• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.222-222
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• 2006

New types of constrained geometry complexes comprising rigid silacycloalkyl group incorporated into the bridging position between cyclopentadienyl and amido functionalities were prepared. The catalytic activities of olefin polymerization were influenced by the change of exo-cyclic ring size on bridge-head silacycloalkyl unit. It has been noted that the activities of this unique series increase with increasing size of the silacycloalkyl bridge and reach the maximum in six-membered silacyclohexyl-bridged CGC complex. It is noteworthy that conformation of silacycloalkanes gives rise to enhanced catalytic activity of the titanium center although the cyclic ring and titanium center are far remoted from each other.

• 한국결정학회지
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• 제15권1호
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• pp.1-4
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• 2004

上記 題目의 化合物, $C_{18}H_{20}O_5S$은 한 對非稱 單位內에 한 個의 分子를 가지고 對稱中心室間群 $P\={1}$로 結晶化 되었다. sulfonate 群內ml S 原子는 O와 C 原子들로 이루워진 四面體 環境을 維特하고 있으며, S-O 二重結合 平均 길이는 1.420(2) ${\AA}$이며 S-O 單一結合 길이는 1.598(2) ${\AA}$이고 S-C 結合 길이는 1.742(3) ${\AA}$이다. C(7)-S-O(3)-C(8) 의 비틀림 角은 100.3(2)$^{\circ}$이며, 두 個의 six-membered rings의 二面角은 42.73(20)$^{\circ}$이다.

• 약학회지
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• 제24권3_4호
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• pp.151-157
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• 1980

Color transition mechanism of shikonin as an acid-alkali indicator was studied. It was confirmed that the presence of phenolic hydroxy radical was essential for the color change of shikonin. But in accordance with shikonin sodium salt (blue color), which was presumed to make chelation as six membered rings. Shikonin in alkaline solution, by dissociated phenolic protons of naphthoquinone nucleous, converted to the corresponding anion and instead of disappearance tautomerization, electron delocalization occurred and an additional pair of nonbonding electrons in the anion was available for interaction with .phi. electron system of the ring with further extension of the conjugation. It was responsible for its blue color(corresponding color: orange) with needs less energy difference (${\phi}{\rarw}{\phi}^{*}$) because of conjugation extension. Shikonin sodium salt seems to have similar nuclear structure as shikonin anion.

• Bulletin of the Korean Chemical Society
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• 제9권4호
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• pp.198-202
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• 1988

Several new palladium(II) complexes of aminophosphines, $(Pd(L)X_2)$, (L = $Ph_2PNH$ ++ $NR_2$; R = $CH_3(L_1)$, $C_2H_5(L_2)$ : X = Cl, Br, I, and NCS) that contain two different donor atoms of nitrogen and phosphorus as ${\pi}$-electron acceptor, were synthesized and characterized by conductivity measurement, ir, and UV/Vis-spectra. For the dithiocyanatopalladium(II) complexes with aminophosphines, it was confirmed that the thiocyanate group trans to phosphorus is coordinated as Pd-NCS mode and the one trans to nitrogen as Pd-SCN mode, and the aminophosphines form six-membered chelate ring. The spectra of dihalogenopalladium(II) complexes with aminophosphines show that the band maxima are shifted to the short wavelengths as the concentration is decreased.

• Bulletin of the Korean Chemical Society
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• 제19권3호
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• pp.358-362
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• 1998

A series of six-membered ring organosilicon compounds, 1-aryl-1-(1H-1,2,4-triazol-1-yl)alkyl-1-silacyclohexanes 3a-c, have been synthesized by four-step reactions starting from 1-(chloroalkyl)trichlorosilanes. Their fungicidal activities were tested in in vitro for ten fungi and in vivo assay for four fungi occurring in rice, barley, tomato, and etc. and compared with the flusilazole. Especially, 1-p-fluorophenyl-1-[1-(1H-1,2,4-triazol-1-yl)alkyl]-1-silacyclohexanes (3a, alkyl=methyl; 3b, alkyl=ethyl) showed good fungicidal activity with broad spectrum close to the flusilazole in in vivo assay.

• 대한화학회지
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• 제32권5호
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• pp.428-435
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• 1988

Isonitrosoacetylacetone 및 여러가지 디아민으로 부터 유도된 리간드와의 니켈(Ⅱ) 및 팔라듐(Ⅱ) 착물들, 즉, $Ni(IAA)_2-en$, $Ni(IAA)_2-pn$, $Ni(IAA)_2-tn$, Pd(IAA)$_2$-en, PdCl(IAA)-pn, 그리고 Pd(IAA)$_2$-tn을 합성하였다. 여기서 (IAA)$_2$-en, (IAA)$_2$-pn, (IAA)$_2$-tn, 그리고 (IAA)-pn 은 각각 N,N'-enthylenbis(isonitrosoacetylacetone imine), N,N'-propylenebis(isonitrosoacetylacetone imine), N,N'-trimethylenebis(isonitrosoacetylacetone imine), 그리고 N-(2-aminopropyl)isonitrosoacetylacetone imine 을 표시한다. 합성된 이들 니켈(Ⅱ) 및 팔라듐(Ⅱ) 착물들의 원소분석, 적외선 스펙트럼, 핵자기공명스펙트럼, 그리고 전자스펙트럼등을 측정한 결과, $Ni(IAA)_2$-tn 및 Pd(IAA)$_2$-en에서 리간드의 한 isonitroso 기는 질소원자를 통하여 금속이온에 배위되어 5각형 고리를 이루고, 다른 isonitroso기는 산소원자를 통하여 금속이온에 배위되어 6각형 고리를 이룬다. 그리고, $Ni(IAA)_2$-en, Ni(IAA)$_2$-pn, 그리고 Pd(IAA)$_2$-tn에서 리간드의 두개의 isonitroso기는 모두 질소원자를 통하여 금속이온에 배위되어 5각형 고리를 이룬다. 한편, PdCl(IAA)-pn 은 팔라듐과 한분자의 isonitrosoacetylacetone 및 propylenediamine의 반응으로 생성된다.

• 한국결정학회지
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• 제9권1호
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• pp.1-5
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• 1998

[Cu(L)]I2, 2H2o(1) (L:3,14-Dimethyl-2,6,13,17-tetrazatricyclo[14,4,01.18, 07.12] docosane) 착물을 합성하고 구조를 규명하였다. 이 착물은 삼사정계, 공간군 P1, a=8.400(1)Å, b=8.986(3) Å, c=9.156(1) Å, α=82.42(1)˚, β=73.61(1)˚ λ=81.04(2)˚, Z=1로 결정화되었으며, 최종 신뢰도 R값은 288K에서 1926개 회석반점에 대하여 0.042이었다. 이 착물의 결정구조는 평면 사각구조를 갖고 Cu-N의 평균 거리는 2.029(11)Å이었다. 이 착물의 육면 고리가 오면 고리는 RRSS 배역을 갖는 이차 NH와 함께 각각 의자 형태와 고우시 형태를 갖는다.

• Molecules and Cells
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• 제21권1호
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• pp.129-134
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• 2006

Lon, also known as protease La, belongs to a class of ATP-dependent serine protease. It plays an essential role in degradation of abnormal proteins and of certain short-lived regulatory proteins, and is thought to possess a Ser-Lys catalytic dyad. To examine the structural organization of Lon, we performed an electron microscope analysis. The averaged images of Lon with end-on orientation revealed a six-membered, ring-shaped structure with a central cavity. The side-on view showed a two-layered structure with an equal distribution of mass across the equatorial plane of the complex. Since a Lon subunit possesses two large regions containing nucleotide binding and proteolytic domains, each layer of the Lon hexamer appears to consist of the side projections of one of the major domains arranged in a ring. Lon showed a strong tendency to form hexamers in the presence of $Mg^{2+}$, but dissociated into monomers and/or dimers in its absence. Moreover, $Mg^{2+}$-dependent hexamer formation was independent of ATP. These results indicate that Lon has a hexameric ring-shaped structure with a central cavity, and that the establishment of this configuration requires $Mg^{2+}$, but not ATP.

• 대한화학회지
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• 제51권3호
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• pp.232-239
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• 2007

1,1'-Bis(dimethylsilyl)ferrocene과 다양한 aldehydes를 소량의 Ni(PEt3)4 촉매하에서 반응시켰을 경우 hydrosilylation 반응에 의한 비고리형의 monohydrosilylation 된 생성물이 얻어졌다. 그러나 촉매를 Ni(PEt3)4 대신에 (C2H4)Pt(PPh3)를 사용한 경우에는 고리형의 double silylation 된 6각 고리 생성물이 얻어졌다. 특히 Pt 촉매하에서 4-cyanobenzaldehyde silylation 반응은 double silylation 된 5,6-ferrocenylene-1,1,4,4-tetramethyl-2-oxa-2-cyanophenyl-1,4-disilacyclohexane의 결정을 얻었다.

• Mass Spectrometry Letters
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• 제1권1호
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• pp.9-12
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• 2010

Trimethylboroxine (TMB) is a six-membered ring compound containing Lewis acidic boron and Lewis basic oxygen atoms that can bind halide anion and alkali metal cation, respectively. We employed Fourier transform ion cyclotron resonance spectroscopy to study the gas-phase binding of $LiBrLi^+$ and $F^-(KF)_2$ to TMB. TMB forms association complexes with both $LiBrLi^+$ and $F^-(KF)_2$ at room temperature, providing direct evidence for the ditopic binding. Interestingly, the $TMB{\cdot}F^-(KF)_2$ anion complex is formed 33 times faster than the $TMB{\cdot}Li^+BrLi$ cation complex. To gain insight into the ditopic binding of an ion pair, we examined the structures and energetics of $TMB{\cdot}Li^+$, $TMB{\cdot}F^-$, $TMB{\cdot}LiF$ (the contact ion pair), and $Li^+{\cdot}TMB{\cdot}F^-$ (the separated ion pair) using Hartree-Fock and density functional theory. Theory suggests that $F^-$ binds more strongly to TMB than $Li^+$ and the contact ion-pair binding ($TMB{\cdot}LiF$) is more stable than the separated ion-pair binding ($Li^+{\cdot}TMB{\cdot}F^-$).