Synthesis, crystal structure, and magnetic properties of a new manganese(II) complex with nitronyl nitroxide

A new manganese(II) complex [MnCl₂(NIT-1′-MeBzIm)₂] · 3H₂O (NIT-1′-MeBzIm = 2-{2′-[(l′-methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been prepared and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group C2/c, Z = 4. Crystal data: C₃₀H₃₈Cl₂MnN₈O₈, M = 764.52, a = 17.261(3) Å, b = 21.317(4) Å, c = 11.744(2) Å, β = 108.464(2)°. The X-ray analysis reveals that Mn(II) atom is six-coordinated with a distorted octahedral geometry. The complex was linked by intermolecular hydrogen bonds, leading to a 2D network configuration. Magnetic investigation indicates the existence of interamolecular interactions is ferromagnetic with J = 1.11 cm^?1.     

Synthesis,crystal structure and magnetic properties of a nickel(II) complex with pyridine-substituted nitronyl nitroxide radicals

The complex [Ni(NIT2Py)(PDA)(H₂O)]·(MeOH)(H₂O) [NIT2Py = 2-(2-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; PDA = 2,6-pyridine dicarboxylic acid] has been prepared and structurally characterized. The Ni^II ion is in a distorted octahedral environment: one nitrogen atom and one oxygen atom from the NIT2Py, one nitrogen atom from the PDA and one oxygen atom from the H₂O in the basal plane; two oxygen atoms from the PDA in the axial position. The units of [Ni(NIT2Py)(PDA)(H₂O)] were connected as a one dimension chain by intermolecular hydrogen bonds. The complex exhibits intramolecular antiferromagnetic interactions between the Ni^II ion and the NIT2Py.     

Synthesis,crystal structure and magnetic properties of a nickel(II) complex containing a 2-pyridyl-substituted nitronyl nitroxide

A new complex of formula [Ni(NIT2Py)₂Cl(H₂O)]Cl·2CH₃OH, where NIT2Py is 2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, was synthesized and characterized structurally and magnetically. The structure consists of a [Ni(NIT2Py)₂Cl(H₂O)]⁺ ion, a chloride anion and two methanol molecules. The nickel(II) ion lies in a distorted octahedral environment; two nitrogen atoms and two oxygen atoms from NIT2Py ligands from the basal plane; one oxygen atom from a water molecule and one chloride anion occupy axial positions. Variable temperature magnetic susceptibility data show that there is strong antiferromagnetic coupling between the nickel(II) ion and nitronyl nitroxide radicals. The results suggest that the sign of the magnetic interaction depends on structural and ligand effects.     

A new zinc(II) complex containing nitronyl nitroxide radicals: Synthesis, crystal structure, and magnetic properties

A new one-dimensional dicyanamide bridged zinc(II) complex containing nitronyl nitroxide radicals [Zn(Hfac)₂(NIT-1′-MeBzIm)] (NIT-1′-MeBzIm = 2-{2′-[(l′-methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, Hfac = hexafluoroacetylacetonate) has been prepared and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P2₁/c, Z = 4. Crystal data: C₂₅H₂₁F₁₂N₄O₆Zn, Mr = 766.83, a = 12.1812(13) Å, b = 16.8770(18) Å, c = 15.5230(16) Å, β = 98.009(2)°, V = 3160.1(6) ų, ρ _c = 1.612 g/cm³, μ(MoK _α) = 0.893 mm^?1, F(000) = 1540, R = 0.0925 and wR = 0.2652 for 5875 observed reflections with I > 2σ(I). The X-ray analysis reveals that the zinc(II) ion is six-coordinated with a distorted octahedral geometry. These units develop as 1D species by intermolecular hydrogen bonds. Magnetic investigation indicates the existence of weak intermolecular interactions is antiferromagnetic with J = ?1.35 cm^?1, where the spin Hamitonian is defined as H = ?2Σ _i,j J _i,j S _i S within the complex.     

Synthesis, crystal structures, and magnetic properties of a new nickel(II) complex with nitronyl nitroxide

A new nickel(II) complex [Ni(NIT-1′-MeBzIm)₂(H₂O)₂] · ClO₄ · H₂O (NIT-1′-MeBzIm = 2-{2′-[(l′-methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been prepared and structurally characterized by single-crystal X-ray diffraction. Complex I crystallizes in monoclinic, space group C2/c, Z = 4. Crystal data: C₃₀H₄₆N₈O₁₆ClNi, Mr = 869.06, a = 13.958(3), b = 15.904(4), c = 18.514(5) Å, β = 101.047(3)°. The X-ray analysis reveals that Ni²⁺ ion resides in a distorted octahedron center, the complex was linked by intermolecular hydrogen bonds, resulting in a 2D network configuration. Magnetic investigation indicates the existence of interamolecular interactions is antiferromagnetic with J = ?40.76 cm^?1.     

Synthesis and crystal structures of the nickel(II) complex with nitronyl nitroxide

Two nickel(II) complexes [Ni(NIT-l′-MeBzlrn)₂(Dca)₂] (I, II) (NIT-l′-MeBzIm = 2-{2′-[(l′methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide) have been prepared and structurally characterized by single-crystal X-ray diffraction. They are structural epimers. The complexe crystallizes in monoclinic, space group P2₁/n, Z = 4. Crystal data: C₃₄H₃₈N₁₄NiO₄, M _r = 765.49, a = 15.019(3), b = 18.803(4), c = 15.756(3) Å, β = 109.399(3)°, γ = 90° (I); a = 13.934(3), b = 11.046(2), c = 24.570(5) Å, β = 90.024(2)° (II). The X-ray analysis reveals that Ni²⁺ ion resides in a distorted octahedral center. The complex was linked by intermolecular hydrogen bonds, resulting in a ID chain structure for I and a 2D network configuration for II.     

Synthesis,crystal structure and ferromagnetic properties of a novel acetate bridged dicadmium(II) complex with nitronyl nitroxide

The novel dinuclear cadmium(II) complex [Cd₂(NIT-1′-MeBzIm)₂(CH₃COO)₄] (I), where NIT-1′-MeBzIm = 2-{2′-[(1′-methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, has been prepared and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in monoclinic crystal system, space group C2/c, Z = 4. Crystal data: C₃₈H₅₀Cd₂N₈O₁₂, M _r = 1035.66, a = 18.6492(16), b = 11.9605(10), c = 19.9208(17) Å, β = 92.1650(10)°. The X-ray analysis reveals that two Cd(II) atoms were bridged by two acetate groups to form a centrosymmetric Cd(II)-Cd(II) dinuclear entity, Cadmium atom is six-coordinated with a distorted octahedral geometry. The complex is linked by intermolecular hydrogen bonds leading to a 2D network configuration. Magnetic investigation indicates the existence of weak intramolecular interactions; i.e., the complex I is ferromagnetic with J = 1.97 cm^?1.     

1D chlorine bridged mercury(II) complex containing nitronyl nitroxide radicals: Synthesis, crystal structures, and magnetic properties

A novel 1D chlorine bridged mercury(II) complex containing nitronyl nitroxide radicals, [Hg₂(NIT-1′-MeBzIm)Cl₄] _n (NIT-1′-MeBzIm = 2-{2′-[(1′-methyl)benzimidazolyl]}-4,4,5,5-tetrameth-ylimidazoline-1-oxyl-3-oxide), has been prepared and characterized by magnetic and single-crystal X-ray diffraction studies. The complex crystallizes in triclinic, space group P $\bar 1$ , Z = 2. Crystal data: C₁₅H₁₉C₁₄Hg₂N₄O₂, M = 830.32, a = 7.4454(16), b = 9.463(2), c = 16.180(3) Å, α = 94.245(2)°, β = 100.747(2)°, γ = 102.523(2)°, V = 1085.5(4) ų, ρ _c = 2.540 g/cm³, μ(MoK_α) = 14.636 mm^?1, F(000) = 762, R = 0.0312 and wR = 0.0779 for 3990 observed reflections with I > 2σ(I). The X-ray analysis reveals that the Hg²⁺ ions shows two coordination geometries of five-coordinated with a distorted square pyramidal coordination geometry and quadrilateral geometry. The units of [Hg₂(NIT-1′-MeBzIm)C_l4] _n were connected as 1D chain structure by the chlorine bridges. Magnetic investigation indicates the existence of weak intramolecular interactions is antiferromagnetic with J = ?1.23 cm^?1, where the spin Hamitonian is defined as H = $ - 2\sum\nolimits_{i,j} {J_{i,j} S_i S} $ within the complex.     

Synthesis,crystal structures and magnetic properties of nitronyl nitroxide radical-coordinated copper(II) complexes

Transition Metal Chemistry - The coordination compound constructed for nitronyl nitroxide radical NIT-Ph-4-Br and CuII(hfac)2(H2O)2 building blocks...     

Synthesis,structure and magnetic properties of a Pr(III) complex with chelating nitronyl nitroxide radicals

The synthesis and structure of Pr(III) complex with chelating nitronyl nitroxide radicals of formula [Pr(III)(NIT2Py)₂(NO₃)₃] (NIT2Py?=?2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) is reported. Pr(III) is ten-coordinate with three bidentate nitrate anions and two radicals. The radical behaves as a bidentate chelating ligand through one oxygen atom of the nitronyl nitroxide group and one nitrogen atom of a pyridine ring. The electronic spectrum for the complex in THF and magnetic susceptibilities from 77–300?K are reported.     

Synthesis and crystal structures of cobalt(II) and nickel(II) complexes containing nitronyl nitroxide radical and dicyanamide

Two new complexes [Co(NIT-1′-MeBzIm)₂(Dca)₂] (I) and [Ni(NIT-1′-MeBzIm)₂(Dca)(H₂O) · NO₃ · H₂O (II) (NIT-1′-MeBzIm = 2-{2′-[(l′-methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; Dca = N(CN)₂) were prepared and structurally characterized by single-crystal X-ray diffraction. Relevant crystallographic parameters are as follows: monoclinic, P2_1/c space group, Z = 4; crystal data: C₃₄H₃₈N₁₄O₄Co, M = 765.71, a = 14.343(4), b = 14.322(4), c = 18.626(5) Å, β = 105.956(3)° for I. Orthorhombic Pna2₁ space group, Z = 4; crystal data: C₃₂H₄₂N₁₂O₉Ni, M = 797.49, a = 24.426(4), b = 11.0326(18), c = 13.980(2)Å for II. The X-ray analysis reveals that Co²⁺ ion and Ni²⁺ ion resides in a approximate sdistorted octahedron center. In I, the complex was linked by intermolecular hydrogen bonds, resulting in a 1D chain configuration. In II, the complex was linked by intermolecular hydrogen bonds, resulting in a 2D network configuration.     

配合物[Ni(qina)2(H2O)2]的合成及结构

近年来,晶体分子结构在设计和组装各种光、电磁离子交换、催化等新型功能材料方面受到广泛关注[1-5].在分子体系形成的过程中,配位键构成分子主体,而氢键、π-π堆积和金属-金属等弱相互作用则是分子之间构筑成超分子结构的稳定因素[6-8].喹哪啶酸(qina)具有鳌合配位能力和疏水性能,其配合物往往通过π-π堆积形成超分子化合物[9].     

Synthesis,structure, and properties of a 1-D copper(II) complex with nitronyl nitroxide radicals

A 1-D chain complex [Cu(NIT4Py)(IDA)]_∞ (NIT4Py = 2-(4′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and IDA = iminodiacetate) has been prepared and characterized by single-crystal X-ray diffraction, IR, TGA, and magnetic analysis. Each Cu(II) is five-coordinate with distorted square pyramidal geometry. Each IDA bridges two Cu(II) ions via one carboxylate which occupies the axial site of Cu(II), leading to a chain structure composed of Cu(II)-radical cations and IDA anions. In the complex, there exist three magnetic exchange pathways, (i) interaction between units of (Cu(II)-NIT4Py) through IDA, (ii) Cu(II)-NIT4Py interaction, and (iii) NIT4Py-NIT4Py interaction through space. Compared with the first two magnetic interactions, the last magnetic exchange interaction should be too weak to be counted because of the large distance of the neighboring NIT4Py molecules (4.993 Å). Analysis of the magnetic properties was performed using the Bleany–Bowers (dimer) model, showing that the complex exhibited both weak antiferromagnetic interaction between the Cu(II) and NIT4Py, and between the units of (Cu(II)-NIT4Py) through IDA with exchange coupling parameters J = ?7.28 cm^?1 and zJ′ = ?0.40 cm^?1.     

Synthesis, structure and magnetic property of [Ce(DMSO)2(H2O)Fe(CN)6]

The title complex, [Ce(DMSO)₂(H₂O)Fe(CN)₆] (1), was obtained by solution reactions and structurally characterized by X-ray diffraction. The title complex is characteristic of a novel cyano-bridged two-dimensional stair-like layered structure. The magnetic property of the title complex is reported herein. The χ_M T value at 300 K is ca. 0.92 emu K mol^?1. The temperature dependence behavior of molar magnetic susceptibility of the complex clearly indicates the presence of an antiferromagnetic interaction.     

A novel nitronyl nitroxide radical containing thiophene and pyridine rings and its manganese(II) complex: synthesis,structure, and magnetic properties

A novel nitronyl nitroxide NIT-thien-3-Py (2-(3-(m-pyridyl)-2-thienyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) and its Mn(II) complex [Mn(hfac)₂(NIT-thien-3-Py)]₂ (hfac = hexafluoroacetylacetonate) have been obtained. X-ray analysis indicates that the Mn(II) complex possesses a cyclic dimer structure in which two radical ligands link two Mn(II) ions through their NO groups and pyridine rings. The study of the magnetic data indicates that the manganese(II) ion strongly and antiferromagnetically interacts with the directly bonding NO group and there is weak ferromagnetic coupling between two Mn–NO pairs through the thiophene and pyridine rings of the radical ligand in agreement with a spin polarization mechanism.     

Bis[di(hydroxymethyl)phosphinato]diaquacobalt(II), [Co(H2O)2{(HOCH2)2PO2}2]: Synthesis, properties, and crystal structure

The synthesis and some properties of the Co(II) complex with di(hydroxymethyl)phosphinic acid (HL) of the composition CoL₂·2H₂O are described. X-ray powder diffraction analysis confirmed the phase homogeneity of the polycrystalline sample. The crystal structure is determined by X-ray diffraction method. The Co atom is located in the center of octahedron formed by the O atoms of two ligands L and of two water molecules. The ligand L performs bidentate-chelate function and is bonded to the Co atom through the O atoms of the phosphinate group and of one alcohol group.     

Synthesis,crystal structure and magnetic property of a three-dimensional manganese(II) complex

The solvothermal reaction of MnCl₂·4H₂O, H₂asp and CH₃ONa gave rise to a new manganese(II) complex, {[Mn(asp)(H₂O)]·(H₂O)₂} _n (1) (H₂asp?=?5-aminoisophthalic acid). Single-crystal X-ray diffraction analysis reveals that complex 1 is a three-dimensional consisting of two-dimensional layers extended by hydrogen bonding interactions. The two-dimensional layer contains 8-, 14-, and 16-membered rings. A variable temperature magnetic measurement of 1 displays weak antiferromagnetic behavior.     

Synthesis,crystal structure and magnetic properties of a cobalt(II) complex with pyridine-substituted imino nitroxide radicals

The mononuclear Co(im4-py)₄(N₃)₂ complex [im4-py = 2-(p-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl] has been synthesized and structurally characterized. It crystallizes in the triclinic space group Pl¯ with the Co^II ion octahedrally coordinated and bound to four radical ligands through the nitrogen atom of the pyridine rings; the azido groups occupy the apical positions. The complex exhibits weak intramolecular antiferromagnetic interactions between the Co^II ion and the imino nitroxide radicals; intermolecular antiferromagnetic interactions are observed.     

A Novel 3D Extended Network Cobalt Paradodecatungstate:Synthesis,Characterization and Crystal Structure of [Co(H2O)5]2[Co(H2O)4]3[H2W12O42]·11H2O

A cobalt paradodecatungstate [Co(H2O)5]2[Co(H2O)4]3[H2W12O42]·11H2O has been successfully synthesized and structurally characterized by X-ray crystallography. Structure analysis indicates that the title compound is of monoclinic, space group P21/n, with a = 13.449(3), b =19.585(4), c = 13.990(3) (A),β = 113.79(3)°, V = 3371.8(12) (A)3, Z= 2, R= 0.0519 and wR= 0.1242.The title compound exhibits a novel 3D extended network structure constructed by interconnecting the paradodecatungstate polyanion [H2W12O42]10- clusters and cobalt11 coordination ions.     

Syntheses,crystal structures and magnetic properties of a new thienyl-substituted nitronyl nitroxide and its copper(II) complex

A new building block for molecule-based magnetic materials???thiophene-substituted nitronyl nitroxide, NIT2-thp, [1, NIT2-thp?=?4,4,5,5-tetramethyl-2-(thiophenal-2-yl)imidazoline-1-oxyl-3-oxide] and its copper(II) complex [Cu(hfac)₂]₃(NIT2-thp)₂ (2) (hfac?=?hexafluoroacetylacetonate) have been synthesized and characterized structurally and magnetically. For 1, dimers were formed and arranged through intermolecular interactions, the shortest contact between nitroxide groups is 4.115?Å among adjacent dimers. In 2 two types of copper interaction with 1 give three colinear Cu(II) ions linked by two μ???1,4 bridging nitroxide ligands. The central metal ion is in a distorted octahedron, axially coordinated by two nitroxide oxygen atoms, while the two external metal ions are in distorted square-pyramidal environments with the nitroxide oxygen atom coordinated in the basal plane. Magnetic susceptibility data for 1 and 2 have been measured in the range 3–300?K. There are antiferromagnetic interactions (J?=??3.89?cm^?1) between the dimers of 1 and also ferromagnetic interactions in 2. The magnetic properties of 1 and 2 are discussed in connection with their crystal structures.