Yuangen Yao

Complicated magnetic behavior in one-dimensional nickel(III) chain complex [1-(4′-cyanobenzyl)pyridinium][Ni(mnt)2](mnt2−=maleonitriledithiolate)

Abstract A new ion-pair complex [1-(4′-cyanobenzyl)pyridinium] [Ni(mnt)2] (1), in which mnt2−=maleonitriledithiolate, have been fabricated and its X-ray single crystal structural analyses at 293, 180 and 140 K shown that the [Ni(mnt)2]− anions and [CNBzPy]+ cations form a well-separated stacking column along c-axis direction, within which [Ni(mnt)2]− anions are uniformly spaced to give a one-dimensional (1-D) chain structure. Bulk magnetic properties of this complex have been investigated in the temperature range of 2–400 K and shown there exists spin kink at ∼190 K. In low temperature region, weak ferromagnetic behavior occurs in 1.

Structural, morphological, and magnetic study of nanocrystalline cobalt-nickel-copper particles

Nanocrystalline Co(x)Ni(y)Cu(100-x-y) particles were synthesized by the reduction of metal acetates in a mixture of polyol and Tween 80. Inductively coupled plasma (ICP) analysis revealed that the actual wt% of Co, Ni, and Cu in these nanoparticles was nearly the same as in the starting solutions. The structures of the particles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) spectroscopy, and vibrating sample magnetometry (VSM). The results of XRD and VSM confirmed that there was no metastable alloying in the particles. The particles were composites, consisting of nanoscale crystallites of face-centered cubic (fcc) Cu, face-centered cubic (fcc) Ni, and face-centered cubic (fcc) Co. During preparation the nucleation of Cu occurred first; then small Cu nuclei acted as cores for the precipitation of Co and Ni. The particles showed an increase in saturation magnetization (M(s)) as the concentration of Co or Ni in the particles was increased. The changes of both M(s) and coercivity of the particles with increasing annealing temperatures were studied. The coercivity of the particles was very high; it could reach as high as 489 Oe for Co34.3Ni31.2Cu34.5) .

Spontaneous magnetization in [1-(4-cyanobenzyl)pyridinium][Pt(mnt)2]: synthesis, crystal structure and magnetic property

Abstract A new complex [1-(4-cyanobenzyl)pyridinium][Pt(mnt) 2 ] ( 1 ), in which mnt 2− xa0=xa0maleonitriledithiolate, has been prepared and characterized. In the solid state, anions and cations of 1 form completely segregated stacking column, and the [Pt(mnt) 2 ] − anion column behaves as one-dimensional (1-D) spaced magnetic chains. 1 spontaneously magnetizes at low temperature, which may arises from spin canting.

Syntheses and crystal structures of two new nickel 1,2,5-thiadiazole-3, 4-dithiolate complexes as benzylpyridinium salts

Two new complexes, [BrBzPy]2[Ni(tdas)2] (1) and [BrFBzPy]2[Ni(tdas)2] (2), have been prepared by reaction of disodium 1,2,5-thiadiazole-3,4-dithiolate (Na2tdas), NiCl2·6H2O and 1-(4′-bromobenzyl) pyridinium bromide (BrBzPyBr) or 1-(4′-bromo-2′-fluorobenzyl)pyridinium) bromide (BrFBzPyBr). Crystallographic data for 1: monoclinic, P21 /c, au2009=u200911.333(1), bu2009=u200912.602(1), cu2009=u200912.267(1)u2009Å, βu2009=u2009115.65(1)°, Vu2009=u20091579.4(18)u2009Å3, Zu2009=u20094. Data for 2: triclinic, , au2009=u20097.437(2), bu2009=u200910.382(2), cu2009=u200911.330(2)u2009Å, αu2009=u2009110.07(3), βu2009=u200992.58(3), γu2009=u200993.32(3)°, Vu2009=u2009818.5(2)u2009Å3, Zu2009=u20091. In the complexes, the [Ni(tdas)2]2− anion exhibits a quasi-planar structure. The topology of the countercation results in different stacks of molecules in the complexes.

Synthesis and crystal structure of metal complexes of Schiff bases derived from Glycylglycine and Salicylaldehyde [Ni(H2O)6(Ml)2]·nH2O (M = Cu, Ni; L = C11H9N2O4)

Complexes [Ni(H2O)6(ML)2]·nH2O (M = Cu, Ni; L = Schiff base derived from glycylglycine and salicylaldehyde, C11H9N2O4) were synthesized and characterized. The [Ni(H2O)6(CuL)2]·10H2O complex 1 crystallized in the space group , with a = 7.217(1), b = 11.674(1), c = 12.678(1)u2009Å, α = 66.56(1), β = 76.60(1), γu2009= 80.46(1)°, and Z = 1. The [Ni(H2O)6(NiL)2]·2H2O complex 2 crystallized in the group P2(1)/c, with a = 10.564(2), b = 20.246(4), c = 6.965(2)u2009Å, β = 103.14(1)°, and Z = 2. Hydrogen bonding involving [ML]−, Ni(H2O)6 2+ and molecular water forms a three-dimensional (3D) supermolecule. The determination of variable-temperature magnetic susceptibilities indicates an antiferromagnetic interaction between the metallic atoms of 1, and a corresponding ferromagnetic interaction for 2.

Intramolecular photo-substitution in the inclusion compound of mono[6-deoxy-6-(2-aminoethyl thio-1,2-dicyane ethylenylthio)]-β-cyclodextrin with cyclopentadienyl manganese tricarbonyl in DMF solution

Abstract A novel host of β-cyclodextrin (β-CD) derivative, mono[6-deoxy-6-(2-aminoethyl thio-1,2-dicyane ethylenylthio)]-β-CD ( 3 ), and its inclusion compound 4 with cyclopentadienyl manganese tricarbonyl (CpMn I (CO) 3 ) have been prepared and characterized by spectroscopic methods. It is experimentally evident that the inclusion complexation stabilized the guest extremely when complex 4 was heated. Upon irradiation of inclusion compound 4 in DMF solution, an interesting intramolecular photo-substitution resulting in the formation of a self-stabilized compound mono[6-deoxy-6-(2-aminoethyl thio-1,2-dicyane ethylenylthio)]-β-CDue5f8Mn II Cp(DMF) 2 ( 7 ) was observed. Based upon a double-recognition between the host and the organometallic guest, compound 7 became very stable in DMF solution.

Synthesis and characterization of a dipeptide–copper(II)– 2-aminomethylbenzimidazole ternary complex

A new ternary complex [Cu(glygly)(AMBZ)(H2O)]Cl·H2O (1) (glyglyu2009=u2009glycylglycine anion, AMBZu2009=u2009 2-aminomethylbenzimidazole) has been prepared and characterized by single-crystal X-ray diffractometry and ESR, electronic and IR spectroscopy. The copper(II) ion has a slightly distorted square-pyramidal coordination, being equatorially coordinated by the bidentate 2-aminomethylbenzimidazole and the bidentate glycylglycine anion and axially by a water molecule. The individual complex molecules are hydrogen bonded to their neighbors, forming a polymeric hydrogen-bonded lattice. Spectroscopic data are in accordance with the crystal structure.

Syntheses and crystal structures of two maleonitriledithiolate complexes containing the 1-(R-benzyl)pyrazinium cation (R = 4′-nitro or 4′-bromo)

The complexes [NO2BzPz]2[Ni(mnt)2] (1) and [BrBzPz]2[Pd(mnt)2] (2) have been prepared by reaction of Na2mnt, NiCl2·6H2O or PdCl2, and the corresponding 1-(R-benzyl)pyrazinium bromide salt (R = 4′-nitro, R = 4′-bromo). Crystallographic data for 1: monoclinic, P21/n, a = 7.3494(15), b = 15.223(3), c = 15.054(3)u2009Å, β = 102.42(3)°, V = 1644.8(6)u2009Å3, Z = 2. Data for 2: monoclinic, P21/n, a = 7.399(2), b = 19.024(4), c = 12.224(2)u2009Å, β = 94.62(3)°, V = 1715.0(7)u2009Å3, Z = 4. In both complexes, the [M(mnt)2]2− anion has a centre of symmetry at the metal atom and two cations are related to each other by the symmetry centre. The [M(mnt)2]2− anion exhibits a quasi-planar structure in both complexes, which show similar crystal packing.

Molecular and crystal structure of two nickel(II) 1,2-dithiooxalato-S,S′ complexes using 1-(Rbenzyl)pyridinium cation (R = 4′-bromo-2′-fluoro or 4′-bromo)

Abstract[BrFPy]2[Ni(dto)2] (1) and [BrPy]2[Ni(dto)2] (2) complexes have been prepared by reaction of Na2[Ni(S2C2O2)2] and the corresponding 1-(Rbenzyl)pyridinium bromide salt (R1 = 4′-bromo-2′-fluoro, R2 = 4′-bromo). The crystallographic data for 1: monoclinic P21/c, a = 14.2192(1) Å, b = 14.2533(4) Å, c = 15.6535(3) Å, β = 96.463(1)°, V = 3152.34(11) Å3, Z = 4. Two cations, [Br1F1Py]+ and [Br2F2Py]+, both adopt a conformation where both the aromatic rings are twisted to the corresponding N(1)–C(10)–C(11) or N(2)–C(22)–C(23) reference plane. Data for 2: triclinic n