Synthesis, Structural Characterization and Antimicrobial Activity of a Novel Cobalt(II) Complex Based on 3-Methyl-1-Phenyl-4-(2-Thienoyl)-Pyrazol-5-One

New cobalt(II) complex, [Co(O2C15H11N2S)2(OH2)2]∙2H2O (1∙2H2O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)2∙6H2O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H2O. Compound 1∙2H2O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H2O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H2O displayed moderate activity (10 ∙2H2O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).

Synthesis, Structural Characterization and Antimicrobial Activity of a Novel Cobalt(II) Complex Based on 3-Methyl-1-Phenyl-4-(2-Thienoyl)-Pyrazol-5-One

New cobalt(II) complex, [Co(O2C15H11N2S)2(OH2)2]∙2H2O (1∙2H2O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)2∙6H2O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H2O. Compound 1∙2H2O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H2O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H2O displayed moderate activity (10 ∙2H2O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).

Ultrafine ordered L1_(2)-Pt-Co-Mn ternary intermetallic nanoparticles as high-performance oxygen-reduction electrocatalysts for practical fuel cells

The long-range periodically ordered atomic structures in intermetallic nanoparticles(INPs)can significantly enhance both the electrocatalytic activity and electrochemical stability toward the oxygen reduction reaction(ORR)compared to the disordered atomic structures in ordinary solid-solution alloy NPs.Accordingly,through a facile and scalable synthetic method,a series of carbon-supported ultrafine Pt_3Co_(x)Mn_(1-x)ternary INPs are prepared in this work,which possess the"skin-like"ultrathin Pt shells,the ordered L1_(2) atomic structure,and the high-even dispersion on supports(L1_(2)-Pt_3Co_(x)Mn_(1-x)/~SPt INPs/C).Electrochemical results present that the composition-optimized L1_(2)-Pt_3Co_(0.7)Mn_(0.3)/~SPt INPs/C exhibits the highest electrocata lytic activity among the series,which are also much better than those of the pristine ultrafine Pt/C.Besides,it also has a greatly enhanced electrochemical stability.In addition,the effects of annealing temperature and time are further investigated.More importantly,such superior ORR electrocatalytic performance of L1_(2)-Pt_3Co_(0.7)Mn_(0.3)/~SPt INPs/C are also well demonstrated in practical fuel cells.Physicochemical characterization analyses further reveal the major origins of the greatly enhanced ORR electrocata lytic performance:the Pt-Co-Mn alloy-induced geometric and ligand effects as well as the extremely high L1_(2) atomic-ordering degree.This work not only successfully develops a highly active and stable ordered ternary intermetallic ORR electrocatalyst,but also elucidates the corresponding"structure-function"relationship,which can be further applied in designing other intermetallic(electro)catalysts.

Influence of heme oxygenase-1 expression on immune liver fibrosis induced by cobalt protoporphyrin in rats

AIM:To investigate the effect of heme oxygenase-1 (HO-1)expression on immune liver fibrosis induced by cobalt protoporphyrin(CoPP)in rats. METHODS:An immune liver fibrosis model of rat was established by administering human serum albumin (HSA).The rats were divided into CoPP,liver fibrosis and normal control groups.Rats in the CoPP group received intraperitoneal CoPP concurrently with HSA. Expression of HO-1 protein was observed by Western blotting and immunohistochemistry.Hematoxylin and eosin(HE)staining was performed to assess fibrosis proliferation and distribution,proliferation extent of fibroblasts,and alterations in hepatocytes and inflammatory cells.TypeⅠandⅢcollagens were detected with Van Gieson’s(VG)staining and Foot’s reticular fiber staining,respectively.In addition, spindle-shaped cells existing at perisinusoidal locations beyond portal and septa areas were investigated with HE staining. RESULTS:Western blotting and immunohistochemistry showed that the expression of HO-1 protein was higher in the CoPP group than in the liver fibrosis group(P<0.05).Compared with the liver fibrosis group,the serological index of hepatic fibrosis in the CoPP group decreased significantly(P<0.05).HE,VG and Foot’s staining revealed that administration of CoPP reduced the extent of hepatic fibrosis.The levels of serological indicators and the number of spindle-shaped cells at perisinuous locations beyond the portal and septa areas were reduced in the CoPP group.Only a few inflammatory cells were seen around the portal areas and central veins in the CoPP group. CONCLUSION:Increased endogenous HO-1 may suppress liver fibrosis by protecting liver cells, inhibiting inflammatory cell infiltration and hepatic stellate cell transformation.

Synthesis and Crystal Structure of a Cobalt(Ⅱ) Coordination Polymer with Benzene-1,3,5-triacetate and 1,2-Di(pyridin-4-yl)ethene

A novel coordination polymer, [Co3（bta）2（dpe）3（H2O）2]·2H2O （1, H3bta = benzene-1,3,5-triacetic acid, and dpe = 1,2-di（pyridin-4-yl）ethene）, has been hydrothermally prepared and characterized by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The crystal is of triclinic system, space group P , with a = 9.5687（15）, b = 11.2470（17）, c = 13.686（2） , α = 78.262（3）, β = 89.271（4）, γ = 81.292（3）°, V = 1425.2（4） 3, C60H56N6O16Co3, Mr = 1293.90, Dc = 1.508 g/cm3, F（000） = 667, μ = 0.940 mm-1 and Z = 1. The final R = 0.0707 and wR = 0.1413 for 4950 observed reflections （I 2σ（I））. In the title complex, the bta ligand acts as a four-dentate bridging ligand to link up cobalt atoms into lamellar frameworks which are further interlinked by the dpe ligands to generate a trinodal （3,4,6）-connected （4.62）2（42.68.83.102）（64.82） net.

Syntheses,Crystal Structures,and Magnetic Properties of Cobalt(Ⅱ) Complexes with 1,1-Cyclohexanediacetic Acid

Two new Co（Ⅱ） coordination polymers,{[Co_3（Hchda）_2（chda）_2（bpp）_2（H_2O）_2]}_n 1 and {[Co（chda）（bpe）（H_2O）]·3H_2O}_n 2（H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis（4-pyridinyl）propane and bpe = 1,2-bis（4-pyridinyl）ethylene）,were hydrothermally synthesized and then characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis（TGA）,and single-crystal X-ray diffraction.Complex 1 possesses an infinite metal-organic layer based on triply bridged linear trinuclear subunits and complex 2 exhibits a square（4,4） grid layer with dangling lateral arms resulting from eight-membered rings above and below the layer.In addition,magnetic properties of complexes 1 and 2 are also given.

Construction of a New Two-fold Interpenetrated Three-dimensional Cobalt(Ⅱ)Coordination Polymer Based on 2,5-Thiophenedicarboxylic Acid and Bis(imidazol-1-yl)methane

A cobalt coordination polymer, {[Co2（tdc）2（bimm）2]·（3 DMF）}n, was synthesized based on 2,5-thiophenedicarboxylic acid（H2 tdc） and bis（imidazol-1-yl）methane（bimm） mixed ligands. The asymmetric unit of the complex contains two Co2＋） cations, two tdc2-dianions, two neutral bimm ligands, and three free DMF molecules. In the complex, deprotonated tdc2-dianions alternately bridge the adjacent Co2＋ cations to generate chains, which are further connected by the flexible bimm ligands to form a 3 D structure containing adamantanoid-like subunits. In topology, the structure of 1 represents a 4-connected uninodal two-fold interpenetrated dia（66） topology. Moreover, the solid UV-Vis absorption spectra of the complex have also been investigated.

Cobalt Determination by Means of Flow Injection On-line Sorbent Preconcentration-Flame Atomic Absorption Spectrometry with 1-Nitroso-2-naphthol as a Complexing Reagent

The suitability of 1-nitroso-2-naphthol(NN) as a complexing agent for on-line preconcentration of cobalt eluted on the C_(18) microcolumn by means of the FI-FAAS system was tested. Various parameters affecting the complex formation and its elution were optimized. A 2.3×10^(-3) mol/L reagent solution and the aqueous sample solution acidified with 0.1% (volume fraction) nitric acid were on-line mixed (6.4 mL/min) on a reaction coil set at (65±1)℃ and flowed through the microcolumn for 30 s. The pH of the mixed solution was adjusted to 3—4 with HNO_3(1 mol/L) or NaOH(1 mol/L). The adsorbed complexes in the microcolumn were eluted into the nebulizer of FAAS in 10 s with ethanol acidified with 1% HNO_3(3.0 mL/min). A good precision(1.6% for 100μg/L Co(Ⅱ), n=10), a high enrichment factor 17.2, with detection limit (3σ) 3.2μg/L, and sample throughput (90 h^(-1)) were obtained. The method was applied to the certified reference materials(CRMs), NBS-362 and NBS-364, for the determination of cobalt and the results were in good agreement with the certified values.

Synthesis, Crystal Structure and Characterization of α-(1-Benzimidazolyl)-hypnone Cobalt(Ⅱ) Complex: [CoCl(C_7H_5N_2CH_2COPh)_4]Br

The crystal structure of [CoCl(C_7H_5N_2CH_2COPh)_4]Br has been determined by means of X-ray crystallography. The molecular structure consists of a discrete [CoCl(C_7H_5N_2CH_2COPh)_4]+ cation and one Br- anion. In the [CoCl(C_7H_5N_2CH_2COPh)_4]+ cation, the coordination geometry of the central Co atom is square-pyramidal with four tertiary N atoms of benzimidazole from four α-(benzimidazol-1-yl)-hypnone ligands in the basal position and one chloride anion in the apical position. In the solid state, [CoCl(C_7H_5N_2CH_2COPh)_4]+ and Br- anion possess intermolecular and intramolecular interactions, which stabilize the crystal structure. The characterization of the title compound were also carried out by using elemeutal analysis, FTIR, UV spectrometries and TG-DSC.

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.

Chemical forms of cobalt and nickel extracted by M1,M3 and CaCl_(2)-DTPA

Mehlich 1(M1), mehlich 3(M3) and CaCl 2 DTPA have been used to predict the available micronutrient in soil. However, the forms of micronutrient extractable by these extractants are not known. In the present study, ten soils, collected from five provinces and the capital of China, representing a wide range of chemical and physical properties, were analyzed by sequential extraction to isolate five forms of cobalt and nickel, they are exchangeable, carbonate bound, Fe Mn oxide bound, organically bound and residual forms. The chemical forms extracted by M1, M3 and CaCl 2 DTPA were also investigated. The results show strong correlation between the carbonate bound or organically bound forms of Co or Ni and the amounts of extractable by any of the above three extractants. The main forms extracted by these extractants are carbonate and organically bound forms. The ranking of these three extractants for extraction of Co and Ni are M1>M3=CaCl 2 DTPA and M1=M3>CaCl 2 DTPA, respectively.

Synthesis,Structure,Fluorescent Property and Natural Bond Orbital(NBO) Analysis of a One-dimensional Cobalt(III) Complex Containing 1,3-Benzenedicarboxylate and 2-Methyldipyrido[3,2-f:2',3'-h]quinoxaline Ligand

A novel metal-organic coordination polymer [Co（m-BDC）（Medpq）·2H2O]n（m-H2BDC = benzene-1,3-dicarboxyalic acid,Medpq = 2-methyldipyrido[3,2-f：2＇,3＇-h]quinoxaline） has been hydrothermally synthesized and structurally characterized by elemental analysis,IR spectrum and single-crystal X-ray diffraction.The title compound crystallizes in monoclinic,space group C2/c with a = 19.986（4）,b = 15.789（3）,c = 16.292（3）（A°）,β = 126.54（3）°,V = 4130.3（14）（A°）^3,C23H18N4O6Co,Mr = 505.34,Dc = 1.625 g·cm^-3,Z = 8,μ = 0.883 mm^-1,F（000） = 2072,the final R = 0.0772 and wR = 0.1428.The crystal structure of complex 1 is an infinite zigzag-like chain of hexacoordinate Co^3＋ ions,in which the Co^3＋ ions are bridged in two coordination modes by m-BDC^2＋ ligands and decorated by Medpq ligands,showing a slightly distorted octahedral geometry.Additionally,the compound shows strong fluorescence in the solid state at room temperature.Natural bond orbital（NBO） analysis is performed by using the NBO method built in Gaussian 03 Program.The calculation results show a covalent interaction between the coordinated atoms and Co^3＋ ions.

Synthesis of 1-(5-nitro-3-benzopseudothiazolyl)-3-(4-phenylazophenyl)-triazene and Its Color Reaction with Cobalt

A new chromogenic reagent, 1 -（5 - nitro- 3 - benzopsendothiazde）- 3 -（4 - phenylazophenyl） - triazene （NBPTPAPT） has been synthesized and used as a sensitive reagent for the spectrophotometric determination of cobalt. In the presence of Tween - 80, the reagent with Co （ Ⅱ ） forms a yellow complex （1 ： 2） in the buffer solution of Na2B4O7 - NaOH at pH 10.54. The apparent molar absorptivity is 1.220× 10^5 L· mol^- 1· cm^- 1 with the linear range of 0 - 240μg/ L for Co （Ⅱ） by dual-wavelength spectrophotometry. Trace cobalt in vitamin B12 and tea samples has been determined with satisfactory results.

α-二亚胺钴配合物催化1,3-丁二烯高活性与高顺式-1,4选择性聚合(英文)

合成了一系列α-二亚胺钴配合物[ArN=C(Me)-(Me)C=NAr]CoCl2(Ar = C6H5, 3a; 4-MeC6H4, 3b; 4-MeOC6H4, 3c; 4-FC6H4,3d; 4-ClC6H4, 3e; 2-MeC6H4, 3f; 2-EtC6H4, 3g; 2-iPrC6H4, 3h; 2,4,6-Me3C6H2, 3i; 2,6-Et2C6H3, 3j; 2,6-iPrC6H3, 3k)和作为对比的吡啶双亚胺二氯化钴配合物(4a), 并用X射线单晶衍射方法研究了配合物3i, 3k和4a的分子结构. α-二亚胺钴配合物在倍半乙基氯化铝的作用下对丁二烯聚合有较高的催化活性, 得到的顺式-1,4结构含量达98%, 且有较高分子量(Mn≈ 1×104-1×105)的聚丁二烯. 配体的电子效应影响催化剂的活性及顺式-1,4选择性, 而配体的空间位阻对丁二烯聚合几乎没有影响. 详细研究了聚合时间、聚合温度、烷基铝助催化剂及铝比等条件对丁二烯聚合行为的影响.

球形氢氧化镍表面镀覆钴的结构与电极1C倍率放电容量

采用水合联氨或次亚磷酸氢钠作还原剂,分别在酒石酸钾钠和氨的配合体系中镀覆球形氢氧化镍,对一定金属钴镀覆量下的产物进行了XRD和SEM分析与观测. 制成的粘结式电极的1 C倍率大电流放电容量测量结果表明,镀覆钴可提高放电容量11%-32%.

微乳液1-(2-吡啶偶氮)-2-萘酚分光光度法测定蔬菜样品中的钴

以十二烷基硫酸钠-溴代十六烷基三甲胺(SDS-CIMAB)复合微乳液为介质,对Co(Ⅱ)-1-(2-吡啶偶氮)-2-萘酚的显色反应条件进行了研究.结果表明该体系的λ_(max)=580nm,ε_(580)=3.4×10~4L·mol·cm^(-1),Co(Ⅱ)测定的线性范围为0～2.40mg/L.回收率在96%～103%之间,该法选择性好,用于蔬菜中Co(Ⅱ)含量的测定,得到了满意的结果.

1-(5-硝基-2-吡啶偶氮)-2,7-萘二酚吸光光度法测定微量钴

报道了 1 (5 硝基 2 吡啶偶氮 ) 2 ,7 萘二酚与钴的显色反应 ,结果表明 ,在Tween 80存在下 ,pH 5 .2 6.5时试剂与钴形成稳定的蓝色配合物 ,其最大吸收波长位于 63 5nm ,表观摩尔吸光系数为 6.44× 10 4 L·mol- 1·cm- 1,配合物中钴与试剂的组成比为 1∶2 ,钴浓度在 0 5 μg/10ml范围内服从比耳定律。方法用于标准钢、金川精矿等试样中钴的测定 ,结果满意。

HO-1诱导剂体外灌注对大鼠移植肝脏保护作用的研究

目的探讨在移植肝脏低温保存期间灌注血红素加氧酶-1(heme oxygenase-1,HO-1)诱导剂钴原卟啉(cobalt protoporphyrin,CoPP)对大鼠移植肝脏的保护作用。方法以Wistar大鼠为供体,SD大鼠为受体,根据供肝体外灌注低温保存期间所灌注的液体不同,将其分为4组:空白对照组、CoPP组、nodosin组和锌原卟啉(zinc protoporphyrin,ZnPP)组。每组各建立12对大鼠原位肝移植模型,各组分别在移植手术后1 d、3 d、7 d、21 d处死3只大鼠切取肝脏组织标本,进行肝脏组织病理检查与Suzuki评分。结果原位肝移植术后1 d、3 d、7 d,CoPP组和nodosin组大鼠的肝脏病理损伤比空白对照组和ZnPP组轻,但Suzuki评分差异无统计学意义(P>0.05)。原位肝移植术后21 d,nodosin组与CoPP组的病理损伤均较空白对照组轻,两组的Suzuki评分与空白对照组比较差异有统计学意义(P<0.01,P<0.05)。ZnPP组的移植肝脏损伤较重,ZnPP组的Suzuki评分与nodosin组比较差异有统计学意义(P<0.01)。结论在移植肝低温保存期间灌注HO-1诱导剂可以减轻大鼠肝移植术后肝脏组织的病理损伤,而且在术后晚期对移植肝保护效果更加明显。

CoO/SiO_2-Al_2O_3催化剂上苯胺和1,6-己二醇气相高效合成1-苯基氮杂环庚烷

研究了CoO/SiO2-Al2O3催化剂上苯胺和1,6-己二醇气相催化合成1-苯基氮杂环庚烷的反应,并采用N2吸附-脱附、X射线衍射、H2程序升温还原和NH3程序升温脱附技术对催化剂进行表征.结果表明,CoO/SiO2-Al2O3催化剂表现出较高的活性和选择性.当CoO担载量为0.3mmol/g时,催化剂前体在700°C(2.8°C/min)下焙烧4h以及在325°C下50%H2-50%N2(60ml/min)混合气中原位还原2h,产物收率达到80%.催化剂的比表面积大、活性组分分散度高以及酸性较弱时有利于目标产物的生成.

1-(6-硝基-2-苯并噻唑)-3-(4-硝基苯)-三氮烯与钴的显色反应

在TritonX 100表面活性剂存在下,研究了1 (6 硝基 2 苯并噻唑) 3 (4 硝基苯) 三氮烯(NBTNPT)与钴的显色反应.在pH10.0～11.5的Na2B4O7 NaOH缓冲溶液中,NBTNPT与钴生成N(NBTNPT)∶N(Co2+)=2∶1的配合物,其最大负吸收峰在波长535nm处,表观摩尔吸光系数为1.33×105L·mol-1·cm-1,ρ(Co2+)为0～360μg/L时符合比耳定律.用该方法测定维生素B12注射剂中的微量钴,测定结果满意.