• 제목/요약/키워드: binuclear Co(III) complex

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$Fe^{II}-Co^{III}$이핵착물의 광유발 전자이동반응 (Light-Induced Electron Transfer Reactions in FeⅡ-CoⅢ Binuclear Complexes)

  • 이규환
    • 대한화학회지
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    • 제38권8호
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    • pp.598-602
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    • 1994
  • 이핵착물 $(NC)_5FeII-L-CoIII(NH_3)_5$ 분자내에서의 광유발 전자이동반응을 정류상태 광분해 실험으로 조사하여 속도상수를 결정하고 다리리간드 L의 종류에 따른 영향을 고찰하였다. 금속 결합자리 사이에 콘쥬게이션이 유지되는 BP, PHEN, DAP 리간드는 klight가 약 $3{\times}10^{-2} sec^{-1}$, 양자수율이 상한값인 1이였으며 콘쥬게이션이 유지되지 못하는 BPEA리간드인 klight가 약 $2{\times}10^{-4} sec^{-1}$, 양자수율이 0.03으로 측정되었다. 이로부터 광유발 전자이동반응이 전하이동 들뜬 상태 MLCT*를 거치는 "화학적 메카니즘"인 것으로 증명하였다.

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1,4-Dicyanobutene Bridged Binuclear Iridium (I, III) Complexes and Their Catalytic Activities

  • Park, Hwa-Kun;Chin, Chong-Shik
    • Bulletin of the Korean Chemical Society
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    • 제8권3호
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    • pp.185-189
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    • 1987
  • Reactions of $Ir(ClO)_4(CO)(PPh_3)_2$ with dicyano olefins, cis-NCCH = CH$CH_2$$CH_2$CN (cDC1B), trans-NCCH = CH$CH_2$$CH_2$CN (tDC1B), trans-NC$CH_2$CH = CH$CH_2$CN (tDC2B), and NC$CH_2$$CH_2$$CH_2$$CH_2$CN (DCB) produce binuclear dicationic iridium (I) complexes, $[(CO)(PPh_3)_2Ir-NC-A-CN-Ir(PPh_3)_2(CO)](ClO_4)_2$ (NC-A-CN = cDC1B (1a), tDC1B (1b), tDC2B (1c), DCB (1d)). Complexes 1a-1d react with hydrogen to give binuclear dicationic tetrahydrido iridium (Ⅲ ) complexes, $[(CO)(PPh_3)_2(H)_2Ir-NC-A-CN-Ir(H)_2(PPh_3)_2(CO)](ClO_4)_2$ (NC-A-CN = cDC1B (2a), tDC1B (2b), tDC2B (2c), DCB (2d)). Complexes 2a and 2b catalyze the hydrogenation of cDC1B and tDC1B, respectively to give DCB, while the complex 2c is catalytically active for the isomerization of tDC2B to give cDC1B and tDC1B and the hydrogenation of tDC2B to give DCB at $100^{\circ}C$.

비수용매에서 이핵성 네자리 Schiff Base Cobalt(II), Nickel(II) 및 Copper(II) 착물들의 전기화학적 성질 (제 5 보) (Electrochemical Properties of Binuclear Tetradentate Schiff Base Cobalt(II), Nickel(II) and Copper(II) Complexes in Nonaqueous Solvents. (V))

  • 조기형;최용국;이송주;김찬영;임채평
    • 대한화학회지
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    • 제36권5호
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    • pp.709-719
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    • 1992
  • 이핵성 네자리 Schiff base 의 cobalt(II), nickel(II) 및 copper(II) 착물인 [Co(II)_2(TSBP)(L)_4], [Ni(II)_2(TSBP)(L)_4] 및 [Cu(II)_2(TSBP)] (TSBP: 3,3',4,4'-tetra(salicylideneimino)-1,1'-biphenyl, L: Py, DMSO 및 DMF)들을 합성하여 원소분석, IR-spectrum, UV-visible spectrum, T.G.A. 및 D.S.C.를 측정하여 이핵성 착물로 주어짐을 확인하였다. 지지전해질로서 0.1M TEAP-L (L; Py, DMSO 및 DMF)에서 1mM-착물용액의 순환전압-전류법과 D.P.P.법으로 전기화학적 성질을 측정한 결과 이핵성 cobalt(II) 착물은 일전자의 확산 지배적인 네단계의 산화-환원과정이 Co(III)_2 {^\longrightarrow \\_\longleftarrow^e^-}Co(III)Co(II)_2{^\longrightarrow \\_\longleftarrow^e^-}Co(II){^\longrightarrow \\_\longleftarrow^e^-}Co(I){^\longrightarrow \\_\longleftarrow^e^-}Co(I)_2 으로 일어나고 이핵성 nickel(II) 및 copper(II) 착물들은 일전자의 확산지배적인 두 단계의 산화-환원과정이 M(II)_2 {^\longrightarrow \\_\longleftarrow^e^-}M(I)M(I){^\longrightarrow \\_\longleftarrow^e^-}M(I)_2 (M; Ni 및 Cu)으로 일어남을 알았다.

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Synthesis of Binuclear Bismacrocyclic Iron(II) Complex by the Aerobic Oxidation of Iron(II) Complex of 1,4,8,11-Tetraazacyclotetradecane

  • Myunghyun Paik Suh;Gee-Yeon Kong;Il-Soon Kim
    • Bulletin of the Korean Chemical Society
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    • 제14권4호
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    • pp.439-444
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    • 1993
  • The aerobic oxidation of the Fe(II) complex of 1,4,8,11-tetraazacyclotetradecane, [Fe(cyclam)$(CH_3CN)_2](ClO_4)_2$, in MeCN in the presence of a few drops of $HClO_4$ leads to low spin Fe(III) species [Fe(cyclam)$(CH_3CN)_2](ClO_4)_3$. The Fe(III) cyclam complex is further oxidized in the air in the presence of a trace of water to produce the deep green binuclear bismacrocyclic Fe(II) complex $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$. The Fe(II) ions of the complex are six-coordinated and the bismacrocyclic ligand is extensively unsaturated. $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$ crystallizes in the monoclinic space group $P2_1/n$ with a= 13.099 (1) ${\AA}$, b= 10.930 (1) ${\AA}$, c= 17.859 (1) ${\AA}$, ${\beta}$= 95.315 $(7)^{\circ}$, and Z= 2. The structure was solved by heavy atom methods and refined anisotropically to R values of R= 0.0633 and $R_w$= 0.0702 for 1819 observed reflections with F > $4{\sigma}$ (F) measured with Mo K${\alpha}$ radiation on a CAD-4 diffractometer. The two macrocyclic units are coupled through the bridgehead carbons of ${\beta}$-diimitie moieties by a double bond. The double bonds in each macrocycle unit are localized. The average bond distances of $Fe(II)-N_{imine}$, $Fe(II)-N_{amine}$, and $Fe(II)-N_{MeCN}$ are 1.890 (5), 2.001 (5), and 1.925 (6) ${\AA}$, respectively. The complex is diamagnetic, containing two low spin Fe(II) ions in the molecule. The complex shows extremely intense charge transfer band in the near infrared at 868 nm with ${\varepsilon}$= 25,000 $M^{-1}cm^{-1}$. The complex shows a one-electron oxidation wave at +0.83 volts and two one-electron reduction waves at -0.43 and-0.72 volts vs. Ag/AgCl reference electrode. The complex reacts with carbon monoxide in $MeNO_2$ to form carbonyl adducts, whose $v_{CO}$ value (2010 $cm^{-1}$) indicates the ${\pi}$-accepting property of the present bismacrocyclic ligand.