• Journal of the Korean Chemical Society
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• v.9 no.3
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• pp.121-123
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• 1965

Polarographic studies of Ni(II) ion complexed with monoethanolamine, MEA, in aqueous solution have been carried out using sodium perchlorate as a supporting electrolyte. With use of D. C. and A. C. polarograms polarographic behaviors of the complex have been discussed. The wave obtained from basic solutions are found to be well defined and reversible, while reduction of the complex at pH smaller than 8.8 seems to be kinetic controlled with different complex species. Reducing species of the complex on the mercury electrode is determined to be $Ni(MEA)_3OH$ instead of $Ni(MEA)_2(OH)_2$ which is reported by other workers. Overall stability constant of $Ni(MEA)_3OH$ is obtained to be $10^{20}.$

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2299-2304
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• 2012

Two new metal(II) complexes, $[Mn(dpa)(phen)(H_2O)_2]_n$ (1) ($H_2dpa$ = dephenic acid, phen = 1,10-phenanthroline) and $[Ni_2(nda)(phen)_2(H_2O)_6](nda)(H_2O)$ (2) ($H_2nda$ = 2,6-naphthalenedicarboxylic acid) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. In complex 1, Mn(II) ion is six-coordinated, and Mn(II) ions are bridged by dpa ligands into 1D chains. While, the complex 2 is dimer and two Ni(II) ions are bridged by one nda ligand cooperated with the terminal ligand phen. In each complex, the dicarboxylate ligand is coordinated to metal(II) ions as a bis-monodentate.

• Journal of the Korean Chemical Society
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• v.62 no.6
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• pp.427-432
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• 2018

The reaction of [$[Ni(L)]Cl_2{\cdot}2H_2O$ (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[$14,4,0^{1.18},0^{7.12}$]docosane) with 1,1-cyclohexanediacetic acid ($H_2cda$) yields mononuclear nickel(II) complex, [$Ni(L)(Hcda^-)_2$] (1). This complex has been characterized by X-ray crystallography, electronic absorption, cyclic voltammetry and thermogravimetric analyzer. The crystal structure of 1 exhibits a distorted octahedral geometry with four nitrogen atoms of the macrocycle and two 1,1-cyclohexanediacetate ligands. It crystallizes in the triclinic system P-1 with a = 11.3918(7), b = 12.6196(8), $c=12.8700(8){\AA}$, $V=1579.9(2){\AA}^3$, Z = 2. Electronic spectrum of 1 also reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes one wave of a one-electron transfer corresponding to $Ni^{II}/Ni^{III}$ process. TGA curve for 1 shows three-step weight loss. The electronic spectra, electrochemical and TGA behavior of the complex are significantly affected by the nature of the axial $Hcda^-$ ligand.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1729-1732
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• 2011

• Journal of the Korean Chemical Society
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• v.30 no.6
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• pp.526-531
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• 1986

The stability constants of 1,15-diaza-3,4:12,13-dibenzo-5,8,11-trioxacycloheptadecane (NenOdien H$_4$, L) with transition metal ions such as $Co^{2+},\;Ni^{2+},\;Cu^{2+},\;and\;Zn^{2+}$ have been determined by potentiometry in 95% methanol solution at 25$^{\circ}$C. The complex formation of the NenOdien $_4$ with the transition metal ions depends on the basicity of the donor atoms. The order of complex stability was Co(II) < Ni(II) < Cu(II) > Zn(II). The geometries of the complexes in solid state were discussed by visible-near infrared and infrared spectrophotometry, elemental analysis and electro-conductivity. The results suggest that the geometries of the solid complexes are octahedral for $[CoL_2(OH_2)Cl]Cl{\cdot}2H_2O$, $[NiL_2(OH_2)Cl]Cl{\cdot}2H_2O$, and $[ZnLCl_2]{\cdot}\frac{1}{2}H_2O$ and square pyramidal for [CuLCl]Cl, respectively.

• Journal of the Korean Chemical Society
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• v.30 no.5
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• pp.475-482
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• 1986

Rates and equilibriurn of complex formation between $Ni^{2+}$ and D-penicillamine have been investigated in aqueous solutions. Kinetic study on the complex formation were performed in the pH range of 8∼9 by the use of pressure-jump technique. D-Penicillamine coordinates to the nickel(II) ion utilizing sulfur and nitrogen as donor atoms in the high pH condition (pH 9.2). However, in the pH range of 8.25∼9.07, the stepwise stability constant becomes drastically reduced and the undissociated mercapto group does not participate in bonding. The rate-determining step of the complexation reaction is found to be the release of a water molecule from the inner-coordination sphere of $Ni^{2+}$ ion.

• Korean Journal of Crystallography
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• v.12 no.4
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• pp.222-226
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• 2001

The title complex, $Ni(L)_4(NCS)_2$(1) (L=2-ethylimidazole) has been synthesized and charac-terized by X-ray single crystallography. The complex 1 crystallizes in the tertragonal system P4nc space group with a=10.587(2), $c=12.927(3){\AA}$, Z=2m, $R_1$=0.581 and $wR_$=0.1675 for 672 independent reflection. The central Ni(II) atom of the complex has a regular octa-hedral coordination geometry, with the 2-ethylimidazole ligands bonding through nitrogen atom and the isothiocyanate ligands bonding through nitrogen atom in a trans arrangement.

• Journal of the Korean Chemical Society
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• v.49 no.1
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• pp.47-55
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• 2005

• Bulletin of the Korean Chemical Society
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• v.21 no.5
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• pp.483-486
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• 2000

A method is described for the fluorimetric determination of nickel, based on the formation of $Ni(II)-\alpha-(2-Benzimidazolyl)-\alpha'$, $\alpha''$ -(N-5-Nitro-2-Pyridylhydrazone)-toluene complex in the presence of a non-ionic surfactant. The complex has practically no fluorescence in the absence of surfactant, but the addition of Triton X-100 makes possible the fluorimetric determination of low concentrations of Ni(II) as it enhances the fluorescenceintensity of the complex by up to about 5-fold. This method is very sensitive and selectrive for the direct determination of nickel ion. The optimum conditions are a Triton X-100 concentration of 2.0 mL(5.0%, v/v) and pH $9.0\pm0.2(ammonium$ chloride-ammonia buffer). The fluorescence is measured at 337 nm of emission wavelength under 300 nm of excitation wavelength. The fluorescence intensity is a linear function of the concentration of Ni(II) in the range 5-70 ng/mL, and the detection limit is 2.0 nm/mL. The proposed method has been successfully applied to the determination of trace amounts of Ni(II) in food and human hair samples.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3765-3770
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• 2010

Selective oxidation of olefins has been carried out in water medium with tert-butylhydroperoxide (TBHP, 70% aqueous) as an oxidant using polymer-anchored Ni(II) complex as a catalyst. Several parameters were varied to optimize the reaction conditions. Under the optimized reaction conditions olefins gave selectively allylic oxidation products. The present polymer anchored Ni(II) complex can be recycled five times without any appreciable loss in catalytic activity.