A Novel Binuclear Cu(Ⅱ) Complex with Nitroxide Radicals Exhibiting Ferromagnetic Interactions

A new binuclear Cu（Ⅱ） complex with nitronyl nitroxide radicals [Cu（NIT3Py）2Cl2]2（NIT3Py = 2-（3＇-pyridinyl）-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide） has been synthesized and structurally characterized by X-ray diffraction analysis.It crystallizes in monoclinic,space group C2/c with a = 38.483（4）,b = 7.2450（8）,c = 27.559（3） ,β = 134.0180（10）°,V = 5525.6（10） 3,C48H64Cl4Cu2N12O8,Mr = 1206.00,Z = 4,Dc = 1.450 g/cm3,μ（MoKα） = 1.025 mm-1,F（000） = 2504,S = 1.066,the final R = 0.0471 and wR = 0.1121 for 3286 observed reflections（I 2σ（I））.The title complex consists of centrosymmetric dinuclear units [Cu（NIT3Py）2Cl2]2,in which the copper ions are square-pyramidally coordinated by two pyridyl nitrogen atoms of two radical ligands and three chlorine anions,two of which bridge the copper ions.The magnetic measurements show ferromagnetic interactions between the copper ions and the radical ligands.

Syntheses and Magnetic Properties of Cu（Ⅱ）－RE（Ⅲ） Heterobinuclear Complexes with N，N′－Bis（3－carboxyisalicylidene）－trimethylenediamine

ine heterobinuclear complexes of Cu (Ⅱ)-RE (Ⅲ) with N, N′-bis-(3-car-boxylsalicylidene ) trimetliylenediamine (TS) were syntliesized and characterized bymeans of elemental analyses, molar conductivity, thermogravimetry,IR and elec-tronic spectra. The measurements of variable-temperature magnetic susceptibilitysliow that there exists only a very weak antiferromagnetic spin exchange interactionbetween the ions of Cut(Ⅱ) and RE(Ⅲ) in CuRETSCI . 3H_2O.

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,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） A,α = 70.8090（10）,β = 80.568（2）,γ = 77.440（2）o,V = 1984.3（4） A^3,Dc = 1.551 g/cm^3,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-η^1：η^0 3-carboxylate groups of MNA^2-.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,Structure and Magnetic Properties of Novel Carboxylato-bridged Pentanuclear Copper(Ⅱ)-Lanthanoid(Ⅲ)Complexes

Six novel pentanuclear complexes [Cu 3Ln 2(ClCH 2CO 2) 12 (H 2O) 8]·2H 2O (Ln=La, Pr, Sm, Gd, Dy, or Er) were synthesized by the reaction of chloroacetic acid with Cu and Ln ions in aqueous solutions. The X ray crystallography established the structure of the Gd complex, which contains a pair of quadruply acetato bridged CuGd dinuclear subunits, and each of them is linked to the central Cu atom by a single acetato bridge. The coordination sphere of each Gd atom is completed by three aqua ligands [Gd-O=0.242 8(5)-0.244 4(4) nm] to form an 8 coordinated distorted square antiprism. The central Cu atom is coordinated by two oxygen atoms from the two bridging acetato groups and two oxygen atoms from the two monodentate acetato groups in a slightly distorted square planar fashion, while each terminal Cu atom is coordinated by the four acetato oxygen atoms at the basal plane and an aqua ligand at the apical position to form a square pyramid. The variable temperature (4 320 K) magnetic susceptibility data of the Gd complex were measured, and fitted to the Curie Weiss law with C =16.38 K cm 3·mol -1 and θ =-1.55 K, indicating very weak antiferromagnetic interaction.

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

A new dinuclear copper（Ⅱ） complex [Cu（CH3COO）（C7H5N4）（H2O）]2·3.5H2 O has been hydrothermally synthesized with copper acetate, o-acetamidobenzoic acid and 3-（pyridin-2-yl）-1,2,4-triazole. It crystallizes in the monoclinic space group P21/c, with a = 12.0188（7）, b = 13.7993（8）, c = 8.7488（5） A, β = 101.7350（10）o, V = 1420.67（14） A3, D3 c = 1.568 g/cm, Z = 1, F（000） = 690, the final GOOF = 1.145, R = 0.0437, and w R = 0.1097. The crystal structure shows that the whole molecule consists of two copper ions bridged by two μ2-η1：η0 3-（pyridin-2-yl）-1,2,4-triazole anions. The coordination environment of Cu（Ⅱ） ion is Cu O2N3, giving a distorted square pyramidal geometry. The thermal stability and magnetic properties of the complex were investigated.

Synthesis,Crystal Structure and Magnetic Properties of a Ni(Ⅱ) Supramolecular Complex Based on Aromatic Polycarboxylate Ligand

A Ni（Ⅱ） supramolecular complex,[Ni 2 （btec）（3py） 2 （H 2 O） 8 ]（H 2 O） 4 （1）,has been synthesized by Ni（ClO 4） 2 ·6H 2 O,benzene-1,2,4,5-tetracarboxylic acid （H 4 btec） and terminal ligand 3-hydroxypyridine （3py） in aqueous solution.The title compound crystallizes in triclinic system,space group P1,with a=8.5637（12）,b=9.4138（13）,c=10.3611（14）,α=67.9540（10）,β=85.1740（10）,γ=76.9890（10）°,V=754.33（18） 3,Z=2,M r=386.96,D c=1.704 Mg/m 3,μ=1.345 mm-1,F（000）=402,the final R=0.0222 and wR=0.0563 for 2675 observed reflections with I 2σ（Ⅰ）.The adjacent discrete molecules are further self-assembled by intermolecular π-π and O-H···O hydrogen bonding interactions to construct a 3D supramolecular framework.Magnetic measurement shows weak ferromagnetic interaction in the range of 2～300 K.

Synthesis, Structure and Magnetic Property of a Binuclear Nickel(Ⅱ) Complex

A new binuclear complex [Ni2（2,2＇-bpy）2（C8H3NO6）2（H2O）4] 1 （2,2＇-bpy = 2,2＇- bipyridine, C8H3NO6 = 4-nitrophthalate） has been synthesized by a hydrothermal reaction and characterized by X-ray single-crystal diffraction analysis. The complex crystallizes in triclinic, space group P1 with a = 7.206（2）, b = 10.337（4）, c = 12.480（4） , α = 89.887（11）, β = 77.033（9）, γ = 78.349（6）o, V = 886.3（5） 3, Z = 1, C36H30Ni2N6O16, Mr = 920.08, Dc = 1.724 g cm-3, F（000） = 472, μ = 1.152 mm-1, the final R = 0.0458 and wR = 0.1163 for 3372 observed reflections with I 2σ（Ⅰ）. The two Ni（Ⅱ） ions are bridged by two 4-nitrophthalates both in a bis-monodentate mode. Magnetic measurements reveal that the intramolecular exchange couplings in the dimer are ferromagnetic with 2J/k = 2.32 K, D =-1.44 K and g = 2.18.

Synthesis,Crystal Structure and Magnetic Properties of an Oxalato-bridged Dinickel(Ⅱ) Complex with Nitronyl Nitroxide Radicals

A new oxalato-bridged dinickel（Ⅱ） complex [Ni2（NIT-MeImz）4（C2O4）]（Ac）2·8H2O has been synthesized and characterized structurally as well as magnetically.It crystallizes in monoclinic,space group C2/c with a=24.608（4）,b=21.399（3）,c=17.992（3）,β=131.680（2）°,V=7076（2）3,C50H86N16Ni2O24,Mr=1412.77,Z=4,Dc=1.326 g/cm3,μ（MoKα）=0.614 mm-1,F（000）=2984,R=0.0751 and wR=0.1791 for 2956 observed reflections with Ⅰ＆gt;2σ（Ⅰ）.X-ray analysis reveals that the crystal structure consists of [Ni2（NIT-MeImz）4（C2O4）]2＋ moiety and two Ac^- anions. Each nickel（H） ion is six-coordinated with a distorted octahedral geometry： two nitrogen atoms and two oxygen atoms from NIT-Melmz together with two other oxygen atoms from the oxalato ion. The 2-D net structure is formed and arranged through intermolecular H-bonding interactions. Magnetic measurements show antiferromagnetic interactions for this complex.

A Novel Mononuclear Copper(Ⅱ) Complex:Crystal Structure and DNA Cleavage Ability

The reaction of N-tosylatirdine with 1,2-diaminopropane in dry benzene solution yields an intermediate H2L, N,N,N＇,N＇-tetrakis（2-（p-tolylsulfonyl）aminoethyl） propane-1,2-diamine. The mononuclear copper（Ⅱ） complex, [CuLH2O]·H2O, was synthesized by the reaction between the intermediate and copper（Ⅱ） in absolute methanol. The complex has been characterized by IR, UV-vis and X-ray diffraction technology, and its crystal crystallizes in the orthorhombic system, space group Pbca with a = 15.589（1）, b = 21.897（2）, c = 27.645（2） A, V = 9436.4（1）A^3, Dc = 1.352 g/cm^3, Z = 8, Mr = 960.68, F（000） = 4040, μ（MoKa） = 0.698 mm-1, S = 0.98, R = 0.0537 and wR = 0.1180 for 5804 observed reflections （I 〉 2σ（I））. In the crystal structure, a one-dimensional chain is formed by abundant hydrogen bond interactions. The interaction of the complex with DNA was monitored using agarose gel electrophoresis. The result shows that the complex can transform the supercoiled to nicked and liner forms, and has a concentration-dependent cleavage activity.

Synthesis, Crystal Structure and Magnetic Properties of a One-dimensional Loop-like Iron(Ⅱ) Complex:[Fe(Haip)_2(H_2O)_2]_n (Haip = 5-Ammoniumisophthalato)

An iron（Ⅱ） coordination polymer, [Fe（Haip）2（H2O）2]n （1, Haip = 5-ammoniumiso- phthalato）, has been hydro/solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectrum and magnetic measurement. Compound 1 crystalizes in monoclinic, space group P2/c with a = 6.9874（14）, b = 9.960（2）, c = 12.894（4） A, β = 117.47（2）°, Fe（C8H6NO4）2（H2O）2, Mr = 452.16, V= 796.2（3） A3, Z = 2, Dc = 1.886 g.cm-3, p = 1.017 mm-1, F（000） = 464.0, 2.71〈0〈28.42°, R = 0.0307, wR = 0.0840 and S = 1.005. Single-crystal X-ray diffraction analysis reveals that 1 features an infinite one-dimensional loop-like chain structure and Haip ligand in 1 is of zwitterionic form. Magnetic measurement results show the dominated ferromagnetic interactions among Fe11 atoms.

Syntheses and Magnetism of μ-1, 3, 5-Benzenetricarboxylato Trinuclear Manganese(Ⅱ) and Nickel(Ⅱ)Complexes

Two new manganese(Ⅱ ) trinuclear complexes and two new nickel (Ⅱ) trinuclear compIexes, namely, [Mn3 (BZT ) (Phen )6] (ClO4 )3 (complex 1 ), [Mn (BZT)· (Nphen )6] (ClO4 )3 (complex 2), [Ni3 (BZT) (Phen)6] (ClO4 )3· 5H2O (complex3) and [Ni3 (BZT ) (Nphen )6] (ClO4 )3 (complex 4 ) (BZT = 1, 3, 5-benzenetricarboxylato, Phen = 1, 10-phenthroline, Nphen = 5-nitro-1, 10-phenanthroline )have been synthesized. The complexes were characterized using elemental analysis,IR and electronic reflection spectra. These complexes are proposed to have extended 1, 3, 5-benzenetricarboxylato-bridged structure and to consist of three manganese (Ⅱ) or three nickel(Ⅱ). The X-band ESR spectra of the complex 1 and complex 2were recorded at room temperature. The variable-temperature magnetic susceptibilities of complex 1 and complex 3 were measured over 4. 2-300 K. According to experimental results of the variable-temperature magnetic susceptibility, the magnetic interaction between the paramagnetic centers is too weak to be detected using the usual magnetic susceptibility technique.

Synthesis and Magnetism of 2-Hydroxy-1,3-propylene-bis(oxamato)-bridged Co^(Ⅱ)CuCo^(Ⅱ)CoCo^(Ⅱ)Complexes

Four new heterotrinuclear complexes have been synthesized and characterized, namely [(CoL 2) 2Cu(pbaOH)](ClO 4) 2, where pbaOH denotes 2 hydroxy 1,3 propylenebis(oxamato) and L stands for 1,10 phenanthroline(phen), 5 nitro 1,10 phenanthroline(NO 2 phen), 2,2 bipyridyl(bpy) and 4,4 dimethyl 2,2 bipyridyl(Me 2bpy). The temperature dependence of the magnetic susceptibility of [(Cophen 2) 2Cu(pbaOH)](ClO 4) 2·H 2O has been studied in the range of 4—300 K, the plot of χ M T vs. T exhibits a minimum at about 120 K, but abnormal magnetic behavior below 78 K.

Efficient DNA Cleavage by Copper(Ⅱ) Complex Derived from 1, 1′-Dimethyl-2, 2′-biimidazole Ligand

The cleavage of DNA （pBR322） by [Cu（Dime-biim）2（H2O）]（ClO4）2 （Dime-biim=1, 1＇- dimethyl-2, 2＇-biimidazole） was investigated. The results showed that the complex could cleave DNA efficiently at pH=8.0 and 37℃.

DNA Cleavage by Copper (Ⅱ) Complexes Without added Coreactants

The cleavage activity of complexes between copper (Ⅱ) and four different amino acidor amino acid methyl ester on DNA was tested at physioloical pH and temperature., It was found that Cu (Ⅱ)-L-His and Cu (Ⅱ)-L-His methyl ester complexes could cleane DNA. The extent ofDNA cleavage is largely dependent on the metal ion-to-ligand ratio. The cleavage of doublestranded DNA mediated by Cu (Ⅱ)-L-His complexes occurs via a hydrolytie mechanism.

Cleavage of DNA by a New Mixed-ligand Cu(Ⅱ) Complex

Cleavage of DNA pUC19 by [Cu(saldien)(NH3)]Cl2 (here, saldien=bis(salicylicdene)- diethylenetriamine) was investigated at different pHs, times, concentrations, and 37℃. It was found that the copper(Ⅱ) complex could cleave DNA without added coreactants.

Mass spectrometry assisted assignments of binding and cleavage sites of Zn(Ⅱ)complex towards oxidized insulin B chain

The electrospray ionization mass spectrometry investigation showed that the binding sites of [ZnL]^2＋, where L is 2-[bis（2- aminoethyl）amino]ethanol, with oxidized insulin B chain are Phel, His5 and Arg22, which lead to the selective cleavages of the peptide bonds at Phe1-Val2, His5-Leu6, Glu21-Arg22, and Arg22-Gly23 of oxidized insulin B chain.

Synthesis and Magnetic Properties of Copper (Ⅱ) Complexes with Pyridine N-Oxide-2-ylmethy-lidenedithiocarbazate as Ligands

A series of copper (Ⅱ) complexes with pyridine N- oxide- 2- ylmethylidened-ithiocarbazates as ligands were synthesized and characterized by IR spectra, electronic spectra and magnetic moments measurement at room temperature. Variable temperature magnetic susceptibilites (3-300K) of four complexs were measured and fitted with the Bleaney-Bowers dimer equation by considering the magnetic interaction between molecules. The fitting results show the existence of intramolecular ferromagnetic interactions and intermolecu-lar anti-ferromagnetic interactions in these copper( Ⅱ) complexes.

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.