• 제목/요약/키워드: complexation

검색결과 490건 처리시간 0.025초

The Fluorescent 7-Aminodipyrido[3,2-a:2',3'-c] phenazine(7-amino-dppz) Functionalized as an Europium Ion ($Eu^{3+}$) Sensor

  • Choi, Chang-Shik;Lee, Ki-Hwan
    • Rapid Communication in Photoscience
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    • 제1권2호
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    • pp.31-33
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    • 2012
  • The Fluorescent 7-aminodipyrido[3,2-a:2',3'-c]phenazine (7-amino-dppz, 1) is functionalized as an europium ion ($Eu^{3+}$) sensor, which showed the effective emission quenching when europium cation is chelated to the bpy site of 1 compound. The complexation ratio indicated that the 1 compound forms a 1 : 1 complex with $Eu^{3+}$.

Novel-1,3-Alternate Calix[4]thiacrown Ethers

  • Sim, Won-Bo;Lee, Jai-Young;Kwon, Jong-Chul;Kim, Moon-Jib;Kim, Jong-Seung
    • Bulletin of the Korean Chemical Society
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    • 제23권6호
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    • pp.879-884
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    • 2002
  • A series of novel 1,3-alternate calix[4]-mono-thiacrown and -bis-thiacrowns were synhesized within good yields. The three dimensional 1,3-alternate conformation was confimed by X-ray crystal structure. From the results of two phase extraction and NMR studies on the ligand-metal complex, one can conclude that the calix[4]thiacrown ethers showed the very high selectivity for silver ion over other metal ions by an electrostatic interaction between sulfur atom and silver ion and by a $\pi-metal$ complexation.

클로닉신과 시클로덱스트린과의 포접복합체 형성 (Inclusion Complexation of Clonixin with Cyclodextrins)

  • 박선주;김길수
    • Journal of Pharmaceutical Investigation
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    • 제25권4호
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    • pp.283-289
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    • 1995
  • The aim of this study is to increase the solubility and dissolution rate of clonixin by inclusion complex formation. Inclusion complexes of clonixin, a non-steroidal antiinflammatory drug, with ${\beta]-cyclodextrin$ were $2-hydrolrypropyl-{\beta]-cyclodextrin$ were prepared by freeze drying method. Inclusion complex formation of clonixin with cyclodextrins was determined by UV, IR and DSC. The apparent stability constants were calculated from the phase solubility diagrams. Dissolution rate and solubility of clonixin in water markedly increased by the complex formation.

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Complexation and Conformational Flexibility of Calix[4]arence Dibenzocrown Ethers

  • 김종승;Akira Ohki;조문환;김종국;라도영;조남숙;Richard A. Bartsch;이근우;오원진
    • Bulletin of the Korean Chemical Society
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    • 제18권9호
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    • pp.1014-1017
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    • 1997
  • 1,3-Dipropyloxycalix[4]arene dibenzocrown ethers were synthesized in the fixed 1,3-alternate conformation by the reaction of 1,3-dipropyloxycalix[4]arenes with a dibenzo dimesylates. Complexation toward alkali metal ions using ISEs showed a high cesium selectivity. Conformational flexibility of the corresponding 1,3-alternate calixcrown ether (4) with respect to the NMR time scale is found to depend on the temperature and polarity of the NMR solvent.

Selective Transport of Pb(II) Ion by Acyclic Polyethers Bearing Amide End-Groups

  • 김종승;이상철;김응태;조재훈;조문환;유재형;이종해
    • Bulletin of the Korean Chemical Society
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    • 제18권12호
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    • pp.1256-1260
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    • 1997
  • A series of acyclic polyethers bearing amide end-groups and lipophilic alkyl chains (3-5) were successfully synthesized with quantitative yields. Based upon the transport experiment in a bulk liquid membrane (BLM) system and solvent extraction, a very high selectivity of Pb2+ over other transition metal cations was observed. Measurement of thermodynamic parameters for complexation in methanol at 25 ℃ gave a strong evidence for excellent selective complexation for lead ion over other transition metal ions.

무정형 알루미늄 산화물에 의한 양이온 중금속의 표면착화 (Surface Complexation of Cationic Metal Adsorption Onto Amorphous Aluminum Oxide)

  • 박연종;양재규;최상일
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제13권1호
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    • pp.101-109
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    • 2008
  • 국내 화학회사에서 발생되는 연마분진 폐기물에 대한 흡착제로서의 재이용성을 평가하기 위하여 연마분진을 $550^{\circ}C$에서 하소시켜 얻어진 무정형 알루미늄 산화물(AMA-L)을 이용하여 양이온 중금속인 구리, 카드뮴, 납 등에 대한 흡착특성을 파악하였으며 MINEQL + 프로그램을 적용하여 AMA-L과 양이온 중금속 이온간의 표면흡착결합 반응을 모사하여 흡착실험결과와 비교하였다. 구리와 카드뮴, 납의 단일성분에 대한 AMA-L의 흡착실험결과, 납 > 구리 > 카드뮴의 순서로 친화력의 차이가 발생하는 것을 확인하였다. 구리와 카드뮴의 농도변화에 따른 AMA-L 흡착실험 결과 구리와 카드뮴의 농도를 증가시킴에 따라 두 성분의 흡착효율은 모두 감소되는 것으로 나타났으며 구리와 카드뮴이 동시에 존재하는 이성분계 흡착의 경우에는 단일성분으로 존재하는 경우와 유사한 흡착율을 나타내었으며 경쟁이온의 영향을 거의 받지 않는 것으로 확인이 되었다. 또한, AMA-L에 대한 흡착특성에 대한 MINEQL+를 이용한 모사결과 단일성분과 이성분계 흡착에 대한 흡착특성은 비교적 잘 일치하는 것으로 나타났다.

공공도서관의 복합화에 따른 공간의 구조적 변화에 관한 연구 (Research on changes of spatial configuration due to complexation of public library)

  • 송승언;김석태
    • 한국실내디자인학회논문집
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    • 제20권6호
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    • pp.311-320
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    • 2011
  • Public libraries in Korea have undergone changes from libraries for just reading or keeping books to libraries with cultural facilities that provide information through various media. It was because of the "plan for building the information-oriented library" in 2000 that made the complexation of public library in progress. The alterations of the system have changed the structure as well as the grade ranks but haven't been considered enough for administrators or visitors. Hereupon, we are to study of the features by analyzing how the application of the system changed the structure of library. There are four stages in research methods. First, concept of public library and functional elements requested in the process of complexation were studied from literature. Second, vertical, horizontal and circulate changes were studied by applying subject libraries into prior research stereotyping the libraries. Third, mutual relations between each place were studied through J-Graph by elements. Lastly, rank changes according to centrality of space and users were quantitatively studied with space syntax. 4 notable changes were found in these analyses. (1)Vertical, horizontal and circulate structure of public libraries were homogenized. Since 2001, however, they have become diversified as all-in-one or detachable. (2)The space structure of library before 2001 was shallow tree shape while in 2001, period of transition, was the tree shape mixed with ring shape. As time goes on, it has become shallow tree shape again but connected by ring shape in part of reading and common space and in digital reference room. (3)Digital reference room was center of the space around 2001 and it ranked top for integration. After 2007, however, it has become setting off-center. (4)About the purpose of using public libraries, using it as space for administrators ranked top followed by space for visitors and common space before. For now, common space ranks top and space for visitors and administrators. 5 subject public libraries were selected respectively before and after 2001.

디클로페낙나트륨 및 디클로페낙나트륨과 ${\beta}$-시클로덱스트린 포접물의 흰쥐 위 점막 손상 비교 (Comparison of Diclofenac Sodium and Diclofenac $Sodium-{\beta}-cyclodextrin$ Complexation on Gastric Mucosal Injury in Rats)

  • 박재훈;김종환;김주일;김승조;서성훈;이경태
    • Journal of Pharmaceutical Investigation
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    • 제27권1호
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    • pp.11-14
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    • 1997
  • This laboratory has recently reported the solubility and in vivo absorption enhancement of diclofenac sodium by ${\beta}-cyclodextrin$ complexation. The acute gastroduodenal mucosa injury provoked by administration of 34 mg/kg and 68 mg/kg of a diclofenac sodium (DS) and equivalent dose of new formulation [diclofenac sodium-beta-cyclodextrin complexation$(DS-{\beta}-CD)$] was evaluated and compared. Microscopic examinations, performed after 18-hrs treatment, demonstrated that $DS-{\beta}-CD$ was less gastrolesive than DS. The drop in gastrophy after a single dose of the assigned drug was considerably greater for DS than for $DS-{\beta}-CD$, which registered similar values to control. Since gastrophy is an expression of the anatomy-functional integrity of the gastric barrier, the results indicate that $DS-{\beta}-CD$ exerts less direct acute damage on the gastric mucosa. Therefore, when administered short-term, $DS-{\beta}-CD$ appears to be less gastrolesive than the standard DS formulation.

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구연산 기반 구리-니켈 합금도금에 대한 분광학적/전기화학적 특성 연구 (Spectroscopic and Electrochemical Study on the Citrate-based CuNi Codeposition)

  • 이주열;임성봉;김만;정용수
    • 한국표면공학회지
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    • 제44권3호
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    • pp.117-123
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    • 2011
  • We investigated the spectroscopic and electrochemical properties of the citrate-based CuNi solution at different solution pH and analyzed various surface properties of CuNi codeposition layer. By combining UV-Visible spectroscopic data with potentiodynamic polarization curves, it could be found that the complexation of $Ni^{2+}$-citrate pair was completed at lower solution pH than $Cu^{2+}$-citrate pair and was affected by the coexistent $Cu^{2+}$ ions, while the complexation between $Cu^{2+}$ ions and citrate was not sensitive to the presence of $Ni^{2+}$ ions. Also, the electron transfer from cathode to $Cu^{2+}$-citrate and$Ni^{2+}$-citrate was hindered by strong complexation between $Cu^{2+}/Ni^{2+}$ ions and citrate and so apparent codeposition current densities were reduced as the solution pH increases. CuNi codeposited layers had a higher Cu content when they were prepared at high pH solution due to the suppression of Ni deposition, and when codeposition was executed in an agitated condition due to the acceleration of mass transfer of $Cu^{2+}$ ions in the solution. Actually, solution pH had little effect on the surface morphology and deposits orientation, but greatly influenced the corrosion resistance in 3.5% NaCl solution by modifying the chemical composition of CuNi layers and so pH 3 was expected as the most suitable solution pH in the viewpoint of corrosion coatings.