• Journal of the Korean Chemical Society
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• v.34 no.2
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• pp.143-158
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• 1990

Metal complexes were prepared by reacting uranium (Ⅵ), thorium (Ⅳ) and rare earth metal (Ⅲ) ions including Nd (Ⅲ), Sm (Ⅲ) and Ho (Ⅲ) with macrocyclic ligands including five crown ethers, nine crownands and one cryptand ligands, and subjected to NMR studies in order to examine coordination sites of the ligands and compositions of the complexes formed. Among the marcocyclic ligands, crown ethers and crownand ligands have shown down-field shifts of the methylene protons of the lcigands by forming stable complexes with all the metal ions and the differences of chemical shifts were decreased as increasing of the cavity-size of crown ethers for the same metal ions and decreasing of the atomic number of the rare earth metals for the same ligands. It has been found that crownand 22 gave a stable complex with uranium(Ⅵ) ion by the coordination through both oxygen and nitrogen atoms of the ligand whereas no complex was formed with the rare earth metal(Ⅲ) ions, which on the other hand were found to form stable complexes with cryptand 221. The rest of the crowand ligands have also been found to form stable complexes with uranium(Ⅵ) ion by coordinating through all the oxygen and nitrogen atoms of the ligands whereas no complexes were formed with the rare earth metal(Ⅲ) ions. It has also been shown by 1H-NMR study that uranium(Ⅵ), thorium(Ⅳ) and rare earth metal(Ⅲ) ions formed 1:1 complexes with the macrocyclic ligands except for thorium(Ⅳ) complex of 12C4 in which the mole ratio of metal to ligand is 1:2. More stable metal complexes show larger changes in chemical shifts of the coordinated ligand protons. Finally, the rare earth metal(Ⅲ) complexes of 18C6 have shown ligand exchange reaction with the solvent molecules in acetylacetone solution, which was not observed for the uranium (Ⅵ) complexes.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.679-684
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• 1992

New Pd(IV) complexes have been prepared through the reactions of $trans-[Pd(en)_2Cl_2](ClO_4)_2 $(en = ethylenediamine) with Guanine, Adenine, or Uracil anion as purine and pyrimidine base. We identified the ratio of central metal versus ligands by $C{\cdot}H{\cdot}N$ elemental analysis and proposed the coordinating site of the base by infrared spectrum, $^1H-NMR,\; and\; ^{13}C$-NMR spectrum. Guanine or Adenine ligand coordinated at N7 site and an en ligand exchanged for $ClO_4^-$ counter ions of the starting material . As these results, the complexes showed the formula $[Pd(en)L_2(ClO_4)_2](ClO_4)_2{\cdot}(en)$, (L = Guanine, Adenine). But in the Uracil complex no exchange of the en ligand and $ClO_4^-$ occured and Uracil anion preferred the N1 to N3 as coordinating site, the complex $[Pd(en)_2(Urac)_2](ClO_4)_2(Urac = Uracil anion).$

• Journal of the Korean Chemical Society
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• v.37 no.6
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• pp.612-617
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• 1993

Some vanadium(III) complexes have been prepared from the reaction of VC$l_3$ with N, P, O-donating ligands and characterized by elemental analysis, $^1$H-NMR infrared and UV-Visible spectroscopy. 3,5-Lutidine, 1,2-phenylenediamine, 8-hydroxyquinoline, 9,10-phenanthrenequinone, triphenylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane and 1,1'-bis(diphenylphosphino)ferrocene were chosen as coordinating ligands. Stretching frequency ${\nu}g$(V-Cl) of complexes appears) at 298∼367 cm-1, which show octahedral geometries. Stretching frequency of ${\nu}g$(V-X) (X = N, P, O) indicates that ligands are coordinated to vanadium(III). Stretching frequency ${\nu}g(C{\equiv}N)$ of acetonitrile in these complexes are characteristically shifted to about 70 c$m^{-1}$ higher compared with that of a free ligand (2260 c$m^{-1}$). Bending frequency of $\delta(C{\equiv}N)$ is also shifted to about 60 c$m^{-1}$ higher compared with that of a free ligand (377 c$m^{-1}$). Finally each vanadium(III) complex showed the following formulation; [VC$l_3$(L)$_2$MeCN] or [VC$l_3$(L-L)MeCN].

• Mycobiology
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• v.40 no.1
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• pp.20-26
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• 2012

The complexes of tailor made ligands with life essential metal ions may be an emerging area to answer the problems of multi drug resistance. The coordination complexes of VO(II), Co(II), Ni(II) and Cu(II) with the Schiff bases derived from isatin with 3-chloro-4-floroaniline and 2-pyridinecarboxaldehyde with 4-aminoantipyrine have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, molar conductance, electronic spectra, FT-IR, FAB mass and magnetic susceptibility measurements. FAB mass data show degradation of complexes. Both the ligands behave as bidentate and tridentate coordinating through O and N donor. The complexes exhibit coordination number 4, 5 or 6. The Schiff base and metal complexes show a good activity against the bacteria; $Staphylococcus$ $aureus$, $Escherichia$ $coli$ and $Streptococcus$ $fecalis$ and fungi $Aspergillus$ $niger$, $Trichoderma$ $polysporum$, $Candida$ $albicans$ and $Aspergillus$ $flavus$. The antimicrobial results also indicate that the metal complexes are better antimicrobial agents as compared to the Schiff bases. The minimum inhibitory concentrations of the metal complexes were found in the range 10-40 ${\mu}g/mL$.

• Journal of the Korean Chemical Society
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• v.36 no.6
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• pp.906-913
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• 1992

The polymeric compound [{$W(NO)_2Cl_2$}$_n$] were prepared by reductive nitrosylation of $WNaNO_2$ and acidified $WFeSO_4$ with $WWCl_6$ at room temperature. The reactions of [{$W(NO)_2Cl_2$}$_n$] with unidentate and bidentate ligands afforded neutral monomeric [$W(NO)_2Cl_2L_2$(or L-L)] in a relative high yields (70$\sim$90%). 3,5-lutidine, ${\gamma}$-cyanopyridine, 1,2-phenylenediamine, 1,10-phenanthroline, sym-diphenylethylenediamine, 9,10-phenanthrenequinone, 1,3-bis(diphenylphosphino)propane, 1,1'-bis(diphenylphosphino)ferrocene and 8-hydroxyquinoline were used as coordinating ligands. These dinitrosyltungsten complexes were characterized by elemental analysis, $^1H$-NMR, infrared, and UV-visible spectroscopy are reported. The spectral data indicated that geometric structures of the products were cis-dinitrosyl-trans-dichloro-cis-$L_2$ of $C_{2v}$ symmetry.

• Bulletin of the Korean Chemical Society
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• v.15 no.11
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• pp.990-996
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• 1994

New ferrocene-based chelate amines, $Fe[C_5H_4CH(Me)NMe_2]_2\;(3), \;Fe[C_5H-3(CH(Me)NMe_2)(PPh_2)-1,2]_2\;(4),\;(C_5H_5)Fe(C_5H_3(CH_2NMe_2)(CH(CN)NMe_2-1,2)\;(6),\;and\;(C_5H_5)Fe(C_5H_3(CH_2NMe_2)(CH(Me)NMe_2-1,2)$ (7) have been prepared. The reaction and the coordination chemistry of 4 and other related compounds (S,R)-(1-N,N-dimethylaminoethyl)-2-dicyclohexylphosphino)ferrocene (CPFA) and 1,1'-bis-(diphenylphosphino)ferrocene (BPPF) with $Rh_2(OAc)_4(MeOH)_2$ were investigated. The reaction of the chiral ligand (S,R)-CPFA forms a complex of the type (${\eta}^1$-(S,R)-CPFA-P)$_2Rh_2(OAc)_4$ (8) in which the ligand is coordinated to both rhodium centers in a monodentate fashion through phosphorus. In contrast, the bisphosphine analogues such as BPPF and 4 afford chelate complexes of the type (${\eta}^2-PP)Rh_2(OAc)_4$ (9 & 10) where both ligands act as a chelate bidentate to a single rhodium atom. All these complexes were characterized by microanalytical and spectroscopic techniques. In one case, the structure of 8 was determined by X-ray crystallography. Crystals are monoclinic, space group C2 (No. 5), with a=26.389 (3), b=12.942 (1), c=11.825 (1) A, ${\beta}$=111.22(1)$^{\circ}$, V=3964.7 (8) $A^3$, Z=4, and $D_{calc}$=1.58 g $cm^{-3}$. Two Rh(II) centers are bridged by four $AcO^-$ groups in the ${\eta}^1$ : ${\eta}^1$ mode across a Rh-Rh single bond, and octahedral coordination at Rh(1) and Rh(1') is completed by axially coordinating (S,R)-CPFA and a briding $AcO^-$, respectively.

• Journal of the Korean Chemical Society
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• v.24 no.2
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• pp.121-128
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• 1980

Isonitrosobenzoylacetone is particularly interesting, as the isonitroso group has two potentially coordinating sites which can compete with the cabonyl groups in forming bonds with the metal ions. In this paper tris(isonitrosobenzoylacetonato)cobalt(III) and bis(isonitrosobenzoylacetonato)palladium(II) have been prepared, and their structures have been investigated. Spectroscopic studies lead to the conclusion that the both complexes do not contain an OH group in the chelated five-membered ring structure in which the ligand coordinates to metal through oxygen of the acetyl group and nitrogen of the isonitroso group. The coordination manner of this ligand is similar to that of isonitrosobenzoylacetone obtained by Patel and Haldar.

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.101-107
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• 1994

Some molybdenum(III) and (IV) complexes have been prepared from the reaction of $MoCl_4$·2MeCN with N, P, O-donating ligands and characterized by elemental analysis, infrared and UV-Visible spectroscopy. 3,5-Lutidine, 1,2-phenylenediamine, 8-hydroxyquinoline, 9,10-phenanthrenequinone, triphenylphosphine and 1,2-bis(diphenylphosphino)ethane were chosen as coordinating ligands. Stretching frequencies $\upsilon$ (Mo-Cl) of Mo(IV) appear at higher frequencies than those of Mo(III) complexes due to the increasing oxidation number of metal. $MoCl_4(L)_2$ exhibit one Mo-Cl stretching frequency, whereas Mo$Cl_4$(L^L) exhibit four Mo-Cl stretching frequencies. The number of Mo-Cl stretching frequency suggestes the former complexes have trans($D_{4h}$) and the latter complexes have cis($C_{2v}$) symmetry. Stretching frequency ${\nu}g(C{\equiv}N)$ of acetonitrile in Mo(III) complexes are shifted to about 30 $cm^{-1}$ higher frequency compared with that of a free ligand (2260 $cm^{-1}$). These spectral data indicates that Mo(III) complexes are in the octahedral geometries with the coordinated acetonitrile. Finally each molybdenum(III) and (IV) complexes showed the following formulation; $[MoCl_4(L)_2]$,[Mo$Cl_4$(L^L)], $[MoCl_3(L)_2MeCN]$ and [Mo$Cl_3$(L^L)MeCN].

• Journal of the Korean Chemical Society
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• v.36 no.6
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• pp.872-878
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• 1992

Some vanadium(III) complexes have been prepared by the reaction of VCl3${\cdot}$3MeCN with ligands and characterized by elemental analysis, 1H-NMR, infrared and UV-Visible spectroscopy. 3,5-lutidine(lutd), 8-hydroxyquinoline(oxine), 1,2-phenylenediamine(phda), ethylenediamine(en), and sym-diphenylethylenediamine(dpen) were chosen as coordinating ligands. ${\nu}$(V-Cl) of lutidine complex occurs at 418 $cm^{-1}$ and the other complexes (oxine, phda, en, dpen) occur at 337∼347 $cm^{-1}$. The value of ${\nu}$(V-Cl) indicates that the former complex has trigonal bipyramid structure and the latter complexes have octahedral structure. The ${\nu}$(C${\equiv}$N) of acetonitrile in oxine and phda complexes are characteristically shifted to about 70 $cm^{-1}$ higher frequency compared with that of free ligand (2260 $cm^{-1}$). The ${\delta}$(C${\equiv}$N) is also shifted to about 60 $cm^{-1}$ higher frequency compared with that of free ligand (377 $cm^{-1}$). Finally each vanadium(III) complex showed the following formulation; [$VCl_3(lutd)_2$], [$VCl(oxine)_2$MeCN]$Cl_2$, [$VCl(phda)_2$MeCN]$Cl_2$, [$VCl_2(en)_2$]Cl, [$VCl_2(dpen)_2$]Cl.

• Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.43-54
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• 2011

Gene structure of copper/zinc-superoxide dismutase (Cu/Zn-SOD; sod1) was characterized in Hemibarbus mylodon (Teleostei; Cypriniformes), an endangered freshwater fish species in Korean peninsula. Full-length cDNA of H. mylodon SOD1 consisted of a 796-bp open reading frame sequence encoding 154 amino acids, and the deduced polypeptide sequence shared high sequence homology with other orthologs, particularly with regard to metal-coordinating ligands. Genomic structure of the H. mylodon sod1 gene (hmsod1; 1,911 bp from the ATG start codon to the stop codon) was typical quinquepartite (i.e., five exons interrupted by four introns); the lengths of the exons were similar among species belonging to various taxonomic positions. The molecular phylogeny inferred from sod1 genes in the teleost lineage was in accordance with the conventional taxonomic assumptions. 5'-flanking upstream region of hmsod1, obtained using the genome walking method, contained typical TATA and CAAT boxes. It also showed various transcription factor binding motifs that may be potentially involved in stress/immune response (e.g., sites for activating proteins or nuclear factor kappa B) or metabolism of xenobiotic compounds (e.g., xenobiotic response element; XRE). The hmsod1 transcripts were ubiquitously detected among tissues, with the liver and spleen showing the highest and lowest expression, respectively. An experimental challenge with Edwardsiella tarda revealed significant upregulation of the hmsod1 in kidney (4.3-fold) and spleen (3.1-fold), based on a real-time RT-PCR assay. Information on the molecular characteristics of this key antioxidant enzyme gene could be a useful basis for a biomarker-based assay to understand cellular stresses in this endangered fish species.