• Journal of the Korean Chemical Society
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• v.37 no.7
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• pp.672-676
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• 1993

The complexation of bilirubin with zinc(II) and copper(II) ions was studied spectrophotometrically. In the zinc(II)-bilirubin (Zn-BR) system, complex is formed, but the copper(II) ion oxidizes bilirubin to biliverdin and then to the further oxidation products. The electrochemical reduction behavior of ZN-BR complex has been investigated with DC polarography and cyclic voltammetry. The three polarographic waves were obtained for the reduction of ZN-BR complex in DMF solution. Thde reduction current of the third wave was diffusion current, but that of the first and the second waves contained a little kinetic current.

• Bulletin of the Korean Chemical Society
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• v.27 no.4
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• pp.563-567
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• 2006

The application of a synergistic solvent extraction by the formation of ternary complex with pyrocatechol violet (PV) and benzalkonium chloride (BC) was studied for determination of trace Zn(II) in water samples. The pH of sample solution and the amount of PV and BC added were optimized for the formation of the stable complex, a proper solvent was selected for the effective extraction, and the concentration of nitric acid was fixed for the back extraction of the complex from the solvent. After the ionic strength of 100 mL sample solution was adjusted to 0.1 M by adding NaCl and the pH was fixed at 9 with a carbonate buffer, 1.0 mL of 2% PV solution was added to form Zn(II)-PV complex then the Zn(II)-PV/BC ternary complex was made by adding 1.0 mL of 10% BC solution. The ternary complex was extracted into 10 mL of MIBK. And the ternary complex was back-extracted with 10 mL of 1.0 mol/L nitric acid to determine Zn(II) by a flame atomic absorption spectrophotometer (flame-AAS). The interference of concomitant ions on the extraction of Zn(II) was investigated. This procedure was applied to the analysis of three real samples such as Dalbang-dam water, laboratory tap water and Jungnajin seawater. The recoveries of Zn(II) in spiked samples were 86.58-104.1%.

• Journal of the Korean Chemical Society
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• v.35 no.2
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• pp.135-141
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• 1991

The complexation of N,N'-oxalylbis(salicylaldehyde hydrazone) (OBSH) with Zn (II), Cd (II), and Pb(II) ions was studied by polarographic method in DMSO solution. The order of stability constants was Cd(II) < Zn(II) < pb(II), and all heavy metal ions formed stable complex with OBSH ligand. The stability constants of complexation were measured at various temperatures. As the results, enthalpy and entropy changes of the complexation were distributed on the complex stabilities.

• Journal of the Korean Chemical Society
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• v.47 no.2
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• pp.121-126
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• 2003

Tris(2-cyclohexylaminoethyl)amine (L) was synthesized by the Schiff base condensation reaction of tris(2-aminoethyl)amine with cyclohexanone, followed by reduction. The thermodynamic characteristics, mole ratio and formation constant of [Zn(II)-L] complex were measured by the cyclic voltammetry and isothermal titration. In the case of Zn(II), well-defined cathodic and anodic peak were obtained at -1.02V and -0.48V vs Ag/AgCl , respectively. For the [Zn(II)-L] complex, both peaks were obtained at -1.19V and -0.45V vs Ag/AgCl, respectively. In addition, the peak height gradually increases as the scan rate increases, suggesting that the currents obtained were diffusion - controlled. The mole ratio and stability constant of the complex measured cyclic voltammerty were 1:1 and logK$_f$= 5.8, respectively. And the mole ratio and stability constant of the complexe calculated by isothermal titration method was 1:1 and logK =5.4, respectively. ${\Delta}$H, ${\Delta}$G and T${\Delta}$S for the complex formation were -53.0 kJ/mol, -31.1 kJ/mol, and -21.9 J/K at 25 ${\circ}$C, respectively.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1849-1852
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• 2005

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2929-2934
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• 2014

The reaction between $[CdBr_2{\cdot}4H_2O]$ and anhydrous $[ZnCl_2]$ with N,N'-bidentate N-(pyridin-2-ylmethylene)-cyclopentanamine (impy) in ethanol yields dimeric $[(impy)Cd({\mu}-Br)Br]_2$ and monomeric $[(impy)ZnCl_2]$ complexes, respectively. The X-ray crystal structure of Cd(II) and Zn(II) complexes revealed that the cadmium atom in $[(impy)Cd({\mu}-Br)Br]_2$ and zinc in $[(impy)ZnCl_2]$ formed a distorted trigonal-bipyramidal and tetrahedral geometry, respectively. Both complexes showed moderate catalytic activity for the polymerisation of methyl methacrylate (MMA) in the presence of modified methylaluminoxane (MMAO), with polymethylmethacrylate (PMMA) syndiotacticity of about 0.70.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.3109-3112
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• 2009

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.733-737
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• 2006

In this paper, we report the coordination state and structure of $Zn(cyclam)Cl_{2})$ complex that was studied by the Raman spectrum and conductivity method. The complex of zinc(II) ion with 1,4,8,11-tetraazacyclotetradecane(cyclam) ligand is formed in aqueous solution. According to the Raman spectrum of $Zn(cyclam)Cl_{2})$ complex, $H_{2}O$ molecule and $Cl^{-}$ ion compete for the trans coordination site of zinc(II) ion. We also have investigated the competition effect of $H_{2}O$ molecule and $Cl^{-}$ ion by the conductivity method. On addition of 1,4,8,11-tetraazacyclotetradecane(cyclam) ligand to the aqueous $ZnCl_{2}$ solution, 2: 1 electrolyte is changed to 1:1 electrolyte. We suggest the possibility of elimination of heavy metal because of the affinity effect of macrocyclic polyamine(1,4,8.11-tetraazacyclotetradecane) for the heavy metal,.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3743-3748
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• 2013

A tetradentate ligand of 2-phenyl-4,6-di(pyridin-2-yl)pyrimidine (L) has been synthesized and its complexes with $ZnI_2$ and CuI have been obtained by hydrothermal method. single crystal X-ray diffraction analysis indicates that ligand L coordinates with Zn(II) ions to form a simple four-coordinate di-nuclear complex, while the complexation of L with Cu(I) constructs a one-dimensional chain polymer. The existence of $I^-$ ion hampers the L to assemble grid-type complexes with Zn(II) and Cu(I). Fluorescence spectra show that the L emits blue fluorescence while its Cu(I) polymer decrease the fluorescence intensity and Zn(II) complex quenches the fluorescence.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7555-7563
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• 2015

The complex formation from Zn(II) ion and 2-(2-hydroxyethylamino)-2-(hydroxymethyl)-1,3-propanediol (Monotris), Bis(2-hydroxyethyl)imino-tris(hydroxymethyl)methane(Bistris) in aqueous solution at $25^{\circ}C$ and at an ionic strength of 0.10 M have been studied potentiometrically. For the Zn(II)-Monotris system, in the Monotris (L) complex $ZnL^{2+}$, one of the hydroxyl oxygen atoms as well as the amine nitrogen of the ligand are coordinated. In basic media, the coordinated hydroxyl group is deprotonated. For the Zn(II)-Bistris system, in the Bistris(L) complex $ZnL^{2+}$, two of the hydroxyl oxygen atoms as well as the amine nitrogen of the ligand are coordinated. In basic media, one of the coordinated hydroxyl groups is deprotonated. In very high basic media, an additional hydroxyl group undergoes deprotonation. The equilibrium constants for the formation of $ZnL^{2+}$, $ZnLH_{-1}{^+}$, $ZnLH_{-2}$, $Zn_2L_2H_{-2}{^{2+}}$ and $Zn_2L_2H_{-3}{^+}$ have been determined.