Synthesis and Crystal Structure of a New One-dimensional Zn(II) Nitronyl Nitroxide Complex Bridged by Pyridine-2,4-dicarboxylate Anion

1 INTRODUCTION The synthesis and study of transition metal com- pounds incorporating organic free radicals directly bound to their coordination sphere are a major re- search aim in the field of molecular magnetism[1]. Exceptional stability, ease of chemical modification and versatility in their coordination properties have made nitroxide free radicals one of the most attrac- tive spin carriers for the design of molecular magne- tic materials[2, 3]. The structures and magnetic prope- rties …     

Synthesis,crystal structure and magnetic properties of Co(NIT4Py)(H2PDA)(H2O)3

A Co(II)-pyridyl substituted nitronyl nitroxide complex Co(NIT4Py)(H₂PDA)(H₂O)₃ has been synthesized and structurally characterized (NIT4Py: 2-(4′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and H₂PDA: 2,5-pyridine dicarboxylic acid). The compound is in the monoclinic space group P2(1)/c, a = 16.892(5) Å, b = 7.371(2) Å, c = 18.856(5) Å, β = 108.770(5)°, V = 2223.0(11) ų, Z = 4 and F(000) = 1064. The cobalt is in a distorted octahedral environment with one nitrogen from NIT4Py, one oxygen atom from H₂PDA, two oxygens from two water molecules in the basal plane and one nitrogen from H₂PDA and one water in the axial positions. The molecules are connected as a layered structure by intermolecular hydrogen bond interactions. Variable temperature magnetic susceptibility measurements reveal the occurrence of weak antiferromagnetic interactions in the compound.     

Synthesis and Crystal Structure of a Novel Complex [Ag(NIT3Py)_3]·(ClO_4)(H_2O)

1 INTRODUCTION Nitronyl nitroxide radicals (NITR), stable organic radicals, have played an important role in the design and synthesis of molecular magnetic materials[1, 2]. However, nitronyl nitroxide radicals are poor elec- tron-donor ligands and their coordination ability is limited. Recently, it has led to the development of functionalized nitronyl nitroxide radicals in which a strong coligand is incorporated. Due to the strong coordinate ability of nitrogen atom from pryidinyl ring,…     

Synthesis and Crystal Structure of a Novel Complex [Ag(NIT3Py)3]·((ClO4)(H2O)

A novel complex [Ag(NIT3Py)3]·((ClO4)(H2O) has been synthesized and structurally characterized by X-ray diffraction method. It crystallizes in the rhombohedral system, space group R3 with a = 15.8227(17), b = 15.8227(17), c = 31.445(3) (A),γ = 120°, V = 6817.8(12) (A)3, Dc = 1.370 g/cm3, Z = 6, μ= 0.566 mm-1, Mr = 937.18, F(000) = 2916, R = 0.0715, wR = 0.2115 and GOF = 1.086. The structure consists of Ag(NIT3Py)3+ cation moiety, one water molecule and one perchloric ion. The Ag(I) ion is in a trigonal planar coordination environment formed by three nitrogen atoms from three NIT3Py ligand molecules.     

Synthesis, crystal structure and magnetic properties of a novel complex [Cu(NIT2Py)(PDA)(H2O)]·(CH3OH)(H2O)

A novel complex [Cu(NIT2Py)(PDA)(H₂O)]·(CH₃OH)(H₂O) has been synthesized and structurally characterized by X-ray diffraction methods. It crystallizes in the monoclinic space group P2(1)/c. The structure consists of [Cu(NIT2Py)(PDA)(H₂O)] moiety, one solvent methanol molecule and one water molecule. The copper(II) ion is in a distorted octahedral environment: one nitrogen atom and one oxygen atom from the NIT2Py, one nitrogen atom from the PDA (2,6-pyridine dicarboxylic acid) and one oxygen atom from the aqueous in the basal plane; two oxygen atoms from the PDA in the axial position. The units of [Cu(NIT2Py)(PDA)(H₂O)] were connected as one dimension chain by the intermolecular hydrogen bonds. The complex exhibits intramolecular antiferromagnetic interactions between the Cu(II) ion and the NIT2Py.     

Synthesis, Crystal Structure and Optical Properties of a New Nd(Ⅲ) Nitronyl Nitroxide Complex [Nd(NIT2Py)2(NO3)3]

A new Nd(Ⅲ) nitronyl nitroxide complex [Nd(NIT2Py)2(NO3)3] (NIT2Py = 2-(2'-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been synthesized and structurally characterized by X-ray diffraction.It crystallizes in monoclinic, space group P21/n with a = 12.396(4), b =11.134(4), c = 23.360(7)(。A), β = 98.178(6)°, V= 3191.2(18)(。A)3, C24H32NgNdO13, Mr = 798.83, Dc =1.663 g/cm3, μ(MoKα) = 1.704 mm-1, F(000) = 1612, Z = 4, the final R = 0.0425 and wR = 0.0957for 6532 independentreflections with Rint = 0.0642 and 4552 observed reflections (I ＞ 2σ(I)).The complex exists as discrete mononuclear molecules and the neodymium(Ⅲ) ion is ten-coordinated with three bidentate nitrate anions and two radical ligands (NIT2Py) via bidentate chelating mode.The optical properties of the complex are discussed.     

Synthesis and crystal structures of two metal-nitroxide complexes including a phenanthroline-substituted nitroxide radical

Two metal-nitroxide complexes, [Cu(IMPhenCOO)(CH₃OH)]₂ ·?(NO₃)₂ (1) and [Co(NIT2Py)(H-2,5-PDA)₂] ·?0.5CH₃OH ·?2H₂O (2) (IMPhenCOOH =?2-carboxyl-9-(4,4,5,5-tetramethylimidazoline-1-oxyl-2-yl)-1,10-phenanthroline, NIT2Py =?2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and H₂-2,5-PDA =?pyridine-2,5-dicarboxylic acid), have been synthesized and structurally characterized by X-ray diffraction. Complex 1 exists as discrete binuclear molecules and each copper(II) is five-coordinate with one tridentate radical ligand (IMPhenCOOH), the other radical ligand through one carboxyl oxygen and one methanol molecule. Complex 1 is the first structurally characterized complex containing the phenanthroline-substituted nitroxide radical. In 2, the Co(II) is six-coordinate with one radical ligand (NIT2Py) and two bidentate pyridine-2,5-dicarboxylate anions.     

Hydrothermal Synthesis and Crystal Structure of a Coordinated Polymer： [Ni（pda）（H2O）3]n （pda = Pyridine-2,3-dicarboxylate）

1 INTRODUCTIONThe design and synthesis of metal-organic coor- dinated polymer have attracted considerable atten- tion in recent years. The infinite networks construc- ted from transition metal complexes have intere- sting structures as well as potential applications as smart electronic, magnetic porous materials, cataly- sis, host-guest chemistry, and so on[1～4]. In the as- sembly and synthesis of polymer structures, the me- tal ions, bi- or multi-dentate ligand, solvent and the ratio of …     

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 and Crystal Structure of a Tetranuclear Carboxylate-bridged Lanthanum(III)-Zinc(II) Complex [La_2Zn_2(m-CNC_6H_4COO)_(10)(Py)_2(C_2H_5OH)_2]

1 INTRODUCTION In the past few years, more extensive attention had been paid to the research on the chemistry of the heterometallic complexes containing simultaneously lanthanide (Ln) and transition metal ions[1～9]. Interest has been largely focused on the magnetic properties resulting from the Gd(III)-Cu(II) couple, which has been found to be directly ferromagnetic irrespective of the structural details[1～5]. Recent studies have further revealed that the magnitude of the ferromagnet…     

Fe(bipy)(CN)(4)](-) as a versatile building block for the design of heterometallic systems: synthesis, crystal structure, and magnetic properties of PPh(4)[Fe(III)(bipy)(CN)(4)] x H(2)O, [[Fe(III)(bipy)(CN)(4)](2)M(II)(H(2)O)(4)] x 4H(2)O, and [[Fe(III)(bipy)(CN)(4)](2)Zn(II)] x 2H(2)O [bipy = 2,2'-Bipyridine; M = Mn and Zn

The new cyano complexes of formulas PPh(4)[Fe(III)(bipy)(CN)(4)] x H(2)O (1), [[Fe(III)(bipy)(CN)(4)](2)M(II)(H(2)O)(4)] x 4H(2)O with M = Mn (2) and Zn (3), and [[Fe(III)(bipy)(CN)(4)](2)Zn(II)] x 2H(2)O (4) [bipy = 2,2'-bipyridine and PPh(4) = tetraphenylphosphonium cation] have been synthesized and structurally characterized. The structure of complex 1 is made up of mononuclear [Fe(bipy)(CN)(4)](-) anions, tetraphenyphosphonium cations, and water molecules of crystallization. The iron(III) is hexacoordinated with two nitrogen atoms of a chelating bipy and four carbon atoms of four terminal cyanide groups, building a distorted octahedron around the metal atom. The structure of complexes 2 and 3 consists of neutral centrosymmetric [[Fe(III)(bipy)(CN)(4)](2)M(II)(H(2)O)(4)] heterotrinuclear units and crystallization water molecules. The [Fe(bipy)(CN)(4)](-) entity of 1 is present in 2 and 3 acting as a monodentate ligand toward M(H(2)O)(4) units [M = Mn(II) (2) and Zn(II) (3)] through one cyanide group, the other three cyanides remaining terminal. Four water molecules and two cyanide nitrogen atoms from two [Fe(bipy)(CN)(4)](-) units in trans positions build a distorted octahedron surrounding Mn(II) (2) and Zn(II) (3). The structure of the [Fe(phen)(CN)(4)](-) complex ligand in 2 and 3 is close to that of the one in 1. The intramolecular Fe-M distances are 5.126(1) and 5.018(1) A in 2 and 3, respectively. 4 exhibits a neutral one-dimensional polymeric structure containing two types of [Fe(bipy)(CN)(4)](-) units acting as bismonodentate (Fe(1)) and trismonodentate (Fe(2)) ligands versus the divalent zinc cations through two cis-cyanide (Fe(1)) and three fac-cyanide (Fe(2)) groups. The environment of the iron atoms in 4 is distorted octahedral as in 1-3, whereas the zinc atom is pentacoordinated with five cyanide nitrogen atoms, describing a very distorted square pyramid. The iron-zinc separations across the single bridging cyanides are 5.013(1) and 5.142(1) A at Fe(1) and 5.028(1), 5.076(1), and 5.176(1) A at Fe(2). The magnetic properties of 1-3 have been investigated in the temperature range 2.0-300 K. 1 is a low-spin iron(III) complex with an important orbital contribution. The magnetic properties of 3 correspond to the sum of two magnetically isolated spin triplets, the antiferromagnetic coupling between the low-spin iron(III) centers through the -CN-Zn-NC- bridging skeleton (iron-iron separation larger than 10 A) being very weak. More interestingly, 2 exhibits a significant intramolecular antiferromagnetic interaction between the central spin sextet and peripheral spin doublets, leading to a low-lying spin quartet.     

Synthesis and Crystal Structure of a Novel Co(II)-Nitronyl Complex [Co(IM2-Py)(PCA)(N_3)_2]

1 INTRODUCTION The design and synthesis of molecule-based mag-netic materials is one of the major subjects of mate-rials science. Nitronyl nitroxides acting as useful pa-ramagnetic building blocks have been extensively usedto assemble molecular magnetic materials in the pastfew years[1～5]. However, their weakly basic charac-ter strongly limits their coordination ability. Mean-while, the azide anion is a versatile ligand which canlink the transition metal atoms with different coor-dinatio…     

Synthesis, Crystal Structure and Optical Properties of a New Nd(III) Nitronyl Nitroxide Complex [Nd(NIT2Py)_2(NO_3)_3]

1 INTRODUCTION Nitronyl nitroxides, independently or in combina- tion with metal ions, have been one of the most widely studied systems in molecular magnetism for understanding the radical-radical or metal-radical interactions as well as for synthesizing organic ferro- magnets and metal-radical magnetic materials[1～3]. Meanwhile, investigations on molecular coordina- tion compounds of lanthanide ions have also attrac- ted great attention due to their luminescence[4, 5] or magnetic propert…     

2D氢键网络镉配合物Cd(pyridine-2-sulfonato)2(H2O)2和锌配合物Zn(pyridine-2-sulfonato)2(H2O)2的合成和晶体结构

合成了镉的吡啶-2-磺酸配合物Cd(C5H4NSO3)2(H2O)2 1和锌的吡啶-2-磺酸配合物Zn(C5H4NSO3)2(H2O)2 2。 研究表明, 2个化合物属异质同晶, 均属单斜晶系, 空间群为C2/c. 化合物1晶胞参数为:a = 13.7671(5), b = 7.2778(3), c = 16.1559(9) ? b = 106.656(3)? V = 1550.8(1) 3, Z = 4, Dc = 1.990 g/cm3, m =1.719 mm-1, F(000) = 920, R = 0.0225, wR = 0.0584, 共收集到1759个独立衍射点, 其中I≥2(I)的可观测点为1681个;化合物2晶胞参数为:a = 13.711(1), b = 7.1451(9), c = 15.972(1) , b =107.079(5)? V = 1495.7(3) 3, Z = 4, Dc = 1.855 g/cm3, m = 1.964 mm-1, F(000) = 848, R = 0.0310, wR = 0.0831, 共收集到1707个独立衍射点, 其中I≥2(I)的可观测点为1592个。在2个标题配合物中, Cd2+离子(或Zn2+离子)由2个吡啶-2-磺酸中的2个氮和2个氧以及2个水分子中的2个氧配位形成畸变的N2O4八面体配位构型。每个配合物分子具有晶体学2次旋转轴对称性。配合物分子之间通过许多OH(配位水分子)LO(未配位磺酸根)氢键联结成二维结构网络。     

Synthesis and Crystal Structure of an Azide Bridged Binuclear Zinc(II) Complex Including the Reduced Derivative of Nitronyl Nitroxide,[Zn(Him2Py)(N3)2]2

1 INTRODUCTION The design and synthesis of transition metal complexes with organic free radicals is one of the major challenges in the field of molecular magnetic materials[1,2]. Nitronyl nitroxide radicals are normal- ly used as spin carriers due to th…     

Synthesis and Crystal Structure of a Nitronyl Nitroxide Complex {[Zn(NIT4Py)(fum)(H2O)2]·H2}n

The title compound {[Zn(NIT4Py)(fum)(H2O)2]·H2O}n, where N1T4Py=2-(4'-pyridinyl)-4,4,5,5-tetra-methylimidazoline-l-oxyl-3-oxide and rum=fumarate, has been prepared and structurally characterized by X-ray diffraction. It crystallizes in triclinic, space group P1 with a =6.9533(9), b=9.805(1), c=15.248(2)A, a=94.608(2), β=92.328(2),γ=105.840(2)°,C16H24N3O9Zn, Mr=467.75, V=994.8(2) A3, Z=2, Dc=1.562 g/cm3,μ(MoKa)=1.289 mm-1,F(000)=486, the final R=0.0243 and wR=0.0622 for 3505 independent reflections with Rint=0.0125. The Zn(Ⅱ) adopts a distorted five-coordinate triangle bipyramidal geometry. The basic framework structure of the complex is a 1-D chain. The intrachain hydrogen bonds are helpful to stabilize the 1-D chain structure. Furthermore, the chains are connected by O-H…O hydrogen bonds to give a 2-D double-layer network.     

Synthesis and Crystal Structure of [Zn(FcCOO)_2(2,2'-bipy)(H_2O)]_2·H_2O

A novel complex [Zn(FcCOO)2(2,2'-bipy)(H2O)]2·H2O (Fc = (η5-C5H5)Fe(η5-C5H4), 2,2'-bipy = 2,2'-bipyridine) has been synthesized and characterized by elemental analysis, IR and X-ray diffraction. It crystallizes in monoclinic system, space group P21/c with a = 6.8187(4), b = 21.7155(13), c = 19.7411(12) A, α = 90, β = 97.7420(10), γ = 90o, C64H58Fe4Zn2N4O11, Mr = 1413.28, V = 2896.4(3) A3, Dc = 1.620 g/cm3, Z = 2, F(000) = 1444, μ(MoKα) = 1.857 mm-1, R = 0.0523 and wR = 0.0982 for 3219 observed reflections (I > 2σ(I)). Structural analysis shows that the zinc atom is coordinated with three oxygen atoms from two ferrocenemonocarboxylates and one water molecule together with two nitrogen atoms from 2,2'-bipyridine, giving a distorted square-pyramidal coordination geometry. The complex molecules are linked to form an infinite one-dimensional chain by both intermolecular hydrogen bonds and π-π stacking interactions of the bipyridine rings.     

Synthesis and Crystal Structure of a Novel Zinc Complex [Zn(OH_2)(HDPA)_2]·3H_2O

1INTRODUCTION In recent years,dicarboxylic acids have been wide-ly used as poly-dentate ligands involved in various metal chelation reactions to form transition or rare earth metal complexes with interesting properties in material science[1~3]and biological systems[4~7].For example,Kim,Y.and his coworkers focus on the syn-theses of copper(II)complexes containing ligands of malonate and pyrazine to study their electronic con-ductivity and magnetic property[8].The importance of Tr(II)/dic…     

Syntheses and Crystal Structures of Molybdenum-Sulfur Clusters Mo_3S_4 (dtp)_3(o-CH_3OC_6H_4COO)(Py) and Mo_3S_4 (dtp)_3(p-HOC_6H_4COO)(DMF)·EtOH

1 INTRODUCTION Recent years have seen a drastic increase of compounds containing the Mo3S4 core. A major synthetic route to these compounds is by the reaction of the aqua ion [Mo3S4(H2O)9]4+ with different kinds of ligands replacing some or all of the water molecules. In this way, Mo3S4(dtp)4(H2O), which was synthesized by the spontaneous- assembly method in 1986[1] and its structural characterization and chemical reactivity have been well recognized [2], can be rationally synthesize…     

Fe(Phen)(CN)4]-: a versatile building block for the design of heterometallic systems. Crystal structures and magnetic properties of PPh4[Fe(Phen)(CN)4]*2H2O and [[Fe(Phen)(CN)4]2M(H2O)2]*4H2O [Phen = 1,10-phenanthroline; M = Mn(II) and Zn(II)

The mononuclear PPh4[Fe(phen)(CN)4]*2H2O (1) complex and the cyanide-bridged bimetallic [[Fe(phen)(CN)4]2M(H2O)2]*4H2O compounds [M = Mn(II) (2) and Zn(II) (3); phen = 1,10-phenanthroline; PPh4 = tetraphenylphosphonium cation] have been synthesized and structurally and magnetically characterized. Complex 1 crystallizes in the monoclinic system, space group P2(1)/c, with a = 9.364(4) A, b = 27.472(5) A, c = 14.301(3) A, beta = 97.68(2) degrees, and Z = 4. Complexes 2 and 3 are isostructural and they crystallize in the monoclinic system, space group P2(1)/n, with a = 7.5292(4) A, b = 15.6000(10) A, c = 15.4081(9) A, beta = 93.552(2) degrees, and Z = 2 for 2 and a = 7.440(1) A, b = 15.569(3) A, c = 15.344(6) A, beta = 93.63(2) degrees, and Z = 2 for 3. The structure of complex 1 is made up of mononuclear [Fe(phen)(CN)4]- anions, tetraphenyphosphonium cations, and water molecules of crystallization. The iron(III) is hexacoordinate with two nitrogen atoms of a chelating phen (2.018(6) and 2.021(6) A for Fe-N) and four carbon atoms of four terminal cyanide groups (Fe-C bond lengths varying in the range 1.906(8)-1.95(1) A) building a distorted octahedron around the metal atom. The structure of complexes 2 and 3 consists of neutral double zigzag chains of formula [[Fe(phen)(CN)4]2M(H2O)2] and crystallization water molecules. The [Fe(phen)(CN)4]- entity of 1 is present in 2 and 3 acting as a bridging ligand toward M(H2O)2 units [M = Mn(II) (2) and Zn(II) (3)] through two cyanide groups in cis positions, the other two cyanide remaining terminal. Two water molecules in trans positions and four cyanide-nitrogen atoms from four [Fe(phen)(CN)4]- units build a distorted octahedral surrounding Mn(II) (2) and Zn(II) (3). The M-O bond lengths are 2.185(3) (2) and 2.105(3) A (3), whereas the M-N bond distances vary in the ranges 2.210(3)-2.258(3) A (2) and 2.112(3)-2.186(3) A (3). The structure of the [Fe(phen)(CN)4]- complex ligand in 2 and 3 is as in 1. The shorter intrachain Fe-M distances through bridging cyano are 5.245(5) and 5.208(5) A in 2 and 5.187(1) and 5.132(1) A in 3. The magnetic properties of 1-3 have been investigated in the temperature range 2.0-300 K. Complex 1 is a low-spin iron(III) complex with an appreciable orbital contribution. The magnetic properties of 3 correspond to the sum of two magnetically isolated spin triplets, the magnetic coupling between the low-spin iron(III) centers through the -CN-Zn-NC- bridging skeleton (iron-iron separation larger than 10.2 A) being negligible. More interestingly, 2 exhibits one-dimensional ferrimagnetic behavior due to the noncompensation of the local interacting spins (S(Mn) = 5/2 and S(Fe) = 1/2) which interact antiferromagnetically through bridging cyano groups. A comparison between the magnetic properties of the isostructural compounds 2 and 3 allow us to check the antiferromagnetic coupling in 2.