• 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.

• Bulletin of the Korean Chemical Society
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• v.12 no.3
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• pp.276-281
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• 1991

Electrochemical behaviors of optically active sparteine-Cu(II) dihalide complexes were investigated by polarography and cyclic voltammetry (CV). These Cu(II) complexes are rather easier to be reduced to Cu(I) states when comparison is made with other nonplaner copper complexes, We have assigned the CV peaks and polarographic waves related to the redox processes for these complexes. We could also observe the exchange reaction of Cu(II) ion in the complex with mercury metal in the cell having mercury pool. The redox mechanism of these complelxes is as follows; The 1st wave appeared at +0.47 V/+0.65 V corresponds to the reaction of $SpCuX_2+ e{\rightleftarrow}SpCuX_{2^-}$ and the 2nd one at +0.26 V/+0.21 V does the reaction of $SpCuX_{2 ^-} +e{\rightleftarrow}SpCuX_2^{2-}$. The 3rd one at -0.35 V/-0.27 V is dueto the reduction of mercury complex formed via exchange reaction. Where, X is chloride ion.

• Journal of the Korean Society of Clothing and Textiles
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• v.12 no.1 s.26
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• pp.27-35
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• 1988

In order to investigate a practical application of the fibrous adsorbent to heavy metal ions, acrylic fibers were treated with the hydroxylamine solution that was producted by hydroxylamine hydrochloride and potasium hydroxide in a condition of strong alkaline and $70^{\circ}C$. The adsorption mechanism of copper(2) ion on the fibrous adsorbent, that is hydroxylaminated acrylic fibers, was studied. The adsorption of copper(2) ion was explained in terms of the activated adsorption that are formed the complex with the ligand, such as C=N, N-H, NHOH, on the surface of the adsorbent. The activation energy was evaluated to be 3.8 Kcal/mol. and the times of adsorption equilibrium was approximately 10 minutes. The uptake of copper(2) ion was found to be effected with the increase of temperatures and the pH dependence.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1339-1342
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• 2010

$^{31}P$ NMR and ESI-MS studies of $Cu^{2+}$ binding to Fenitrothion (FN) were performed by experimentally and theoretically. The calculated $^{31}P$ NMR chemical shifts for FN-$Cu^{2+}$ complexes are in good agreement with experimental chemical shifts in order, and the results present an important information for organophosphorus pesticide metal complexes. ESI-MS and low energy CID MS/MS experiments of FN-$Cu^{2+}$ complexes combined with accurate mass measurements give insight into the metal localization and allow unambiguous identification of fragments and hydrolysis products.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.356-360
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• 2003

Nitroso-2-naphthol-3,6-disulfonic acid, disodium salt (NRS) was used as an organic ligand to prepare basic drug-selective polymeric membrane electrode. The sensing membrane of the electrode consited of basic drug-meta1(II)-NRS as an ion-exchanger site in a poly(vinyl chloride) matrix plasticized with 2-nitrophenyl octyl ether (NPOE). The metal ions used were Fe$^{2+}$, Co$^{2+}$, Ni$^{2+}$ and Cu$^{2+}$. The electrodes exhibited fast and wide linear response in the basic drug concentration of 10$^{-5}$ ∼10$^{-3}$ mol/l with a response slope of 50∼60 mV/decade in a buffer solution of pH 4∼8. The electrodes exhibited good selectivity for many basic compounds.mpounds.

• Journal of the Semiconductor & Display Technology
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• v.20 no.1
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• pp.54-58
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• 2021

The RGO with controllable oxygen functional groups is a novel material as the active layer of resistive switching memory through a reduction process. We designed a nanoscale conductive channel induced by local oxygen ion diffusion in an Au / RGO+GQD / Al resistive switching memory structure. A strong electric field was locally generated around the Al metal channel generated in BIL, and the local formation of a direct conductive low-dimensional channel in the complex RGO graphene quantum dot region was confirmed. The resistive memory design of the complex RGO graphene quantum dot structure can be applied as an effective structure for charge transport, and it has been shown that the resistive switching mechanism based on the movement of oxygen and metal ions is a fundamental alternative to understanding and application of next-generation intelligent semiconductor systems.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.314-318
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• 2007

The feasibility of the employment of waste oyster shell as an adsorbent for fluoride ion has been tested by considering the effect ionic condition on the adsorption of fluoride ion on oyster shell. The adsorption capacity of oyster shell for fluoride ion was found not to be significantly influenced by the ionic strength of aqueous environment. The existence of complexing agent such as nitrilotriacetic acid in wastewater decreased the adsorbed amount of fluoride ion by forming a stable complex of $CaT^-$ and the adsorption reaction of fluoride ion on oyster shell was examined to be endothermic. The coexisting heavy metal ionic adsorbate in wastewater hindered the adsorption of fluoride ion, however, its adsorbed amount was increased as the particulate size of adsorbent was decreased. Finally, a serial adsorption column test has been conducted for a practical application of adsorption process and the breakthrough of the column adsorption was observed in 22 hours under the experimental condition.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.626-631
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• 2006

The adsorption features of copper ion have been investigated by taking the barley residue which occurring from the beer production process as an adsorbent. Under the experimental conditions, adsorption equilibrium of copper ion was attained within 30 minutes after the adsorption started and the adsorption reaction was observed to be first order. As the temperature increased, the adsorbed amount of copper ion at equilibrium was also increased, which indicated that the adsorption reaction was endothermic. Based on the experimental results which obtained by varying the temperatures, several thermodynamic parameters for copper adsorption reaction were estimated. Regarding the electrokinetic behavior of barley residue, its electrokinetic potential was observed to be positive below pH 5 and turned into negative above this pH. In the pH range from 1.5 to 4, copper adsorption was found to be increased, which was well explained by the electrokinetic behavior of barley residue in the pH range. When nitrilotriacetic acid, which is a complexing agent, was coexisted with copper ion, equilibrium adsorption of copper ion was decreased and this was presumed to be due to the formation of metal complex. In addition, the adsorbed amount of copper ion was examined to be increased when $KNO_3$ was coexisted, however, it approached a saturated value above a certain concentration of $KNO_3$.

• Bulletin of the Korean Chemical Society
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• v.17 no.4
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• pp.331-334
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• 1996

New copper(Ⅱ) complex of the pentaaza non-macrocyclic ligand 1-(2-aminoethyl)-3-(N-{2-aminoethyl}aminomethyl)-1,3-diazacyclohexane (2) and a dinuclear copper(Ⅱ) compex of the bis(macrocyclic) ligand 3, in which two 1,5,8,10,12,15-hexaazabicyclo[11.3.11.5]heptadecane subunits are linked together by an ethylene chain through the uncoordinated nitrogen (N10) atoms, have been prepared selectively by the reaction of the metal ion, 1,4,8-triazaoctane, ethylenediamine, and formaldehyde. The dinuclear complex [Cu2(3)]4+ has been also prepared by the reaction of [Cu(2)]2+ with ethylenediamine and formaldehyde. The reaction products largely depend on the molar ratio of the reactants employed. The mononuclear complex or each macrocyclic subunit of the dinuclear complex contains one 1,3-diazacyclohexane ring and has a square-planar geometry with a 5-6-5 or 5-6-5-6 chelate ring sequence. In acidic solution, the copper(Ⅱ) complex of 2 dissociates more slowly than those of other related non-cyclic polyamines.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3543-3548
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• 2010

A kinetic study on nucleophilic displacement reactions of 2-pyridyl X-substituted benzoates 1a-e with potassium ethoxide (EtOK) in anhydrous ethanol is reported. Plots of pseudo-first-order rate constants ($k_{obsd}$) vs. $[EtOK]_o$ exhibit upward curvature. The $k_{obsd}$ value at a fixed $[EtOK]_o$ decreases steeply upon addition of 18-crown-6-ether (18C6) to the reaction mixture up to [18C6]/$[EtOK]_o$ = 1 and then remains nearly constant thereafter. In contrast, $k_{obsd}$ increases sharply upon addition of LiSCN or KSCN. Dissection of $k_{obsd}$ into $k_{EtO^-}$ and $k_{EtOM}$ has revealed that ion-paired EtOK is more reactive than dissociated $EtO^-$, indicating that $K^+$ ion acts as a Lewis acid catalyst. Hammett plots for the reactions of 1a-e with dissociated $EtO^-$ and ion-paired EtOK result in excellent linear correlation with $\rho$ values of 3.01 and 2.67, respectively. The $k_{EtOK}/k_{EtO^-}$ ratio increases as the substituent X in the benzoyl moiety becomes a stronger electron-donating group. $K^+$ ion has been concluded to catalyze the current reaction by stabilizing the transition state through formation of a 6-membered cyclic complex.