Syntheses, Crystal Structures and Magnetic Properties of a New Nitronyl Nitroxide Radical and Its Cu(Ⅱ) Complex

A new compound (NIT-mNO2 = 4,4,5,5-tetramethylimidazoline-2-yl-(2'-chlor-5'- nitrophenyl)-3-oxide-1-oxyl) 1 and its complex (Cu(NIT-mNO2)(hfac)2) 2 have been synthesized and structurally and magnetically characterized. Complex 1 crystallizes in monoclinic, space group P21/n with a = 10.6798(9), b = 11.2705(9), c = 12.9559(10) , β = 107.3770(10)o, V = 1488.3(2) 3, C13H15ClN3O4, Mr = 312.73, Z = 4, Dc = 1.396 g/cm3, μ(MoKa) = 0.276 mm-1, F(000) = 652, the final R = 0.0606 and wR = 0.1773 for 3405 independent reflections with Rint = 0.0203. The nitronyl nitroxide unit (imidazoline ring) is not coplanar with the phenyl ring with the dihedral angle between them of 55.75o. The compound results in a 1-D zig-zag chain structure by intermolecular H-bond interaction. Compound 2 crystallizes in triclinic, space group P1 with a = 10.3699(10), b = 10.6286(11), c = 15.1683(15), α = 77.5330(10), β = 773080(10), γ = 87.3420(10)o, V = 1592.5(3) 3, C23H17ClF12N3O8Cu, Mr = 790.39, Z = 2, Dc = 1.648 g/cm3, μ(MoKa) = 0.888 mm-1, F(000) = 788, the final R = 0.0793 and wR = 0.2153 for 5794 independent reflections with Rint = 0.0196. The Cu(II) ion is located at a center of symmetry, and each Cu(II) is surrounded by six oxygen atoms at the vertices of a distorted tetragonal octahedron. Four of the six oxygen atoms belong to two hfac ligands and occupy the equatorial coordination sites, while the other two of NIT-mNO2 act as μ-1,5 bridge between the Cu(II) ion, thus forming a 1-D chain structure. The magnetic susceptibility data indicate intermolecular antiferromagnetic interactions between compound 1 and intrachain ferromagnetic behaviors.     

Syntheses, Crystal Structures and Magnetic Properties of a New Nitronyl Nitroxide Radical and Its Cu(Ⅱ) Complex

A new compound (NIT-mNO2 = 4,4,5,5-tetramethylimidazoline-2-yl-(2'-chlor-5'- nitrophenyl)-3-oxide-1-oxyl) 1 and its complex (Cu(NIT-mNO2)(hfac)2) 2 have been synthesized and structurally and magnetically characterized. Complex 1 crystallizes in monoclinic, space group P21/n with a = 10.6798(9), b = 11.2705(9), c = 12.9559(10) , β = 107.3770(10)o, V = 1488.3(2) 3, C13H15ClN3O4, Mr = 312.73, Z = 4, Dc = 1.396 g/cm3, μ(MoKa) = 0.276 mm-1, F(000) = 652, the final R = 0.0606 and wR = 0.1773 for 3405 independent reflections with Rint = 0.0203. The nitronyl nitroxide unit (imidazoline ring) is not coplanar with the phenyl ring with the dihedral angle between them of 55.75o. The compound results in a 1-D zig-zag chain structure by intermolecular H-bond interaction. Compound 2 crystallizes in triclinic, space group P1 with a = 10.3699(10), b = 10.6286(11), c = 15.1683(15), α = 77.5330(10), β = 773080(10), γ = 87.3420(10)o, V = 1592.5(3) 3, C23H17ClF12N3O8Cu, Mr = 790.39, Z = 2, Dc = 1.648 g/cm3, μ(MoKa) = 0.888 mm-1, F(000) = 788, the final R = 0.0793 and wR = 0.2153 for 5794 independent reflections with Rint = 0.0196. The Cu(II) ion is located at a center of symmetry, and each Cu(II) is surrounded by six oxygen atoms at the vertices of a distorted tetragonal octahedron. Four of the six oxygen atoms belong to two hfac ligands and occupy the equatorial coordination sites, while the other two of NIT-mNO2 act as μ-1,5 bridge between the Cu(II) ion, thus forming a 1-D chain structure. The magnetic susceptibility data indicate intermolecular antiferromagnetic interactions between compound 1 and intrachain ferromagnetic behaviors.     

Synthesis, Crystal Structure and Magnetic Properties of a New Zn(Ⅱ)-Nitronyl Nitroxide Complex

A new complex [Zn(NIT-1'-MeBzIm)Cl2(H2O)] (NIT-1'-MeBzIm = 2-{2'-[(1'-methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide) has been prepared and structurally characterized by X-ray diffraction method. Crystal data: monoclinic, space group P21/n, Z = 4, C15H21Cl2N4O3Zn, Mr = 441.63, a = 7.2225(10), b = 30.849(4), c = 8.8758(13) (A), β= 103.904(2)°, V = 1919.6(5) A3, Dc = 1.528 g/cm3, μ(MoKα) = 1.579 mm-1, F(000) = 908, R = 0.0436 and wR = 0.1029 for 2456 observed reflections with Ⅰ> 2σ(Ⅰ). X-ray analysis reveals that the Zn(Ⅱ) ion is four-coordinated with a distorted tetrahedron. There also exist H-bonds, π-π piling interactions and weak intermolecular contacts between the NO groups which form a mutual stagger 3-D network configuration. Magnetic investigation reveals that there exists intermolecular antiferro- and ferromagnetic interactions in the title complex.     

Syntheses, Crystal Structures and Magnetic Properties of a New Nitronyl Nitroxide Radical and Its Cu（II） Complex

A new compound （NIT-mNO2 = 4,4,5,5-tetramethylimidazoline-2-yl-（2＇-chlor-5＇- nitrophenyl）-3-oxide-l-oxyl） 1 and its complex （Cu（NIT-mNO2）（hfac）2） 2 have been synthesized and structurally and magnetically characterized. Complex 1 crystallizes in monoclinic, space group P211n with a = 10.6798（9）, b = 11.2705（9）, c = 12.9559（10）A, β = 107.3770（10）°, V = 1488.3（2） A^3, C13H15ClN3O4, Mr = 312.73, Z = 4, Dc = 1.396 g/cm^3, g（MoKa） = 0.276 mm^-1, F（000） = 652, the final R = 0.0606 and wR = 0.1773 for 3405 independent reflections with Rint = 0.0203. The nitronyl nitroxide unit （imidazoline ring） is not coplanar with the phenyl ring with the dihedral angle between them of 55.75°. The compound results in a 1-D zig-zag chain structure by intermolecular H-bond interaction. Compound 2 crystallizes in triclinic, space group Pi with a = 10.3699（10）, b = 10.6286（11）, c = 15.1683（15）A, a = 77.5330（10）, ,β = 773080（10）, y = 87.3420（10）＊, V = 1592.5（3） A^3, C23HITCIFI2N3O8Cu, Mr = 790.39, Z = 2, Dc = 1.648 g/cm^3, μ（MoKa） = 0.888 mm^-1, F（000） = 788, the final R = 0.0793 and wR = 0.2153 for 5794 independent reflections with Rint = 0.0196. The Cu（Ⅱ） ion is located at a center of symmetry, and each Cu（Ⅱ） is surrounded by six oxygen atoms at the vertices of a distorted tetragonal octahedron. Four of the six oxygen atoms belong to two hfac ligands and occupy the equatorial coordination sites, while the other two of NIT-mNO2 act as μ-1,5 bridge between the Cu（Ⅱ） ion, thus forming a 1-D chain structure. The magnetic susceptibility data indicate intermolecular antiferromagnetic interactions between compound 1 and intrachain ferromagnetic behaviors.     

Crystal Structures and Magnetic Properties of Two New Schiff Base Complexes

Two new Schiff base complexes, [NiL]ClO4 1 and [CuL]ClO4.0.5H2O 2, were synthesized and characterized, where L is the 1:1 condensation product of salicylaldehyde and diethylenetriamine. Their crystal structures and magnetic properties were determined and investigated. The H-bonding interactions concern just in neighbor cation and anion, do not extendin to network for both 1 and 2. The temperature dependence of the magnetic susceptibilities(2-300K) showed that 1 is diamagnetism and 2 is paramagnetism with weak antiferromagnetic exchange interactions between adjacent spin carriers, no magnetic ordering taking place in these two complexes.     

Three Co(Ⅱ) Coordination Polymers Incorporated with a Bent Connector: Crystal Structures and Magnetic Properties

Based on the bent ligand 1 H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4-triazole(3,4?-Hbpt) with Co(Ⅱ) ions as well as a series of polycarboxylate co-ligands, three new coordination polymers were yielded, namely, {[Co(op)(3,4?-Hbpt)(H_2O)_3]?2 H_2O}n(1), [Co(cyc)(3,4′-Hbpt)(H_2O)]n(2) and [Co(pro)(3,4′-Hbpt)(H_2O)]n(3)(here, op = o-phthalic anion, cyc = 1,1-cyclobutanedicarboxylic anion, pro = propanedioic anion). In cooperation with the auxiliary polycarboxylate co-ligands, a variety of Co(Ⅱ) coordination networks, such as 1-D chain 1 and 2-D layer 2 and 3 have been assembled. The magnetic behaviors of compounds 1～3 were studied. All of them indicated the existence of interesting spin-canting behavior.     

Structures and Magnetic Properties of Three Heterobimetallic 3d–4f Hexanuclear Complexes

Three butterfly heterhexanuclear 3d–4f clusters have been prepared under solvothermal conditions and structurally characterized by IR spectroscopy, elemental analyses, thermal analyses, and single-crystal X-ray diffraction. Each of hexanuclear clusters was built from butterfly Co ₂ ^III Ln ₂ ^III clusters and two Ln^III ions by the bridging of pivalate. Variable-temperature magnetic susceptibilities measurements of the complexes in the temperature range 2–300 K indicate dominant antiferromagnetic exchange interactions.     

Two Cd(Ⅱ) and Cu(Ⅱ) Complexes Based on 1-Butylbenzimidazole: Crystal Structures and Weak Interactions

1-Butylbenzimidazole L reacted with Cd(NO3)2·4H2O to afford complex [CdL(NO3)3H2O]·[HL] 1. The heptacoordinated Cd(Ⅱ) center adopts a distorted pentagongal bipyramidal geometry, and complex [CdL(NO3)3H2O]-entity and the protonated benzimidazium salt [HL]+ are connected via N-H···O hydrogen bond to form a dimeric unit [CdL(NO3)3H2O]·[HL]. A 3-D supramolecular network of 1 is formed through N-H···O and O-H···O hydrogen bonds together with π-π stacking interactions. Reaction of L with CuCl2 afforded a mononuclear complex, [CuL2Cl2] 2, in which the tetracoordinated Cu(II) center adopts a distorted tetrahedral geometry. In contrast, 2-D supramolecular layers of 2 are formed by C-H···Cl hydrogen bonds. The fluorescent emission spectra of L, 1 and 2 are described.     

Synthesis,Crystal Structure and Magnetic Properties of a Cobalt(Ⅱ) Complex with Quinoxaline-substituted Nitronyl Nitroxide Radicals

A new complex with the formula [Co(acac)_2(NITQ)_2]×2CH_2Cl_2 1(acac = acetylacetone, NITQ = 2-(2′-quinoxalinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), was synthesized and elucidated structurally as well as magnetically in detail. The crystal belongs to the monoclinic system, space group P2_1/c with a = 9.6896(1), b = 20.539(4), c = 12.147(2) ?, β = 93.84(3)°, M_r = 997.65, V = 2412.1(8) ?~3, Z = 2, Dc = 1.374 g/cm, F(000) = 1038, m = 0.635 mm~(-1), the final R = 0.0539 and w R = 0.1289 for 5998 observed reflections(I 2σ(I)). The Co(Ⅱ) ion is coordinated by two nitrogen atoms of quinoxaline rings from two NITQs and four oxygen atoms from two acac ions to complete a distorted octahedral coordination environment. Compound 1 is further linked into a three-dimensional(3D) supramolecular network by hydrogen-bonding, Cl×××O weak contact and π···π stacking interactions. The magnetic measurements show compound 1 exhibits weak ferromagnetic interactions.     

Synthesis and Crystal Structure of a New Lanthanum(III) 4-Cyanobenzoate Complex

A new dinuclear La(III) complex [La2(4-cba)4[H(4-cba)2]2(phen)2(H2O)4] (4-Hcba = 4-cyanobenzoic acid and phen = 1,10-phenanthroline) 1 has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100 ℃ and structurally characterized by single- crystal X-ray diffraction. Crystallographic data: C88H58La2N12O20, Mr = 1881.28, triclinic P1, a = 7.518(3), b = 17.033(6), c = 17.551(6), α = 115.333(4), β = 92.9910(10), γ = 99.366(5)°, V = 1985.3(12)3, Z = 1, Dc = 1.574 g/cm3, F(000) = 944 μ = 1.145 mm–1, the final R = 0.0281 and wR = 0.0686 for 6708 reflections with I > 2σ(I). In 1, two nine-coordinated La(III) ions are connected by two 4-cba ligands in a syn-syn bidentate coordination mode, and the other six 4-cba ligands terminate the La(III) ions, resulting in an isolated dinuclear structure. Two different types of intramolecular hydrogen bonds, asymmetrical O-H…O and symmetrical O…H…O, exist in the crystal. The title complex molecules are connected through hydrogen bonds and weak π-π stacking interactions to generate a 2-D layered network. The thermogravimetric analysis of 1 has also been discussed.     

Syntheses,Crystal Structures and Magnetic Properties of Two New Low-dimensional Manganese (Ⅱ) Coordination Compounds

Two new low-dimensional Mn(Ⅱ) coordination compounds of Mn(H_2pimdc)_2(phen)(compound 1) and [Mn(Hpimdc)(phen)]n·nH_2O(compound 2) were synthesized, where H_3pimdc is a 2-propyl-imidazole-4,5-dicarboxylic acid and phen is 1,10-phenanthroline. Both compounds were thoroughly analyzed by X-ray single-crystal diffraction, element analysis, IR spectra, PXRD and thermal analysis. X-ray single-crystal diffraction analyses indicate that the phen ligands terminate metal ions on two sides to prevent the linkage between the neighboring metal ions into a higher dimensional structure in compounds 1 and 2. Compound 1 is constructed from mononuclear molecules which form the 1D helical supramolecular chain by N–H···O hydrogen bonds. In compound 2, Hpimdc is a tetradentate bridging ligand, which binds Mn(Ⅱ) ions to generate a single-stranded right helical chain parallel to the b axis. These 1D chains are additionally coupled by H-bonds as well as π···π stacking interactions, which formed a 3D supramolecular structure. Additionally, compound 2 demonstrated temperature-dependent magnetic susceptibility and negative value of θ(equal to –9.09 K), which is indicative of weak antiferromagnetic interactions between Mn(Ⅱ) ions.     

Synthesis, Crystal Structure and Magnetic Properties of Cobalt(II) Complex Involving Imino Nitroxide Radicals

1 INTRODUCTION The synthesis and study of transition metal com-plexes incorporating organic free radicals have arou-sed great interest in the field of molecular magne-tism[1]. Nitronyl nitroxide radicals (NITR), stable or-ganic radicals, have been widely used as molecularunits in the design and construction of magnetic ma-terials[2～5]. These radicals are especially attractivedue to that their donor atoms can assemble an exten-ded coordination geometry with changing magneticcoupling. A…     

Synthesis, Structure and Magnetic Properties of a Diphenoxo-bridged Binuclear Copper(II) Complex

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Crystal Structure and Properties of a Copper(Ⅱ) Complex Containing p-Toluenesulfonate and Imidazole Ligands

A novel supramolecular mixed ligand complex of formula [Cu(PTS)2(Him)2(H2O)2] (C20H26CuN4O8S2,PTS=p-toluenesulfonate,Him=imidazole) has been synthesized in aqueous solution and characterized by elemental analysis,IR and single-crystal X-ray diffraction.The compound crystallizes in the monoclinic system,space group P21/n,Z=2,a=5.650(2),b=14.671(3),c=14.638(3),β=100.10(3)°,V=1194.60(4)3,Dc=1.607 g/cm3,μ(MoKα)=1.143 mm-1,F(000)=598,R=0.0615 and wR=0.1503 for 1752 observed reflections with I 2σ(I).The copper(II) ion in the complex adopts a slightly distorted octahedral coordination geometry and is six-coordinated with N2O4 donor set consisting of two nitrogen atoms and four oxygen atoms provided by the ligands of two imidazole molecules,two water molecules and two p-toluenesulfonate ions.The sulfonate group of the PTS ligand remains weak-coordinated and forms a number of hydrogen bonds with water molecules and imidazole ligands.X-ray structural analysis reveals that the coordination molecules are connected to form a 3-D supramolecular framework by electrostatic interaction,weak van der Waals forces,hydrogen bonding and π-π interaction.The thermal behaviour of the title complex was investigated by using DSC and TG-DTG techniques.     

Syntheses,Crystal Structures,DFT Calculation and Optical Properties of a Schiff Base and Its Dinuclear Mercury(Ⅱ) Complex

A pyridine-contained Schiff base ligand L(L =(pyridine-2-vinyl)hydrazine) has been synthesized and fully characterized. By self-assembly of the ligand with HgI_2, a binuclear complex Hg_2I_4L(C) was obtained. The structures of L and C were analyzed through single-crystal X-ray diffraction. L crystallizes in monoclinic, space group P21/n with a=11.286(5), b=3.981(5), c=23.865(5) ?, β=100.043(5)°, V=1056(1) ?~3, Z=4, Dc=1.323 g/m~3, F(000)=440, Μr=210.24, μ=0.084 mm~(-1), the final R=0.0928 and w R=0.2867 for 6955 observed reflections with I 2(I). The complex is of monoclinic system, space group P21/n with a=8.706(5), b=17.468(5), c=14.675(5) ?, β=93.922(5)°, V=2227(2) ?~3, Z=4, Dc=3.338 g/m~3, F(000)=1928, Μr=1119.02, μ=19.321 mm~(-1), the final R=0.0366 and w R=0.1276 for 3920 observed reflections with I 2(I). The structural analysis revealed that the molecule of L possesses a well planar structure. However, in the complex, the coordinated ligand distorts greatly. The absorption spectra of L and the complex in ethanol were experimentally and theoretically studied. The result indicates that the complex exhibits different absorption spectrum compared with the free ligand.     

Syntheses,Crystal Structures,and Magnetic Properties of Cobalt(Ⅱ) Complexes with 1,1-Cyclohexanediacetic Acid

Two new Co(Ⅱ) coordination polymers,{[Co_3(Hchda)_2(chda)_2(bpp)_2(H_2O)_2]}_n 1 and {[Co(chda)(bpe)(H_2O)]·3H_2O}_n 2(H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis(4-pyridinyl)propane and bpe = 1,2-bis(4-pyridinyl)ethylene),were hydrothermally synthesized and then characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis(TGA),and single-crystal X-ray diffraction.Complex 1 possesses an infinite metal-organic layer based on triply bridged linear trinuclear subunits and complex 2 exhibits a square(4,4) grid layer with dangling lateral arms resulting from eight-membered rings above and below the layer.In addition,magnetic properties of complexes 1 and 2 are also given.     

Synthesis,Crystal Structure and Magnetic Property of a Novel Cu(Ⅱ)-Fluconazole-azide Complex

The title compound formulated as Cu2(C13H11N6OF2)(N3)3CH3OH was synthesized and structurally characterized by elemental analysis,IR and single-crystal X-ray diffraction.In the structure of the complex,the deprotonated fluconazole and azide anion link two copper centers to construct a binuclear SBU and the azide anion exhibits a μ1,1-coordination mode.Each triazole group of fluconazole links two SBUs and the compound exhibits a chain-like architecture with strong antiferromagnetism.     

Synthesis,Crystal Structure,Spectroscopic Characterization,Thermal Stability and Magnetic Properties of a Dinuclear Copper(Ⅱ) Complex

A new copper(Ⅱ) complex [Cu2(MNA)2(2,2‘-bipy)2]·2.5H2 O with methy-5-norbornene-2,3-dicarboxylic acid(MNA) and 2,2’-bipyridine as ligands has been synthesized in the mixed solvents of DMF and water.It crystallizes in monoclinic,space group P 1,with a = 10.4191(11),b = 12.8883(13),c = 16.1114(16) ?,α = 70.8090(10),β = 80.568(2),γ = 77.440(2)o,V = 1984.3(4) ?3,Dc = 1.551 g/cm3,Z = 2,F(000) = 962,the final GOOF = 1.051,R = 0.0431 and w R= 0.0980.The crystal structure shows that the whole molecule consists of two independent dinuclear units,in which two copper ions are bridged by two μ2-η1:η0 3-carboxylate groups of MNA2-.The coordination environment of Cu(Ⅱ) ion is Cu O3N2,giving a distorted square pyramidal geometry.The spectroscopic characterization,thermal stability and magnetic properties of the complex were investigated.     

Synthesis,Crystal Structure and Magnetic Properties of a New Zn（Ⅱ）-Nitronyl Nitroxide Complex

A new complex [Zn（NIT-1′-MeBzlm）Cl2（H2O）] （NIT-1′-MeBzlm = 2-{2′-[（1′- methyl）benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide） has been prepared and structurally characterized by X-ray diffraction method. Crystal data： monoclinic, space group P21/n, Z = 4, C15H21Cl2N4O3Zn, Mr = 441.63, a = 7.2225（10）, b = 30.849（4）, c = 8.8758（13）A, β = 103.904（2）°, V = 1919.6（5）A^3, Dc = 1.528 g/cm^3, μ（MoKα） = 1.579 mm^-1, F（000） = 908, R = 0.0436 and wR = 0.1029 for 2456 observed reflections with I〉 2σ（I）. X-ray analysis reveals that the Zn（Ⅱ） ion is four-coordinated with a distorted tetrahedron. There also exist H-bonds, π-π piling interactions and weak intermolecular contacts between the NO groups which form a mutual stagger 3-D network configuration. Magnetic investigation reveals that there exists intermolecular antiferro- and ferromagnetic interactions in the title complex.