• 대한화학회지
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• 제33권5호
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• pp.510-515
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• 1989

테트라에틸렌펜타아민과 포름알데히드의 주형축합반응으로부터 새로운 펜타아자 거대두고리 리간드인 1,3,6,9,12-펜타아자비시클로[10,2,1]펜타데칸(D)의 니켈(II) 및 구리(II) 착화합물 $[Ni(D)]^{2+},\;[Cu(d)]6{2+}\;그리고\;[Cu(D)Cl]^+$를 합성하였다. 거대두고리 리간드인 D에는 한 개의 이미다졸리딘 고리가 있다. $[Ni(D)]^{2+}와 [Cu(D)]^{2+}$는 5-5-5-6 킬레이트고리 배열로 된 평면사각형 구조를 이루며, 5-배위 착이온인 $[Cu(D)Cl]^+$의 구조는 그의 전자스펙트럼으로 볼 때 사각피라미드일 것으로 보인다. 이들 니켈(II) 및 구리(II) 착화합물의 합성과 확인 그리고 분광학적인 특성과 화학적인 특성이 논의된다.

• 대한화학회지
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• 제36권2호
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• pp.212-217
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• 1992

수용액내에서 gadolinium-벤조산 착물형성 반응의 열역학적 함수값들을 이온상수 0.1M $NaClO_4$, $25^{\circ}C$ 조건하에서 구하였다. gadolinium-벤조산 착물의 안정도는 여분의 엔트로피 효과에 기인하는 것으로 판단되며, 벤조산 리간드의 경우 한 자리 리간드에 비해 높은 안정도 상수값을 나타내었다. 이러한 높은 안정도는 리간드내의 벤젠고리의 공액효과로 예측되었다. 합성된 Ga$(ben)_3$의 고체 IR스펙트럼 결과, 벤조산 리간드가 두 자리 리간드로 작용하여 킬레이트를 형성하였으며, 80${\sim}$300K 온도 범위에서의 자화율 데이터는 Curie-Weiss 법칙에 잘 적용됨을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2900-2904
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• 2013

We present the synthesis and characterization of DTPA-bis(histidylamide) (1a), DTPA-bis(aspartamide) (1b), and their gadolinium complexes of the type $[Gd(L)(H_2O)]$ (2a:L = 1a; 2b:L = 1b). Thermodynamic stabilities and $R_1$ relaxivities of 2a-b compare well with Omniscan$^{(R)}$, a well-known commercial, extracellular (ECF) MRI CA which adopts the DTPA-bis(amide) framework for the chelate: $R_1$ = 5.5 and 5.1 $mM^{-1}$ for 2a and 2b, respectively. Addition of the Cu(II) ion to a solution containing 2b triggers relaxivity enhancement to raise $R_1$ as high as 15.3 $mM^{-1}$, which corresponds to a 300% enhancement. Such an increase levels off at the concentration beyond two equiv. of Cu(II), suggesting the formation of a trimetallic ($Gd/Cu_2$) complex in situ. Such a relaxivity increase is almost negligible with Zn(II) and other endogenous ions such as Na(I), K(I), Mg(II), and Ca(II). In vivo MR images and the signal-to-noise ratio (SNR) obtained with an aqueous mixture of 2b and Cu(II) ion in an 1:2 ratio demonstrate the potentiality of 2 as a copper responsive MRI CA.

• BMB Reports
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• 제35권2호
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• pp.206-212
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• 2002

The NS2B-NS3(pro) polyprotein segment from the dengue virus serotype 2 strain 16681 was purified from overexpressing E. coli by metal chelate affinity chromatography and gel filtration. Enzymatic activity of the refolded NS2B-NS3(pro) protease complex was determined in vitro with dansyl-labeled peptide substrates, based upon native dengue virus type 2 cleavage sites. The 12mer substrate peptides and the cleavage products could be separated by reversed-phase HPLC, and were identified by UV and fluorescence detection. All of the peptide substrates (representing the DEN polyprotein junction sequences at the NS2A/NS2B, NS2B/NS3, NS3/NS4A and NS4B/NS5 sites) were cleaved by the recombinant protease NS2B-NS3(pro). No cleavage was observed with an enzymatically inactive S135A mutant of the NS3 protein, or with a modified substrate peptide of the NS3/NS4A polyprotein site that contained a K2093A substitution. Enzymatic activity was dependent on the salt concentration. A 50% decrease of activity was observed in the presence of 0.1M sodium chloride. Our results show that the NS3 protease activity of the refolded NS2B-NS3(pro) protein can be assayed in vitro with high specificity by using cleavage-junction derived peptide substrates.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.215-219
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• 2004

Metal-chelate derivatives have been investigated intensively as an emitting layer and recognize to have excellent electroluminescence(EL) properties. We synthesized new luminescent material, 1,4-dihydoxy-5,8-naphtaquinone $Aiq_3$ complex($Al_2Nq_4$) and investigated the electrical optical properties. OLED has potential candidates for information display with merits of thickness, low power and high efficiency. Although the OLED show a lot of advantages for information display, it has the limit of inorganic(metal)/ organic interface. In this study, the two methods are used to study the interface of metal/organic in OLED. First, we treated $O_2$ plasma on an ITO thin film by using RIE system, and analyzed the ingredient of ITO thin film according to change of the processing conditions. We used the RDS and the XPS for the ingredient analysis of the surface and bulk. We measured electrical resistivity using Four-Point-Probe and calculated sheet resistance, and ITO surface roughness was measured by using AFM. We fabricated OLED using substrate that was treated optimum ITO surface. Second, we used the buffer layer of CuPc to improve the characteristics of the interface and the hole injection in OLED. The result of the study for electrical and optical properties by using I V L T System(Flat Panel Display Analysis System), we confirmed that the electrical properties and the luminance properties were improved.

• Bulletin of the Korean Chemical Society
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• 제18권10호
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• pp.1061-1066
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• 1997

The complexes M(CO)4-1,2-(PPh2)2-1,2-C2B10H10 (M=Cr 2a, Mo 2b, W 2c) have been prepared in good yields from readily available bis-diphenylphosphino-o-carboranyl ligand, closo-1,2-(PPh2)2-1,2-C2B10H10 (1), by direct reaction with Group Ⅵ metal carbonyls. The infrared spectra of the complexes indicate that there is an octahedral disposition of chelate bis-diphenylphosphino-o-carboranyl ligand around the metal atom. The crystal structure of 2a was determined by X-ray diffraction. Complex 2a crystallizes in the monoclinic space group P21/n with cell parameters a = 12.2360(7), b = 17.156(1), c = 16.2040(6) Å, V = 3354.1(3) Å3, and Z =4. Of the reflections measured a total of 2514 unique reflections with F2 > 3σ(F2) was used during subsequent structure refinement. Refinement converged to R1 = 0.066 and R2 = 0.071. Structural studies showed that the chromium atom had a slightly distorted pseudo-octahedral configuration about the metal center with two phosphine groups of o-carborane occupying the equatorial plane cis-orientation to each other. These metal carbonyl complexes are rapidly converted to the corresponding metal carbene complexes, [(CO)3M=C(OCH3)(CH3)]-1,2-(PPh2)2-1,2-C2B10H10 (M= Cr 3a, Mo 3b, W 3c), via alkylation with methyllithium followed by O-methylation with CF3SO3CH3.

• Bulletin of the Korean Chemical Society
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• 제19권6호
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• pp.671-676
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• 1998

The formation and dissociation rates of $Ce^{3+}$ Complexes of the 1,4,7,10-tetraaza-13,16-dioxacyclooctadecane-NN', N",N"'-tetraacetic acid (1), 1,4,7,10-tetraaza-13,16-dioxacyclooctadecane-N,N',N",N"'-tetramethylacetic acid (2), and 1,4,7,10-tetraaza-13,16-dioxacyclooctadecane-N,N',N",N"'-tetrapropionic acid (3) have been measured by the use of stopped-flow spectrophotometry. Observations were made at 25.0±0.1 ℃ and at an ionic strength of 0.10 M $NaClO_4$. The complexation of $Ce^{3+}$ ion with 1 and 2 proceeds through the formation of an intermediate complex $(CeH_3L^{2+})^*$ in which the $Ce^{3+}$ ion is incompletely coordinated. This may then lead to be a final product in the rate-determining step. Between pH 4.76 and 5.76, the diprotonated $(H_2L^{2-})$ from is revealed to be a kinetically active species despite of its low concentration. The stability constants $(logK(CeH_3L^{2+}))$ and specific water-assisted rate constants $(k_{OH})$ of intermediate complexes have been determined from the kinetic data. The dissociation reactions of $Ce^{3+}$ complexes of 1, 2, and 3 were investigated with $Cu^{2+}$, ions as a scavenger in acetate buffer. All complexes exhibit acid-independent and acid-catalyzed contributions. The effect of buffer and $Cu^{2+}$ concentration on the dissociation rate has also been investigated. The ligand effect on the dissociation rate of $Ce^{3+}$ complexes is discussed in terms of the side-pendant arms and the chelate ring sizes of the ligands.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1734-1740
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• 2001

Feeding trials using weanling pigs and broiler chicks were conducted to evaluate the efficacy of different metal-amino acid chelates and complexes at various levels of copper and zinc on the performance and fecal excretions. A total of 200 weanling pigs (Large White ${\times}$ Yorkshire ${\times}$ Duroc, $11.20{\pm}0.81kg$) were randomly assigned to 5 dietary treatments following a randomized complete block design. Each treatment was replicated 4 times with 10 pigs per pen. The dietary treatments were designated as : A-diet containing 170 ppm Cu from $CuSO_4$ and 120 ppm Zn from $ZnSO_4$, B-diet containing 85 ppm Cu from Cu-amino acid chelate (CAC) and 60 ppm Zn from Zn-amino acid chelate (ZAC), C-diet containing 170 ppm Cu from CAC and 120 ppm Zn from ZAC, D-diet containing 85 ppm Cu from Cu-lysine complex (CL) and 60 ppm Zn from Zn-methionine complex (ZM), and E-diet containing 170 ppm Cu from CL and 120 ppm Zn from ZM. On the other trial, 144 of one day old broiler chicks were randomly distributed to 6 dietary treatments following a completely randomized design. Each treatment was replicated 3 times with 8 chicks per replicate. The dietary treatments were as follows: 1-diet with 60 ppm Cu from $CuSO_4$ and 40 ppm Zn from $ZnSO_4$, 2-diet with 120 ppm Cu from $CuSO_4$ and 80 ppm Zn from $ZnSO_4$, 3-diet with 60 ppm Cu from CAC and 40 ppm Zn from ZAC, 4-diet with 120 ppm Cu from CAC and 80 ppm Zn from ZAC, 5-diet with 60 ppm Cu from CL and 40 ppm Zn from ZM, and 6-diet with 120 ppm Cu from CL and 80 ppm Zn from ZM. In Exp. 1 with pigs, there was no difference on average daily gain and average daily feed intake observed among treatments. There was improvement (p<0.05) on the overall feed conversion ratio (FCR) of pigs fed diet containing 120 ppm Zn and 170 ppm Cu from metal-amino acid chelates relative to those fed diet containing inorganic sources of Cu and Zn but equally efficient as those fed diet containing metal-amino acid complexes. Pigs fed diet containing either metal-amino acid chelates or complexes as sources of Cu and Zn had higher (p<0.05) Cu and Zn concentration in serum and lower (p<0.05) in feces than those receiving diet with inorganic sources. In Exp. 2 with broiler chicks, the overall FCR was not different among treatments. Higher (p<0.05) Cu and Zn concentration in serum was obtained from birds fed diet with 60 ppm Cu and 40 ppm Zn from metal-amino acid chelates compared to those fed diet with inorganic sources of Cu and Zn. Also, the feces collected from birds fed diet with either metal-amino acid chelates or complexes contained generally lower Cu and Zn than those birds fed diet with inorganic sources. The higher the dietary level of Cu and Zn the higher the Cu and Zn concentration in the feces. Based on the results, both metal-amino acid chelates and complexes of Cu and Zn at low levels (Zn 60 ppm, Cu 85 ppm for weanling pigs and Zn 40 ppm, Cu 60 ppm for broiler chicks) are not different from that of high levels of inorganic sources in maintaining growth performance and serum concentration. The fecal excretions for Cu and Zn were greatly reduced when organic sources were used.

• 대한핵의학회지
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• 제30권3호
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• pp.351-360
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• 1996

새로운 내부 방사선 치료용(Internal radiotherapy) $^{166}Ho$-CHICO와 CHIMA를 개발하고자 한다. $^{166}Ho$-CHICO 형성에 pH, 반응시간, chitosan 농도, $^{166}Ho$의 양 등의 영향을 실험하고, 형성된 $^{166}Ho$-CHICO로부터 $^{166}Ho$-CHIMA를 제조하여 $^{166}Ho$-CHICO와 CHIMA의 체내외 안정성 검사 등의 실험을 수행하였다. $^{166}Ho$-CHICO 형성시 최적의 조건은 pH 3.0에서 0.75% 이상의 chitosan 용액과, chitosan 무게에 대해 최대 20%까지는 $^{166}Ho$이 정량적으로 착물을 형성하였고, $^{166}Ho$-CHICO를 알칼리 처리하여 $^{166}Ho$ CHIMA를 제조하였다. 그리고 $^{166}Ho$-CHICO와 CHIMA는 체내외에서 매우 안정하였다. $^{166}Ho$-CHICO와 CHIMA는 매우 이상적인 carrier로서의 특성을 지닌 천연의 chitosan에 $^{166}Ho$을 쉽게 정량적으로 표지할 수 있고, 높은 체내외 안정성으로 미루어보아 내부 방사선 치료용 제제로서의 이용 가능성이 매우 높으며, 앞으로 충분한 동물실험을 거치면 신규 내부 방사선 치료제로서 새로운 장을 열 수 있을 것이다.

• 분석과학
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• 제6권5호
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• pp.417-424
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• 1993

5,7-디클로로-8-히드록시퀴놀리놀(Hdcq)과 2-메르캅토피리미딘(Hmpd)를 포함하는 8-배위 테트라키스 몰리브데늄(IV) 착물을 합성하였다. $Mo(mpd)_4$, $Mo(dcq)(mpd)_3$, $Mo(dcq)_2(mpd)_2$, $Mo(dcq)_3(mpd)$와 $Mo(dcq)_4$ 착물들을 TLC plate에서 분리하였다. 이 착물들의 특성을 $^1H-nmr$ 스펙트럼과 자외선-가시광선 스펙트럼으로 조사하였다. 리간드의 질소원자에 대한 ${\alpha}$위치 양성자의 화학적 이동값은 낮은 장으로 이동되었으며, $Mo(dcq)(mpd)_3$와 $Mo(dcq)_3(mpd)$는 같은 위치의 양성자가 2:1의 상대적 세기로 나타났고 $Mo(dcq)_2(mpd)_2$는 거의 같은 세기였다. 이들 착물의 입체화학을 nmr 스펙트럼과 Orgel 규칙으로 고찰했다. 이 착물들의 전자전이 스펙트럼은 세기(${\varepsilon}$>10,000~25,000)와 낮은 에너지($16,600{\sim}19,800cm^{-1}$) 흡수띠를 관찰하여 이를 전하이동 흡수띠로 해석하였다.