• 제목/요약/키워드: Transition-metal complexes

검색결과 140건 처리시간 0.023초

Aminophosphine류가 배위된 전이금속(Pd, Ni) 착물의 촉매반응; I. 탄소-탄소 짝지움 반응 (Catalytic Reactivity of Transition Metal (Pd, Ni) complexes with Aminophosphines; I. Carbon-Carbon coupling reactions)

  • 정맹준;이철재;김동엽
    • 한국산업융합학회 논문집
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    • 제7권1호
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    • pp.107-113
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    • 2004
  • Several transition metal complexes, [$M(L)X_2$](M=Pd(II), Ni(II); X=CI, Br) are prepared with aminophosphine ligands such as 1,2-bis{(diphenylphosphino)amino}ethane{$Ph_2PNHCH_2CH_2NHPPh_2$}($L_1$), 1,2-bis{(diphenylphosphino)amino}propane{$Ph_2PNHCH(CH_3)CH_2NHPPh_2$}($L_2$), trans-1,2-bis{(diphenylphosphino)amino}cyclohexane{$Ph_2PNHC_6H_{10}NHPPh_2$}($L_3$) and 1,2-bis{(diphenylphosphino)amino}benzene{$Ph_2PNHC_6H_4NHPPh_2$}($L_4$). The properties of these complexes are characterized by optical spectroscopic methods including UV/vis spectroscopy, CD, IR, $^1H$- and $^{31}P-NMR$ together with conductometer and elemental analysis. All complexes are stable under atmospheric environment. Catalytic reactivity for C-C coupling between [$M(L)X_2$] and Grignard reagents(RMgX; R=phenyl, propyl, buthyl) by thermolysis were investigated utilizing GC/mass, $^1H$- and $^{13}C-NMR$. When mol scale is 1:20 at [$Pd(L)Cl_2$] and Grignard reagents, the high catalytic activity for C-C coupling is apparent. The [$M(L)X_2$](X=Cl, Br) complexes which have strong bond at M-P exhibit high yields for C-C coupling reactions. When the central metal ion is Pd(II), the high catalytic activity for C-C coupling is apparent. The complex coordinated with Br shows higher catalytic activity for C-C coupling reactions compared to Cl.

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Microwave-assisted Synthesis of Mixed Ligand Complexes of Zn(II), Cd(II) and Hg(II) Derived from 4-aminopyridine and Nitrite Ion: Spectral, Thermal and Biological Investigations

  • Dhaveethu, Karuthakannan;Ramachandramoorthy, Thiagarajan;Thirunavukkarasu, Kandasamy
    • 대한화학회지
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    • 제57권3호
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    • pp.341-351
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    • 2013
  • Zn(II), Cd(II) and Hg(II) complexes with a general composition[$M(L)_2(X)_2$], where L=4-aminopyridine (4AP) and $X=NO_2{^-}$ were prepared under microwave irradiation. The metal complexes were characterized by elemental analyses, molar conductance, IR, Far-IR, electronic, NMR ($^1H$, $^{13}C$), XPS spectral and thermal studies. The spectroscopic studies reveal the composition, different modes of bonding, electronic transition, different chemical environment of C and H atoms and the electronic state of the metal atoms. On the basis of the characterization data, tetrahedral geometry is suggested for all the complexes. The free ligand (4-aminopyridine) and their metal complexes were screened against phytopathogenic fungi and bacteria in vitro and the activities were compared.

A Series of Transition-metal Coordination Complexes Assembled from 3-Nitrophthalic Acid and Thiabendazole: Synthesis, Structure and Properties

  • Xu, Wen-Jia;Xue, Qi-Jun;Liang, Peng;Zhang, Ling-Yu;Huang, Yan-Feng;Feng, Yu
    • Bulletin of the Korean Chemical Society
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    • 제35권1호
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    • pp.218-224
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    • 2014
  • In order to explore new coordination frameworks with novel designed 3-nitrophthalic acid and the same N-donor ancillary ligand, a series of novel coordination complexes, namely, $[Cd_2(3-NPA)_2(TBZ)_2(H_2O)_2]{\cdot}2H_2O$(1), $[Zn_2(3-NPA)_2(TBZ)_2]$(2), $[Zn_2O(3-NPA)(TBZ)(H_2O)]_n$(3), $[Co(3-NPA)(TBZ)(H_2O)]_n$(4) (3-$NPAH_2$ = 3-nitrophthalic acid), have been hydrothermally synthesized through the reaction of 3-nitrophthalic acid with divalent transition-metal salts in the presence of N-donor ancillary coligand (TBZ = thiabendazole). As a result of various coordination modes of the versatile 3-$NPAH_2$ and the coligand TBZ, these complexes exhibit structural diversity. X-ray structure analysis reveals that 1 and 2 are 0D molecular rings, while 3 and 4 are one-dimensional (1D) infinite chain polymers. And the weak O-H${\cdots}$O hydrogen bonds and C-H${\cdots}$O nonclassical hydrogen bonds as well as ${\pi}-{\pi}$ stacking also play important roles in affecting the final structure where complexes 1, 3 and 4 have 3D supramolecular architectures, while complex 2 has a 2D supramolecular network. Also, IR spectra, fluorescence properties and thermal decomposition process of complexes 1-4 were investigated.

Thermo-Physical Properties of Some Coumarin Complexes

  • M. G. Abd El Wahed;K. El Manakhly;N. El Khososy;A. El Farargy
    • Bulletin of the Korean Chemical Society
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    • 제18권6호
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    • pp.594-599
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    • 1997
  • A number of complexes of transition metal ions with some coumarin derivatives have been prepared and their structures were elucidated with the help of conductometric, photometric and infrared studies. The stability constants of various complexes were determined, in aqueous medium, at different temperatures potentiometrically. The thermodynamic characteristics, ΔG, ΔH and ΔS, were calculated. The electrical behaviour of prepared compounds was followed.

The Structural Features and Rotational Barriers in Indenyl Allyl Metal Complexes

  • Sungkwon Kang
    • Bulletin of the Korean Chemical Society
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    • 제10권6호
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    • pp.554-559
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    • 1989
  • The electronic structure, conformational preferences, and rotational barriers have been studied for transition metal indenyl allyl complexes by means of extended Huckel calculations. After geometrical optimization the exo conformation of allyl moiety is favored over the endo. The rotational barrier of indenyl ring in (Indenyl)Mo(CO)_2(Allyl)$ is computed to be 3.8 kcal/mol. Population analysis is applied to account for the conformational preferences and rotational barriers. A series of substituted allyl complexes has been also optimized. It shows steric hindrance plays a crucial role in setting the allyl orientation.

POLYVINYLPYRROLIDONE METAL COMPLEXES. FORMATION STABILITY AND THEIR BIOLOGICAL ACTIVITY

  • Lee, V. A.;S. Sh. Rashidova
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.463-465
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    • 1998
  • The peculiarities of the polyvinylpyrrolydone (PVP) interaction with transition metal ions of the first row in solution were studied. It was shown that PVP macromolecules due to their swelling conformation in organic solvents form the stable metal complexes. Metal ions were bond with oxygen and nitrogen atoms of PVP lactam rings. In water solution every metal ion interacts with one or two oxygen atoms out of 10-12 monomer units of the polymer. The additional contraction of PVP macromolecule coils in water have been found out by dissolving of the polymer metal complexes (PMC) synthesized in organic media. Toxicity, blood forming and immune stimulating activity and pharmaco-kinetic too of obtained polymers and their metal completes have been investigated. The factors and effects that responsible fur changing of PMC physical-chemical and biological properties have been estimated.

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DMF용액에서 세자리 Schiff Base를 가진 전이금속(II) 착물들의 합성과 구조결정 (Synthesis and Characterization of Transition Metal(Ⅱ) Complexes with Tridentate Schiff Base in DMF Solution)

  • 오정근;최용국
    • 대한화학회지
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    • 제43권5호
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    • pp.511-516
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    • 1999
  • 2-hydroxy-1-naphthaldehyde와 2-aminopyridine으로부터 $N_2O$형의 세자리 Schiff Base 리간드인 (2-hydroxy-1-naphthyllidine)-o-iminopyridine [NOIPH]리간드와 Cobalt(II), Nickel(II) 및 Copper(II) Acetate들과 반응시켜 Schiff Base 전이금속(II) 착물들을 합성하였다. 이 리간드와 전이금속(II)착물들의 구조를 원소분석, IR, UV-vis, NMR 분광법 및 TGA 방법으로 확인하였다. 중심 금속인 전이금속(II) 이온은 $N_2O$형의 주개원자를 갖는 세자리 리간드의 페놀기에 있는 산소와는 이온결합을, 아로매틱 아민의 질소와는 배위결합을 형성하여 비이온성의 착물을 형성하였다. 착물에서 리간드들은 전이금속(II) 이온과 2:I의 몰비로 결합하며 4배위 구조임을 알았다.

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Interaction of the Post-transition Metal Ions and New Macrocycles in Solution

  • Jung, Oh-Jin
    • Bulletin of the Korean Chemical Society
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    • 제14권6호
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    • pp.687-691
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    • 1993
  • Complexation of $Cd^{2+},\;Pb^{2+}\;and\;Hg^{2+}$ ions with four cryptands were studied by potentiometry and solution calorimetry in various weight percent methanol-aqueous solvent at 25${\circ}$C under $CO_2$free nitrogen atmosphere. The stabilities of the complexes were dependent on the cavity size of macrocycles. The $Hg^{2+}$ ion stability constants are higher than those of $Cd^{2+}\;and\;Pb^{2+}$ ion. All the cryptands formed complexes having 1 : 1 (metal to ligand) mole-ratio except for $Hg^{2+}-L_1$ (cryptand 1,2b: 3,5-benzo-9,14,17-trioxa-1,7-diazabicyclo-(8,5,5) heptadecane) and $Cd^{2+}-L_2$ (cryptand 2,2b: 3,5-benzo-10,13,18,21-tetraoxa-1,7-diazabicyclo (8,5,5) eicosane) complexes. $Hg^{2+}-L_1$ complex was a sandwitch type, and the $Cd^{2+}-L_2$ complex showed two stepwise reactions. Thermodynamic parameters of the $Cd^{2+}-L_2$ complex were $6.08(log\;K_1)$, -7.28 Kcal/mol $({\Delta}H_1)$, and $4.78\;(log\;K_2)$, -4.62 Kcal/mol $({\Delta}H_2)$, respectively, for 1 : 1 and 2: 1 mole-ratio. The sequences of the selectivity were increased in the order of $Hg^{2+}\;>Pb^{2+}\;>Cd^{2+}$ ion for $L_3\;and\;L_4$ macrocycles, and the $L_2$-macrocycle has a selectivity for $Cd^{2+}$ ion relative to $Zn^{2+},\;Ni^{2+},\;Pb^{2+}\;and\;Hg^{2+}$ ions. Thus, it is expected that the $L_2$ can be used as carrier for seperation of the post transition metals by macrocycles-mediated liquid membrane because $L_2$ is not soluble in water, and the difference of stability constants of the metal complexes with $L_2$ are large as compared with the other transition metal complexes. The $^1H\;and\;^{13}C-NMR studies indicated that the nitrogen atoms of cryptands have greater affinity to the post transition metal ions than the oxygen atoms, and that the planarities of the macrocycles were lost by complexation with the metal ions because of the perturbation of ring current of benzene molecule attached to macrocycles and counter-anions.

새로운 N,N,O계 세 자리 리간드의 합성과 전위차적정법에 의한 전이금속 착물의 안정도상수의 결정 (Synthesis of New N,N,O Tridentate Ligands and Determination of Stability Constants of Transition Metal Complexes by Potentiometry)

  • 김선덕;이도협
    • 한국환경과학회지
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    • 제15권8호
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    • pp.799-809
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    • 2006
  • Hydrobromic acid salts of new N, N, O tridentate ligands containing phenol, 2-[(2-Methylamino- ethyl- amino)-methyl]-phenol(H-MMP. 2HBr), 5-Bromo-2-[(2-Methylamino-ethylamino)-methyl]-phenol (Br- MMP. 2HBr), 5-Chloro-2-[(2-Methylamino-ethylamino)-methyl]-phenol(Cl-MMP. 2HBr), 5-Methyl-2-[(2-Methylamino-ethylamino)-methyl]-phenol(Me-MMP. 2HBr), 5-Methoxy-2-I(2-Methylamino-ethylamino)- methyl]-phenol(MeO- MMP. 2HBr) and. 1-[(2-Methylamino-ethylamino)- methyl]-naphthalen-2-ol(Nap- MMP. 2HBr) were synthesized. The synthesized ligands were confirmed by C. H. N. atomic analysis, UV-visible and IR spectroscopies, $^1$H NMR, $^{13}$C NMR and mass analysis. The potentiometry study revealed that the proton dissociation constants(logK$_n^H$) of the synthesized ligands and stability constants (logK$_{ML}$, logK$_{LM2}$) of transition metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) ions occurred in three steps and the order of the calculated overall proton dissociation constants(log$\beta_p$) and stability constants (logK$_{ML}$) of ligands was Br-MMP. 2HBr < Cl-MMP 2HBr < H-MMP. 2HBr < Nap-MMP. 2HBr < Me-MMP. 2HBr < MeO-MMP. 2HBr. The order showed a similar trend to that of Hammett substituent constants($\delta_p$). The synthesized ligands usually form 2:1(ML$_2$) complexes with transition metal ions. The order of the stability constants of each transition metal ions was Co(II) < Ni(II) < Cu(II) ;> Zn(II) ;> Cd(II) ;> Pb(II).

Retention Behavior of Transition Metal ions with Some Complexing Agents on Cation Exchanger

  • Park, Yang-Soon;Joe, Kih-Soo;Lee, Gae-Ho;Han, Sun-Ho;Eom, Tae-Yoon
    • Bulletin of the Korean Chemical Society
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    • 제14권6호
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    • pp.692-696
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    • 1993
  • Prediction of retention times in transition metal-mandelate and transition metal-tartrate complex systems were studied on the cation exchanger. Plots of k' vs [mandelate] and k' vs [tartrate] were obtained under the condition of a constant competing cation concentration. The equation to predict the retention time of transition metal ion was derived from the ion exchange equilibria. Individual capacity factors (${k_1}',\;{k_2}'$) and stability constants ($K_1,\;K_2$) of the complexes were calculated from the non-linear least square method. Good resolution of the transition metals was predicted by the stepwise equation in the gradient method. The values of retention times from the calculation and the experiment agreed well each other.