Two Tri-spin Complexes Based on Lanthanide (Ln~Ⅲ =Dy~Ⅲ and Tb~Ⅲ ) and Nitronyl Nitroxide Radicals: Syntheses, Structures and Properties

Two new tri-spin radical-Ln（III）-radical complexes, [Ln（hfac）3（NITPh-Ph）2] （Ln = Dy （1） and Tb （2）, NITPh-Ph = 4＇-biphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, and hfac = hexafluoroacetylacetonate） have been synthesized and characterized by X-ray diffraction analysis, elemental analysis, IR, Uv-visible and magnetic properties. X-ray analysis reveals that the two complexes are isomorphous and crystallize in the triclinic system, space group P1. For complex 1, a = 12.402（3）, b = 15.414（3）, c = 17.383（3） A, a = 68.61（3）, β = 81.97（3）, y = 79.40（3）°, V = 3031.7（11） A3, Z = 2, Mr = 1401.86, Dc = 1.536 g/cm^3, kt = 1.344 mm^-1, F（000） = 1398, the final GOF = 1.173, R = 0.0670 and wR = 0.1376 for 9035 observed reflections with 1 〉 2a（/）; while for complex 2, a = 12.397（3）, b = 15.391（3）, c = 17.395（4） A, a = 68.62（3）, fl = 81.97（3）, ）, = 79.60（3）°, V = 3030.0（11） A3, Z = 2, Mr = 1398.29, Dc = 1.537 g/cm^3,μ = 1.344 mm-1, F（000） = 1398, the final GOF = 1.130, R = 0.0644 and wR = 0.1382 for 8989 observed reflections with 1 〉 2a（/）. They all consist of the discrete adducts, in which the central Ln（lll） ions are coordinated by six oxygen atoms from three hfacs and two oxygen atoms from nitronyl radicals. The temperature dependency of magnetic susceptibilities for these two complexes is studied, showing that the magnetic interactions are governed by the depopulation of the Ln Stark levels.

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.

Synthesis and Crystal Structure of Dicopper(II) Compound Containing Oxalate and Reduced Imino Nitroxide Radicals

A new dicopper(II) compound with oxalate and reduced imino nitroxide radicals [Cu2(m-C2O4)(Him2-py)2(H2O)2](NO3)2 (Him2-py=1-hydroxy-2-(2-pyridyl)-4,4,5,5-tetramethyli- midazoline) has been synthesized and its crystal structure was determined by X-ray diffraction method. The complex crystallizes in monoclinic, space group P21/n with a = 9.913(4), b = 19.057(8), c = 10.169(4) ? b = 114.292(7), V = 1751(1) 3, C26H38Cu2N8O14, Mr = 813.72, Dc = 1.543 g/cm3, m(MoKa) = 1.290 mm-1, F(000) = 840, Z = 2, the final R = 0.0398 and wR = 0.0986 for 1878 observed reflections (I>2s(I)). The imino nitroxide 2-(2-pyridyl)-4,4,5,5-tetramethyl- imidazoline-1-oxyl (im2-py) is reduced in the reaction to yield Him2-py which consists of oxalato-bridged centrosymmetric [Cu2(m-C2O4)(Him2-py)2(H2O)2]2+ ions and noncoordinated NO3- anions. Each copper(II) ion is in a distorted tetragonal pyramid environment: two nitrogen atoms from Him2-py and two oxygen atoms from the oxalate group are in the basal plane, and one water molecule at the axial position.

A New One-dimensional Dicyanamide Bridged 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（NO3）（NIT-1′-MeBzIm）（dca）]n·（H2O）n （NIT-1′-MeBzIm = 2-{2′-[（1′-methyl）benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, dca = dicyanamide anion） has been prepared and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in triclinic, space group P^-1, with a = 7.428（3）, b = 9.839（3）, c = 16.708（6） A^°, α = 93.270（4）, β = 101.642（4）,γ= 100.632（4）°, C17.5H21N8O5.5Zn, Mr = 496.79, V = 1169.7（7） A^°^3, Dc = 1.411 g/cm^3, μ（MoKα） - 1.096 mm^-1, Z = 2, F（000） = 512, R = 0.0583 and wR = 0.1663 for 4295 observed reflections with I 〉 2σ（I）. X-ray analysis reveals that the zinc（Ⅱ） ion is six-coordinated with a distorted octahedral geometry. These units develop as 1D species where dicyanamide ligands bridge zine（ID ions. In addition, molecules are linked by π-π piling interactions to form 1-D double-chains. Magnetic investigation indicates that the weak intramolecular interactions are antiferromagnetic with J = -0.27 cm^-1, where the spin Hamitonian is defined as H = -2∑ijJijSiS within the complex.

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.

Nitroxide radical cathode material with multiple electron reactions

Organic materials with redox-active centers are regarded as promising candidates for rechargeable batteries in recent years for their light weight, low cost, environmental friendliness and structural diversity [1–4]. Organic materials, such as conducting polymers (polyacetylene, polypyrrole, polyaniline, etc.)[5], conjugated carbonyl compounds (quinone compounds, imides, etc.)[6–9] and nitroxide radical (N-O.)[10,11] compounds have been attempted as cathode materials in lithium-ion batteries (LIBs).

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

A novel compound [Co(IM2-Py)2(NO3)]?(NO3) (IM2-Py = 2-(2?-pyridyl)-4,4,5,5- tetramethylimidazoline-1-oxyl) has been prepared and structurally characterized by X-ray diffrac- tion method. It crystallizes in orthorhombic, space group P212121 with a = 11.031(2), b = 13.492(3), c = 20.467(4) ?, V = 3046.0(11) ?3, C24H32CoN8O8, Mr = 619.51, Z = 4, Dc = 1.351 g/cm3, μ(MoKα) = 0.620 mm?1, F(000) = 1292, R = 0.0506 and wR = 0.0845 for 3752 observed reflections with I > 2σ(I). X-ray analysis reveals that the crystal structure consists of [Co(IM2- Py)2(NO3)]+ moiety and a NO3 anion. The cobalt(II) ion is six-coordinated with a distorted octahedral geometry. Tempera- ? ture dependence of susceptibility measurements show that there exist an antiferromagnetic inter- action in the compound.

Syntheses and Crystal Structures of Two New Zinc(Ⅱ) Nitroxide Radical Complexes Bridged by Isophthalate

Two novel complexes [Zn（NIT3-py）（ip）]n 1 and [Zn（im3-py）（ip）]n 2 （NIT3-py = 2-（3＇-pyridyl）-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide, im3-py = 2-（3＇-pyridyl）-4,4,5,5-tetramethylimidazoline-1-oxyl, ip = isophthalate） have been synthesized and structurally determined by X-ray diffraction. Crystal data for 1： C32H36N6O8Zn, Mr= 698.04, monoclinic, space group Cc with a = 23.600（3）, b = 10.2073（12）, c = 13.4027（16）A,β = 92.586（2）°, V = 3225.3（7） A^3, Dc= 1.438 g/cm^3, F（000） = 1456,μ（MoKa） = 0.822 mm^-1, Z = 4, the final R = 0.0390 and wR = 0.1032 for 6037 independent reflections with Rint = 0.0214. Crystal data for 2： C32H36N6O6Zn, Mr= 666.04, monoclinic, space group C2/c with a = 24.434（4）, b = 13.543（2）, c = 10.2379（16） A, β = 109.024（2）°, V = 3202.8（9）A3 Dc= 1.381 g/cm^3, F（000） = 1392,μ（MoKa） = 0.820 mm^-1, Z = 4, the final R = 0.0304 and wR = 0.0658 for 2833 independent reflections with Rint = 0.0307. X-ray analysis reveals that both Zn（ Ⅱ ） ions are four-coordinated by two pyridyl-N atoms from nitroxide radicals and two carboxylate oxygen atoms to form distorted tetrahedral geometries. Each isophthalate dianion binds two Zn（ Ⅱ ） ions in a monodentate mode, leading to a I-D chain structure.

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.

Syntheses and Crystal Structures of Zinc(II) and Nickel(II) Complexes Involving Reduced Nitroxide Radicals

Two novel complexes [Zn（Him-thz）2（NO3）]·NO3 1 and [Ni（Him-thz）2（NO3）]·NO3 2 （Him-thz = 2-（2＇-thiazole）-4,4,5,5-teramethyl-dihydro-1H-imidazolyl-1-hydroxy） have been prepared and structurally characterized by X-ray diffraction method. Both complexes crystallize in orthorho- mbic, space group P21 21 2, Z = 2. Crystal data for 1： ZnC20H30N8O8S2, Mr = 640.2, a = 13.1630（14）, b = 10.5149（11）, c = 10.6670（11） A°, V= 1476.4（3）A°^3, Dc = 1.440 g/cm^3, μ（MoKa） = 1.028 mm^-1, F（000） = 664, R = 0.0398 and wR = 0.0901 for 2131 observed reflections with I 〉 2σ（I）. Crystal data for 2： NiC20H30N8O8S2, Mr = 633.36, a = 13.1611（7）, b = 10.4833（6）, c = 10.6928（6） .4,, V = 1475.30（14）A°^3, Dc = 1.426 g/cm^3 ,μ（MoKa） = 0.854 mm^-1, F（000） = 660, R = 0.0281 and wR = 0.0797 for 3099 observed reflections with I 〉 2σ（I）. X-ray analysis reveals that the crystal structures consist of [M（Him-thz）2（NO3）]^＋ （M = Zn, Ni） moiety and a NO3^- anion. Both Zinc（Ⅱ） and Nickel（Ⅱ） ions are six-coordinated with distorted octahedral geometries.

Synthesis and Uncommon Structural Characterization of Novel Zinc and Cadmium Complexes with Imino Nitroxide Radical

Two novel complexes {[Zn（IM4py）2（tp）（H2O）]2H2O}. 1 and {[Cd（IM4py）2（tp）- （H2O）]1.25H2O},, 2 （IM4py = 2-（4＇-pyridinyl）-4,4,5,5-tetramethylimidazoline-l-oxyl and tp = terephthalate dianion） have been synthesized and characterized by elemental analyses, IR spectrum and single-crystal X-ray diffraction. Crystal data for complex I： monoclinic, space group C2/c, a = 20.648（7）, b = 12.130（4）, c = 14.036（4） A, β = 106.351（5）°, C32H42N6O9Zn, Mr = 720.09, V = 3373.3（2） A3, Z= 4, Dc = 1.418 g/cm^3μt（MoKα） = 0.790 mm^-1, F（000） = 1512, the final R = 0.0407 and wR = 0.0894 for 3480 independent reflections with Rint = 0.0432. Crystal data for complex 2： monoclinic, space group C2/c, a = 21.332（6）, b = 12.063（3）, c = 14.246（4） A, β = 106.704（4）°, C32H40.50N6O8.25Cd, Mr = 753.60, V= 3511.2（2） A^3, Z = 4, Dc = 1.426 g/cm^3,μ（MoKα） = 0.679 mm^--1, F（000） = 1554, the final R = 0.0419 and wR = 0.0961 for 3627 independent reflections with Rint = 0.0440. The framework structures of complexes 1 and 2 are 3-D networks via the hydrogen bonds among 1-D chains. The notable characteristics of the two complexes are that the coordination polyhedron of Zn（Ⅱ） adopts a rare distorted five-coordinate square pyramidal geometry in 1, and the Cd（Ⅱ） complex exhibits an unusual distorted seven-coordinate pentagonal bipyramid in 2.

Synthesis,Crystal Structure and Magnetic Property of a New Cd(Ⅱ) Complex with Four Nitronyl Nitroxide Radicals

A new Cd（Ⅱ） complex with four nitronyl nitroxide radicals [Cd（NIT4Py）4Cl2]（NIT4Py = 2-（4＇-pyridinyl）-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide） has been synthesized and structurally characterized by X-ray diffraction analysis.It crystallizes in triclinic,space group P1 with a = 7.2441（4）,b = 13.6964（8）,c = 13.7354（8） ,α = 89.8610（10）,β = 77.9180（10）,γ = 87.2250（10）°,V = 1331.01（13） 3,C48H64CdCl2N12O8,Mr = 1120.41,Z = 1,Dc = 1.398 g/cm3,μ（MoKα） = 0.573 mm-1,F（000） = 582,S = 1.043,the final R = 0.0257 and wR = 0.0641 for 4333 observed reflections（I 〉2σ（I））.The title complex exists in the mononuclear-metal structures,in which each Cd（Ⅱ） ion adopts a distorted octahedral geometry and is coordinated by two Cl-anions and four pyridyl-N atoms from four NIT4Py ligands.The magnetic measurements show weak antiferromagnetic interactions between the nitroxide radicals.

Synthesis,Crystal Structure and Magnetic Behavior of a Novel Cd(Ⅱ) Complex with Four Nitroxide Radicals

A novel diamagnetic-metal Cd（Ⅱ） complex with four nitroxide radicals[Cd（IM4Py）4Cl2]（IM4Py=2-（4＇-pyridinyl）-4,4,5,5-tetramethylimidazoline-1-oxyl） was synthesized and characterized by elemental analyses,IR spectra,UV-Vis spectra and X-ray single crystal diffraction.The complex crystallized in triclinic space group P1 with a=0.93285（14） nm,b=1.16827（18） nm,c=1.3660（2） nm,α=112.759（2）°,β=104.524（2）°,γ=92.008（3）°,V= 1.3143（3） nm3,Z=1,Dc=1.335 g/cm3,the final R1=0.0423 and wR2=0.1009.In the title complex,each Cd（Ⅱ） ion adopting a distorted octahedral geometry is coordinated by two Cl-anions and four pyridyl-N atoms from four IM4Py ligands.The magnetic measurements show the weak antiferromagnetic interactions between the nitroxide radicals.

Bis-radicals (nitronyl nitroxide and imino nitroxide) Substituted Benzene with Long Alkyl Chain: Synthesis, Magnetic Study and Formation of LB film

The titled compound 1 as well as compounds 2 and 3 with similar chemical structures were prepared and characterized. The magnetic properties of 1 were investigated with SQUID (MPMS, quantum design) magnetometer. Studies with Langmuir-Blodgett (LB) technique indicated that stable condensed film of 1 could be formed at air-water interface and could be transferred onto various solid substrate under suitable conditions.

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（NITPhlM）2] （Ln = Nd （1）, Eu （2）, Tb （3）, Er （4）; hfac = hexafluoroacetylacetonate; NITPhlM = 2-[4-（1-imidazole）phenyl]-4,4,5,5-tetramethylimidazoline-l-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 coor- dination of their nitronyl nitroxide groups and imidazole rings. Interestingly, each Ln ion is either bound to two nitronyl ni- troxide 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.

Exchange Interaction of a Novel Heterospin Polynuclear Complex Containing Transition Metals and Imino Nitroxide Radicals: {[(CuL)Ni(IM-2Py)_2](ClO_4)_2}_2·2H_2O

A novel heterospin complex {[(CuL)Ni(IM 2Py) 2](ClO 4) 2} 2·2H 2O (L=2,3 dioxo 5,6:14,15 dibenzo 1,4,8,12 tetraazacyclo pentadeca 7,12 diene, IM 2Py=2 (2′ pyridyl) 4,4,5,5 tetra^methyl 4,5 dihydro 1 H imidazoline 1 oxyl) has been synthesized and its crystal structure was determined by X ray diffraction analysis. In order to interpret the exchange interaction of this asymmetric heterospin system, a theoretical model has been established. Using this theoretical model the magnetic susceptibility data have been fitted and lead to coupling constant values equal to 1 4 cm -1 (Ni Rad) and -38 0 cm -1 (Ni Cu), respectively.

Halogen Bonding or Hydrogen Bonding between 2,2,6,6-Tetramethyl- piperidine-noxyl Radical and Trihalomethanes CHX3 （X=CI, Br, I）

The halogen and hydrogen bonding complexes and trihalomethanes （CHX3, X=C1, Br, I） are between 2,2,6,6-tetramethylpiperidine-noxyl simulated by computational quantum chem- istry. The molecular electrostatic potentials, geometrical parameters and interaction energy of halogen and hydrogen bonding complexes combined with natural bond orbital analysis are obtained. The results indicate that both halogen and hydrogen bonding interactions obey the order CI〈Br〈I, and hydrogen bonding is stronger than the corresponding halogen bond- ing. So, hydrogen bonding complexes should be dominant in trihalomethanes. However, it is possible that halogen bonding complex is competitive, even preponderant, in triiodomethane due to the similar interaction energy. This work might provide useful information on specific solvent effects as well as for understanding the mechanism of nitroxide radicals as a bioprobe to interact with the halogenated compounds in biological and biochemical fields.

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.

Synthesis, Crystal Structure and Magnetic Properties of a Novel Azide-bridged Copper(Ⅱ) Coordination Polymers Containing Nitroxy Nitroxide

A novel azide-bridged copper（Ⅱ） coordination polymer, [Cu3（NITpPy）4（N3）6]n （NITpPy = 4-pyridyl-4,4,5,5-tetramethylimidazline-3-oxide-1-oxyl）, was structurally and magnetically characterized. It crystallizes in the triclinic space group P with a = 7.6932（10）, b = 14.5556（19）, c = 16.122（2） , α = 108.443（2）, β = 95.251（2）, γ = 104.236（2）°, V = 1631.7（4） 3, C48H64Cu3N30O8, Mr = 1379.87, Z = 1, Dc = 1.404 g/cm3, μ（MoKα） = 1.041 mm-1, F（000） = 713, the R = 0.0510 and wR = 0.1185 for 4285 observed reflections with I 2σ（I）. X-ray analysis reveals that the Cu（Ⅱ） ions are linked by nitrogen atom of μ1,1 azido ligands to form a Cu-Cu-Cu unit. The units are linked by μ1,3 azido ligands through a bridging style to form a one-dimensional coordination polymer. The variable-temperature magnetic susceptibility data of the complex show ferromagnetic interactions in the complex.

Synthesis and Crystal Structure of a New Zn(II) Nitronyl Nitroxide Complex [Zn(NIT4Py)(PDA)(H_2O)_3]

A new Zn（Ⅱ） nitronyl nitroxide complex [Zn（NIT4Py）（PDA）（HzO）3] （NIT4Py = 2-（4＇-pyridyl）-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, H2PDA = pyridine-2,5-dicarboxylic acid） has been synthesized and structurally characterized by X-ray diffraction. It crystallizes in monoclinic, space group P2 1/c with a = 16.881（8）, b = 7.356（4）, c = 18.857（9） A°,β = 108.616（6）°, V = 2219.1 （19）A°^3 ,C 19H25N4O9Zn, Mr = 518.80, Dc = 1.553 g/cm^3, μ（MoKa） = 1.165 mm^-1, F（000） = 1076, Z = 4, the final R = 0.0269 and wR = 0.0715 for 3193 observed reflections with I 〉 2σ（I）. The complex exists as discrete mononuclear molecules and the zinc（Ⅱ） ion is six-coordinated with one radical ligand （NIT4Py）, one bidentate pyridine-2,5-dicarboxylate anion and three water molecules. A three-dimensional network structure is formed through the intermolecular interactions.