Synthesis,Crystal Structure and Magnetic Behavior of a New Manganese(Ⅱ) Coordination Polymer [Mn(DPPZ)(PZDC)(H_2O)] (DPPZ=Dipyrido[3,2-a:2',3'-c]-phenazine and H_2PZDC=Pyrazine-2,3-dicarboxylic Acid)

The title complex, [Mn（DPPZ）（PZDC）（H2O）] 1 （DPPZ = dipyrido[3,2 -a：2＇,3＇- c]phenazine and H2PZDC = pyrazine-2,3-dicarboxylic acid）, has been hydrothermally synthesized and structurally characterized by X-ray single-crystal diffraction, elemental analyses, IR, TG- DTA and magnetic susceptibility measurement. It crystallizes in triclinic, space group P1^- with a = 6.6842（5）, b = 7.5741（6）, c = 20.5755（15）A, α = 90.1160（10）, β = 97.0560（10）, γ = 97.3350（10）°, V= 1025.16（13）A^3, Z = 2, MnC24H14N6O5, Mr= 521.35, Dc= 1.689 g/cm^3, F（000） = 530, μ（MoKa） = 0.699 mm^-1, R = 0.0366 and wR = 0.0810. Compound 1 contains one- dimensional chains which are further stacked through π-π interactions to form a 3D supramolecular architecture. The water molecule O（1W） is involved in hydrogen bonding interactions with symmetric carboxylate oxygen atom 0（4） at （x＋ 1, y＋1, z） and symmetric PZDC nitrogen atom N（6） at （1-x, 1-y, 1-z）, which completes the structure of 1. Magnetic susceptibility measurement indicates that the compound behaves a weak antiferromagnetic exchange interaction.

Hydrothermal Synthesis, Crystal Structure and Thermal Analyses of Pyrazine-2,3-dicarboxylic Acid Bridged Co(II) Coordination Polymer of _∞~2[Co(phen)(μ-L)_(3/3)]·H_2O (H_2L = Pyrazine-2,3-dicarboxylic Acid)

A novel pyrazine-2,3-dicarboxylic acid bridged Co(II) phen complex 2 ∞ [Co- (phen)(μ-L)3/3]?H2O (H2L = pyrazine-2,3-dicarboxylic acid) has been hydrothermally synthesized, and X-ray single-crystal diffraction analysis shows that it crystallizes in the monoclinic system, space group P21/n with a = 11.480(2), b = 11.885(2), c = 12.939(3) ?, β = 110.55(3)°, V = 1653.1(6) ?3, Mr = 423.25, Dc = 0.425 g/cm3, Z = 4, R = 0.0361 and wR = 0.1011. The title complex consists of 2D 2 ∞ [Co(phen)(μ-L)3/3] layers and crystal water molecules. Each Co atom is octahedrally coordinated by three N atoms and three O atoms to form 2D 2 ∞ [Co(phen)(μ-L)3/3] polymeric layers. Furthermore, such 2D layers are stacked into 3D supramolecular frameworks via Van der Waals’ intermolecular forces, strong and weak hydrogen-bond interactions. The coordination phen and crystal water molecules are resided into cavities of the frameworks.

Synthesis,Crystal Structure and Theoretical Calculations of a Zinc(Ⅱ) Coordination Polymer Assembled by Pyrazine-2,3-dicarboxylic Acid and Bis(imidazol) Ligands

A new metal-organic coordination polymer [Zn（pzdc）（mbix）]n·nH2O（H2pzdc = pyrazine-2,3- dicarboxylic acid, mbix = 1,3-bis（imidazol-1-ylmethyl）-benzene） 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. Yellow crystals crystallize in monoclinic system, space group P21/n with a = 8.5519（6）, b = 14.8764（10）, c = 16.4108（11） A, β = 103.4520（10）o, V = 2030.5（2）A^3, C（20）H（18）N6O5Zn, Mr = 487.77, Dc = 1.596 g/cm^3, F（000） = 1000, Z = 4, μ（MoK α） = 1.257 mm^-1, the final R = 0.0260 and w R = 0.0706 for 3445 observed reflections（I 〉 2σ（I））. The structure of 1 exhibits a one-dimensional chain-like structure. In addition, natural bond orbital（NBO） analysis was performed by the PBE0/LANL2DZ method in Gaussian 03 Program. The calculation results show obvious covalent interaction between the coordinated atoms and Zn（Ⅱ） ion.

A Benzimidazole-pyridine-2,3-dicarboxylic Acid Bridged Zinc(Ⅱ)Coordination Complex–crystal Structure,Quantum Chemistry and Luminescence

The structure of a zinc（Ⅱ） coordination complex（1）, [C14 H10 N3 O5 Zn1.5]n or [Zn1.5（bzim）（pydc）（H2 O）]n（H2 pydc = pyridine-2,3-dicarboxylic acid, Hbzim = benzimidazole）, has been determined by X-ray crystallography and characterized by elemental analysis, IR spectrum and luminescence. Chemical formula： C14 H10 N3 O5 Zn1.5. It crystallizes in the monoclinic system, space group P21/c with a = 12.303（4）, b = 12.052（4）, c = 10.212（3） ？, β = 104.147（4）, V = 1468.3（8） ？3, Z = 4, Mr = 398.30, Dc = 1.802 g/cm3, F（000） = 800, μ = 2.501 mm-1 and S = 1.000. The 2-D network architecture of 1 is constructed from benzimidazole, zinc and pyridine-2,3-dicarboxylic acid. The quantum-chemical calculations have been performed on ‘molecular fragments’ extracted from the crystal structure using the B3 LYP method in Gaussian 09. The luminescence spectrum shows that complex 1 emits blue luminescence.

Hydrothermal Synthesis and Crystal Structure of a Coordinated Polymer: [Ni(pda)(H_2O)_3]_n (pda =Pyridine-2,3-dicarboxylate)

The coordinated polymer [Ni（pda）（H2O）3]n 1 （pda = pyridine-2,3-dicarboxylate） with one-dimensional chain structure has been obtained by hydrothermal method. Its structure was determined by X-ray crystallography with the following data： monoclinic, space group P21/c, a = 6.4153（4）, b = 21.6454（14）, c = 7.3783（5） A, β = 113.079（1）°, V = 942.56（11） A^3, Z = 4, C7H9NNiO7, Mr = 27.7.86, Dc = 1.958 g/cm^3,F（000） = 568 and μ（MoKa） = 2.081 mm^-1. The final R = 0.0194 and wR = 0.0515 for 1511 observed reflections with I 〉 2σ（I）. The title complex presents an infinite 1-D polymeric chain structure consisting of repeated basic units [Ni（pda）（H2O）3]n. The center Ni（Ⅱ） ions are coordinated by one nitrogen atom and three oxygen atoms from pda ligand as well as three H2O molecules in a slightly distorted octahedral environment. The intermolecular hydrogen bonds link the 1 D chains to form a 2D layered architecture.

Hydrothermal Synthesis and Crystal Structure of a New Three-dimensional Co(Ⅱ) Coordination Polymer Based on 2,3-Thiophenedicarboxylic Acid

A new Co（ll） polymer [Co（tdc）（l,4-bimb）]n 1 （H2tdc = thiophene-2,3-dicarboxy- lic acid, 1,4-bimb -- 1,4-bis（imidazol-1 ＇-yl）butane） was synthesized under hydrothermal conditions The compound crystallizes in the monoclinic system, space group C2/c with a = 15.643（9）, b = 8.839（5）, c=12.952（7） A, β = 105.964（6）°, V= 1721.8（16） A3, Z = 4, Mr = 419.32, Dc= 1.618 Mg/m3,μ = 1.149 mm-1, F（000） = 860, the final R = 0.0243 and wR =0.0613 for 1460 observed reflections with I 〉 2σ（I）. The compound presents a three-dimensional （3D） network extended by both tdc2- anions and 1,4-bimb ligands in which the tdc2- anions employ a chelating coordination mode. From the topology point of view, the structure could be described as a 3D 4-connected 65.8 CdSO4-type net. Infrared spectroscopy, elemental analyses, thermogravimetric analysis and powder X-ray diffraction properties of 1 are also investigated.

Improved Synthesis and Structure of 3-Carboxy-2-pyrazinecarbohydroxamic Acid

3-Carboxy-2-pyrazinehydroxamic acid was prepared by a one pot reaction starting from pyrazine-2,3-dicarboxylic anhydride with a high yield, and characterized by IR, Mass spectrum, 1H NMR and 13C NMR spectra and single-crystal X-ray diffraction. It crystallizes in triclinic, space group Pī with a=4.8659（10）, b=7.4233（15）, c=11.602（2）, α=96.904（2）, β=92.422（3）, γ=107.454（2）°, V=395.51（14）3 , Z=2, Dc=1.689g/cm3 , F（000）=208, μ（MoKα）=0.149 mm-1 , the final R=0.0473 and wR=0.1306 for 2853 observed reflections （I〉2σ （I））. A three-dimensional framework was assembled through intermolecular hydrogen bonding between water and 3-carboxy-2-pyrazine-carbohydroxamic acid molecules.

Synthesis,Structure and Photoluminescence of a New Cadmium(Ⅱ) Complex Involving in situ Decarboxylation

A new luminescent dinuclear cluster complex [Cd2（pzc）2（AmTAZ）（HEO）4（NO3）]·NO3 （Hpzc = pyrazine-2-carboxylic acid, AmTAZ = 3-amino-4H-1,2,4-triazole） has been prepared by the assembly of Cdn with pyrazine-2,3-dicarboxylic acid and 3-amino-lH-1,2,4-triazole-5-car- boxylic acid ligands under hydrothermal conditions, in which in situ decarboxylation of H2pzdc and HAmTZC ligands simultaneously occurred, and HEpzdc was transformed into Hpzc while HAmTZC into AmTAZ. The crystal structure is of triclinic, space group P1 with a = 7.096（2）, b = 11.140（4）, c = 14.887（5）А, α= 92.641（4）, β= 91.348（6）, γ= 96.058（6）°, V = 1168.5（7）А^3, C12H18Cd2N10O14, Mr = 751.16, Z = 2, Dc = 2.126 g/cm^3, F（000） = 730,μ=1.910 mm^-1, R = 0.0320 and wR = 0.0998 for 4549 observed reflections （I 〉 2σ（I））. The dinuclear cluster of 1 is extended into a 3D supramolecular architecture through intermolecular hydrogen bonding interactions. Complex I exhibits strong blue photoluminescence at room temperature.

Syntheses,Structures,Luminescent Properties and Photocatalytic Activities of Two Lead(Ⅱ)Compounds

Two lead（ll） compounds, [Pb（qlc）（phen）2（NO3）]e-H20 （1） and [Pb（qlc）z（phen）]-3H20 （2） （Hqlc = quinoline-3-carboxylic acid, phen = 1,10-phenanthroline）, were synthesized and charac- terized by elemental analysis, single-crystal X-ray diffraction, IR and thermogravimetric analysis. Crystal 1 is of monoclinic, space group C2/c with a = 25.246（5）, b = 12.543（3）, c = 18.917（4） A, β = 105.77（3）°, V= 5765（2） A3, Z = 4, C68H46N12OllPb2, Mr = 1621.53, Dc = 1.886 g.cm-3,/.t（MoKa） = 5.912 mm-1, F（000） = 3152, GOOF = 1.080, the final R = 0.022 and wR = 0.0571 for 4822 observed reflections （1 〉 2a（/））. Crystal 2 is oftriclinic, space group Pi with a = 8.7883（10）, b = 11.7031 （13）, c = 15.9320（17） A, a = 69.9400（10）, fl = 78.9780（10）, 7 = 79.1650（10）°, V = 1497.4（3） A3, Z = 2, C32H26NaO7Pb, Mr. = 785.71, Dc = 1.729 g.cm-s, p（MoKa） = 5.688 mm-1, F（000） = 756, GOOF = 1.106, the final R = 0.0313 and wR = 0.088 for 59i5 observed reflections （1 〉 2σ（I））. Single-crystal X-ray diffraction analysis reveals that 1 exhibits a two-dimensional （2D） layer based on π-π stacking interactions between phen. Simultaneously, the adjacent 2D layers are assembled via π-π stacking interactions between phen and quinoline tings into a 3D supramolecular structure. The zero- dimensional structure of 2 is also further extended by π-π interactions to form a 2D supramolecular layer. Furthermore, these two compounds exhibit photoluminescence at room temperature in the solid state and their photocatalytic activities have been studied by degradation methylene blue.