• Bulletin of the Korean Chemical Society
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• v.17 no.1
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• pp.69-72
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• 1996

The NMR dipolar shift in tetrahedral and tetragonally-distorted tetrahedral complexes for Cu(Ⅱ) has been calculated adopting nonmultipole expansion method. The exact solution of ΔB/B(ppm) is exactly in agreement with multipolar results when R, the distance between the paramagnetic ion and the nucleus, is larger than 0.2 nm. The major contribution to the dipolar shift arises from 1/R3 term but the other terms, 1/R5 and 1/R7, contribute significantly to the pseudocontact shift when R is shorter than 0.5 nm. The shift is mainly due to the 3d orbitals and sensitive to distortion parameters at short range of R.

• Journal of the Korean Chemical Society
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• v.32 no.1
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• pp.30-36
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• 1988

The effect of high pressure on the stability of copper(II), cadmium(II) and zinc (II) complex ions with ethylenediamine, propylenediamine, diethylenetriamine has been investigated polarographically. 0.10M KN$O_3$ solution was used as a supporting electrolyte. The concentration of chelating agents was varied from 0.01M to 1.00M. The dissociation constants of metal complex ions were increased with increasing the pressure from 1 atmosphere to 1,500 atmospheres. The increment of the dissociation constant per unit atmosphere varied from 1.1 ${\times} 10^{-3}$% for Cu(dien)$_2^{2+}$ to 5.0 ${\times} 10^{-3}$ % for Zn(en)$_2^{2+}$.

• Korean Journal of Environmental Agriculture
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• v.5 no.1
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• pp.43-47
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• 1986

In order to evaluate the pollution potential of agricultural crops after the construction of Onsan Industrial Complex (non-ferrous metal refineries), concentrations of hazardous heavy metals were analyzed for crop samples (rice, barley, soybean, vegetables and fruits) grown near the Complex in 1978. Although a slight difference was found among the kinds, parts and growing regions of the crops, no definite tendency was observed. The mean/maximum concentrations of crop samples were 0.23/4.0ppm As, 0.4/1.2 ppm Cd, 4.88/12.7ppm Cu, 0.09/0.4 ppm Hg, 3.86/5.0 ppm Pb and 41.3/105 ppm Zn, which may serve as the natural background data for this region.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.197-209
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• 2014

환경 오염에 대한 우려의 목소리가 높아지면서 Green chemistry 분야가 각광을 받고 있다. 이 분야에서는 환경에 영향을 적게 미치기 위한 방법의 일환으로 촉매를 연구하며, 그 촉매는 착화합물인 경우가 많다. 그러나 착화합물 내에서 리간드와 금속 이온간의 결합은 예측하기 어렵다. 이는 전형금속보다는 전이금속에서 더욱 심하며, 그 중 한 예로 전이금속에서는 여러 개의 금속 이온이 서로 직접적으로 결합한 채 리간드와 결합하는 착화합물이 발견되기도 한다. 다중 금속 착화합물(Multimetal Complex)로 부르는 이러한 구조는 특유의 복잡함 때문에 잘 알려져 있지 않음에도 불구하고 착화합물의 물리적, 화학적 성질에 직접적으로 영향을 주기에 촉매나 센서, 특히 이를 이용하여 구조체를 만드는 MOF(Metal-Organic Framework) 분야에서는 꼭 알고 있어야 하는 사항이다. 이 연구에서는 GAMESS로 density functional theory (B3LYP functional)를 이용한 양자계산을 수행하여 그 중 가장 간단한 구조인 Dimetal Complex, 그 중에서도 MOF 내에서 많이 발견되는 수차 형태(Paddle wheel) 착화합물에 대해서 다루었다. Cu를 기준으로 그와 비슷한 주기나 족에 있는 Ru, Ag, Zn 등의 금속으로 만든 Paddle wheel 구조의 에너지를 비교하여 Cu가 다른 금속에 비해 이 구조를 안정하게 형성할 수 있는 이유를 알아보았다. 더 나아가 이 구조가 MOF의 형성과 성질에 어떠한 연관성이 있는지 분석함으로써 어떠한 조건이 MOF의 성질을 극대화시킬 수 있는지도 알아보았다.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1053-1060
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• 1996

$\beta$-ketohexanal as a chelating extractant was synthesized from the reaction of ethyl formate and methyl propyl ketone in the presence of sodium amide, and the equilibrium characteristics in the extraction of copper by $\beta$-ketohexanal-chloroform were investigated. The equilibrium constants such as the dissociation constant and the partition coefficients of $\beta$-ketohexanal, the stability constant and the partition coefficient of copper chelating complex, and the overall equilibrium constant in the extraction of copper were determined by spectrophotometric measurements, and the mechanism of extraction was proposed. The percent of extracted copper by $\beta$-ketohexanal-chloroform was near 100%, and the selective extraction of copper from Cu-Zn-Cd mixture was possible. Copper was found to be extracted as $CuR_2$ and the equilibrium reaction was expressed as $Cu^{2+}+2{\overline{HR}}{\rightleftarrows}{\overline{CuR{_2}}}+2H^+$.

• Journal of the Korean Chemical Society
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• v.23 no.6
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• pp.385-391
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• 1979

It was found that cupric ion selective electrode, which was prepared by mixing CuS and $Ag_2S$ with the ratio four to one and PVC, was hard and durable. The response potentials were reproducible and linear in the range from 1.0 ${\times}$ $10^{-1}M$ to 1.0 ${\times}$ $10^{-5}M$ copper (II) solution and its slope was 25.0 mV per decade concentration at $298^{\circ}K$, slightly different from Nernstian slope. The copper (II) indicating electrode was applied in precipitation titration of 1.0 ${\times}$ $10^{-2} M Cu(II)$ sample solution containing proper amounts $NaNO_3$ with 0.1 M NaOH standard solution. Also, this electrode could be used in complex titration of Zn(II), Mg(II), Ca(II) with EDTA and stability constant of EDTA complex of Ca(II) and Mg(II) was calculated by using known Cu-$EDTA^{2-}$ stability constant.

• Journal of the Korean Chemical Society
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• v.35 no.6
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• pp.645-652
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• 1991

The stability constants$(K_f)$ of the complexes of some transition and post-transition metal ions (Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Cd(Ⅱ), Pb(Ⅱ), Hg(Ⅱ)) with $N_2O_3$-donor macrocyclic ligand, 1,15-diaza-3,4 : 12,13-dibenzo-5,8,11-trioxacyclooctadecane ($NtnOdienH_4$), have been determined by potentiometry in aqueous solution at $25^{\circ}C$. Log $K_f$ values of the complexes were : Co(Ⅱ): 3.83, Ni(Ⅱ) : 4.56, Cu(Ⅱ) : 7.74, Zn(Ⅱ) : 4.98, Cd(Ⅱ) : 3.91, Pb(Ⅱ) : 6.65, and Hg(Ⅱ) : 14.87. The order of stabilities of transition metal complexes was the same as the natural order of stability proposed by Williams-Irving. In post-transition metal complexes, the order of stabilities was Cd(Ⅱ) < Pb(Ⅱ) < Hg(Ⅱ), and the covalent character in metal ion-donor atoms bonds appeared a dominant factor in the stability. In methanol solution, each metal ion forms 1 : 1 complex, while Ni(Ⅱ) ion forms both 1 : 1 and 1 : 2 complexes. It was confirmed by $^1H-$ and $^{13}C-$NMR spectral study that the nitrogen atoms in the ligand were major contributors for the complexation of post-transition metal ions with the ligand. It was shown, by elementry analysis, electrical conductivity and magnetic susceptibility measurements, and spectral analysis, that solid Cu(Ⅱ)-and Zn(Ⅱ)-complexes have a distorted octahedral and a tetrahedral structure, respectively.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.48-53
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• 1998

The purpose of this study was to compare heavy metal concentrations in uncontaminated soil with those in soil influenced by industrial activities, and to investigate the relationship between change of heavy metal content and the kind of industry at the Iksan 1st Industrial Complex that has started since 1975. Soils sampled in 0-3㎝ and 3-6㎝ soil depth, respectively were analized for content of Cd, Cu, Ni, Pb and Zn. Change of heavy metal content in soil of the industrial complex were more accumulated 16 to 25% of Cd and Cu, 93% of Pb and Zn, respectively in samples compared with natural soil uncontaminated. But there was no different in Ni content between two soil. Distribution of Cd in soil layer of 0 to 3cm was the highest concentration of 5 ppm more at the textile industries, and then higher at the chemicals and the food processing industries. In 3 to 6㎝ soil layer Cd content was the highest concentration of 5 ppm more at the metal processing industries, and then higher at the textile industries. Cd accumulation in soil was different according to a kind of industry and soil depth. Cu content was the highest value of 400 ppm more in soil layer of 0 to 3cm at the manufacturing electric wires industry area and showed the accumulation phenomenon in soil layer 3 to 6cm at the ohmmeter, machines and electric wires industry area. Ni content was 35 ppm more in soil of the metal plating and processing industries regardless of soil sampling layer. Then it was 25 ppm more in soil of the building stones and semiconductor industries. Pb content was from 400 to 1000 ppm in soil of the chemicals and textiles industries regardless of soil sampling layer. Zn content was 1200 ppm more in soil of the chemicals and silk fabrics industries regardless of soil depth, and then lower in order to soil of leather processing${\le}$metal plating industries. In conclusion, changes of heavy metal kinds and content in soil of this industrial complex area were caused by the type or kinds of industrial activities. Changes of Pb and Zn content in soil were dominated at this area.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1988-1992
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• 2010

4-Amino-1,2,4-triazole copper complex (4-ATzCu) was synthesized, and its thermal behaviors, nonisothermal decomposition reaction kinetics were studied by DSC and TG-DTG techniques. The thermal decomposition reaction kinetic equation was obtained as: $d\alpha$ / dt =$10^{22.01}$ (1-$\alpha$)[-ln(1-$\alpha$)]$^{1/3}$ exp($-2.75\times10^4$ /T). The standard mole specific heat capacity of the complex was determined and the standard molar heat capacity is 305.66 $J{\cdot}mol^{-1}{\cdot}K^{-1}$ at 298.15 K. The entropy of activation $({\Delta}S^{\neq})$, enthalpy of activation $({\Delta}H^{\neq})$, and Gibbs free energy of activation $({\Delta}G^{\neq})$ are calculated as 171.88 $J{\cdot}mol^{-1}{\cdot}K^{-1}$ 225.81 $kJ{\cdot}mol^{-1}$ and 141.18 $kJ{\cdot}mol^{-1}$, and the adiabatic time-to-explosion of the complex was obtained as 389.20 s.

• Journal of the Korean Chemical Society
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• v.62 no.5
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• pp.358-363
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• 2018

The purpose of this study is to show the possibility of using Cu catalyst in removal of $NO_x$ from automobile exhaust which is regarded as the primary source of fine dust PM2.5. The energy and the bond lengths of the three possible structures of Cu-NO complex, which is formed by binding NO molecule to Cu, and the changes in IR and Raman spectra are calculated using MPW1PW91 method on the level of 6-311(+)G(d,p) of basis sets with Gaussian 09 program. As a result, the enthalpy of formation of the Cu-NO complexes are obtained as ${\Delta}H=104.89$, 91.98, -127.48 kJ/mol for the linear, bent, and bridging forms of them, respectively. And the bond lengths between N and O in NO complexes, which becomes longer than NO molecule, indicates that O is easily reduced from Cu-NO. In addition, the Cu-NO complexes using Cu catalyst can be easily measured by infrared or Raman spectroscopy because in the IR and Raman spectra of the NO and Cu-NO complexes the positon and the intensity of bands are definitely different in each vibration mode.