIRCONIUM AND HAFNIUM——THE CRYSTAL AND MOLECULAR STRUCTURES OF OXO-BRIDGED TETRAKIS(CYCLOPENTADIENYL)BIS (o.TOLYL)AND TETRAKIS(METYLCYCLOPEN-TADIENYL) BIS(p-TOLYL)BINUCLEATED ZIRCONIUM COMPOUNDS

This paper reports the crystal and molecular structures of tetrakis (cyclopentadienyl) bis(o-tolyl)-μ-oxo-dizirconium [dimer (Ⅰ)] and tetrakis (methylcyclopentadienyl) bis (p-tolyl)-μ-oxo-dizirconium [dimer (II)]. Both of them belong to monoclinic system and possess the same spacegroup C_2~5h- 2_1/a. The cell dimer (Ⅰ) containing four molecules is defined by a=19.122A,b=16.319A, c = 9.296A, β= 92°1′; the cell dimer (Ⅱ) containing two molecules is defined bya = 20.076A, b = 8.205A, c = 10.016A, β= 104°41′. The important difference of molecular configurations between the two dimers lies in thatthe dimer (Ⅰ) has no symmetry center and its Zn-O-Zr oxo-bridge presents a slightly bentconfiguration while the dimer (Ⅱ) takes the oxgen atom as a symmetry center and its oxo-bridge present linear linkage. In accordance with the above-mentioned molecular configuration, steric effect and elec-tronic structure have been further discussed.