• Title/Summary/Keyword: Copper(II)

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Influence of Jahn-Teller Distortion on the Magnetic Coupling in Oxalato-Bridged Copper(II) Dimers: An Orbital Interpretation of the Superexchange Mechanism

  • Kang, Dae-Bok
    • Bulletin of the Korean Chemical Society
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    • 제26권12호
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    • pp.1965-1968
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    • 2005

  • Extended H$\ddot{u}$ckel molecular calculations have been used to analyze how the magnitude of exchange coupling is influenced by the structural distortions in a series of dinuclear six-coordinate copper(II) complexes bridged by the planar bis-bidentate oxalate anion. Copper(II) ions have distorted octahedral surroundings, one being axially elongated and the other compressed. The magnetic interaction is strong in the former complexes and very weak in the latter. This is interpreted as resulting from a switching of magnetic spin orbitals due to the structural distortions (bond elongation or compression) of the copper sites.

  • https://doi.org/10.5012/bkcs.2005.26.12.1965 인용 PDF KSCI

Cation Exchange Capacity in Korean Soils Determined by the Copper(II) Acetate Spectrophotometry Method

  • Park, Won-Pyo;Chang, Kong-Man;Koo, Bon-Jun;Hyun, Hae-Nam
    • 한국토양비료학회지
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    • 제50권6호
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    • pp.653-662
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    • 2017

  • Copper(II) acetate spectrophotometry method (CASM) was used for the rapid and convenient determination of cation exchange capacity (CEC) in soils. This method is composed of a single-step exchange reaction that adsorbs copper and is measured through spectrophotometry. The CEC of 16 Korean soils were measured using 1M ammonium acetate method (AAM) and the CASM. The CEC values determined by CASM and AAM were not significantly different, and were highly correlated ($r=0.966^{**}$). Due to the convenience, cost effectiveness, and time saving analysis of CASM, this method is recommended for most soil laboratories to measure CEC in Korean soils. However, CASM may not be applicable for soils that have a much higher CEC (greater than $20cmol_c\;kg^{-1}$).

  • https://doi.org/10.7745/KJSSF.2017.50.6.653 인용 PDF KSCI

Antifungal Activities of Biorelevant Complexes of Copper(II) with Biosensitive Macrocyclic Ligands

  • Raman N.;Joseph J.;Velan A. Senthil Kumara;Pothiraj C.
    • Mycobiology
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    • 제34권4호
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    • pp.214-218
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    • 2006

  • Four copper(II) complexes have been prepared using macrocyclic ligands. The macrocyclic ligands have been synthesized by the condensation reaction of diethyl phthalate with Schiff bases derived from o-phenylene diamine and Knoevenagel condensed ${\beta}-ketoanilides$ (obtained by the condensation of acetoacetanilide and substituted benzaldehydes). The ligands and copper complexes have been characterized on the basis of Microanalytical, Mass, UV-Vis., IR and CV spectral studies, as well as conductivity data. On the basis of spectral studies, a square-planar geometry for the copper complexes has been proposed. The in vitro antifungal activities of the compounds were tested against fungi such as Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans. All the synthesized copper complexes showed stronger antifungal activities than free ligands. The minimum inhibitory concentrations (MIC) of the copper complexes were found in the range of $8{\sim}28\;{\mu}g/ml$. These compounds represent a novel class of metal-based antifungal agents which provide opportunities for a large number of synthetic variations for modulation of the activities.

  • https://doi.org/10.4489/MYCO.2006.34.4.214 인용 PDF KSCI

Preparation and Properties of New Di-N-alkylated 14-Membered Tetraaza Macrocycles and Their Nickel(II) and Copper(II) Complexes

  • 강신걸;송정훈;황동막;김기문
    • Bulletin of the Korean Chemical Society
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    • 제21권11호
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    • pp.1106-1110
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    • 2000

  • New 14-membered tetraaza macrocycles 1,8-diallyl-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane $(L^2)$ and 1,8-bis(n-propyl)-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane $(L^3)$ have been prepared by direct react ion of 2,5,5,7,9,12,12,14-octamethyl-1,4,8,11-tetraazacyclotetradecane $(L^1)with$ allyl bromide or n-propyl bromide. The nickel(II) and copper(II) complexes of $L^2andL^3have$ been prepared. The macrocycles show high copper(II) selectivity against nickel(II) ion in methanol solutions containing water. The wavelengths (ca. 505 nm) of the d-d bands for the nickel(II) complexes are extraordinarily longer than those for the complexes of $L^1and$ other related di-N-alkylated 14-membered tetraaza macrocycles. Crystal structure of $[NiL^2](ClO4)_2$ shows that the average Ni-N bond distance $(1.992\AA)$ of the complex is distinctly longer than those of other related nickel(II) complexes. Effects of the N- and C-substituents on the properties of the macrocyclic compounds are discussed.

  • https://doi.org/10.5012/bkcs.2000.21.11.1106 인용 PDF

Sulfa제-Cu착화합물의 형성에 관하여 II Spectrophotometry 에 의한 Copper Sulfa-Drug Complex 의 화학조성결정 (Studies on the Formation of Copper Complexes of Sulfa-Drug II.Study on Chemical Constisuent of Copper Sulfa-Drug Complex by Continuous Variation Method.)

  • 이왕규
    • 약학회지
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    • 제8권4호
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    • pp.96-99
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    • 1964

  • In the previous study, the composition ratios of the Cu-sulfa drugs complexes determined by gravimetric and solvent extraction method reported. In this paper, the continuous variations method has been used to know whether the complexes are simple complexes or chelates, and to recertify the composition ratios of the complexes at pH 7-8. It has been certified that the ratio of $Cu^{+2}$ ion to sulfa drugs in 1:2 from the result of this experiment.

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