Synthesis, crystal structure and magnetic properties of a novel manganese(II)-nitronyl nitroxide-azido(μ_(1,1) and μ_(1,3)) one-dimensional complex

A novel one-dimensional manganese(Ⅱ) complex containing nitronyl nitroxide radical [Mn2(IM2-py)2(Ac)2((μ1.1-N3)(μ1,3-N3) . EtOH]n was synthesized and characterized structurally and magnetically. It crystallizes in the monoclinic space group p21/n. Each Mn(Ⅱ) ion is six-coordinated in a distorted octahedral environment. The two N atoms of the nitronyl nitroxide radical and the two O atoms of acetate ligands are in the equatorial plane, whereas the two different azido bridging ligands are in trans axial position. Mn(Ⅱ) ions are linked by nitrogen atom of μ1,1-azido and oxygen atoms of two carboxy groups to form a Mn-Mn unit. Mn-Mn units are linked by azido ligands through u1,3 bridging style to form a one-dimensional chain. The compound is connected by the coordination bonds,π-π interactions and hydrogen bonds as a three-dimensional structure. Magnetic susceptibility data support that there are stronger antiferromagnetic interactions between the radical and Mn(Ⅱ) ion, weak antiferromagnetic inter     

Syntheses,Crystal Structures and Magnetic Properties of Two Nitrophenyl Substituted Nitronyl Nitroxide Radical-lanthanide Complexes

Syntheses, structures and magnetic properties of two nitrophenyl substituted nitronyl nitroxide radical-lanthanide complexes [Ln(hfac)3(NITmNO_2)2](Ln = Sm(ⅡI)(1), Tb(ⅡI)(2), hfac = hexafluoroacetylacetonate, NITmNO_2 = 2-(3-nitrophenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide) have been described in this paper. X-ray analysis shows that the two complexes have similar mononuclear trispin radical-Ln(ⅡI)-radical structures, in which the central Ln(ⅡI) ions are all eight coordinated in D2 d dodecahedral(DD) geometry formed by six oxygen atoms from three hfac and two oxygen atoms from nitronyl nitroxide. The magnetic study indicates the antiferromagnetic interaction between Sm(ⅡI) ion and NITmNO_2 in complex 1, while weak ferromagnetic interaction between Tb(ⅡI) ion and NITmNO_2 in complex 2.     

A Cu(Ⅱ) Complex with IM-MeImz-к2 N,O Mode in [Cu(IM-MeImz)2]·(SCN)2: Synthesis, Crystal Structure and Magnetic Properties

A new copper(Ⅱ) compound with imino nitroxide radicals [Cu(IM-MeImz)2]·(SCN)2 (IM-meImz =2-(5-methylimidazol-4-yl)-4,4,5,5-tetramethyl-2-imidazoline-1-oxyl) has been synthesized and characterized structurally and magnetically. It crystallizes in monoclinic, space group P21/c with a = 9.3604(7), b = 10.3012(7), c = 16.6684(12) (A), β = 105.0290(10)°, V = 1552.25(19)(A)3, C24H34CuN10O2S2, Mr = 622.27, Z = 2, Dc = 1.331 g/cm3, μ(MoKα) = 0.876 mm-1, F(000) =650, the final R = 0.0374 and wR = 0.1079. X-ray analysis demonstrates that the IM-MeImz ligand is coordinated to the copper(Ⅱ) ion as an unusual didentate chelate with a κ2 N(MeImz),O(IM) mode in the complex. The square-planar coordination sites at Cu(Ⅱ) are occupied by two O and two N atoms from the imino nitroxide radicals. The complex molecules are connected as a onedimensional polymer structure by intermolecular interactions. Magnetic measurements show that there are intramolecular antiferromagnetic interactions between the Cu(Ⅱ) ion and radicals.     

Synthesis,Structure and Slow Magnetization Relaxation of Co(Ⅱ) Complexes from a Flexible Imidazole-based Ligand

The employment of a flexible imidazole-based ligand(H_2L), condensed from 1 Himidazole-2-carbaldehyde and 1,2-bis(aminooxy)ethane, and Co~(2+) salt has led to the formation of Co(Ⅱ) complexes [Co(H_2L)_2Cl]Cl·4CH_3OH(1) and [Co(H_2L)(NCS)_2]_2·2C_4H_(10)O(2), in the presence of different anions, i.e, Cl-and SCN-, respectively. Single-crystal X-ray analyses show that complex 1 with a square pyramid(C_(4v)) local environment exhibits a two-dimensional(2D)layered(4,4)-net framework and complex 2 displays a dinuclear molecule box with a T_d local environment. By comparison between complexes 1 and 2, the versatile configuration of ligand including cis-and trans-form isomer has a significant effect on the structures of the resulting complexes. The magnetic properties of 1 and 2 are also investigated. The ac magnetic susceptibility revealed that 2 exhibits the characteristic of slow magnetization relaxation.     

Synthesis,Characterization and Molecular Structure of a Diiron Complex(μ-SCH_2CH_2CH_2S-μ)Fe_2(CO)_5(Ph_2PCH_3)

The title complex,(μ-pdt)Fe_2(CO)_5(Ph_2PCH_3)(pdt = SCH_2CH_2CH_2S),was obtained by the reaction of the parent complex(μ-pdt)Fe_2(CO)_6 with Ph_2PCH_3 and Me_3NO·2H_2O in good yield(90%). The title complex was characterized by IR,~1H NMR,~(31)P{~1H} NMR and ~(13)C{~1H} NMR spectroscopy as well as by single-crystal X-ray diffraction analysis. The molecular structure shows that the title complex contains a butterfly diiron propanedithiolate cluster with five terminal carbonyls and a monophosphine ligand Ph_2PCH_3. The crystal packing diagram reveals that intermolecular C H···O hydrogen bonds between CH_2 and carbonyls,π-π stacking interactions and van der Waals' interactions stabilize the solid state to form a three-dimensional network.     

DNA Interaction and Cytotoxic Activity of a Chiral Amino-alcohol Schiff Base Derived Cu(Ⅱ) Complex

A novel copper(Ⅱ) complex based on chiral amino-alcohol derived Schiff base ligand,[Cu_4(R-L)_4(H_2O)_2]·(CH_3COOH)_2·(H_2O)(1,(R)-H_2 L =(R)-3-phenyl-2-(2-hydroxy-3-methoxybenzylideneamino) propane-1-ol),was synthesized and characterized by EA,IR,UV-Vis,ESI-MS,circular dichroism spectra and single-crystal X-ray diffraction.Complex 1 crystallizes in orthorhombic,space group Ρ2_12_12 with a = 15.7660(14),b = 49.526(3),c = 10.4213(9) ?,V = 8137.2(12) ?~3,Ζ = 4,C_(72)H_(81)Cu_4N_4O_(19),Mr = 1560.57,μ = 1.096 mm~(-1),F(000) = 3244,Flack = 0.06(3),the final R = 0.0924 and w R = 0.2451(I 2σ(I)) for 41108 observed reflections.The interactions of the complex with calf thymus DNA(CT-DNA) were investigated by some spectroscopic technique methods.The results show the complex exhibits strong binding with CT-DNA.In addition,in vitro cytotoxicity test of 1 towards four kinds of human cancerous cell lines(He La,HL-60,Caco-2 and A549) showed substantial cytotoxic activity.The experimental investigations indicated that the chirality of complex 1 play an important role in cytotoxicity and interactions with DNA.     

One-dimensional lanthanide complexes bridged by nitronyl nitroxide radical ligands with non-chelating nitrogen donors: Structure and magnetic characterization

A series of new lanthanide-radical complexes [{Ln(hfac)3}2(NITPhIM)2] (Ln = Nd (1), Eu (2), Tb (3), Er (4); hfac = hexafluoroacetylacetonate; NITPhIM = 2-[4-(1-imidazole)phenyl]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been prepared and characterized. Single crystal X-ray diffraction analyses reveal that these complexes are isostructural with one-dimensional chain structures. These consist in Ln(hfac)3 units bridged by the paramagnetic ligands by the means of coordination of their nitronyl nitroxide groups and imidazole rings. Interestingly, each Ln ion is either bound to two nitronyl nitroxide groups or to two imidazole units, and the different Ln centers alternate along the chain. Magnetic studies show that complex 3 exhibits a single-chain magnet behavior.     

Syntheses,Structures and Catalytic Properties of Two Mn(Ⅱ) and Cd(Ⅱ) Coordination Polymers through in Situ Ligand Reaction

Two coordination polymers, namely [Mn(μ-Hcpia)(bipy)(H_2O)_2]_n(1) and [Cd_3(μ_3-Hcpia)_2(μ-Hbiim)_2(μ-H_2biim)(H_2O)_2]_n(2), have been constructed hydrothermally using H_2cbia(H_2cbia = 5-(4'-cyanobenzoxy)isophthalic acid), bipy(bipy = 4,4'-bipyridine), H_2biim(H_2biim = 2,2'-biimidazole), and manganese or cadmium chlorides at 160℃. Interestingly, the H_3cpia(H_3cpia = 5-(4'-carboxylphenoxy)isophthalic acid) ligand was generated by in situ hydrolysis of cyano group in H_2cbia. The products were isolated as stable crystalline solids and were characterized by IR spectra, elemental analyses, thermogravimetric analyses(TGA), and single-crystal X-ray diffraction analyses. Both compounds crystallize in the triclinic system, space group P1. Compound 1 discloses a 1D linear chain of the 2C1 topological type. Adjacent chains are assembled into a 2D supramolecular sheet through O–H···O/N hydrogen bonds. Compound 2 features a 3D framework with a 3,4,4 T25 topology. The luminescent and catalytic properties of two compounds were investigated. Compound 1 exhibits a superior catalytic activity in the cyanosilylation at room temperature.     

A 3D Nickel(Ⅱ) Complex Constructed by Bis(2-dimethylaminoethyl) Ether: Solvothermal Synthesis,Crystal Structure and Catalytic Properties

Treatment of bis(2-dimethylaminoethyl) ether(BDMAE) with nickel acetate afforded a novel 3D nickel(Ⅱ) complex [Ni(BDMAE)(H_2O)_3·(CH_3COO)_2·(H_2O)_2] under solvothermal conditions. Its crystal structure was characterized by elemental analysis, IR spectrum, PXRD and single-crystal X-ray diffraction analysis. The complex belongs to the orthorhombic system, space group C2221 with a=8.823(2), b=13.932(3), c=17.563(4) ?, V=2158.9(8) ?~3, Z=4, C_(12)H_(36)N_2NiO_(10), Mr=427.14, Dc=1.314 g/cm~3, F(000)=920 and μ=0.944 mm~(-1). Single-crystal X-ray diffraction reveals that the mononuclear nickel(Ⅱ) ion is six-coordinated to one oxygen, two nitrogen atoms of the BDMAE ligand and three oxygen atoms of coordinated water molecules. The complex exhibits a 3D supramolecular structure through a variety of intermolecular and intramolecular hydrogen bonding interactions. In addition, the complex has been investigated for catalytic properties towards the Henry reaction of nitromethane with p-nitrobenzaldehyde, and the results indicated that the 1-p-nitrophenyl-2-nitroethanol product was obtained in excellent yield under optimum conditions with the complex as the catalyst.     

Solvothermal Synthesis,Crystal Structure and Photoluminescence Property of a 3D Lead(Ⅱ) Coordination Polymer Based on Terephthalic Acid

Solvothermal reaction of Pb(NO_3)_2·6H_2O with rigid linear ligand terephthalic acid(H_2pta) in N,N-dimethylformamide(DMF) produced a new three-dimensional(3D) lead(Ⅱ)coordination polymer[Pb_2(pta)_(1.5)(μ4-OH)(DMF)]_n 1,and its structure was characterized by single-crystal X-ray diffraction analyses.In polymer 1,the μ_4-OH bridges the nearby lead(Ⅱ) ions into an infinite one-dimensional(1D) chain,and then the organic ligand pta~(2-) joins the neighbored chains into a 3D structure by two similar connection modes in different configurations.The solid-state photoluminescent studies revealed that 1 exhibits a strong greenish emission mainly originating from ligand-to-metal charge transfer between the delocalized π bonds of the aromatic carboxylate ligand pta~(2-) and the p orbitals of the Pb~(2+) centers.     

Hydrothermal Syntheses,Crystal Structures and Luminescence Properties of Cu(Ⅱ) and Cd(Ⅱ) Complexes Assembled by 6-Hydroxypicolinic Acid and 1,10-Phenanthroline

Two new complexes based on 6-hydroxypicolinic acid(H_2picO) and 1,10-phenanthroline(phen), such as [Cu_4(picO)_4(phen)_4]·12 H_2O(1) and {[Cd_4(picO)_4(phen)_4(H_2O)_2]·5H_2O}_n(2), have been synthesized and characterized by IR, elemental analyses, thermogravimetric analyses and X-ray diffraction technique. Single-crystal X-ray diffraction analyses revealed that the two complexes both crystallize in the triclinic system, space group P(16)-. For complex 1, the picO ligands adopt a tridentate coordination mode to link copper(Ⅱ) ions into dimmers. PicO ligands also adopt a tridentate mode in complex 2, which connects the cadmium(Ⅱ) to form a one-dimensional chain. Moreover, luminescent properties of 1 and 2 were also investigated.     

A Cu(II) Complex with IM-MeImz-κ~2 N,O Mode in [Cu(IM-MeImz)_2]·(SCN)_2: Synthesis, Crystal Structure and Magnetic Properties

A new copper(II) compound with imino nitroxide radicals [Cu(IM-MeImz)2]?(SCN)2 (IM-meImz =2-(5-methylimidazol-4-yl)-4,4,5,5-tetramethyl-2-imidazoline-1-oxyl) has been synthesized and characterized structurally and magnetically. It crystallizes in monoclinic, space group P21/c with a = 9.3604(7), b = 10.3012(7), c = 16.6684(12) , β = 105.0290(10)o, V = 1552.25(19) 3, C24H34CuN10O2S2, Mr = 622.27, Z = 2, Dc = 1.331 g/cm3, μ(MoKα) = 0.876 mm-1, F(000) = 650, the final R = 0.0374 and wR = 0.1079. X-ray analysis demonstrates that the IM-MeImz ligand is coordinated to the copper(II) ion as an unusual didentate chelate with a κ2 N(MeImz),O(IM) mode in the complex. The square-planar coordination sites at Cu(II) are occupied by two O and two N atoms from the imino nitroxide radicals. The complex molecules are connected as a onedimensional polymer structure by intermolecular interactions. Magnetic measurements show that there are intramolecular antiferromagnetic interactions between the Cu(II) ion and radicals.     

Four Complexes of Mn(Ⅱ), Co(Ⅱ), Ni(Ⅱ) and Cu(Ⅱ) Based on 2-Morpholine-4-yl-4,6-di-pyrazol-1-yl-1,3,5-triazine

Three azide bridged complexes, namely, [Mn_2L_2(N_3)_4(H_2O)_2](1), [Co_2L_2(N_3)_4]·(H_2O)_3(2) and [Ni_2L_2(N_3)_3(H_2O)]N_3·(H_2O)_4(3)(L = 2-morpholine-4-yl-4,6-di-pyrazol-1-yl-1,3,5-triazine), were synthesized by the reaction of L ligand, sodium azide with Mn(Ⅱ), Co(Ⅱ) and Ni(Ⅱ) chlorides. The copper(Ⅱ) chloride combined with thiocyanate and L ligand to form a mononuclear complex [CuL(CH_3OH)(SCN)(NCS)](4). Complexes 1~4 were characterized by IR, elemental analysis and X-ray crystallographic analysis. It was worth noting that two Mn(Ⅱ) atoms were connected by the end-to-end mode in 1, while Co(Ⅱ) and Ni(Ⅱ) atoms were connected by the end-on mode in 2 and 3. In complex 4, the central copper atom was coordinated with a sulfur atom and a nitrogen atom of the two thiocyanate ligands, respectively. Hydrogen bonds, π-π stacking interactions, thermogravimetric analysis and fluorescence properties of 1~4 were studied.     

SYNTHESIS AND MAGNETIC PROPERTY OF CARBOXYL BRIDGING DICOPPER(Ⅱ) COMPLEXES

Two new dicopper(Ⅱ) complexes with two carboxyl bridgings in one molecule[Cu(dm-phen)(HCOO)]_2(NO_3)_2 3H_2O(1). [Cu(ds-phen)(CH_3COO)]_2 (NO_3)_2 3H_2O(2). one dicopper(Ⅱ) complex with one carboxyl bridging and one hydroxo bridging in one molecule [Cu_2(OH)(C_2H_5COO)(ds-phen)_2]. (NO_3)_2 H_2O(3) and one cononuclear Cu(Ⅱ) complex [Cu(de-phen)(CF_3COO)](NO_3).H_2O(4)(dm-phen= 2,9-dimethyl-1,10-phenanthrolin)were prepared and characterized. The effective magnetic moment, u elf, was measured and their magnetic properties were discussed. The coordination modes of carboxyl moieties in all the title complexes were proposed.     

Heterometal–organic frameworks: Three novel copper(Ⅱ)–lanthanide(Ⅲ) 15-metallacrown-5 complexes based on pyrazinohydroxamic acid as new multiple-binding pentagonal platform

Reactions of copper(Ⅱ) sulfate or copper(Ⅱ) perchlorate,samarium(Ⅲ),erbium(Ⅲ) or neodymium(Ⅲ)nitrate(5/1 equiv.) with pyrazinohydroxamic acid(H_2Pyzha) in H_2O/Me0 H led to three new heterobimetallic 15-metallacrown-5 complexes.In a MeOH/H_2O solution,when adding inorganic salts,the ligands exist as protonated metallacrowns.In the solid state,their structures are more complicated as confirmed by X-ray analysis:metallacrown[Sm(H_2O)_3 {Cu(pyzha)}_5(H_2O)_2(MeOH)(HSO_4)_2]·(H_2O)_2(HSO_4)(1);[Nd(H_2O)_2(MeOH) {Cu(pyzha)}_5(ClO_4)_2(H_2O)_5(NO_3)](2);[Eu(H_2O)_2(MeOH) {Cu(pyzha)}_5(ClO_4)_2(H_2O)_5(NO_3)](3).The differentiation of atomic and ionic radii between the encapsulated lanthanide(Ⅲ) could be used to control the bowl-shape distortion of the metallacrowns from the planar geometry.The complex 1 clearly exhibits fluorescence behavior of samarium(Ⅲ),while 2and 3 show that of copper(Ⅱ) and ligand.     

Simultaneous assembly of mononuclear and dinuclear dysprosium(Ⅲ) complexes behaving as single-molecule magnets in a one-pot hydrothermal synthesis

Two dysprosium(Ⅲ) complexes derived from 2,2'-bipyridine-6,6'-dicarboxylic acid(H_2bpdc),[Dy(bpdc)(Hbpdc)]-3H_2O(1) and[Dy_2(bpdc)_3(H_2O)_3]·2.125H_2O(2),were isolated from the same hydrothermal reaction container as different phases.Compound1 is a mononuclear complex with a DyN_4O_4 coordination polyhedron;whereas compound 2 is a dinuclear complex with two types of eight coordinated dy sprosium(Ⅲ) ions,showing DyN_4O_4 and DyN_2O_6 coordination polyhedra,respectively.Remarkably,a new type of(H_2O)_6 supramolecular aggregate exists in the crystal structure of 2.Magnetic investigations revealed that 1 is a field-induced single-ion magnet with an effective energy barrier of 45.6 K,exhibiting two-step magnetic relaxation;while an intramolecular ferromagnetic interaction exists in 2,which is a field-induced single-molecule magnet,displaying two-step magnetic relaxation too,with effective energy barriers of 53.4 and 92.1 K,respectively.     

Synthesis,Crystal Structure and Theoretical Calculations of a Manganese(Ⅱ) Coordination Polymer Assembled by 2,5-Thiophenedicarboxylic Acid and 3-(2-Pyridyl)pyrazole Ligands

A new Mn(Ⅱ) complex, [Mn_(0.5)(tdc)_(0.5)(L)]_(2n)(1, H2 tdc = 2,5-thiophenedicarboxylic acid, L = 3-(2-pyridyl)pyrazole), has been successfully synthesized under hydrothermal conditions. Its structure has been determined by single-crystal X-ray diffraction analysis, elemental analyses, IR, TG and UV spectrum. Single-crystal X-ray diffraction analysis reveals that complex 1 belongs to the orthorhombic system, space group Pnna with a = 11.5184(6), b = 16.8399(8), c = 11.7249(5) ?, V = 2274.26(19) ?3, Z = 4, D3c = 1.505 g/cm, μ = 0.715 mm-1, Mr = 515.41, F(000) = 1052, the final R = 0.0336 and w R = 0.0802 with I 2σ(I). It exhibits a one-dimensional zigzag-chain structure, which was stabilized through intermolecular C–H···O and intramolecular N–H···O hydrogen bonding interactions. Moreover, we analyzed Natural Bond Orbital(NBO) by using the PBE0/LANL2 DZ method built in Gaussian 09 Program. The calculation results showed obvious covalent interaction between the coordinated atoms and Mn(Ⅱ) ion.     

氮氧自由基单核钬配合物的合成与结构

A novel mononuclear Ho(Ⅲ) nitronyl nitroxide complex [Ho(hfac)₃(NITPhDma)₂], (NITPhDma=2-(4-dimethylamino-phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, hfac=hexafluoroacetylacetonate), was synth-esized and structurally characterized by X-ray diffraction. It crystallizes in monoclinic, space group P2₁/n with a=1.274 5(1) nm, b=1.753 1(2) nm, c=2.482 8(2) nm, β=93.753(2)°. The Ho(Ⅲ) ion is eight-coordinated with a distorted dodecahedron environment. Each NITPhDma radical acts as monodentate ligand towards Ho(Ⅲ) ion through the NO group, and the complex molecules are well isolated. CCDC: 775839.     

Synthesis,Crystal Structure and Spectral Property of a Water-bridged Co(Ⅱ) Coordination Polymer with 3-Flavonoxylacetic Acid Ligand

A new cobalt complex with flavonoid carboxylate ligand was synthesized and characterized. X-ray diffraction data revealed that the compound crystallizes in the monoclinic crystal system, space group P2_1/c with a = 7.936(3), b = 21.475(7), c = 20.010(7) ?, β = 102.856(14)o, V = 3325(2) ?~3, Z = 4, C_(34)H_(32)CoO_(15), M_r = 739.53, D_c = 1.477 g/cm~3, F(000) = 1532, μ = 0.591 mm~(-1), R = 0.1123 and w R = 0.1419. In the crystal structure, the Co(Ⅱ) shows 6 coordination geometry, and the flavonoid ligand coordinated with the Co(Ⅱ) ion in a monodentate mode. Hydrogen bonding interactions and π-π stacking interactions lead to the three-dimensional stacking of crystal and increase its stability. Moreover, the thermal stability and luminescent properties of the complex are also investigated. The fluorescence of the complex shows a great reduction of the intensity than that of the ligand.     

A Cu(Ⅱ) Complex with IM-MeImz-к2 N,O Mode in [Cu(IM-MeImz)2]·(SCN)2: Synthesis, Crystal Structure and Magnetic Properties

A new copper(Ⅱ) compound with imino nitroxide radicals [Cu(IM-MeImz)2]·(SCN)2 (IM-meImz =2-(5-methylimidazol-4-yl)-4,4,5,5-tetramethyl-2-imidazoline-1-oxyl) has been synthesized and characterized structurally and magnetically. It crystallizes in monoclinic, space group P21/c with a = 9.3604(7), b = 10.3012(7), c = 16.6684(12) (A), β = 105.0290(10)°, V = 1552.25(19)(A)3, C24H34CuN10O2S2, Mr = 622.27, Z = 2, Dc = 1.331 g/cm3, μ(MoKα) = 0.876 mm-1, F(000) =650, the final R = 0.0374 and wR = 0.1079. X-ray analysis demonstrates that the IM-MeImz ligand is coordinated to the copper(Ⅱ) ion as an unusual didentate chelate with a κ2 N(MeImz),O(IM) mode in the complex. The square-planar coordination sites at Cu(Ⅱ) are occupied by two O and two N atoms from the imino nitroxide radicals. The complex molecules are connected as a onedimensional polymer structure by intermolecular interactions. Magnetic measurements show that there are intramolecular antiferromagnetic interactions between the Cu(Ⅱ) ion and radicals.