• Journal of Environmental Science International
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• v.8 no.4
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• pp.491-496
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• 1999

Removal of Cu(II), Cr(III) and Pb(II) ions from aqueous solutions using the adsorption process on the loesses has been investigated. Variations of contact time, pH, adsorption isotherms and selectivity of coexisting ions were experimental parameters. pH of KJ and YIK samples diluted to 1% solution, was rearly the same with each value of pH 5.58 and 5.49, and both samples showed weak acidic properties. From chemical analysis, both samples contain remarkably different amounts of ${SiO}_{2}$, ${Al}_{2}O_{3}$ and ${Fe}_{2}O_{3}$. From XRD measurement, quartz was mainly observed in both samples. Kaolinite was also observed, also in both samples, but Feldspar was only observed in KJ sample. Adsorption of metal ions on the loesses were reached at equilibrium by shaking for about 30min. The adsorption of Cr(III) ion was higher than that of Cu(II) oand Pb(II) ions. The order of amount adsorbed among the investigated ions was Cr(III)>Pb(II)>Cu(II). In acidic solution, the adsorptivity of loesses was increased as pH increased. The adsorption of Cr(III) ion on the loesses were fitted to the Freundlich isotherms. Freundlich constants(1/n) of KJ and YIK loesses were 0.54 and 0.55, respectively.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.796-800
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• 2004

The structure of [Cu(tpen)]$(ClO_4)_2$ (tpen = N,N,N',N'-tetrakis(2-pyridylmethyl)-1,2-ethanediamine) has been identified by X-ray crystallography. The copper(II) ion is surrounded by two amine N atoms and three pyridine N atoms of the ligand, making a distorted trigonal-bipyramid. Among the six potential N donor atoms (two amine N and four pyridine N atoms), only one pyridine N atom remains uncoordinated. We examined structural changes on addition of $Cl^-$ to $[Cu(tpen)]^{2+}$(1). The addition of $Cl^-$ in methanol resulted in the formation of a novel dinuclear copper(II) complex $[Cu_2Cl_2(tpen)](ClO_4)_2{\cdot}H_2O$. The structure of the dinuclear complex was verified by X-ray crystallography. Each copper(II) ion in the dinuclear complex showed a distorted square planar geometry with two pyridine N atoms, one amine N atom and one $Cl^-$ ion.

• Korean Journal of Materials Research
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• v.21 no.1
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• pp.67-71
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• 2011

La doped CuO-ZnO-$Al_2O_3$ powders are prepared by sol-gel method with aluminum isopropoxide and primary distilled water as precursor and solvent. In this synthesized process, the obtained metal oxides caused the precursor such as copper (II) nitrate hydrate and zinc (II) nitrate hexahydrate were added. To improve the surface areas of La doped CuO-ZnO-$Al_2O_3$ powder, sorbitan (z)-mono-9-octadecenoate (Span 80) was added. The synthesized powder was calcined at various temperatures. The dopant was found to affect the surface area and particle size of the mixed oxide, in conjunction with the calcined temperature. The structural analysis and textual properties of the synthesized powder were measured with an X-ray Diffractometer (XRD), a Field-Emission Scanning Electron Microscope (FE-SEM), Bruner-Emmett-Teller surface analysis (BET), Thermogravimetry-Differential Thermal analysis (TG/DTA), $^{27}Al$ solid state Nuclear Magnetic Resonance (NMR) and transform infrared microspectroscopy (FT-IR). An increase of surface area with Span 80 was observed on La doped CuO-ZnO-$Al_2O_3$ powders from $25m^2$/g to $41m^2$/g.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.849-860
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• 2010

A new $N_3O_2$ pentadentate ligand, N,N'-Bis(2-hydroxybenzyl)-ethylenetriamine(H-BHET 3HCl) was synthesized. The hydrochloric acid salts of Br-BHET 3HCl, Cl-BHET 3HCl, $CH_3O$-BHET 3HCl and $CH_3$-BHET 3HCl containing Br-, Cl-, H-, $CH_3O-$ and $CH_3-$ groups at the para-site of the phenol group of the H-BHEP were synthesized. The structures of the ligands were confirmed by C. H. N. atomic analysis and $^1H$ NMR, $^{13}C$ NMR, UV-visible and mass spectra. The calculated stepwise protonation constants(${\logK_n}^H$) of the synthesized $N_3O_2$ ligands showed six steps of the proton dissociation. The orders of the overall protonation constants($\log{\beta}_p$) of the ligands were Br-BHET < Cl-BHET < H-BHET < $CH_3O$-BHET < $CH_3$-BHET. The orders agreed well with that of para Hammett substituent constants(${\delta}_p$). The calculated stability constants($\logK_{ML}$) between the ligands and heavy metal ions (Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II)) agreed well with the order of the overall proton dissociation constants of the ligands but they showed a reverse order in para Hammestt substituent constants(${\delta}_p$). The order of the stability constants between the heavy metal ions with the synthesized ligands were Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II).

• Journal of the Korean Chemical Society
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• v.27 no.2
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• pp.83-94
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• 1983

The effects of cis and trans configurations of ligands for $[M(II)O_3N_3]$ and $[Ni(II) O_2N_4]$ type complexes [M(II) = Co(III), Ni(II) and Cu(II)] on the calculated dipole moments have been investigated, adpoting the eigenvectors of EHT calculation. The calculated dipole moments for cis complexes are higher than those of trans complexes. The calculated dipole moments for the octahedral trans $[Co(III)O_3N_3]$ type complex fall in the range of experimental values. However the calculated dipole moments for cis $[Ni(II) O_2N_4]$ type complexes fall in the range of the experimental values. These results predicts the trans structure for $[Co(III)O_3N_3]$ and $[Ni(II) O_2N_4]$ type complexes. Those structures are in agreement with the experimental one (Three bidentate (O-N) ligands in $[M(II)O_3N_3]$ type complexes coordinate to the metal ion and two tridentate (O-N-N) ligands in [Ni(II)O2N4] type complexes coordinate to Ni(II) ion).

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1113-1117
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• 2009

The one-dimensional coordination polymers, $[Cu^{II}(L)(NO_3)_2]_n$ (1) and {$[Cu^{II}(L)(NO_3)]{\cdot}2H_2O}_{2n} (2), were synthesized from $Cu(NO_3)_2{\cdot}3H_2O$ and 2-[(pyridin-3-ylmethyl)amino]ethanol (L, PMAE) in methanol by controlling the molar ratio of copper(II) salt. Copper(II) ion in 1 has one pyridine group of PMAE whose an aminoethanol group coordinates adjacent copper(II) ion. As the pyridine group is bonded to neighboring copper(II) ion, 1 becomes a one-dimensional chain. Contrary to 1, the structure of 2 shows that the oxygen atom of ethoxide group is bridged between two copper(II) ions, which forms a dinuclear complex. Additionally, the pyridine group of PMAE included one dinuclear unit is coordinated to the other dimeric one each other, which leads to a one-dimensional polymer. Due to the structural differences, 1 exhibits weak antiferromagnetic interaction, while 2 shows strong antiferromagnetic interaction. Due to direct spin exchange via oxygen of PMAE 2 has a much strong spin coupling than 1.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.256-259
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• 1992

The 14-membered tetraaza macrocyclic ligand 1,8-diethyl-5,12-dimethyl-1,4,8,11-tetraazacyclote tradeca-4,11-diene(B) can be synthesized as its dihydroperchlorate salt by the one-pot reaction of 2-ethylaminoethylamine, methylvinyl ketone, and perchloric acid in absolute ethanol. The reaction of Ni(II) or Cu(II) ion and the salt yields $[M(B)]^{2+}$ (M = Ni(II) or Cu(II)), which reacts with $NaBH_4$ to produce $[M(D)]^{2+}$ (D = 1,8-diethyl-5,12-dimethyl-1,4,8,11-tetraazacyclote tradecane). The complexes $[M(L)]^{2+}$ (L = B or D) have planar geometry and contain two ethyl groups at the donor nitrogen atoms of the ligands. The red solids $[Cu(B)](X)_2(X)$ = $ClO_4-$ or $PF_6^-$) react with water molecules of atmospheric moisture to produce the purple solids in which water molecules are coordinated to the metal ion. Synthesis, characterization, and the properties of the new N-ethylated macrocyclic ligands and their Ni(II) and Cu(II) complexes are reported.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2565-2570
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• 2011

The reaction of bromoacetonitrile with 3,14-dimethyl-2,6,13,17-tetraazatetracyclo[$16.4.1^{2.6}.0^{1.18}.0^{7.12}$]tricosane ($L^{10}$) containing a N-$CH_2$-N linkage produces 17-cyanomethyl-3,14-dimethyl-2,6,13,17-tetraazatetracyclo-[$16.4.1^{2.6}.0^{1.18}.0^{7.12}$]tricosane ($L^{11}$). The mono-N-functionalized macrocyclic complexes $[ML^2]^{2+}$ (M = Ni(II) or Cu(II); $L^2$ = 2-cyanomethyl-5,16-dimethyl-2,6,13,17-tetraazatricyclo[$16.4.0.0^{7.12}$]docosane) can be prepared by the reaction of $L^{11}$ with nickel(II) or copper(II) ion in acetonitrile. The N-$CH_2CN$ group attached to $[ML^2]^{2+}$ readily reacts with water or methanol to yield the corresponding complexes of $HL^3$ bearing one N-$CH_2CONH_2$ pendant arm or $L^4$ bearing one $N-CH_2C(=NH)OCH_3$ group. The $N-CH_2CONH_2$ or $N-CH_2C(=NH)OCH_3$ group of each complex is coordinated to the central metal ion. Both $[NiL^4(H_2O)]^{2+}$ and $[CuL^4]^{2+}$ are quite stable in acidic aqueous solutions, but undergo hydrolysis to yield $[Ni(HL^3)(H_2O)]^{2+}$ or $[Cu(HL^3)]^{2+}$ in basic aqueous solutions. In contrast to $[Cu(HL^3)]^{2+}$, $[Ni(HL^3) (H_2O)]^{2+}$ is readily deprotonated to form $[NiL^3 (H_2O)]^+$ ($L^3$ = a deprotonated form of $HL^3$) in basic aqueous solutions.

• Resources Recycling
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• v.17 no.6
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• pp.17-23
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• 2008

In order to simulate the leaching solution of copper sulfide ore in $FeCl_3$ solutions, synthetic solutions with composition of $FeCl_3$-$FeCl_2$-$CuCl_2$-CuCl-NaCl-HCl-$H_2O$ were prepared. The concentration of iron and copper chloride was varied from 0.1 to 1 m in synthetic solutions. The effect of composition on the mixed solution pH and potential at $25^{\circ}C$ was measured. When HCl concentration was constant, the increase of CuCl concentration increased solution pH. The increase of other solutes excluding HCl and CuCl decreased solution pH owing to the increase of the activity coefficient of hydrogen ion. A high CuCl concentration favored the redox equilibrium in the direction of Cu(I), while $FeCl_3$ had the opposite effect.

• Korean Journal of Materials Research
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• v.5 no.2
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• pp.169-177
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• 1995

The diffusion barrier property of 100-nm-thick titanium nitride (TiN) film between Cu and Si was investigated using sheet resistance measurements, etch-pit observation, x-ray diffractometry, Auger electron spectroscopy, and transmission electron microscopy. The TiN barrier fails due to the formation of crystalline defects (dislocations) and precipitates (presumably Cu-silicides) in the Si substrate which result from the predominant in-diffusion of Cu through the TiN layer. In contrast with the case of Al, it is identified that the TiN barrier fails only the in-diffusion of Cu because there is no indication of Si pits in the Si substrate. In addition, it appears that the stuffing of TiN does not improve the diffusion barrier property in the Cu/TiN/Si structure. This indicates that in the case of Al, the chemical effect that impedes the diffusion of Al by the reaction of Al with $TiO_{2}$ which is present in the grain boundaries of TIN is very improtant. On the while, in the case of Cu, there is no chemical effect because Cu oxides, such as $Cu_{2}O$ or CuO, is thermodynamically unstable in comparison with $TiO_{2}$. For this reason, it is considered that the effect of stuffing of TiN on the diffusion barrier property is not significant in the Cu/ TiN/Si structure.