• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.28-28
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• 2002

The hydrothermal reaction of Ni(NO₃)·6H₂O with 4.4'-oxybis(benzoic acid) (OBCH₂) and trans-1,2-bis(4-pyridyl)ethylene (bipyen) led to the formation of a 3-dimensional coordination polymer with the empirical formular of [Ni(OBC)(bipyen)]·H₂O. The complex has been characterized by X-ray diffraction, elemental analysis, TGA, IR, X-ray power diffraction (XRPD), It crystallized triclinic space group P1 with a = 9.280(2)Å., b = 11.317(4) Å, c = 12.442(3) Å, Z = 2, R (ωR₂) = 0.0346 (0.0846).

• Korean Architects
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• s.477
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• pp.66-70
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• 2009

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.430-431
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• 2018

• Journal of Electrochemical Science and Technology
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• v.8 no.3
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• pp.222-235
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• 2017

First, in this study, the inhibition efficiencies of metal complexes with Cu(II), Ni(II) and Zn(II) of STSC ligand for corrosion control of mild steel in oilfield formation water were investigated. The IEs for a mixture of 500 ppm STSC and 5 ppm metal ion ($Cu^{+2}$, $Ni^{+2}$, $Zn^{+2}$) were found to be 88.77, 87.96 and 85.13 %, respectively. The results were obtained from the electrochemical techniques such as open circuit potential, linear and tafel polarization methods. The polarization studies have showed that all used Schiff base metal complexes are anodic inhibitors. The protective film has been analyzed by FTIR technique. Also, to detect the presence of the iron-inhibitor complex, UV-Visible spectral analysis technique was used. The inhibitive effect was attributed to the formation of insoluble complex adsorbed on the mild steel surface and the adsorption process follows Langmuir adsorption isotherm. The surface morphology has been analyzed by SEM. Secondly, the computational studies of the ligand and its metal complexes were performed using DFT (B3LYP) method with the $6-311G^{{\ast}{\ast}}$ basis set. Finally, it is found that the experimental results were closely related to theoretical ones.

• Journal of the Korean Chemical Society
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• v.57 no.3
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• pp.316-321
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• 2013

Electrocoagulation (EC) technique is applied for the treatment of wastewater containing heavy metals ions such as nickle (Ni), lead (Pb) and cadmium (Cd) by using sacrificial anodes corrode to release active coagulant flocs usually aluminium or iron cations into the solution. During electrolytic reactions hydrogen gas evolve at the cathode. All the experiments were carried out in Batch mode. The tank was filled with synthetic wastewater containing heavy metals and efficiency of electro-coagulation in combination with aluminum and iron electrodes were investigated for removal of such metals. Several parameters, such as contact time, pH, electro-coagulant concentration, and current density were optimized to achieve maximum removal efficiency (%). The concentrations of heavy metals were determined by using Atomic Absorption Spectroscopy (AAS). It is found that the electro-coagulation process has potential to be utilized for the cost-effective removal of heavy metals from wastewater specially using iron electrodes in terms of high removal efficiencies and operating cost.

• Journal of the Korean Chemical Society
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• v.9 no.1
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• pp.45-48
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• 1965

Stability constant, composition of copper (II)-oxamidoxime complex were determined by spectrophotometric method. The ratio of copper (II) and oxamidoxime in the above complex was 1 : 1, and its stability constant was calculated to be $2.4{\times}10^{22}$. The complex solution gave constant absorbancy between the pH range of 4.5 to 6 at 600 $m{\mu}$ in which Beer's law applicable in the concentration range of 0.3 to 2.0 ppm studied in this work. It was noted that some metals such as Fe(III), Ni(II), Co(II), U(VI) interfere copper determination by this method.

• 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.

• Journal of the Korean Chemical Society
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• v.8 no.2
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• pp.62-64
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• 1964

The cation exchange chromatographic studies for the analysis of transition metals have been described. The quantitative separation of a mixture of Fe(Ⅲ), Cu(II), Zn(II), Ni(II), Cd(II), Co(II) and Mn(II) has been obtained by elution, through a 28cm column of the resin, Dowex 50 ${\times}$ 4 (100∼200 mesh), using 0.45 M $NaNO_3$+0.05 M Na-tartrate solution as eluent, starting with the eluent of pH 3.5, followed stepwise by pH 4.0 and 4.5. A comparison between the calculated and the observed peak positions in the elution curve has been shown. The relative stability constants for tartrate complexes of some transition metals have been calculated by using distribution ratios obtained in this separation procedure.

• Analytical Science and Technology
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• v.9 no.4
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• pp.364-372
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• 1996

The sorption and desorption properties of U(VI), Th(IV), Zr(IV), Cu(II), Pb(II), Ni(II), Zn(II), Cd(II) and Mn(II) ions on XAD-16-[2-(2-thiazolylazo)-p-cresol](TAC) chelating resin were studied by elution method for selective separation, concentration and recovery of trace metal ions in sea water. The optimum conditions for the sorption of metal ions were examined with respect to flow rate, pH and concentration of buffer solution. The overall capacities of some metal ions on this chelating resin were 0.41mmol U(VI)/g resin, 0.55mmol Th(IV)/g resin, 0.43mmol Cu(II)/g resin, and 0.32mmol Zr(IV)/g resin, respectively. The elution order of metal ions obtained from breakthrough capacity and overall capacity at pH 5.0 was found as Th(IV)>Cu(II)>U(VI)>Zr(IV)>Pb(II)>Ni(II)>Zn(II)>Cd(II)>Mn(II). Desorption of characteristics for metal ions were investigated with desorption agents such as $HNO_3$, HCl, $HClO_4$, $H_2SO_4$, and $Na_2CO_3$. It was found that most of metal ions except Zr(IV) showed high desorption efficiency with 2M $HNO_3$. But, desorption and recovery of Zr(IV) ion were successfully performed with 1M $H_2SO_4$. The resin was applied for separation and preconcentration of trace amount of U(VI) ion from artificial sea water and the recovery of U(IV) was over 96%.

• Journal of the Korean Chemical Society
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• v.35 no.2
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• pp.119-127
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• 1991

The protonation and the metal ion complexation of 15 to 18 membered diaza crown ether such as 1,12-diaza-3, 4 : 9, 10-dibenzo-5, 8-dioxacyclopentadecane(NtnOenH$_4$), 1,13-diaza-3,4 : 10,11-dibenzo-hydroxy-5,9-dioxacyclohexadecane(NtnOtnH$_4$), 1,13-diaza-3,4 : 10,11-dibenzo-15-hydroxy-5,9-dioxacyclohexadecane(Ntn(OH)OtnH$_4$), 1,15-diaza-3,4 : 12,13-dibenzo-5,8,11-trioxacycloheptadecane (NenOdienH$_4$) and 1,15-diaza-3,4 : 12,13-dibenzo-5,8,11-trioxacyclooctadecane(NtnOdienH$_4$) were studlied by potentiometry and NMR spectroscopy. The protonation constants were used to predict basicity of crown ethers. The sequence of the basicity was NenOdienH$_4$ < Ntn(OH)OtnH$_4$ < NtnOenH$_4$ < NtnOtnH$_4$ < NtnOdienH$_4$. Changes on the basicity were explained in terms of the effects of substituents and the degree of twistness of the macrocyclic ring. The sequence of the complex stabilities were Co(II) < Ni(II) < Cu(II) < Zn(II) for the transition metal complexes and Cd(II) < pb(II) < Hg(II) for the post-transition metal complexes. These changes on the stabilities were dependent on the basicity of the ligand and cavity size of the ring. For the heavy post-transiton metal complexes and Zn(Ⅱ) complex, the former factor was predominent and for the other transition metal complexes, the latter was affected on the stabilities. $^1$H and $^{13}$C-NMR studies for heavy post-transition metal complexes indicated that the nitrogen atom has greater affinity on metal ions than oxygen atom and the planarity of the rings was losed by the complexation with metal ions.