• 대한화학회지
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• 제26권5호
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• pp.310-319
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• 1982

여섯자리형 리간드, N,N,N',N'-tetrakis(2-amino-ethyl)-1,2-ethanediamine (ten), -1,3-propanediamine (ttn), -1,4-butanediamine (ttmd), -(R,R)- 및 -(R,S)-2,4-pentanediamine (tptn)등을 포함하는 코발트(III) 착물을 합성하고, 아울러 이들 착물에서 킬레이트 고리 크기와 confomation의 변화에 대한 d-d 흡수띠의 특성을 전자 흡수스펙트럼으로 조사하였다. $[Co(L)]^{3+}$ 착물에 대한 제일 d-d 흡수띠는 리간드(L)에 대하여 다음과 같은 차례로 약간 낮은 파동수 쪽으로 이동하였음을 알 수 있었다. ttn > (R,R)-tptn > ten > ttmd${\simeq}$(R,S)-tptn. $[Co(R,S-tptn)]^{3+}$ 착물에서 R, S-tptn 리간드는 2,4-pentanediamine 부분에 있는 하나의 methyl 그룹이 axial 방향을 취하면서 여섯자리 리간드로 중심 코발트(III) 이온에 배위하고 있음을 UV, $^{13}C$ NMR, Circular Dichroism등의 분광학적인 자료에서 알 수 있었다.

• Journal of Applied Biological Chemistry
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• 제53권2호
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• pp.108-111
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• 2010

New salens (3) and their Cobalt complexes (4) were prepared from meso-1,2-bis(ortho-hydroxyphenyl)-1,2-diaminoethane (1) and substituted salicylic aldehydes (2). In contrast to symmetric structure of salen ligand (3), salen-Co(III) complexes (4) showed dissymmetric molecular structure due to participation of three hydroxyl groups in complex formation. One of the salens (3b) revealed decrease in Cyclin D1 expression, which represents anti-cancer property.

• Bulletin of the Korean Chemical Society
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• 제32권10호
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• pp.3790-3792
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• 2011

• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.3117-3119
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• 2009

• Applied Biological Chemistry
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• 제41권8호
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• pp.611-612
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• 1998

The transition state analog for metal catalyzed hydrolysis of an ester through cooperative interactions between metal ions as Lewis acid and peroxide was discussed.

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1303-1309
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• 2012

A novel ligand N,N'-(2,6-pyridinedicarbonyl)bis[N-(carboxymethyl)] (L1) was designed and synthesized. Four co-luminescence groups of Sm-La-pyridyl carboxylic acids systems were researched, which are $K_4Sm_{(1-x)}-La_x(L_1)Cl_3{\cdot}y_1H_2O$, $K_4Sm_{(1-x)}La_x(L_2)Cl_3{\cdot}y_2H_2O$, $K_6Sm_{2(1-x)}La_{2x}(L_3)Cl_6{\cdot}y_3H_2O$, $K_4Sm_{(1-x)}La_x(L_4)Cl_3{\cdot}y_4H_2O$. The results indicated the addition of La(III) could sensitize the luminescence of Sm(III) obviously in a certain range, enhancing emission intensity of Sm-pyridyl carboxylic acids relative to the undoped ones. The optimal mole percentages of La(III) in the mixed ions for $L_1$, $L_2$, $L_3$, $L_4$ were confirmed to be 0.6, 0.5, 0.3, 0.6, respectively. The mechanism of the fluorescence enhancement effect was discussed in detail. Furthermore, the binding interaction of $K_4Sm_{0.4}La_{0.6}(L_4)Cl_3{\cdot}5H_2O$ with bovine serum albumin (BSA) have been investigated due to its potential biological activity. The binding site number n was equal to 1.0 and binding constant $K_a$ was about $2.5{\times}10^5\;L{\cdot}mol^{-1}$.

• 한국결정학회지
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• 제17권2호
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• pp.41-45
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• 2006

[ $cis-[Co(13-aneN_4)(N_3)_2]Cl{\cdot}H_2O$ ] (1) (13-ane$N_4$ = 1,4,7,10-tetraazacyclotridecane) 착물(錯物)을 합성(合成)하고 구조(構造)를 규명(糾明)하였다. 이 착물(錯物)은 단사정계(單斜晶系), 공간군(空間群) Pbca, a = 7.8282(4) ${\AA}$, b = 14.3197(7) ${\AA}$, c = 29.9021(15) ${\AA}$, V= 3351.9(3) ${\AA}^3$, Z = 8로 결정화(決定化) 되었다. 착물(錯物) 1의 코발트(III)이온은 거대(巨大)고리 리간드의 4개(個)의 질소원자(窒素原子)와 시스 위치에 2개(個)의 azide 리간드가 결합(結合)한 고천(若干) 일그러진 팔면체(八面體) 구조(構造)를 갖는데, 착물(錯物)의 양이온, 염소(鹽素) 음이온 및 물분자(分子)를 통하여 1차원의 수소결합(水素結合)을 형성(形成)한다.

• 한국산업융합학회 논문집
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• 제8권3호
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• pp.155-160
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• 2005

Kinetic studies were carried out for aquation of carbonatobis(ethylenediamine)cobalt(III) complexes in [H+] aqueous solution by UV/VIS-spectrophotometry. The rate law that in deduced from rate data is $rate=k_H{^+}[H^+]^{1.4}$ {$[Co(en)_2(CO_3)]^+$}1.0 where $k_H{^+}$ is the rate constant considering acidic catalyst, $H^+$ ion whose value is $0.241l{\cdot}mol^{-1}{\cdot}sec^{-1}$. The values of activation parameters Ea, ${\Delta}H^{\ast}$ and ${\Delta}S^{\ast}$ were $15.33Kcal{\cdot}mol^{-1}$, $14.52Kcal{\cdot}mol^{-1}$ and -57.49 e.u. respectively. On the basis of kinetic data and the observed activation parameters, we have proposed the mechanism that proceeds with two step protonations. The rate equation derived from the proposed mechanism has been in agreement with the observed rate equation. It has been seen that our modified mechanism for Harris's proton freequilibrium one prefer to the his concerted mechanism, and more the last product substitute $H_2O$ for $OH^-$ the Harris's mechanism in the acidity range 2 < pH < 5.

• Bulletin of the Korean Chemical Society
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• 제29권9호
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• pp.1774-1780
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• 2008

New PVC based polymeric membrane electrodes (PME) and coated glassy carbon electrodes (CGCE) based on synthesized Schiff base complexes of Co(III); [Co(Salen)$(PBu_3)_2$]$ClO_4$, [Co($Me_2$Salen)$(PBu_3)_2$]$ClO_4$, [Co(Salen)$(PBu_3)H_2O$]$ClO_4$; as anion carriers for potentiometric determination of $ClO_4\;^-$were studied. The PME and also CGCE electrodes prepared with [Co(Me2Salen)$(PBu_3)_2$]$ClO_4$ showed excellent response characteristics to perchlorate ions. The electrodes exhibited Nernstian responses to $ClO_4\;^-$ ions over a wide concentration range with low detection limits ($1.0 {\times} 10^{-6}\;mol\;L^{-1}$ for PME and $9.0 {\times} 10^{-7}\;mol\;L^{-1}$ for CGCE). The electrodes possess fast response time, satisfactory reproducibility, appropriate lifetime and, most importantly, good selectivity toward $ClO_4\;^-$ relative to a variety of other common inorganic anions. The potentiometric response of the electrodes is independent of the pH in the pH range 2.5-8.5. The proposed sensors were used in potentiometric determination of perchlorate ions in mineral water and urine samples. The interaction of the ionophore with perchlorate ions was shown by UV/Vis spectroscopy.

• Bulletin of the Korean Chemical Society
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• 제16권7호
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• pp.654-657
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• 1995

A series of excitation spectra (7Fo→5Do transition) of Eu(Ⅲ) ion in aqueous solution ([Eu(Ⅲ)]=1.12 × 10-2 mol L-1; pH 1.0 to 7.0) were obtained under CO2 free atmosphere using a pulsed tunable dye laser system. The broad and low intensity spectra (peak maximum: 578.89 nm) showed that the trivalent ion (Eu3+) underwent a low degree of hydrolysis at pH below 6.0. Eu(Ⅲ) hydroxo complex formation seemed more significant at pH above 6.0, shown by the occurrence of intense new peak at 578.63 nm. The spectra of those solutions prepared in N2 atmosphere showed no signs of the presence of interfering carbonate species. The Eu(Ⅲ) hydroxo complex formation was not observed when complexation studies between Eu(Ⅲ) ion and weak organic acids (e.g. glutarate and diglycolate) were conducted at pH 6.0 or below.