Synthesis and Crystal Structure of N-(2-Pyridylmethyl)-L-Alanine) Isothiocyanate Cobalt(III)

The title compound, [N-(2-pyridylmethyl)-(L)-alanine]Co(III) thiocyanate (1) was obtained from the reaction of Co(OOCH3)2·H2O with the tridentate reduced Schiff base ligand, N-(2-pyridylmethyl)-(L)-alanine (L) and NH4SCN and characterized by elemental analysis, IR, UV-visible, TGA and single- crystal X-ray diffraction. Structural and spectroscopic analyses reveal [Co(L)2)]SCN to be monomeric with Cobalt(III) adopting a pseudo-octahedral geometry, coordinating to two reduce Schiff base ligands. In the crystal lattice, the thiocyanate anion forms an intermolecular SCN···HNamine hydrogen bond, while adjacent monomers are linked by intermolecular Ocarboxyl···HNamine···H-bonds to form a supramolecular network. This work is therefore undertaken in an attempt to construct coordination framework structures of varying properties using the mixed-ligand strategy involving reduced Schiff bases and the thiocyanate ion.

Synthesis and Crystal Structure of a Dinuclear Cobalt(II) Complex [Co_2(1H-benzimidazole)_4(1,4-bdoa)_2]

A novel dinuclear complex with an empirical formula [Co2(1H-benzimidazole)4(1, 4-bdoa)2] (1,4-bdoa2– = benzene-1,4-dioxyacetate dianion) has been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. It crystallizes in monoclinic system, space group P21/c with a = 11.000(2), b = 19.385(4), c = 11.417(2) ?, β = 95.49(3)o, V = 2423.3(8) ?3, Z = 2, Mr = 1074.77, Dc = 1.473 g/cm3, μ = 0.760 mm–1, F(000) = 1108, the final R = 0.0645 and wR = 0.0714 for 3273 observed reflections (I > 2σ(I)). Two octahedrally coordinated Co(II) atoms are bridged by two 1,4-bdoa2– groups, generating a macrocyclic ring complex. The Co…Co separa- tion is 7.677(3) ?. An extended 3-D supramolecular network is formed through hydrogen bonds and weak π-π stacking interactions.

Synthesis and Crystal Structure of Dichlorobis-(1-methylimidazoline-2(3H)-thione-S) Cobalt(II)

The reaction of anhydrous cobalt(II) dichloride with 1-methylimidazoline-2(3H)- thione in dichloromethane solution gave the title complex, [Co(C4H6N2S)2Cl2]. X-ray single-crystal analysis revealed that the complex crystallizes in a monoclinic system, space group P21/c, a = 13.9707(10), b = 10.0435(7), c = 10.3910(6) ?, β = 91.181(3)o, V = 1457.70(17) ?3, Z = 4, C8H12Cl2N4S2Co, Mr = 358.17, Dc = 1.632 g/cm3, μ = 1.813 mm–1, F(000) = 724, the final R = 0.0710 and wR = 0.1224 for 1549 observed reflections with I > 2σ(I). The Co atom is coordinated by two S atoms from two 1-methylimidazoline-2(3H)-thione ligands and two chloride ions in a slightly distorted tetrahedral geometry. The intramolecular classical hydrogen-bonding interactions involving chloride ions and N–H groups of the heterocyclic thione ligands are observed. The offset π-π stacking interactions between the imidazole rings of adjacent molecules with a face-to-face dis- tance of 3.604 ? are found in the packing diagram.

Spectroscopic and molecular structure characterization of the bis(2-aminophenol)(5, 10, 15, 20-tetraphenylporphyrinato) cobalt(II) complex

The reaction of the cobalt(II) meso-tetraphenylporphyrin (TPP) starting material with an excess of 2-aminophenol (Hon) in organic solvents, yields the cobalt(II) porphyrin species [CoII(TPP)(Hon)2] (1). This compound has been characterized by UV-vis., IR, MSI MS and 1H NMR spectroscopy. The UV-vis data and especially the proton NMR results, for the isolated product, indicated that complex 1 is a Co(II) mesoporphyrin derivative.The X-ray molecular structure of the title compound bis(2-aminophenol) (tetraphenylporphyrinato) cobalt(II) has been determined. This structure is the first one reported of a metalloporphyrin with a 2-aminophenol axial ligand species. The central metal is hexacoordinated by the four nitrogen atoms of the pyrrole rings and the nitrogen atoms of the two Hon trans axial ligands.

Highly Efficient Cobalt (II) Catalyzed O-Acylation of Alcohols and Phenols under Solvent-Free Conditions

Solvent free, highly efficient method has been developed using ecofriendly, heterogeneous reusable cobalt chloride catalyst at ambient reaction conditions for the O-acylation of various alcohols and phenols with acetyl chloride in excellent yield in a short reaction time. The catalyst is recycled several times without loss of catalytic activity.

A Novel Mixed Ligand Dinuclear Complex of Cobalt (II): Synthesis, Characterization and Magnetic Studies

A novel dinuclear complex [Co2(atr)3(mal)2(H2O)2]·4H2O(1) (atr = 4-amino-1,2,4-triazole and mal = malonic acid) containing mixed N and O-donor atoms has been prepared and structurally characterized. The structure is made up of the symmetrically 1, 2, 4-triazole bridged [Co2(atr)3(mal)2(H2O)2] moiety and four lattice water molecules. The single crystal X-ray analysis reveals that the complex has a distorted octahedral structure. Magnetic susceptibility measurements reveals that antiferromagnetic interactions exists between the high spin Co(II) ions within the dinuclear unit.

Synthesis, Characterization and Crystal Structure of Cobalt(II) Complex of a Schiff Base Derived from Isoniazid and Pyridine-4-Carboxaldehyde

A new hydrogen bonded Cobalt(II) Schiff base complex,?N’-(pyridine-4-carboxaldehyde) isonicotinoylhydrazone Cobalt(II), has been synthesized from isoniazid and pyridine-4-carboxaldehyde and characterized by IR spectroscopy, 1H-NMR, elemental analysis, TGA and single crystal X-ray structure determination. X-ray crystal structure analysis shows an octahedral complex with a metal centre coordinated to two ligand molecules through the pyridine nitrogen atoms and four water molecules and containing two nitrate groups as counter ions. The complex crystallizes in the monoclinic crystal system and P2(1)/n space group. The unit cell dimensions are: a = 7.2108(4) Å, b = 16.6020(9) Å, c = 13.0389(6) Å,α = 90°, β = 103.972(4)°, γ = 90°. The molecule is symmetrical about the cobalt centre as observed from the 1H-NMR and 13C-NMR and confirmed by the single crystal X-ray structure of the complex. Thermogravimetric analysis shows two steps decomposition of the complex to leave a metal oxide residue. The title compound is expected to be biologically active as one of the precursors (isoniazid) is a therapeutic agent with well-established clinical applications.

Crystal Structure of Poly[(2,6-di(2’,4’-dicarboxylphenyl)pyridine-κ4 O:O′:O″:O′′′)-(μ2-1,4-bis(1-imidazolyl)benzene-κ2N:N’)cobalt(II)],C_(39)H_(24)Co_(2)N_(7)O_(8)

[Objective]The paper was to synthesize a new structure of metal organic framework,and to provide new materials for plant pathogens testing.[Method]A mixture of 2,6-di(2’,4’-di-carboxylphenyl)pyridine,1,4-bis(1-imidazolyl)benzene,Co(NO_(3))2·6H_(2)O were added to the solution of DMF:H2O=3:3 and heated at 433K for 4 d.[Result]Red crystals of the title compound were obtained(yield 76.3%,based on Co).[Conclusion]The crystal data were obtained as follows:C_(39)H_(24)Co_(2)N_(7)O_(8),monoclinic,P21/c,a=16.222(7)A,b=12.653(5)A,c=17.456(7)A,β=102.386(6)°,V=3500(2)A_(3),Z=4,Rgt(F)=0.0550,wRref(F2)=0.1509,T=293(2)K.

叔胺萃取分离钴(II)、铁(II)

研究了不必预先氧化二价铁,直接用叔胺从氯化物溶液中萃取分离钴(II)、铁(II)的新方法. 考察了不同改性剂对叔胺萃取钴(II)、铁(II)的影响以及各种因素对钴(II)、铁(II)萃取、洗涤及反萃的影响. 提出了用叔胺萃取分离钴(II)、铁(II)的最佳工艺参数.

羟基乙酸-钴(II)-1,10-邻菲咯啉配合物的合成、晶体结构及其DNA结合属性

以羟基乙酸(GA)和1,10-邻菲咯啉(phen)作为配体,合成了一种新型的三元单核钴(II)配合物,Co(GA)2(phen)·2H2O。通过傅里叶红外光谱和元素分析法对该配合物的结构进行了表征,并利用X射线单晶衍射测定了其晶体结构。晶体分析结果表明配合物属单斜晶系,C2/c空间群,晶胞参数:a=8.122(3)nm,b=24.214(7)nm,c=9.085(3)nm,α=105.290(14)°,β=109.843(5)°,γ=90.00°,晶胞体积:V=680.7(9)nm3,晶胞内结构分子数Z=4,最终的偏差因子:R1,wR2分别为0.0463,0.1294[I>2σ(I)]。中心钴离子分别与两个羟基乙酸及一个邻菲咯啉配体配位,形成一个畸变的八面体配位几何构型。采用电子吸收光谱、荧光光谱、粘度等分析方法研究了该配合物与DNA的相互作用,结果表明该配合物的通过经典的嵌插方式与DNA结合,二者的结合常数Kb为3.8×104L·mol-1。琼脂糖凝胶电泳实验进一步表明,在过氧化氢(H2O2)的存在条件下,配合物能对质粒体超螺旋DNA产生切割作用,具有化学核酸酶活性。

双(安息香)缩联苯胺合钴(II)的氧合反应和催化氧化性能研究

在不同温度下测定了双 (安息香 )缩联苯胺合钴 (II) (Co2 L2 )的饱和吸氧量 ,求得其氧加合常数和热力学参数 .合成了该钴 (II)配合物的双氧加合物 ,并用元素分析 ,红外光谱及热重分析得以确证 .将该配合物作为催化剂 ,催化空气中的分子氧氧化异丙苯 ,形成氢过氧化物异丙苯 (CHP) ,讨论了催化剂浓度。

固相配位化学反应研究（LXVII）──固－固相反应合成混配化合物

室温或近室温条件下，Ｃｏ（ａｃａｃ）＿２（Ｈ＿２Ｏ）＿２与第二配体２，２＇－联吡啶、１，１０－啡啰啉、８－羟基喹啉、水杨醛肟固相反应得到４个混配化合物，经ＸＲＤ、ＩＲ、ＵＶ及元素分析表征了这些产物。

以均苯四甲酸根为桥联配体的双核钴(II)配合物的合成与磁性(英文)

作者合成和表征了 3个通式为 [Co2 (PMTA)L4 ]的新双核钴 (II)配合物 ,其中 ,PMTA代表均苯四甲酸根四价阴离子 ,L分别为邻苯二胺 (obda)、2 二甲氨基乙胺 (Me2 en)和 3 二甲氨基丙胺 (Me2 pn) .根据元素分析、摩尔电导测定、红外和电子光谱等手段 ,已推定这些配合物具有均苯四甲酸根桥联的双核钴 (II)结构 ,其中 ,两个钴 (II)离子均处于畸变的八面体配位环境 .作者还测定并解析了配合物 [Co2 (PMTA) (Me2 pn) 4]的变温 (4～ 30 0K)磁化率 ,求得交换积分J =- 0 .2 8cm-1.根据实验结果作者认为 ,在双核钴 (II)配合物中的钴 (II)

外向式杯[4]芳烃偶氮类新试剂的合成及其与钴(II)显色反应的研究

合成了一种外向式杯 [4 ]芳烃偶氮衍生物新试剂 ,试验了其性质 ,并研究了与钴 (II)的显色反应条件。在乳化剂OP存在下及pH9～ 10的缓冲介质中 ,形成稳定的红色络合物 ,其最大吸收波长为 5 10nm ,摩尔吸光系数为 1.60× 10 4 L·mol- 1 ·cm- 1 ,钴含量在 0～ 2 5 μg/ 2 5mL范围内符合比尔定律。本法灵敏度不太高 ,但选择性较好。

Dioxygen Affinity and Catalytic Performance of Bis-(furaldehyde) Schiff Bases Co(II) Complexes in Cyclohexene Oxidation

Oxygenation constants and thermodynamic parameters DeltaH degrees and DeltaS degrees of cobalt (II) complexes with bis-(furaldehyde) Schiff bases (1, 2, 3, 4)were obtained by mearsuring saturated dioxygen uptake of these complexes in pyridine at different temperature. These complexes could activate molecular oxygen and were used as catalysts in cyclohexene oxidation. The influence of ligand structure on the dioxygen affinity and catalytic activity of the complexes were discussed.

Dioxygen Affinities and Catalytic Oxidation Performance of Cobalt (Ⅱ)Complexes with N—Aryl Hydroxamic Acid

The oxygenation of cobalt (II) hydroxamates (CoL2) and its catalytic performance in oxidation of p-xylene to p-toluic acid (PTA) were examined. The effects of X and Y bonded to hydroxamate group on dioxygen affinities and catalytic oxidation performance were also investigated.

Synthesis and Crystal Structure of a Co(II) Coordination Polymer Derived from a Flexible Bipyridyl Derivative Ligand

The self-assembly of a flexible bipyridyl ligand 2,2?-bis(4-pyridylmethyle- neoxy)-1,1?-biphenylene (4,4?-bpp) with cobalt(II) center gave rise to a one-dimensional chain complex [Co(μ-4,4?-bpp)2(SCN)2?H2O]n 1 which has been characterized by single-crystal X-ray diffraction. The polymer crystallizes in monoclinic, space group C2/c with unit cell parameters: a = 13.1888(13), b = 24.230(2), c = 15.4218(17) ?, β = 93.291(6)o, V = 4920.1(8) ?3, Z = 4, C50H42CoN6O5S2, Mr = 929.95, Dc = 1.255 g/cm3, F(000) = 1932 and μ(MoKα) = 0.484 mm-1. The final R and wR are 0.0691 and 0.1670 for 3746 observed reflections with I > 2σ(I). 1 possesses an infinite 1-D polymeric chain structure consisting of the repeated basic square units Co2(μ-4,4?-bpp)2, where the Co(II) center acts as the joint of the square ring. The Co(II) center is coordinated in a slightly distorted octahedral geometry with four nitrogen atoms from four different 4,4?-bpp ligands in the equatorial plane and two trans thiocyanate ligands occupying the axial positions, preventing the formation of an extended framework.

Synthesis and Catalytic Activity of Nickel(Ⅱ)and Cobalt(Ⅱ) Complexes Involving Chiral Leucinol

The title nickel complex I and cobalt complex II were obtained separately from the direct reaction of D-（＋）-leucinol with Ni（II） chloride and L-（-）-leucinol with Co（II） acetate tetra- hydrate in anhydrous methanol. The crystal structures of I and II were determined by single-crystal X-ray diffraction and further characterized by elemental analysis and IR. For I： [Ni（C18H45N3O3）]Cl2, orthorhombic, P212121, a = 11.2807（9）, b = 14.7115（11）, c = 16.3580（13） A, V = 2714.7（4） A3, Z = 4, Pcalcd = 1.177 Mg/m3, the final R = 0.0407, and 16539 reflections observed with I 〉 2σ（/）; For II： [Co（C45HI08N6015）], trigonal, R3：H, a = 23.981（3）, b =23.981（3）, c = 10.8925（15） A, γ = 120°, V = 5425.1（14） A3, Z = 3, Pcalcd = 1.002 Mg/m3, the final R = 0.0625 for 16556 observed reflections with I 〉 2σ（I）. The complexes were then used to catalyze the Henry reaction and obtained good catalytic results. The catalytic activity of the complexes was determined by IH NMR. And research is going towards the application to other organic reactions such as cyanosilylation reaction.

Synthesis,Crystal Structure and Electrochemistry Properties of a Cobalt(Ⅱ) Complex Based on Asymmetry Schiff Base Ligand

A new cobalt（II） complex [Co（NO2-salen）2]·1.5H2O containing mono acetalization Schiff base ligand（NO2-salen = N-5-nitro-salicylideneamino ethanato） has been prepared through one-pot template condensation, and has been structurally characterized by elemental analysis, IR spectra and X-ray diffraction. It is formulated as C18H23CoN6O7.5, crystallizes in the hexagonal system, space group of R-3c with α = 25.895（18）, b = 25.895（18）, c = 35.075（6）, γ = 120o, V = 20368（3） and Z = 36. The ligand of 5-nitrosalicylaldehyde-ethylene-diamine takes unusual mono asymmetry mode. The Co（II） ion exhibits a coordination number of six, and assumes a distorted octahedral geometry with a N2O4 donor set. The neutral monomeric units of [Co（NO2-salen）2]·1.5H2O are linked into a one-dimensional（1D） structure via the intermolecular hydrogen bonds and weak π-π stacking interactions. Cyclic-voltammetry measurement reveals the oxidation and reduction processes for the complex are irreversible in nature.

Synthesis and Characterization of a Cobalt Complex with Maleate and Pyridine

A new polymeric cobalt complex [Co(-male)(py)(H2O)]n (male = maleate; py = pyridine) 1 was prepared by cobalt chloride hexahydrate with disodium maleate and pyridine in an alcohol-aqueous solution. Single-crystal X-ray analysis has revealed that 1 crystallizes in the orthor- hombic system, space group Pnma with a = 18.001(1), b = 7.6001(6), c = 7.4731(6) ? V = 1022.4(1) 3, Z = 4, C9H9CoNO5, Mr = 270.10, Dc = 1.755 g/cm3, F(000) = 548, m(MoK? = 1.683 mm-1, S = 1.002, the final R = 0.0280 and wR = 0.0746 for 883 observed reflections with I > 2s(I). The structure analysis shows an approximate octahedral coordination environment of metal center. The Co(II) ions are bridged by maleic anions in a rare tetradentate coordination fashion with a syn-anti coplanar con- formation of the carboxyl group, forming a two-dimensional corrugated 2-D structure which is further attached into a three-dimensional framework via non-classical CH…O interactions between adjacent layers.