• 한국자기공명학회논문지
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• 제13권2호
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• pp.143-153
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• 2009

Luteinizing Hormone Releasing Hormone (LHRH) is composed of 10 amino acids, and is best known as a neurotransmitter. Because of the 80% homology in animals, much more concerns have focused on the substances that have similar functions or can control LHRH. Ni, Cu-LHRH complexes were synthesized. The degree of complexation was monitored by $^1H,\;^{13}C$-NMR chemical shifts, and final products were identified by ESI-Mass spectrum. Solution-state structure determination of Ni-LHRH complex was accomplished by using NMR results and NMR-based distance geometry (DG). Interproton distances from nuclear Overhauser effect spectroscopy (NOESY) were utilized for the molecular structure determination. Results were compared with previous structures obtained from energy minimization and other spectroscopic methods. Structure obtained in this study has a cyclic conformation which is similar to that of energy minimized, and exhibits a specific a-helical turn with residue numbers (2~7) out of 10 amino acids. Comparison of chemical shifts and EPR studies of Ni, Cu-LHRH complexes exhibit that Ni-LHRH complex has same binding sites with the 4-coordination mode as in Zn-LHRH complex.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제10권S_3호
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• pp.139-148
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• 2001

Heavy metals such as Cu, Ni, Cd, and Pb were chemically extract from the contaminated soils using the chelating agents, EDTA and DTPA. These chemical extraction have been focused on its applicability to a wide range of soils. Results of extractive efficiency for heavy metal follow the order : Cu-EDTA $\geq$ Ni-EDTA > Pb-EDTA > Cd-EDTA > Cu-DTPA> Pb-DTPA. This result is coincided with order of conditional formation constants(Kr) of metal-chelate agent. The second study involved the recovery of the metals and EDTA from complex solutions by an electromembrane process. The overall processes of regeneration, recovery, and reuse were evaluated. The electrochemical studies showed that copper could be chosen as an electrode to plate Cd, Cu, and Pb. At least 95% of 75 of EDTA and associated Cu or Pb could be recovered by the electromembrane process. Recovery of Cd by electodeposition was not possible with the copper electrode. The percent EDTA recovery is equal to the percentage of metal electroplated from the chelates.

• Bulletin of the Korean Chemical Society
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• 제20권3호
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• pp.352-354
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• 1999

The spectrophotometric determination of Cu(Ⅱ) with α-(2-benzimidazolyl)-α',α"-(N-5-nitro-2-pyridylhydrazone)-toluene has been investigated. The optimum conditions of pH, stability, concentration of ligand and surfactant were evaluated. This method is a simple and sensitive method for determination of Cu(Ⅱ) and offers a selective separation of Cu(Ⅱ) from sample solution containin- I ppm below amount of Ni(Ⅱ), Co(Ⅱ), Zn(Ⅱ) and Sn(Ⅱ). Copper was determined by measuring the absorbance of Cu(Ⅱ)-BINPHT complex extracted with benzene in Brij 58 surfactant at 410 nm. Beer's law is obeyed over the concentration range 0∼2.5 μgmL-1 and the detection limit (S/N=2) is 0.06 μgmL-1. The relative standard deviation at the 0.3 μgmL-1 is 2.4% (N=7). The method was applied for the determination of Cu(Ⅱ) in various milks.

• 대한금속재료학회지
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• 제46권1호
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• pp.20-25
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• 2008

The ionic equilibira in mixed solutions of cuprous and cupric chloride were analyzed by considering chemical equilibria, mass and charge balance equations. The activity coefficients of solutes were calculated by using Bromley equation. Required thermodynamic constants and interaction parameters were evaluated from the data reported in the literature. The effect of NaCl and CuCl concentrations on the pH and potential of the mixed solutions was explained in terms of the variation in the concentration of solutes and in the activity of hydrogen ion. The calculated pH values of the mixed solutions agreed well with the measured values. However, the calculated values for the potential of the mixed solutions were lower than the measured values, indicating the necessity of considering the complex formation between cuprous and chloride ion, such as $Cu^2Cl{_4}^{2-}$ and $Cu_3Cl{_6}^{3-}$.

• 대한화학회지
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• 제65권2호
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• pp.93-105
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• 2021

Mononuclear Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Fe(III), Ru(III), and UO2(II) complexes of 2-hydroxy-4-(p-tolyldiazenyl)benzylidene)-2-(p-tolylamino)acetohydrazide (H2L) were prepared by direct method. The ligand and its complexes were isolated in solid state and characterized by analytical techniques such as elemental and thermal analyses, molar conductance, magnetic susceptibility measurements and spectroscopic techniques such as UV-Visible, IR, 1H-NMR and 13C-NMR. The spectral data indicated that the ligand acted as neutral/monobasic bidentate or monobasic/dibasic tridentate ligand bonded to the metal ions through the oxygen atom of ketonic or enolic carbonyl group, azomethine nitrogen atom and deprotonated/protonated phenolic oxygen atom forming either tetragonally distorted octahedral or octahedral. Antimicrobial activities of the ligand and its complexes were evaluated against Escherichia coli, Bacillus subtilis and Aspergillus niger by well diffusion method. The results of antifungal activity showed that the Fe(III) complex (10) exhibited higher antifungal against Aspergillus niger than the other complexes. However, the results of antibacterial activity revealed that Cu(II) complex (4) is the most active against Escherichia coli while the Cu(II) complex (5) and Fe(III) complex (10) exhibited higher antibacterial effect on Bacillus subtilis than the other complexes.

• 한국전기전자재료학회논문지
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• 제20권3호
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• pp.213-217
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• 2007

Copper has been used as an interconnect material in the fabrication of semiconductor devices, because of its higher electrical conductivity and superior electro-migration resistance. Chemical mechanical polishing(CMP) technique is required to planarize the overburden Cu film in an interconnect process. Various problems such as dishing, erosion, and delamination are caused by the high pressure and chemical effects in the Cu CMP process. But these problems have to be solved for the fabrication of the next generation semiconductor devices. Therefore, new process which is electro-chemical mechanical polishing(ECMP) or electro-chemical mechanical planarization was introduced to solve the technical difficulties and problems in CMP process. In the ECMP process, Cu ions are dissolved electrochemically by the applying an anodic potential energy on the Cu surface in an electrolyte. And then, Cu complex layer are mechanically removed by the mechanical effects between pad and abrasive. This paper focuses on the manufacturing of ECMP system and its process. ECMP equipment which has better performance and stability was manufactured for the planarization process.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1322-1328
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• 2007

The catalytic activity of poly[(2,2'-bipyridine)copper(II)-μ4-oxalato] coated on a glassy carbon electrode (GCE) for O2 electroreduction is examined using cyclic voltammetry and rotating disk electrode techniques. The cyclic voltammograms show that O2 is electroreduced on pBpCuOx-coated GCE surfaces at a peak potential of ? 0.25 V in pH 4.7 acetate buffer media. The electroreduction of O2 on pBpCuOx-coated GCE occurs at 450 mV more positive potential than that found at a bare GCE. The catalytic activity originates from Cu(II) coordinated by bipyridine in the complexes and the polymer type Cu-complex films exhibit an enhanced stability compared to monomeric Cu-complexes during the O2 electroreduction. The rotating disk electrode measurements reveal that the electroreduction of O2 on pBpCuOx-coated GCE is a four-electron process. Kinetic parameters for O2 reduction on pBpCuOx-coated GCE are obtained from rotating disk experiments and compared with those on bare glassy carbon electrode surfaces.

• 센서학회지
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• 제30권6호
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• pp.451-455
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• 2021

Porous copper bromide (CuBr) films are highly advantageous for detecting ammonia (NH₃). The fabrication of porous CuBr films requires complex high-temperature processes or multistep processes. Herein, we report the uncomplicated preparation of porous CuBr films by a spin-coating method and the films' excellent NH₃ sensing properties. The porous films were prepared by spin-coating 100, 150, and 200 mM CuBr solutions, and then dried in a vacuum oven for 2 h. All the films showed a high NH₃ response; in particular, the film prepared using a 100 mM CuBr solution showed an extremely high response (resistance ratio = 852) to 5 ppm NH₃. The film also showed fast response and recovery times, 272 s and 10 s respectively, even at room temperature. The outstanding NH₃ sensing characteristics were explained in relation to the porosity and thickness of the prepared films. The high-performance NH₃ sensors used in this study can be used for both indoor air quality and environmental monitoring applications.

• 공업화학
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• 제31권5호
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• pp.475-480
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• 2020

Lactic acid와 키토산을 Cu(II) 이온과 반응시켜 합성한 착물을 사용하여 유기인 유사 독성물질인 DFP (Diisopropyl fluorophosphate) 분해반응에 적용하였다. Cu(II)-lactic acid 착물의 경우 homogeneous 상태에서 분해반응 반감기가 37. 1 min으로 분해성능이 우수하였다. 1 kDa 저분자량 수용성 키토산으로 합성한 Cu(II)-LMWS chitosan 착물은 결정화 후에는 용해도가 낮아 heterogeneous 한 상태에서 분해반응이 진행되었으며 그 반감기는 32.9 h이었다. 이 결과는 기존에 연구된 18 kDa 키토산 Cu(II)착물의 분해반응속도보다 약 16배 정도 증가된 것이다. Cu(II)-LMWS chitosan 착물을 결정화하지 않고 homogeneous한 상태로 진행한 분해반응에서는 반감기가 8.75 h로 용해도에 따라 약 4배의 차이를 확인할 수 있었다.

• 한국환경농학회지
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• 제4권2호
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• pp.88-94
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• 1985

온산(溫山)공업단지 조성(造成)에 따른 토양(土壤)의 오염(汚染)가능성을 조사하기 위하여 1978년 3월부터 1979년 5월말까지 수차에 걸쳐 공업단지 주변의 전답(田畓), 과수원 및 야산(野山)의 토양시료에 대하여 중금속 원소의 농도를 분석한 결과는 다음과 같다. 1) 농경지통양 46개지점의 중금속 농도(풍건물(風乾物) 기준)는 비소 흔적${\sim}9.3ppm$, 카드뮴 흔적${\sim}$0.6 ppm, 구리4${\sim}$22ppm, 수은 흔적${\sim}$0.37ppm, 납 6${\sim}$43ppm, 아연 27${\sim}$93ppm으로서 전국(全國) 논토양의 분석치와 비교할 때 중금속의 오염은 전혀 인정할 수 없었다. 2) 중금속 함량을 논, 밭, 과수원의 토양별로 비교한 결과 As, Cd, Cu, Zn은 토양에 따라 유의차(有意差)가 없었으나 Hg, Pb는 유의차(有意差)가 있었다. 공단내(工團內) 리단위(里單位)지역에 따른 중금속 함량을 비교한 결과 As, Cd, Hg는 유의차(有意差)가 없었으나 Cu, Pb, Zn은 유의차(有意差)가 있었다. 3) 금속제련소 인접지역에서는 아연제련소(亞鉛製鍊所)의 시운전(試運轉)중 사고에 의하여 Cd, Pb, Zn으로 오염(汚染)된 지점이 여러곳 관찰되었으나 정상가동(正常稼動)에 들어간 이후에는 오염이 더 이상 진행되지 않았다.