• Title/Summary/Keyword: Ligand Substitution

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Adsorption Characteristics of U ranium (VI) Ion on Cryptand Synthetic Resin Adsorbent

  • Kim, Hae-Jin
    • 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.

Adsorption of Metal Ions on Cryptand Synthetic Resin (Cryptand 합성수지에 위한 금속 이온들의 흡착)

  • Lee Chi-Young;Kim Joon-Tae
    • 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.

Adsorption Characteristic of Mg(II), Al(III), Pb(II) Metal Ions on Cryptand Ion Exchange Resin from Water Fire Extinguishing Agent (물 소화약제로부터 Cryptand 이온교환수지의 Mg(II), Al(III) 및 Pb(II) 흡착특성)

  • Kim, Joon-Tae;Kim, Kwan-Chun
    • 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.

Adsorption and Separation of U (VI), Co (II), and Dy (III) Metal Ions on Crown Synthetic Resin

  • Kim, Joon-Tae
    • Journal of Integrative Natural Science
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    • v.10 no.1
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    • pp.43-50
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    • 2017
  • Synthetic resins were combined 1-aza-12-crown-4 macrocyclic ligand with styrene divinylbenzene copolymer having 1%, 2%, 8%, and 16% 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 metal ion adsorption for resin adsorbent, the metal ions showed high adsorption at pH 3 or over. Adsorption selectivity for the resin in ethanol solvent was the order of uranium ($UO_2{^{2+}}$) > cobalt ($Co^{2+}$) > dysprosium ($Dy^{3+}$) ion, adsorbability of the metal ion was the crosslink in order of 1%, 2%, 8%, and 16% and it was increased with the lower dielectric constant. In addition, theses metal ions could be separated in the column with 1% crosslink resin by using nitric acid (pH 2.0) as an eluent.

Synthesis and Photoinduced Magnetic Properties of a Mn12 Single Molecule Magnet by the cis-trans Isomerism of Azobenzene

  • George, Sheby M.;Kim, Jin-Kwon
    • Bulletin of the Korean Chemical Society
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    • v.30 no.5
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    • pp.1143-1146
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    • 2009
  • [$Mn_{12}O_{12}(azo-L)_{16}(H_2O)_4$] (1), a new Mn12 single molecule magnet containing a photochromic azobenzene ligand, has been successfully synthesized by substitution of acetate ligand of Mn12 with 6-[4-{4-hexyloxyphenyl( azo)}-phenoxy]hexanoic-1-acid. The reversible photoisomerization of the azobenzene group was confirmed by UV-visible absorption spectroscopy. The temperature and field dependence of dc susceptibility and the temperature and the frequency dependence of ac susceptibility were measured for the cis and the trans isomer of 1. The magnetization value of the cis isomer in dc measurement is higher than that of the trans isomer. The cis isomer of 1 has a slower relaxation because cis-trans photoisomerization of the azobenzene group in peripheral ligands induces changes in its structure and dipole moment.

Adsorption of Uranium (VI) Ion on 1-Aza-12-Crown-4 Synthetic Resin with Styrene Hazardous Material

  • Kim, Joon-Tae
    • Journal of Integrative Natural Science
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    • v.6 no.2
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    • pp.104-110
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    • 2013
  • 1-Aza-12-crown-4 macrocyclic ligand was combined with styrene (2th petroleum in 4th class hazardous materials) divinylbenzene copolymer having 1%, 2%, 3%, and 6% crosslinks by a substitution reaction, in order to synthesize resin. These synthetic resins were confirmed by chlorine content, elementary analysis and IR-spectrum. As the results of the effects of pH, equilibrium arrival time, 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 and adsorption equilibrium of uranium ion was about 2 hours. In addition, adsorption selectivity for the resin in methanol solvent was the order of uranium ($UO_2{^{2+}}$) > iron ($Fe^{3+}$) > lutetium ($Lu^{3+}$) ions, adsorbability of the uranium ion was in the crosslinks order of 1%, 2%, 3%, and 6% was increased with the lower dielectric constant.

Photochemical Studies of Schiff Base Cu(II) Complex: (1) UV-Irradiation of N,$N^{\prime}$-bis(salicylidene)ethylenediamine copper(II)

  • An, Byeong Tae
    • Bulletin of the Korean Chemical Society
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    • v.16 no.3
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    • pp.202-204
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    • 1995
  • The ultraviolet photochemistry of N,N'-bis(salicylidene)ethylenediamine copper(II), Cu(sal)2en, was investigated with low pressure mercury lamp. Redution of Cu(Ⅱ) and formation of Cl- were shown on 254 nm irradiation both for aerated and deaerated chlorinated hydrocarbon solvent such as CH2Cl2, chloroform, and 1,2-dichloroethane. Relatively long lived $({\tau}=100{\mu}sec)$ intermediate was detected by flash photolysis. Overall photo-process can be described as the formation of Cl- and new copper complex, product(1) by chlorohydrocarbon mediation, photoinduced reduction by abstraction of halogen from solvent, followed by redox induced substitution of axial ligand with chlorine. Product(1) is possibly Cu(III) chlorosalicylaldeimido complex and cyclic -CH2CH2- moiety is absent in the structure. 247nm band of Cu(sal)2en should contain ligand to metal charge transfer character.

Syntheses and Reactions of Iridium Complexes Containing Mixed Phosphine-Olefin Ligand: (3-(Diphenylphosphino)propyl)(3-butenyl)phenylphosphine

  • Young-ae W. Park;Devon W. Meek
    • Bulletin of the Korean Chemical Society
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    • v.16 no.6
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    • pp.524-528
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    • 1995
  • The reaction of [IrCl(cod)]2 with ppol ligand, Ph2PCH2CH2CH2P(Ph)CH2CH2CH=CH2, in ethanol gives an iridium complex, whose structure is converted from an ionic form, [Ir(cod)(ppol)]Cl·2C2H5OH (1),in polar solvents (ethanol, methanol and acetonitrile), to a molecular form, [IrCl(cod)(ppol)], in non-polar solvents (benzene and toluene). The cationic complexes, [Ir(cod)(ppol)]AsF6·1/2C2H5OH and [Ir(cod)(ppol)]PF6·1/2CH3CN, were prepared to compare with the ionic form by 31P NMR spectroscopy. When carbon monoxide is introduced to 1, cod is replaced by CO to give the 5-coordinated complex, [IrCl(CO)(ppol)]. Hydrogenation of 1-octene was not successful in the presence of 1. In order to verify the reason for 1 not behaving as a good catalyst for hydrogenation, electrophilic reactions with HCl, I2 and HBF4·etherate were performed, which yielded the oxidative addition product, [IrHCl2(ppol)], the substitution product, [IrI(cod)(ppol)], and another cationic product, [Ir(cod)(ppol)]BF4, respectively. Thus, the iridium complex is not sufficiently basic to activate hydrogen atoms or the olefin of the ppol ligand.

Kinetics and Mechanism of Substitution Reaction of $PPN^+(\eta^n-MeCp)Mn(CO)_2\;Cl^-$ with $PR_3$(R=Me, Et, OEt, $C_6H_5$)

  • Park, Yong Gwang;Lee, Yong Gu;Kim, Gyu Sik
    • Bulletin of the Korean Chemical Society
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    • v.17 no.2
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    • pp.138-142
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    • 1996
  • The transition metal carbonylate, PPN+(${\eta}^5-MeCp)Mn(CO)_2Cl^-$ undergoes a novel ligand substitution reaction with PR3 (R=Me, Et, OEt, $C_6H_5$ in THF at elevated temperatures (40 $^{\circ}C$ up to 60 $^{\circ}C)$ under the pseudo-first-order reaction conditions (usually 20-fold excess of PR3 with respect to metal carbonylate concentrations) where chloride is displaced by PR3. The reaction follows overall first order dependence on [(${\eta}^5-MeCp)Mn(CO)_2Cl^-$]; however, the negative entropy changes of activation (${\Delta}S^{\neq}$=-19.3 e.u. for $P(OEt)_3$; ${\Delta}S^{\neq}$=-16.4 e.u. for $PPh_3$) suggest the existence of the intermediate, ((η3-MeCp)Mn(CO)2(THF)Cl-, which eventually transforms to the product (${\eta}^5-MeCp)Mn(CO)_2(PR_3)$.

Preparation of Dihydroxy Naphthalene/TiO2 Complex via Surface Modification and Their Photocatalytic H2 Production Performances Under Visible Light

  • Hu, Shaozheng;Li, Fayun;Fan, Zhiping
    • Bulletin of the Korean Chemical Society
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    • v.34 no.7
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    • pp.2056-2062
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    • 2013
  • The dihydroxy naphthalene/$TiO_2$ complexes with different substitution patterns were prepared by surface modification. X-ray diffraction, UV-Vis spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy were used to characterize the prepared composite materials. The results indicated that the surface modification did not influence the crystallization of $TiO_2$. The visible-light absorbances of prepared dihydroxy naphthalene/$TiO_2$ complexes could be assigned to the ligand-to-metal charge transfer. The obtained catalyst exhibited outstanding photocatalytic activity and stability under visible light. A linear relationship existed between the percentages of hydroxynaphthalenes coordinated on $TiO_2$ surface and $H_2$ production ability. The substitution pattern of dihydroxy naphthalene and $CH_3OH$ content could also influence the photocatalytic performance remarkably. The photocatalytic $H_2$ production ability was further improved after loading with ultra low concentration of Pt, 0.02 wt %. The possible mechanism was proposed.