• Journal of the Korean Chemical Society
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• v.29 no.2
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• pp.151-157
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• 1985

The intermolecular hydrogen bondings of 1,10-diaza-4,7,13,16-tetraoxacyclooctadecane(cryptand 22), 1,7-diaza-4,10,13-trioxacyclopentadecane(cryptand 21), 1,12,15-triaza-5,8-dioxa-3,4:9,10-dibenzocycloheptadecane ($N_3O_2$) and 1,12-diaza-5,8-dioxa-3,4:9,10-dibenzocyclotetradecane ($N_2O_2$) have been studied in chloroform solutions by $^1H$-nmr spectrometry at various temperatures. The molecules dimerize each other with the hydrogen bonds through N-H groups in the dilute solutions. The formation constants of the hydrogen bonds are in the order of cryptand 22 > cryptand 21 > $N_3O_2$ > $N_2O_2$. It appears that the constants depend on the molecular symmetry, the number of N-H group, and the localization of N-H groups in the molecule.

• Journal of the Korean Chemical Society
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• v.32 no.3
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• pp.233-242
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• 1988

The uranium(VI) complexes with new unsaturated macrocyclic ligands of cryptand types and the neodymium(III) complexes with cryptand 222 and DBC ligands have been investigated polarographically in dimethylsulfoxide solvent. The reduction states, electron numbers involved in the reduction process, effects of the added acid on the polarograms of complexes, and the mechanisms of the reduction electrode reactions have been examined. The stability constants and mole-ratio of new complexes were also obtained by polarographic method. The reaction of ligands was controlled by the diffusion in the reduction with four electrons at a step, whereas the redox reaction with six electrons at three steps in $UO_2\;^{2+}$ complexes with macrocyclic ligands and the redox reaction with one electron at a step in $Nd^{3+}$ complexes with cryptand 222 and DBC have been observed. The imine ligands formed stable complexes with uranium(VI) above pH 7.0, and the neodymium(III) complexes with cryptand 222 and DBC ligands were stable above pH 4.0.

• Journal of environmental and Sanitary engineering
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• v.20 no.4 s.58
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• pp.38-44
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• 2005

Cryptand resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene divinylbenzene (DVB) copolymer with crosslink of $1\%,\;2\%,\;5\%\;and\;10\%$ by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of uranium$(UO_2^{2+})$ ion were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium$(UO_2^{2+})$ > zinc$(Zn^{2+})$ > samarium$(Sm^{3+})$ ion. The adsorption was in order of $1\%>2\%>5\%>10\%$ crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.645-651
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• 2005

• Bulletin of the Korean Chemical Society
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• v.12 no.2
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• pp.130-137
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• 1991

The following new cryptand 221 complexes of lanthanides(Ⅲ) and dioxouranium(Ⅵ) nitrate have been synthesized: $(Ln(C_{16}H_{32}N_2O_5)(H_2O)_2(NO_3)_3\ and \((UO_2)_2(C_{16}H_{32}N_2O_5)(H_2O)_4(NO_3)_4$. These complexes have been identified by elemental analysis, moisture titration, conductivity measurements and various spectroscopic techniques. The proton and carbon-13 NMR as well as calorimetric measurements were used to study the interaction of cryptand 221 with La(Ⅲ), Pr(Ⅲ ), Ho(Ⅲ) and $UO_2(Ⅱ)$ ions in nonaqueous solvents. The bands of metal-oxygen atoms, metal-nitrogen atoms and O-U-O in the IR spectra shift upon complexation to lower frequencies, and the vibrational spectra ({\delta}NMN$) of metal-amide complexes in the crystalline state exhibit lattice vibrations below 300 $cm^{-1}$. The NMR spectra of the lanthanides(Ⅲ) and dioxouranium(Ⅵ) nitrate complexes in nonaqueous solvents are quite different, indicating that the ligand exists in different conformation, and also the $^1H$ and $^{13}C-NMR$ studies indicated that the nitrogen atom of the ring has greater affinity to metal ions than does the oxygen atom, and the planalities of the ring are lost by complexation with metal ions. Calorimetric measurements show that cryptand 221 forms more stable complexes with $La^{3+}$ and $Pr^{3+}$ ions than with $UO^{22+}$ ion, and $La^{3+}/Pr^{3+}$ and $UO^{22+}/Pr^{3+}$ selectivity depends on the solvents. These changes on the stabilities are dependent on the basicity of the ligand and the size of the metal ions. The absorption band (230-260 nm) of the complex which arises from the direct interaction of macrocyclic donor atoms with the metal ion is due to n-{\delta}*$ transition and also that (640-675 nm) of $UO^{22+}$-cryptand 221 complex, which arises from interaction between two-dioxouranium(Ⅵ) ions in being out of cavity of the ligand ring is due to d-d* transition.

• Journal of environmental and Sanitary engineering
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• v.11 no.1
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• pp.17-25
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• 1996

Resins with cryptand 22 macrocyclic ligand attached to chloromethylated styrene-1,4-divinylbenzene by substitution reaction were prepared and the effect of pH, metal concentration and cross-linkage of the matrix on the adsorption for $UO_2^{2+}$, $Cd^{2+}$ and $Sm^{3+}$ was investigated. The metal ion was not adsorbed on the resins pH range below 3 but above pH 4 fast adsorption behavior was showed. The resin selectivity determined in ethanol matrix was in increasing order $UO_2^{2+}{\;}>Cd^{2+}{\;}Sm^{3+}$. In addition, these metal ion could be separated on the column packed with 1% crosslinked resin by pH 2.5 $HNO_3$ as an eluent.

• Analytical Science and Technology
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• v.17 no.2
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• pp.91-97
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• 2004

Cryptand ion exchange resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene divinylbenzene (DVB) copolymer with crosslink of 1%, 2%, 5% and 10% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of uranium ($UO{_2}^{2+}$) ion were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium ($UO{_2}^{2+}$), magnesium ($Mg^{2+}$), neodymium ($Nd^{3+}$) ion. The adsorption was in order of 1%, 2%, 5%, and 10% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

• Journal of environmental and Sanitary engineering
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• v.18 no.2
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• pp.9-15
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• 2003

Resins have been synthesized from chlormethyl styrene 1,4- divinylbenzene(DVB) with 1%, 4%, and 20%-crosslinked and macrocyclic ligand of cryptand type by copolymerization method and the adsorption of uranium(VI), nickel(II) and lutetium(III) ions have been investigated in various experimental conditions. The correlation between the adsorption characteristics of rare earths and transition metal on the resins and stability constants of complexes with macrocyclic ligand have been examined. The uranium ion was not adsorbed on the resins below pH 2.0, but the power of adsorption of uranium ion increased rapidly above pH 3.0. The adsorption power was in the order of 1%, 4% and 20%-crosslinked resin, but adsorptive characteristics of resins decreased in proportion to the order of dielectric constants of solvents.

• Journal of Integrative Natural Science
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• v.10 no.4
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• pp.225-231
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• 2017

Cryptand resins were synthesized by mixing 1-aza-18-crown-6 macrocyclic ligand with styrene divinylbenzene copolymer having 1%, 2%, 5%, and 10% crosslink by a substitution reaction. These synthetic resins were confirmed by chlorine content, elementary analysis, SEM, surface area, and IR-spectrum. As the results of the effects of pH, crosslink of synthetic resin, and dielectric constant of a solvent on uranium ion adsorption for resin adsorbent, the uranium ion showed high adsorption at pH 3 or over. Adsorption selectivity for the resin in methanol solvent was the order of uranium ($UO_2{^{2+}}$) > calcium ($Ca^{2+}$) > neodymium ($Nd^{3+}$) ion, adsorbability of the uranium ion was the crosslink in order of 1%, 2%, 5%, and 10% and it was increased with the lower dielectric constant.

• Journal of environmental and Sanitary engineering
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• v.23 no.1
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• pp.57-65
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• 2008

Resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene(dangerous matter) divinylbenzene(DVB) copolymer with crosslink of 1, 2, 6 and 15% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time and crosslink on adsorption of metal ion　from water fire extinguishing agent by the synthetic resin adsorbent were investigated. The metal ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in water was in increasing order of $Mg^{2+}>Al^{3+}>Pb^{2+}$. The adsorption was in the order of 1, 2, 6, and 15% crosslink resin.