SYNTHESIS AND CHARACTERIZATION OF Co(Ⅱ) COMPLEX OF 14-MEMBERED HEXAAZA MACROCYCLIC LIGAND WITH AXIALLY COORDINATED BROMIDES

The macrocyclic ligand complex, [Co(C_(18)H_(18)N_6) Br_2]·1/2H_2O, has been synthesized by the template condensation of 2, 6-diacetylpyridine with hydrazine in the presence of cobalt (Ⅱ) dibromide and characterized by IR, ESR, electronic spectra and magnetic properties. Based on these data, the complex is proposed to be an approximate elongated octahedron with low spin state. The absorption bands of d-d transition are assigned, and the values of various ligand field parameters have been evaluated and are discussed in terms of their chemical utilities. ESR study on the complex has been carried out. The values of g(?)and g(?) have been determined. From ligand field parameter values and gvalues, μ_(eff)=2.06 BM has been obtained, which is consistent with the experimental value(2.04BM).     

N-乙基-1，10-菲罗啉-2-甲胺镍(Ⅱ)配合物的合成、晶体结构及性质研究(英)

A novel ligand N-ethyl-1,10-phenanthroline-2-methanamine and its Ni(Ⅱ) complex have been synthesized. The crystal structure of the complex has been determined by X-ray diffraction method. The Ni(Ⅱ) is five-coordinated by three nitrogen atoms from the ligand and two Cl^- anions in a distorted trigonal bipyramidal environment: the N(2), Cl(1) and Cl(2) in equatorial plane; the N(1) and N(3) in axial positions. The UV-spectra and IR-spectra of the ligand and its Ni(Ⅱ) complex were recorded and discussed. The thermodynamic properties of the ligand with various bivalent metals were studied by potentiometric titrations and the order of the stability constants is in agreement with the Irving-Williams order in coordination chemistry. CCDC: 221750.     

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.     

LIGAND FIELD PARAMETERS OF Nd~(3+) IN LASER CRYSTALS OF LiNdP_4O_(12)

A ligand—field calculation has been performed on laser crystal LiNdP_4O_(12) with C_(2v) point group. The parameters of ligand field of this crystal is obtained and discussed. The calculated Stark sublevels are in good agreement with the enperimental values within 6.7 cm~(-1).     

Cobalt(II)/manganese(II)-based molecular metamagnets

This mini-review covers recent progress in the field of cobalt(Ⅱ)/manganese(Ⅱ)-based molecular metamagnets, which can undergo magnetic phase transitions to a state with a net magnetic moment under the stimulation of external field. We simply discuss mean field theory describing these compounds and the important role of the magnetic anisotropy. The experimental properties of the known Co(Ⅱ)/Mn(Ⅱ) metamagnets are discussed, with emphasis on the variety of means by which the metamagnetic transitions have been observed and studied.     

Structure of [Co(im)_6]SiF_6:Short Hydrogen Bonds Involving SiF_6~(2-) Ions

A new complex C_(18)H_(24)CoF_6N_(12)Si has been synthesized by the reaction of cobalt(II) fluoride tetrahydrate with imidazole in a glass vessel. SiF_6~(2-)was generated by in situ reaction of fluoride on silica. This complex has been characterized by different techniques such as elemental analysis, IR studies, magnetic measurements, electronic absorption measurements and single-crystal X-ray structure determination. The crystals are hexagonal in the R-3 space group, with a = 13.225(6), b = 13.225(6), c = 12.517(11) ?, and g = 120°. In complex [Co(im)_6]SiF_6, the cobalt atom is six-coordinated to adopt a regular octahedral geometry and the SiF_6~(2-)ion acts as the counter anion. The crystal displays a network structure and SiF_6~(2-) bridging hexagram formation by N-(39)···F-Si interactions between imdazole and SiF_6~(2-). SiF_6~(2-)plays an important role in assembling the supramolecular aggregates.     

Synthesis, Thermal, Electrical and Catalytic Studies of Some Transition Metal Polychelates of Bis-bidentate Schiff Base

Polychelates of Mn（Ⅱ）, Fe（Ⅱ）, Co（Ⅱ）, Ni（Ⅱ）, Cu（Ⅱ）, Zn（Ⅱ） and Cd（Ⅱ） with the bis salen-type ligand derived from 4,4＇-bis[（salicylaldehyde-5）azo]biphenyl and 1,4-diaminobutane have been synthesized. All the polychelalls have been characllrized by elemental analysis, magnetic susceptibility measurements, IR, electronic spectra and thennogravirncuic studies. All the complexes isolated in solid stall are dark coloured and insoluble in water and common organic solvents. The ligand behaves as a bis-bidentall molecule coordinating through the phenolic oxygen and azomethine nitrogen atoms. The thermal decomposition of these metal complexes was investigated by thermogravimetric analysis and data have been analyzed for kinetic parameters using Broido equation. The solid-state electrical conductivity of the ligand and its polychelalls in the form of compressed pellet was studied in the temperaturc range from 313 to 413 K All the polychelalls were found to show semiconducting nature. The Mn（Ⅱ）, Fe（Ⅱ）, Co（Ⅱ） and Ni（Ⅱ） polychelalls have been assessed for the catalytic epoxidation of styrene.     

PMBP缩1-萘胺合钴(Ⅱ)配合物的合成和晶体结构

Using 4-[(1-naphthylamino)phenylmethylene]-5-methyl-2-phenyl-2H-pyrazol-3(4H) one (L), its Co(Ⅱ) complex was synthesized and characterized by IR and UV in which the ligand as a -1 valence bidentate with Co(Ⅱ) form 2∶1 complex. X-ray structure analysis indicates that the Co(Ⅱ) ion is coordinated with oxygen atoms of pyrazolinon, nitrogen atoms of imine and oxygen atoms of DMF molecules to form a distorted six-coordination octahedron. π-π reciprocity and aromatic stack interaction are observed. There are no intra- and inter- hydrogen bond in the crystal and the complexes are held together by electronic and Van der Waals forces.     

10种2-[(N-取代芳胺基)羰基]苯甲酸与Cr(Ⅲ)的配合物研究

Complexes of Cr(Ⅲ) with ten of substituted phthalanilic acids have been prepared and characterized by the basis of elemental analysis, infrared and electronic spectra and magnetic susceptibility. The ligand field parameters, e.g. 10Dq, LFSE, B, β, λ, g-have been evaluated from the spectral and magnetic data for all the complexes. The results show that coordination occurs though two oxygen atoms in amido and hydroxy of carboxylates and the complexes have octahedral structure.     

Microwave Synthesis, Characterization and DNA-binding Properties of a New Cobalt（ Ⅱ ） Complex with 2,6-Bis（benzimidazol-2-yl）pyridine

A new cobalt(Ⅱ) complex with tridentate ligand 2, 6-bis (benzimidazol-2-yl)pyridine has been synthesized by microwave irradiation method and characterized by elemental analysis,electrochemical and spectral methods. The binding of the complex with calf thymus DNA has also been investigated by absorption and fluorescence spectra.     

Thermodynamic Stability Research of Metal Complexes with a Tripodal Amide Ligand and Crystal Structure of its Cobalt（Ⅲ） Complex

A new Co（Ⅲ） complex with a tripodal amide ligand [CoL（N3）3] （L = N-acetyl- N＇,N＇-bis-[（2-pyridyl）methyl]-ethylenediamine） has been synthesized and characterized structurally by X-ray diffraction. It crystallizes in orthorhombic, space group Pnma with a = 9.2515（19）, b = 12.729（3）, c = 17.273（4） A, V = 2034.0（7） A3, C16H20CoN13O, Mr = 469.38, Dc = 1.533 g/cm3, μ（MoKα） = 0.884 mm^-1, F（000） = 968, Z = 4, the final R = 0.0392 and wR = 0.0818 for 2430 observed reflections. In the complex, the amide ligand L acts as a tridentate fashion and coordinates to the Co（Ⅲ） ion through three nitrogen atoms, while the other three positions of the Co（Ⅲ） center are occupied by three terminal azide anions. The complex is connected as a 1D chain structure by intermolecular hydrogen bonds between the uncoordinated amide groups. In order to investigate the coordination ability, thermodynamic stability of the ligand L with the first-series transition metal ions （Co（Ⅱ）, Ni（Ⅱ）, Cu（Ⅱ） and Zn（Ⅱ）） has been studied by potentiometric titration, and the results show that the order of their stability constants conforms to the Irving-Williams sequence.     

A Novel Cobalt（Ⅲ） Complex with Macrocyclic Triamine Ligand for High Capacity Hydrogen Adsorption

The coordination complex of Co(Ⅲ) based on a macrocyclic triamine ligand 1,4-diacetate-1,4,7-triazacyclodecane (L) has been synthesized and characterized. The metal cation is bonded with three nitrogen atoms and two oxygen atoms of L and one chloride ion to form a distorted octahedral geometry. This complex coordinated with macrocyclic ligand possesses large pore volume that will be contributed to observe high H2 adsorption. With respect to the first-principles electronic structure calculations, the feasibility to store hydrogen in the complex is explored. Indeed, the complex has shown a very high total H2 adsorption of 7.2 wt% (wt% = (weight of adsorbed H2)/(weight of host material)), with a binding energy of 0.03 eV/H2.     

Synthesis and Characterization of a New Symmetric Dinucleating Ligand and Its Dizinc(Ⅱ)Complex with Alkoxo and Carboxylate Bridges

<正>A novel dinuclear zinc(Ⅱ)complex[Zn_2L(μ-OAc)](PF_6)_2(CH_3OH)has been synthesized from a new symmetrical compartmental ligand HL in which the pendant arms,bearing pyridyl groups,are bridged by 1,3-diaminopropan-2-ol.X-ray crystal structure shows that the two zinc atoms reside within the adjacent ligand compartments and are bridged by the endogenous alkoxo-O from ligand and one exogenous carboxylate from acetate with a syn-syn mode.The coordination geometry of two zinc atoms is a distorted trigonal bipyramid with the pyridyl-N atoms and bridging alkoxo-O atom providing the equatorial donor set.Such coordination geometry observed in this complex is similar to that found in the dinuclear unit of phospholipase C.     

Synthesis,Crystal Structure,Fluorescent Property and DFT Study of a Novel 1D Polymer [Zn(HMICD)(bpy)]_n·2nH_2O

A new one-dimensional(1D) polymer, [Zn(HMIDC)(bpy)]_n·2n H_2O(1, H_3MIDC = 2-methyl-imidazole-4,5-dicarboxylic acid, bpy = 2,2?-bipyridine), has been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, UV-vis spectrum and fluorescence measurements. Complex 1 crystallizes in orthorhombic system, space group Pbca with a = 14.404(3), b = 8.6900(17), c = 26.570(5) ?, V = 3325.8(11) ?~3, Dc = 1.700 g/cm~3, M_r = 425.70, Z = 8, F(000) = 1744, μ = 1.522 mm~(-1), the final R = 0.0421 and w R = 0.1018. The Zn(Ⅱ) ion is six-coordinated by O and N atoms from one HMIDC ligand, two O atoms from another HMIDC ligand and two N atoms from the bpy ligand. The HMIDC anion, which acts as a tetradentate ligand, chelates two Zn ions to form a one-dimensional(1D) zigzag chain structure. We analyzed the electronic structure and orbital energies of complex 1 by DFT methods, and the results are consistent with the UV-vis spectrum. And we also discussed the luminescent mechanism of complex 1 in detail.     

Syntheses,Crystal Structures and Fluorescence Properties of Two Complexes Based on a New Chiral Ligand

A new homochiral ligand,(R)-2-(4-pyridyl)-4,5-dihydrothiazole-4-carboxylic acid(HL~R), has been synthesized. Two complexes, [ZnL_2~R(H_2O)_2]?H_2O(1) and [MnL_2~R(H_2O)_2]?H_2O(2) have been prepared by the reactions of Zn(Ⅱ) and Mn(Ⅱ) ions with the ligand HLR, and characterized by single-crystal X-ray diffraction analysis and fluorescence. Complexes 1 and 2 are isomorphs, and both of the Zn(Ⅱ) and Mn(Ⅱ) centers in 1 and 2 are six-coordinated by the two NO units of two ligands and two water oxygen atoms, showing distorted octahedral coordination geometry. Complexes 1 and 2 show fluorescent properties in the solid state at room temperature.     

Calculation of ligand-field and Stark sub-levels in laser crystals Nd~(3+):KY(WO_4)_2 and Nd~(3+):KGd(WO_4)_2

The parameters of ligand field of laser crystal Na~(3+):KY(WO_4)_2 and Nd~(3+):KGd(WO_4)_2are obtained by a scheme which involved intermediate coupling and ligand field interaction.Thecalculated Stark-levels are in good agreement with the experimental values.     

Investigation of the Spin Crossover Complex [Fe（bapbpy）（NCS）_2 ] in Its Low-spin and Highspin State by DFT/TD-DFT/BS-DFT Calculations

The spin crossover（SCO） compound [Fe（bapbpy）（NCS）2],where bapbpy contains two fused N,N-bis（2-pyridyl）amines,has been studied by DFT/TD-DFT/BS-DFT methods.Several density functionals and basis sets were used in the calculation to obtain optimized geometries of the compound in the low-（LS） and high-spin（HS） states.The vibrational modes and IR spectra,spin splitting energies,excited states and UV/Vis absorption spectra were obtained.The structural parameters of the calculated isolated complex are in good agreement with the X-ray data.We investigate three dimers of [Fe（bapbpy）（NCS）2] complex for their magnetic properties.It has been found that the complex（1,3） has ferromagnetic character while the others are antiferromagnetic in nature by using a broken symmetry approach in the DFT framework（BS-DFT） with support from the coupling constant values（J） and spin density plots.     

Synthesis and Structure of a Novel Copper（Ⅱ） Dinuclear Complex with 4,4′-Dipyridyl as the Bridge

With N,N′-bis(benzimidazol-2-methyl)amine as the ligand,a novel Cu(Ⅱ) dinuclear complex was synthesized as a mimetic compound of superoxide dismutase(SOD).The complex was characterized with element analysis,UV and IR spectra.The crystal structure was determined by using X-ray diffraction analysis.the crystal structure shows that Cu(Ⅱ) and its coordinated atoms construct distorted octahedron configuration with oxygen atome of (ClO4-)s in the axial directions.The coordinated cations are linked by (ClO4-)s to form nonplanar sheets.All sheets are linked together into three-dimensional network by the intermolecular hydrogen bonds.The result of the activity assay indicates that the complex does have certain biological activity.     

Novel Monomeric Phenanthroline—Thallium（Ⅲ） Complexes Multinuclear NMR Characterization in Organic Solvents

A novel complex of monomeric thallium (Ⅲ） with the nitrogen donor ligand phenanthroline (phen) has been prepared and characterized by multimuclear NMR(^1H,^13C,^205Tl). The three complexes exist in equilibria in DMSO and acetonitrile solution, which was proved by the ^205Tl NMR spectra. The ^1H and ^13C NMR spectra of tris-phen T1(Ⅲ） complex have been measured, where the spin-spin coupling between T1(I=1/2) and ^13C or ^1H signals were observed with the ^1H and ^13C NMR spectroscopy in acetonitrile. The coupling constants are presented and the chemical shifts of complexes are discussed in detail.     

ANALYSIS OF FRAGMENT INTERACTION AND ASSIGNMENT OF ELECTRONIC SPECTRUM FOR COMPLEX ION[S2MoS2FeCl2]^2—

<正> The electronic structures of complex ion [S2MoS2FeCl2]2- (1) and its fragments MoS42- (2) and FcCl2(3) have been calculated base on the LCAO-HFS method with restricted open shell or closed shell. The interaction between the fragments 3 and 2 and the formation of complex ion 1 have been discussed. It was found that the Fe(Ⅱ) donated electrons to the Mo(Ⅵ)and accepted electrons from the sulphur ligand and that the stability of complex ion 1 is contributed from both direct and indirect interactions through the bridging sulphur atoms. In addtion, the electron transition energies of complex ion 1 were calculated and its electronic absorptions were assigned. It was shown that the calculated wavelengths of the absorption bands are in agreement with the observed ones.