• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.2
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• pp.122-130
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• 1996

In an effort to learn more about the reaction mechanisms which lead to the compound nucleation at the interface of cobalt and silicon, electrical noise properties has been investigated for cobalt thin films deposited on silicon substrates by the electron beam evaporation and rf sputtering techniques. Microstructural variations at the Co/Si interfaces have been observed by transmission electronmicroscopy. Amorphous structures are observed at the Co/Si interfaces for samples whose cobalt thicknesses are less than 4nm and a polycrystalline compound nucleation has been occurred for thicker films. 1/f noise power same samples, and the spetral density has been normalized. The amplitude of 1/f noise power spectral density shows a gradual increase as the cobalt thickness is increased, and the amplitude has dropped abruptly after the compound nucleation. The variations of the noise parameters areassumed to be an indiction of the phase transformation along the nucleation reaction path, and amplitude has been interpreted as instabilities of the Co/Si interfacial structures.

• Analytical Science and Technology
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• v.13 no.4
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• pp.534-538
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• 2000

The title compound, $[Co(H_2O)_6](CH_3C_6H_4SO_3)_2$, has been prepared and characterized by X-ray crystallography. The crystal structure of the compound demonstrates a layered material constituted by hexaaquacobalt (II) cations and p-toluenesulfonate anions. Geometrical environment of the cobalt atom is octahedrally coordinated by water molecules. The p-toluenesulfonate anions are arranged with the sulfonate groups turned toward opposite side of the layer, alternately. The layered structure is stabilized by the hydrogen bondings between the ligated water molecules and the anionic sulfonate oxygen atoms.

• YAKHAK HOEJI
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• v.7 no.4
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• pp.92-95
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• 1963

Magnesium Chlorophyllin 으로부터 상법에 의하여 제조한 Chlorin-e에 수용성 Cobalt 염을 작용시켜 Chlorophyllin에 Cobalt Complex 화합물을 제조하였다. Chlorin제법에 있어서 alcohol 용매를 사용해 온 방법은 Chlorin이 alcohol에 대한 용해도가 그히 적은 관계로 목적물을 양호한 수대율로 얻지 못할 뿐만 아니라 이에 따르는 조작도 복잡 불편하였으나 용매 를 빙초산으로 대치하므로써 좋은 성과를 얻을 수가 있었다.

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.305-310
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• 1992

(${\eta}^5$-Cyclopentadienyl)bis(ethylene)cobalt (Jonas reagent), (${\eta}^5$-cyclopentadienyl)di(carbonyl)cobalt, and bis(${\eta}^5$-cyclopentadienyl)cobalt (cobaltocene) were reacted with oximes, respectively, under various conditions for synthesizing cobalt oxime sandwich complex. Jonas reagent and a dienemonooxime, 2,4-hexadienealdoxime underwent the reaction. This produced unexpected compound, (${\eta}^5$-cyclopentadienyl)(2,4-hexadienenitrile)cobalt [VII]. The compound [VII] was identified by NMR, mass spectrometer, IR and elemental analyzer etc.

• Journal of Adhesion and Interface
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• v.15 no.2
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• pp.49-56
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• 2014

In this study, properties of adhesion between adhesion promoter-containing rubber compound and zinc coated steel cord was investigated. Cobalt salt, resorcinol formaldehyde resin (RF resin) and hexamethoxymethylmelamine (HMMM) were used to adhesion promoter. Since cobalt salts accelerate sulphidation rate of zinc at zinc coated steel cord surface, pullout force of rubber compound applying cobalt salts was increased compared to that of rubber compound without applying cobalt salts. Pullout force and rubber coverage of rubber compounds applying all adhesion promoters were superior because strong interlocking between rubber matrix increased modulus due to applying RF resin and HMMM and grown zinc sulfides at zinc coated steel cord surface.

• Journal of the Korean Chemical Society
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• v.37 no.8
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• pp.735-743
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• 1993

The electrocatalytic reduction of oxygen is investigated by cyclic voltammetry and chronoamperometry at glassy carbon electrode and carbon microelectrode coated with a variety of cobalt phenylprophyrins in various pH solutions. Oxygen reduction catalyzed by the monomeric porphyrin Co(Ⅱ)-TPP mainly occurs through the 2e$^-$ reduction pathway resulting in the formation of hydrogen peroxide whereas electrocatalytic process carried out 4e$^-$ reduction pathway of oxygen to H$_2$O at the electrodes coated with cofacial bis-cobalt phenylporphyrins in acidic solution. The electrocatalytic reduction of oxygen is irreversible and diffusion controlled. The reduction potentials of oxygen in various pH solutions have a straight line from pH 4 to pH 13, but level off in strong acidic solution. The reduction potentials of oxygen shift to positive potential more 400 mV at the electrode coated with monomer Co-TPP compound than bare glassy carbon electrode while 750 mV at the electrode coated with dimer Co-TPP compound.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1929-1933
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• 2012

Two cobalt(II) compounds $[Co(2,2{^\prime}-bipy)(H_2O)_2(SO_4)]_n$ (1) and $[Co_2(2,2^{\prime}-bipy)_2(btec)(H_2O)_6]{\cdot}2H_2O$ (2) (2,2'-bipy = 2,2'-bipyridine, $H_4btec$ = 1,2,4,5-benzenetetracarboxylic acid), have been simultaneously synthesized by a one-pot slow solvent evaporation reaction. Their structures were determined by single-crystal X-ray diffraction and further characterized by X-ray powder diffraction (XRPD), IR, elemental and thermogravimetric analysis (TGA). The structural analysis reveals that compound 1 exhibits an infinite 1D chain structure with the octahedral Co(II) centers bridging by the tetrahedral ${\mu}_2-SO{_4}^{2-}$ ligands, while compound 2 possesses a dinuclear $Co_2(2,2^{\prime}-bipy)_2(btec)(H_2O)_6$ unit and the two adjacent octahedral Co(II) ions are linked by the bismonodentately coordinated btec ligand. Additionally, compound 2 exhibits blue fluorescent emission in the solid state at room temperature.

• Resources Recycling
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• v.3 no.1
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• pp.9-16
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• 1994

Fine cobalt metal powders was produced from domestic Stellite scrap by decomposing it with molten sodium hydroxide. Complete decomposition of the scrap could be obtained with the weigth ratio of sodium hydroxide to Stellite being about 2 at the temperature ranges of $750~800^{\circ}C$ for an hour. The cobalt-bearing compound was identified as $Co_2O_3{\dot}H_2O$ by X-ray analysis and D.T.-T.G.a.. The compound was then digested in HCI to form cobalt chloride, and after iron removal by adjusting the pH of the solution, cobaltous or cobaltic hydroxide was precipitated at the pH of about 13 or 4, respectively. The precipitates were reduced by hydrogen in the temperatures of $400~500^{\circ}C$ to fine cobalt powders of high purity with the size of 1.0 to $1.5\mu\textrm{m}$. The recovery of cobalt from Stellite scrap was about 75~86% by weight.

• Journal of the Korean Chemical Society
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• v.12 no.1
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• pp.12-17
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• 1968

A series of octahedral cobalt(III) complexes involving quadridentate bissalicylaldehyde ethylenediimine (SAED) chelating ligand have been prepared as a new compound: [$Co(SAED)X_2]^+,$ where X = ammonia, pyridine, and bidentate ethylenediamine. Properties and configuration of the complexes were studied by the chemical and physical method.

• Analytical Science and Technology
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• v.13 no.1
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• pp.66-71
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• 2000

The intercalated compound of dodecanesulfonate into hydrated cobalt was synthesized. The compound shows a layered structure as determined by high temperature X-ray diffraction. The layer distance of the product is increased from $19.1{\AA}$ to $34.7{\AA}$ by increasing the temperature from $30^{\circ}C$ to $200^{\circ}C$. We can control the layer distance by varying the temperature which is accomplished by changing from the monolayer to the bilayer structure of the intercalated dodecanesulfonate.