• Title/Summary/Keyword: Metal coordination

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Preparation and Crystal Structures of Silver(I), Mercury(II), and Lead(II) Complexes of Oxathia-Tribenzo-Macrocycles

  • Siewe, Arlette Deukam;Ju, Huiyeong;Lee, Shim Sung
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.725-730
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    • 2013
  • An investigation of the coordination behavior of sulfur-containing mixed-donor tribenzo-macrocycles $L^1-L^3$ ($L^1$: 20-membered $O_3S_2$, $L^2$: 20-membered $O_2S_3$, and $L^3$: 23-membered $O_4S_2$) with $d^{10}$-metal ($Ag^+$, $Hg^{2+}$, and $Pb^{2+}$) salts is reported. The X-ray structures of five complexes (1-5) with different structural types and stoichiometries, including mono- to dinuclear species have been determined. Reactions of $L^2$ and $L^3$ with the silver(I) salts ($PF_6{^-}$ and $SCN^-$) afforded two dinuclear 2:2 (metal-to-ligand) complexes with different arrangements: a sandwich-type cyclic dinuclear complex $[Ag_2(L^2)_2](PF_6)_2{\cdot}3CH_2Cl_2$ (1) and a linear dinuclear complex $[Ag_2(L^3)_2(SCN)_2]$ (2), in which two monosilver(I) complex units are linked by an Ag-Ag contact. Reactions of $L^1$ and $L^2$ with mercury(II) salts ($SCN^-$ and $Cl^-$) gave a mononuclear 1:1 complexes $[Hg(L^1)(SCN)_2]$ (3) and $[Hg(L^2)Cl_2]$ (4) with anion coordination in both cases. $L^2$ reacts with lead(II) perchlorate to yield a mononuclear sandwich-type complex $[Pb(L^2)_2(ClO_4)_2]$ (5), giving an overall metal coordination geometry of eight with a square antiprism arrangement. From these results, the effects of the donor variation and the anioncoordination ability on the resulting topologies of the soft metal complexes are discussed.

Early Stage of Pentacene Growth on the CYTOP Doped Graphene Surface

  • Yang, Mi-Hyun;Lee, Kyoung-Jae;Kumar, Yogesh;Ihm, Kyuwook;Kang, Tai-Hee;Ahn, Joung-Real
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.142.1-142.1
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    • 2013
  • The patterning and doping technique enables graphene to replace the metal electrode as a charge injection layer in the pentacene based thin film transistor. However, it is known that pentacene molecules form lying-down coordination on the graphene surface. Pentacene thin film showed that the highly occupied molecular orbital is 0.2~0.4 eV lower in the standing up coordination than in the lying down coordination. Here, we report the formation of standing-up coordination and lowered HOMO level of the pentacene layer grown on the graphene layer doped with CYTOP.

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Folding of Coordination Polymers into Double-Stranded Helical Organization

  • Kim, Ho-Joong;Lee, Eun-Ji;Lee, Myong-Soo
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.248-248
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    • 2006
  • The notable feature of the Cu(II) coordination polymer investigated here is its ability to self-assemble into a double-stranded helical structure with regular grooves along the helical axis, through the combination of metal-chloride dimeric interactions and repulsive interactions, as an organizing force. It is also remarkable that the double-stranded helices self-organize into a 2-D columnar structure in both the bulk state and aqueous solution. These results represent a unique example that weak metal-ligand bridging interactions can provide a useful strategy to construct stable double-stranded helical nanotubes.

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Inorganic polymers of metal (Ⅱ) ions with Schiff's Base of quinizarin-ethylenediamine (Quinizarin-ethylenediamine의 Schiff's Base 와 금속 (Ⅱ) 이온이 만드는 Coordination polymer의 합성에 관하여)

  • Joon Suk Oh;Won Suk Kwak
    • Journal of the Korean Chemical Society
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    • v.13 no.1
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    • pp.29-36
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    • 1969
  • lnorganic polymers, which are composed of metal (Ⅱ) ions and Schiff's Base of quinizarin-ethylenediamine, have been prepared. In order to find out proper conditions for the reaction, some investigations have been carried out to test the effect of pH, kind of solvent and the state of reagent. As a result, the highest yield occurred near pH 7 and it was found that there were not great difference in the kind of solvent and the state of reagent we had used. Most of the polymers are seemed not to be those we have attempted to prepare. They are found to be coordination polymers which have rather low molecular weight.

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Copper(II), Nickel(II) and Palladium(II) Complexes of 2-Oximino-3-thiosemicarbazone-2,3-butanedione

  • Al-Kubaisi, Abdulla H.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.1
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    • pp.37-41
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    • 2004
  • A new tridentate ligand incorporating a monoxime and thiosemi-carbozone moieties has been synthesized. Its copper(II), nickel(II) and palladium(II) complexes have been prepared and characteirzed by physical and spectral methods. Elemental analyses and spectroscopic data of the metal complexes are consistent with the formation of a mononuclear copper(II) complex and binuclear complex with both nickel(II) and palladium(II). In the copper(II) complex the fourth coordination site is occupied by nitrate ion. In the binculear complexes the fourth coordination site is occupied by the deprotonated oxime oxygen of the ligand coordinated to the other metal.

Synthesis and Characterization of Group 13 Compounds of 2-Acetylpyridine Thiosemicarbazone. Single-Crystal Structure of $(iC_4H_9)-2Al(NC_5H_4C(CH_3)$NNC(S)NHPh)

  • 강영진;강상옥;고재정;손정인
    • Bulletin of the Korean Chemical Society
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    • v.20 no.1
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    • pp.65-68
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    • 1999
  • Novel mononuclear group 13 metal complexes with the formula (R2M){NC5H4C(CH3)NNC(S)NH(C6H5)} (M=Al, R=iC4H9 (1); M=Ga, R=iC4H9 (2); M=Al, R=CH2SiMe3 (3); M=Ga, R=CH2SiMe3 (4)) result when 2-acetyl pyridine 4-phenyl-thiosemicarbazone ligand is mixed with trialkyl aluminum or trialkylgallium. These compounds 1-4 are characterized by microanalysis, NMR (1H, 13C) spectroscopy, mass spectra, and singlecrystal X-ray diffraction. X-ray single-crystal diffraction analysis reveals that 1 is mononuclear metal compound with coordination number of 5 and N, N, S-coordination mode.

Protection coordination between residual current device and surge protective devices in low-voltage consumer's installations (저압 수용가 설비에서 누전차단기와 서지방호장치 사이의 보호협조)

  • Lee, Bok-Hee;Kim, Hoe-Gu;Park, Hee-Yeoul;Ahn, Chang-Hwan
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.6
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    • pp.75-81
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    • 2013
  • In this paper, protection coordination between residual current devices and surge protective devices in low-voltage consumer's distribution systems are presented. In the case that a surge protrctive device(SPD) is located on the load side of an residual current device(RCD), when the surge is injected from the source side of the RCD, most of injected surge currents are split into the RCD and the protection coordination between the SPD and RCD is improper, three of 6 specimens experience unintended operation due to test impulse currents. Also when the surges is injected from the load side, a lot of the surge currents is split into the SPD, but a half of test specimens causes nuisance trip. Coordination between SPD and RCD is not valid. When installing SPD, it is important to select SPD after due consideration of the protection voltage level of metal oxide varistor embedded in RCD. It is expected that the results obtained from this work could be useful to improve the protection effects of SPD in low-voltage distribution systems.