• Title/Summary/Keyword: Cu(II) complex

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Spectrophotometric determination of acetylsalicylic acid with copper-$\alpha$-picolin complex in tetrachloromethane ($\alpha$-picolin동에 의한 aspirin의 용매 흡광도 정량법)

  • 백남호;박만기
    • YAKHAK HOEJI
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    • v.13 no.2_3
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    • pp.80-83
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    • 1969
  • Acetylsalicylic acid gives a water-insoluble violet complex with $<\alpha>$-Picolin-Cu(II) reagent. The Complex is extractable well with a mixture of $<\alpha>$-Picolin-tetrachloromethane solution. The Complex salt dissolved in the mixed solution shows a maximum absorption at 620 m$<\mu>$. It has a melting point at $171^{\circ}C-$173^{\circ}C and molar ratio of Acetylsalicylic acid: Cu(II): $<\alpha>$-Picolin was estimated as 2:1:2 by continuous variation method and chelate titration method.

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N3S-ligated Copper(II) Complex Catalyzed Selective Oxidation of Benzylic Alcohols to Aldehydes under Mild Reaction Conditions

  • Dharmalingam, Sivanesan;Koo, Eunhae;Yoon, Sungho;Park, Gyoosoon
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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    • pp.715-720
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    • 2014
  • A Cu(II) complex with an three nitrogens and one sulfur coordination environment was synthesized and characterized. Its redox potential was observed at 0.483 V vs. NHE, very similar to that of a Cu-containing fungal enzyme, galactose oxidase, which catalyzes the oxidation of alcohols to corresponding aldehydes with the concomitant reduction of molecular oxygen to water. The Cu(II) complex selectively oxidizes the benzylic alcohols using TEMPO/$O_2$ under mild reaction conditions to corresponding aldehydes without forming any over-oxidation product. Moreover, the catalyst can be recovered and reused multiple times for further oxidation reactions, thus minimizing the waste generation.

Decomposition Studies of DFP Using Transition Metal Catalysts (전이금속촉매를 사용한 DFP 분해 성능 연구)

  • Kye, Young-Sik;Jeong, Keunhong;Chung, Woo Young
    • Applied Chemistry for Engineering
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    • v.21 no.1
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    • pp.1-5
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    • 2010
  • Cu(II)-organic complexes were synthesized with Lewis base organic ligands including diamine, aminothiol, and dithiol to determine the reactivity for DFP hydrolysis. Results show that the aminothiol catalyst enhances the hydrolysis of DFP in three folds compared to diamine type because aminothiol has higher basicity than diamine. Due to low solubility of Cu(II)(1,2-ethane dithiol)$(NO_3)_2$, it is impossible to compare directly the rates in homogeneous condition. However, the rate of dithol complex is even 1.6 times faster than that of the diamine type. The reactivity of zeolite for DFP hydrolysis is also evaluated. NaY type does not promote the hydrolysis, but RuNaY shows relatively lower reactivity than those of Cu(II)-organic ligands complexes.

Synthesis and Characterization of New Tetraaza Macrocycles Bearing Two or Four N-Methoxyethyl Pendant Arms and Their Copper(II) and/or Nickel(II) Complexes

  • Kang, Shin-Geol;Kim, Hyun-Ja;Kwak, Chee-Hun
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2701-2704
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    • 2010
  • This work shows that both L2 and L3 bearing two and four N-$(CH_2)_2OCH_3$ groups, respectively, can be prepared selectively by the reaction of $L^1$ with 1-bromo-2-methoxyethane. The di-N-substituted macrocycle $L^2$ readily forms its copper(II) and nickel(II) complexes. The N-$(CH_2)_2OCH_3$ groups in $[CuL^2]^{2+}$ are coordinated to the metal ion, whereas those in $[NiL^2]^{2+}$ are not involved in coordination. Interestingly, $L^3$ reacts with $Cu^{2+}$ ion to form $[Cu(HL^3)]^{3+}$, in which one tertiary amino group is not involved in coordination.

Hydrolysis of DFP Using Cu(II)-Lactic Acid and Cu(II)-LMWS-Chitosan Chelates (Cu(II)-Lactic Acid와 Cu(II)-LMWS-Chitosan 착물의 DFP 가수분해반응 연구)

  • Kye, Young-Sik;Jeong, Keunhong;Kim, Dongwook
    • Applied Chemistry for Engineering
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    • v.31 no.5
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    • pp.475-480
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    • 2020
  • Chelates synthesized with Cu(II) ion and lactic acid or chitosan were applied to the hydrolysis of organophosphate simulant, DFP (diisopropyl fluorophosphate). Under the homogeneous reaction condition, Cu(II)-lactic acid chelate hydrolyzed DFP with the half life time of 37.1 min. Cu(II)-LMWS chitosan chelate was synthesized with 1 kDa molecular weight of chitosan, which showed low solubility, and then crystallized. The half life time for hydrolyzing DFP using Cu(II)-LMWS chitosan was 32.9 h indicating that the reaction rate is enhanced as much as 16 times more than that of using 18 kDa chitosan-Cu(II) complex. Under the homogeneous reaction condition, the half life time of Cu(II)-LMWS chitosan was 8.75 h. Therefore, we found out that the solubility of Cu(II)-LMWS chitosan makes the difference in the reaction rate as much as 4 times.

Synthesis, Properties, and X-ray Crystal Structure of Copper(II) Complex with Bis[(2-pyridyl)methyl]-2-(2-pyridyl)ethylamine (Bis[(2-pyridyl)methyl]-2-(2-pyridyl)ethylamine 구리(II) 착물의 합성, 성질 및 X-ray 결정구조)

  • Choi, Ki-Young
    • Journal of the Korean Chemical Society
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    • v.51 no.1
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    • pp.31-35
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    • 2007
  • The tripodal copper(II) complex [Cu(pmea)(H2O)](ClO4)2·H2O (1) (pmea = bis[(2-pyridyl)methyl]-2-(2-pyridyl)ethylamine) has been synthesized and structurally characterized by X-ray diffraction method. It crystallizes in the triclinic system P-1 with a = 9.9362(9), b = 15.7299(17), c = 18.0562(11) A, α = 68.760(8), β = 76.331(6), γ = 77.092(9)°, V = 2526.2(4) A3, Z = 2. Each copper atom reveals a distorted square pyramidal with three nitrogen atoms of the pmea ligand and water molecule occupying the basal plane and one nitrogen atom from the pyridine ring according the axial position. The cyclic voltammogram of 1 undergoes reversible one-electron oxidation to the CuIII and reversible one-electron reduction to the CuI.

Electrochemical Behaviors of Copper-1-(2-Thiazolylazo)-2-naphthol Complex in Acetonitrile (아세토니트릴 용매 중에서 Copper-1-(2-Thiazolylazo)-2-naphthol 착물의 전기화학적 거동)

  • Bae Zun Ung;Lee Heung Lark;Park Tae Myung;Seo Moo Lyong
    • Journal of the Korean Chemical Society
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    • v.35 no.4
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    • pp.405-409
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    • 1991
  • The electrochemical behaviors of copper-1-(2-thiazolylazo)-2-naphthol [Cu(II)-TAN] complex in acetonitrile (AN) solution have been investigated by the use of polarography, controlled potential coulometry and UV-Vis spectroscopy. Cu(II)-TAN complex exhibit three reduction waves at -0.91 V, -1.34 V and -1.65 V vs. S.C.E. in acetonitrile solution containing 5.0 ${\times}\;10^{-3}$M tetraethylammonium perchlorate. Every reduction wave is diffusion controlled. The first reduction wave is considerably reversible and this process is attributed to the formation of anion radical. The second reduction process to the dianion is followed by a chemical reaction producing a complex of hydrazo complex. The third reduction process produce Cu(Hg) amalgam and amine compound.

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