Syntheses, Structural Characterization of Fe and Ni Complexes with Polypyrazolyl Borate Ligand: Fe[HB(pz)_3]_2 and Ni[HB(pz)_3]_2

Fe(Ⅱ) complex Fe[HB(pz)_3]_2(compound 1, pz=pyrazole) and Ni(Ⅱ) complex Ni[HB(pz)_3]_2(compound 2) have been obtained by the reaction of MCI_2(M=Fe and Ni) with NaHB(pz)_3 in MeOH. The two complexes(compounds 1 and 2) were characterized by IR, NMR, elemental analysis and X-ray diffraction. Compound 1 crystallizes in space group P2_1/c with a=1.224(3) nm, b=1.161(2) nm, c=1.648(3) nm, β=107.62(15)°, V=2.233(8) nm3, Z=2. Compound 2 crystallizes in space group P2_1/c with a=0.97926(18) nm, b= 1.7423(3) nm, c=1.3156(2) nm, β=97.055(16)°, V=2.2277(7) nm3, Z=4. The results of X-ray structural analyses show that both compounds 1 and 2 are monomeric neutral, possessing a similar coordination mode and a similar structure around the metal centers. The related spectral characterizations, steric effects and binding properties are discussed.

Synthesis of Branched Polyethylene via Bulky α-Diimine Nickel(II)-Catalyzed Ethylene Chain-Walking Polymerization

The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, which contains both dibenzhydryl and phenyl groups, was determined by X-ray crystallography. The compound has a pseudo-tetrahedral geometry at the Ni center, showing pseudo-C2-symmetry. Upon activation with modified methylaluminoxane (MMAO), Ni1 exhibits high catalytic activity up to 1.02 × 107 g PE (mol Ni h)−1 toward ethylene polymerization, enabling the synthesis of high molecular weight branched polyethylene. The molecular weights and branching densities could be tuned over a very wide range. The polymerization results indicated the possibility of precise microstructure control, depending on the polymerization temperature. The branching densities were decreased with increasing the polymerization temperature.

Syntheses and Crystal Structures of One-dimensional Ni(Ⅱ) Complexes with 5-Tert-butyl Isophthalic Acid

Two new Ni（ Ⅱ） coordination polymers, {[Ni（tbip）（bipy）（H2O）]-0.5H2O}n 1 and [Ni（tbip）（phen）（H2O）]n 2 （Hatbip = 5-tert-butyl isophthalic acid, bipy = 2,2＇-bipyridine, phen = 1,10-phenanthroline）, have been synthesized under hydrothermal conditions and characterized by elemental analysis, X-ray diffraction, and IR spectroscopy. In the two polymers, H2tbip acts as a tridentate ligand. Compound 1 has a tbip bridged 1-D linear chain which is extended by hydrogen bonds into a 1-D double chain, while compound 2 exhibits a 1-D zigzag chain.

Syntheses,Crystal Structures and Antibacterial Activities of Schiff Base of Nickel(Ⅱ)and Copper(Ⅱ)Complexes

A new kind of Schiff base HL（HL= 1-phenyl-3-methyl-4-（p-methylbenzoyl）-5-pyrazolone with L-Leucine methyl ester） and complexes Ni L′_2·0.75C_2H_5OH·0.25H_2O,Cu L′′2（L′ = 1-phenyl-3-methyl-4-（p-methylbenzoyl）-5-pyrazolone with L-leucine ethyl,L′′ = 1-phenyl-3-methyl-4-（p-methylbenzoyl）-5-pyrazolone with L-leucine） have been synthesized and structurally determined by X-ray diffraction. For HL： crystal structure determination indicates that there are two independent HLs with different conformations in one asymmetric unit. For complex 1： the Ni（Ⅱ） ion is six-coordinated by two carbonyl oxygen atoms from pyrazolone ring,two nitrogen atoms from different HL′ and two oxygen atoms from L-Leucine ethyl ester to form a distorted octahedral geometry. For complex 2： the Cu（Ⅱ） ion is four-coordinated by one carbonyl oxygen atom from the pyrazolone ring,one nitrogen atom from HL′′,and two different carboxylic oxygen atoms from L-leucine with the same conformation to form a distorted quadrilateral geometry.

Novel Isatin-Schiff Base Cu (II) and Ni(II) Complexes. X-ray Crystal Structure of Bis[3-(4-hexylphenylimino)-1H-indol-2(3H)-one]-dichlorocopper(II) Complex

Schiff base ligand （HL） derived from 4-hexylaniline with isatin （1H-indole-2,3-dione） and its complexes with Cu（Ⅱ）, Ni（Ⅱ） were prepared and characterized by analytical, spectroscopic （IR, UV-Vis, Mass） techniques, electrical conductivity, magnetic and thermal measurements. The crystal and molecular structure of [Cu（HL）2Cl2] was determined by a single-crystal X-ray diffraction study. The molecular structure of the title compound has an inversion center on the Cu atom.

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.

Syntheses and Crystal Structures of Copper(Ⅱ) and Nickel Complexes with 1,2,3-Triazole-carboxylic Acid

Three novel complexes [Cu（L1）2（H2O）2] （1）, [Ni（L1）2（H2O）2]·（H2O）4（2,HL1=5-methyl-1-（4-methylphenyl）-1,2,3-triazole-4-carboxylic acid） and [Ni2 （HL2）2（CH3OH）6]·（CH3OH）2（3,H3L2=1,2,3-triazole-4,5-dicarboxylic acid） were synthesized and characterized by elemental analysis, IR and X-ray diffraction. Complexes 1 and 2 are mononuclear structures, and are assembled into a two-dimensional sheet by C（7） H（7）···O（3） weak interactions or hydrogen-bonding interaction. Complex 3 is a centrosymmetric dinuclear structure, and is assembled into a three-dimensional supramolecular structure by hydrogen-bonding interaction.

Density Functional Theory Calculations on Ni-Ligand Bond Dissociation Enthalpies

The formation and breaking of Ni-L （L=N-heterocyclic carbene, tertiary phosphine etc.） bond is involved in many Ni-catalyzed/mediated reactions. The accurate prediction of Ni-L bond dissociation enthalpies （BDEs） is potentially important to understand these Ni-complex involving reactions. We assess the accuracy of diffierent DFT functionals （such as B3LYP, M06, MPWB1K, etc.） and diffierent basis sets, including both effective core potentials for Ni and the all electron basis sets for all other atoms in predicting the Ni-L BDE values reported recently by Nolan et al. [J. Am. Chem. Soc. 125, 10490 （2003） and Organometallics 27, 3181 （2008）]. It is found that the MPWB1K/LanL2DZ：6-31＋G（d,p）//MPWB1K/LanL2DZ：6-31G（d） method gives the best correlations with the experimental results. Meanwhile, the solvent effect calculations （with CPCM, PCM, and SMD models） indicate that both CPCM and PCM perform well.

Thermodynamic simulation of metal behaviors in Cu_(2+)−Ni_(2+)−NH_(3)−NH_(4)+−C_(2)O_(4)^(2-)−H_(2)O system

To investigate the behaviors of Cu^(2+)and Ni^(2+)with the change of conditions in Cu_(2+)−Ni_(2+)−NH_(3)−NH_(4)+−C_(2)O_(4)^(2-)−H_(2)O reaction system,mathematical models of thermodynamics based on the principle of mass conservation were established.The simulation results indicate that the precipitation of metal ions from the aqueous phase is a complicated dynamic equilibrium process,during which the coordination reactions of Cu^(2+)and Ni^(2+)with NH3 forming[Cu(NH3)n]^(2+)(n=3−5)and[Ni(NH3)m]^(2+)(m=3−6)are predominant under high pH conditions,respectively.The pH ranges for the simultaneous precipitation of Cu^(2+)and Ni^(2+)are 2.0−6.5 and 2.0−5.5 when[NH3]T equals 0.6 and 4.2 mol/L,respectively,with the prefixed[C_(2)O_(4)^(2-)]T of 0.6 mol/L.Due to the fractional precipitation of Cu^(2+)and Ni^(2+),Cu−Ni composite is obtained after the thermal decomposition of Cu−Ni oxalate complex salts prepared in a pure water system when pH>7.0.By applying the mixed solvent(water/ethanol)as the precipitation medium,the Cu−Ni alloy rods can be finally fabricated with high purity and crystallinity.

Synthesis and Structure of L-Aspartato- nickel(II) Complex with Benzimidazole

The title complex Ni(C4H5NO4)(C7H6N2)31.75(H2O) (C25H26.5N7NiO5.75, Mr = 575.74) has been prepared and its crystal structure was determined by X-ray diffraction method. The crystal of this chiral complex belongs to monoclinic, space group P21 with a = 13.208(1), b = 10.741(1), c = 19.398(1) ? b = 104.39(1)o, V = 2665.8(4) 3, Z = 4, Dc = 1.435 g/cm3, m(MoKa) = 0.780 mm-1 and F(000) = 1198. The final R = 0.0504 and wR = 0.1267 for 9159 observed reflections (I > 2s(I)), and R = 0.065 and wR = 0.1299 for 11006 independent reflections. The complex assumes a distorted octa- hedral coordinate geometry formed by one aspartate dianion and three benzimidazole ligands. The aspartate chelates to the Ni atom as a tridentate ligand. The lattice water molecules are hydrogen- bonded to the Ni complex molecule.

Synthesis, Structure and Magnetic Property of One Ni~Ⅱ Based Coordination Polymer

One new coordination polymer, [Ni（m-bix）（m-BDC）]（1, m-bix = 1,3-bis（imidazol-1-ylmethyl）benzene, m-BDC = 1,3-benzenedicarboxylic acids）, has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, TGA and X-ray single-crystal diffraction. The green block crystal of complex 1（C22H18N4Ni O4） belongs to monoclinic system, space group P21/c with a = 10.0418（3）, b = 23.8651（6）, c = 8.7872（2） A, β = 112.333（3）°, V = 1947.88（9）A3, Z = 4, Dc = 1.572 g/cm^3, Mr = 461.11, F（000） = 952, R = 0.0335 and w R = 0.0683 for 2827 observed reflections（I 〉 2σ（I））. Complex 1 exhibits a novel 6-connected 3D sxd type topological framework. The magnetic characterization of complex 1 shows antiferromagnetic coupling exchange.

Synthesis, Crystal Structure and Catalytic Properties of a New 2D Nickel(II) Coordination Polymer Based on Flexible Bis(benzimidazole)

A new Ni(II) coordination polymer [Ni(L)2(SCN)2]n(L = 1,4-bis(benzimidazol-1-yl)butane) was synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group C2/c with a = 9.4760(3), b = 24.0408(8), c = 16.5871(5) A, β = 99.832(3)°, V = 3723.2(2) A3, Z = 4, Dc = 1.348 g/cm3, F(000) = 1576, the final R = 0.0486 and w R = 0.0936 for 2938 observed reflections with I 】 2σ(I) for the complex. Structural analysis shows that the coordination polymer possesses a 2D(4,4) layer structure which is composed of Ni(II) centers bridged by L ligand with two kinds of conformations and further assembled into a 3D supramolecular network via π-π stacking interactions. In addition, the fluorescence and catalytic properties, for the degradation of Congo red, 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.

Structure and Magnetic Properties of a Bipyridine-bridged One-dimensional Ni(Ⅱ) Coordination Polymer

A polymer, [NiL（bipy）·2H2O]n（1, bipy = 4,4ˊ-bipyridine）, has been acquired by the reaction of Ni（OAc）2·4H2O with N,Nˊ-bis（2-hydroxyl-5-fluorobenzyl）-2-hydrxylpropane dii- mine in the presence of 4,4ˊ-bipyridine. X-ray crystallographic analysis shows that it is comprised of a mononuclear Ni（Ⅱ） complex [NiL] linked by 4,4ˊ-bipyridine. Its crystal crystallizes in the orthorhombic system, space group C2/c with a = 22.595（3）, b = 18.395（2）, c = 15.434（2） , V = 6155（1）3, Dc = 1.259 g/cm-3, Z = 8, Mr = 583.23, F（000） = 2416.0, μ（MoKa） = 0.681 mm-1, S = 1.049, R = 0.0512 and wR = 0.1108 for 6032 observed reflections（I 〉 2σ（I））. There are water hexamers in the complex. A weak overall ferromagnetic behavior has been evaluated by Curie-Weiss rule and by the formula of alternating ferro-ferromagnetic coupling in one-dimensional Ni（Ⅱ） chain, which gives g = 2.005（1） and J1 = 0.31（3） cm-1.

Thermal Decomposition Kinetics of Ni(Ⅱ)Complex with Norfloxacin

The thermal decomposition of the 2H2O (NFA=C16H18FN3O3, norfloxacin) and its kinetics were studied under the nonisothermal condition in nitrogen by TGDTG and DTA methods. The intermediate and residue for each decomposition were identified from TG curve. The Achar method and the MadhusudananKrishnanNinan (MKN) method were used to analyze the nonisothermal kinetic data. The possible reaction mechanisms were investigated by comparing the kinetic parameters. The kinetic equation for the third stage and the mathematical expressions for the kinetic compensation effects of the third stage were obtained.

Synthesis and Structure of (Oxydiacetato)-nickel(II) Complex with Diaminobithiazole

The title complex [Ni(C4H4O5)(C6H6N4S2)(H2O)]2.5H2O has been prepared and its crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic, space group P21/n with a = 16.499(2), b = 10.132(1), c = 11.177(2) , b = 109.76(1)o, V = 1758.4(4) 3, Mr = 452.11, Z = 4, Dc = 1.708 g/cm3, m = 1.391 mm-1, F(000) = 932, R = 0.0424 and wR = 0.1088 for 2341 observed reflec- tions (I>2s(I)). The complex assumes a distorted octahedral coordination geometry formed by one oxydiacetate dianion, one diaminobithiazole and one coordinated water molecule. The parallel thiazole rings of adjacent complex molecules overlap to each other, and the separation of 3.458(7) ?suggests the existence of - stacking.

Synthesis, Structure and Antitumor Activities of [Ni(dien)_2] [Ni(CN)_4] Complex

Ni(II)-dien complex was prepared and characterized by X-ray diffraction. The crystal belongs to triclinic system, space group P-1, with crystallographic parametersa=0.888 13(18) nm,b=0.890 10(18) nm,c=1. 591 8(3) nm, α=77.71(3)°, β=89.12(3)°, γ=61.24(3)°,Z=2. The two dien molecules coordinate to the central Ni atom, the six nitrogen atoms form a distorted octahedron. Preliminary pharmacological tests showed this complex had antitumor activity against HepG2 and HL-60 cell linesin vitro. Key words polyamines - Ni(II) complex - crystal structure - antitumor activity CLC number O 626 Foundation item, Supported by the National Natural Science Foundation of China (29972034)Biography: Li Tao (1976-), male, Ph. D candidate, research direction: ophthalmology and chemicalbiology.

Preparation,Characterization and Crystal Structure Determination of a Nickel Complex [Ni(ftsc)_2NO_3]NO_3(Hftsc=Furan-2-carbaldehyde Thiosemicarbazone)

A new Ni（II） complex, [Ni（ftsc）2NO3]NO3 （Hftsc = furan-2-carbaldehyde thiosemicarbazone）, has been synthesized and characterized by IR, UV spectra and single-crystal X-ray diffraction analysis. It crystalfizes in a monoclinic system, space group P2 1/n, with a = 10.5203（13）, b = 9.2094（11）, c = 20.829（3）A,β = 91.518（2）°, V= 2 017.3（5）A^3, Z = 4, F（000） = 1064, Dc = 1.716 g/cm^3, and wR = 0.0800. The complex contains a six-coordinated nickel（II） center which is bound to two imine nitrogen atoms and two thiolato sulfur atoms of two ligands as well as two oxygen atoms from a nitrate anion to assume a distorted octahedral coordination geometry. In addition, intermolecular N-H…O and C-H…O hydrogen bonds between adjacent molecules link the molecules together to form a three-dimensional structure.

Synthesis and Crystal Structure of a Nickel(Ⅱ) Complex [Ni(H_2btc)_2(hmta)_2(H_2O)] with 1,3,5- Benzenetricarboxylate and Hexamethylenetetramine

The title compound, Ni(H2btc)2(hmta)2(H2O) (C30H35N8NiO13), has been syn- thesized by the reaction of Ni(CH3COO)2?H2O, 1,3,5-benzenetricarboxylate and hexame-thylene- tetramine in DMF and characterized by X-ray single-crystal diffraction. It crystallizes in the orthor- hombic system, space group Pccn with a = 20.610(4), b = 12.246(2), c = 12.907(3) ?, V = 3257(1) ?3, Z = 4, Mr = 774.37, F(000) = 1612, Dc = 1.579 g/cm3 and μ(MoKα) = 0.677 mm?1. The structure was refined to the final R = 0.0476 and wR = 0.1115 for 3221 observed reflections (I > 2σ(I)). Ni(II) ion is penta-coordinated with two oxygen atoms of monodentate carboxylate groups from two 1,3,5- benzenetricarboxylates, two nitrogen atoms from two hexamethylenetetramines in the equatorial plane, and one water molecule in the axial position. The coordination geometry of Ni(II) can be described as a nearly ideal square-pyramid. Hydrogen bonds exist between the complex molecules, leading to a two-dimensional structure.