• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.269-272
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• 2014

• Analytical Science and Technology
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• v.13 no.5
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• pp.558-564
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• 2000

Mononuclear schiff base ligand N,N'-bissalicylidene-1,2-phenylenediamine(BSPD) and binuclear schiff base ligands N,N',N',N'''-tetrasalicylidene-3,3',4,4'-tetraaminodiphenyl-methane (TSTM), N,N',N'',N'''-tetrasalicylidene-3,3'-diaminobenzidine (TSDB) have been synthesized. Proton dissociation constants of the ligands were determined by potentiometric method. The synthesized ligands and complexes formed with Cu(II) ion. These complexes were investigated by cyclic voltammetry and differential pulse voltammetry. The results revealed two step diffusion controlled redox process. The mononuclear complex Cu(II)-BSPD and binuclear complexes $Cu(II)_2$-TSDB and $Cu(II)_2$-TSTM were used in the oxidation reaction of ascorbic acid. The reaction rates were in the order of $Cu(II)_2$-TSTM>$Cu(II)_2$-TSDB>Cu(II)-BSPD, indicating that the binuclear $Cu(II)_2$-TSTM complex had the fastest values.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.295-298
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• 2013

• Bulletin of the Korean Chemical Society
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• v.15 no.12
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• pp.1118-1121
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• 1994

Reactions of alkaline metal carbonates with sulfur are investigated in detail. The evolution of CO and a trace of $SO_2$ were observed in the course of reaction with major component of polysulfides. Some evidences that the reaction proceeds with breaking of terminal sulfur-sulfur bond in the sulfur polymer, and forming CO, $SO_2$ and polysulfide are presented. Polysulfides have the role of keeping free sulfur and allow it to react with other chemicals to rather high temperatures.plexes, whereas the binuclear and mononuclear complexes of Mn$^{2+}$ and Co$^{2+}$

• Bulletin of the Korean Chemical Society
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• v.8 no.3
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• pp.185-189
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• 1987

Reactions of $Ir(ClO)_4(CO)(PPh_3)_2$ with dicyano olefins, cis-NCCH = CH$CH_2$$CH_2$CN (cDC1B), trans-NCCH = CH$CH_2$$CH_2$CN (tDC1B), trans-NC$CH_2$CH = CH$CH_2$CN (tDC2B), and NC$CH_2$$CH_2$$CH_2$$CH_2$CN (DCB) produce binuclear dicationic iridium (I) complexes, $[(CO)(PPh_3)_2Ir-NC-A-CN-Ir(PPh_3)_2(CO)](ClO_4)_2$ (NC-A-CN = cDC1B (1a), tDC1B (1b), tDC2B (1c), DCB (1d)). Complexes 1a-1d react with hydrogen to give binuclear dicationic tetrahydrido iridium (Ⅲ ) complexes, $[(CO)(PPh_3)_2(H)_2Ir-NC-A-CN-Ir(H)_2(PPh_3)_2(CO)](ClO_4)_2$ (NC-A-CN = cDC1B (2a), tDC1B (2b), tDC2B (2c), DCB (2d)). Complexes 2a and 2b catalyze the hydrogenation of cDC1B and tDC1B, respectively to give DCB, while the complex 2c is catalytically active for the isomerization of tDC2B to give cDC1B and tDC1B and the hydrogenation of tDC2B to give DCB at $100^{\circ}C$.

• Applied Biological Chemistry
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• v.41 no.8
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• pp.611-612
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• 1998

The transition state analog for metal catalyzed hydrolysis of an ester through cooperative interactions between metal ions as Lewis acid and peroxide was discussed.

• Journal of the Korean Chemical Society
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• v.32 no.3
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• pp.203-210
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• 1988

Mono-oxo-bridged binuclear molybdenum(V) complex, $[Mo_2O_3(Phen)_2(NCS)_4]$ produces di-oxo-bridged binuclear molybdenum(V) complex, $[Mo_2O_4(Phen)_2(NCS)_2]$ in water + co-solvent, where the co-solvent are acetone, acetonitrile and N,N-dimethylformamide. The rate of conversion of $[Mo_2O_3(Phen)_2(NCS)_4]\;into\;[Mo_2O_4(Phen)_2(NCS)_2]$ has been measured by spectrophotometric method. Temperature was $10^{\circ}C$ to $40^{\circ}C$ and pressure was varied up to 1500 bar. The rate constants are increased with increasing water mole fraction and decreased with increasing concentration of hydrogen ion. The order of oxygen ring formation reaction rate in various cosolvent is as follows, ACT > AN > DMF which is agreed with solvent dielectric constants. The observed negative activation entropy ($[\Delta}S^{\neq}$), activation volume($[\Delta}V^{\neq}$) and activation compressibility coefficient(${\Delta}{\beta}^{\neq}$) values show that the solvent water molecule is strongly attracted to the complex at transition state. From these results, the oxygen ring formation reaction of $[Mo_2O_3(Phen)_2(NCS)_4]$ is believed association mechanism.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1675-1680
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• 2012

Three new cyanide-bridged $Cr^{III}Mn^{II}$ binuclear complexes, $[Mn(phen)_2Cl][Cr(bpmb)(CN)_2]{\cdot}H_2O$ ($\mathbf{1}$) (phen = 1,10-phenanthroline, $bpdmb^{2-}$ = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate), $[Mn(phen)_2Cl][Cr(bpmb)-(CN)_2]{\cdot}H_2O$ ($\mathbf{2}$) ($bpdmb^{2-}$ = 1,2-bis(pyridine-2-carboxamido)-4,5-dimethyl-benzenate), and $[Mn(phen)_2Cl]-[Cr(bpClb)(CN)_2]{\cdot}CH_3OH{\cdot}H_2O$ ($\mathbf{3}$) ($bpClb^{2-}$ = 1,2-bis(pyridine-2-carboxamido)-4-chloro-benzenate) were obtained based on $Mn(phen)_2Cl_2$ and a series of dicyanidechromate(III) building blocks. Single crystal X-ray diffraction analysis shows the structures of the three complexes are dimeric type with two different metal centers linked by a cyanide group from corresponding dicyanidechromate(III) building block. Magnetic investigations indicate the existence of relatively weak antiferromagnetic coupling between Cr(III) and Mn(II) ions with best-fit constants $J_{CrMn}=-2.78(5)cm^{-1}$ for $\mathbf{1}$, $J_{CrMn}=-3.02(2)cm^{-1}$ for $\mathbf{2}$ and $J_{CrMn}=-2.27(3)cm^{-1}$ for $\mathbf{3}$ based on the spin exchange Hamiltonian = $-2J_{CrMn}\hat{S}_{Cr}\hat{S}_{Mn}$. The magneto-structural correlation of cyanide-bridged $Cr^{III}Mn^{II}$ complexes has been discussed at last.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1669-1678
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• 2011

Six new binuclear copper(II) complexes have been prepared by template condensation of the dialdehydes 1,8-[bis(3-formyl-2-hydroxy-5-methyl)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-a) and 1,8-[bis(3-formyl-2-hydroxy-5-bromo)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-b) with appropriate aliphatic diamines, and copper(II) perchlorate. The structural features of the complexes have been confirmed by elemental analysis, IR, UV-vis and mass spectra etc. The electrochemical behavior of all the copper(II) complexes show two irreversible one electron reduction process. The room temperature magnetic moment studies depict the presence of an antiferromagnetic interaction in the binuclear complexes. The catechol oxidation and hydrolysis of 4-nitrophenylphosphate were carried out by using the complexes as catalyst. The antimicrobial screening data show good results. The binding of the complexes to calf thymus DNA (CT DNA) has been investigated with absorption and emission spectroscopy. The complex [$Cu_2L^{1a}$] displays significant cleavage property of circular plasmid pBR322 DNA in to linear form. Spectral, electrochemical, magnetic and catalytic studies support the distortion of the copper ion geometry that arises as the macrocyclic ring size increases.

• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.439-444
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• 1993

The aerobic oxidation of the Fe(II) complex of 1,4,8,11-tetraazacyclotetradecane, [Fe(cyclam)$(CH_3CN)_2](ClO_4)_2$, in MeCN in the presence of a few drops of $HClO_4$ leads to low spin Fe(III) species [Fe(cyclam)$(CH_3CN)_2](ClO_4)_3$. The Fe(III) cyclam complex is further oxidized in the air in the presence of a trace of water to produce the deep green binuclear bismacrocyclic Fe(II) complex $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$. The Fe(II) ions of the complex are six-coordinated and the bismacrocyclic ligand is extensively unsaturated. $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$ crystallizes in the monoclinic space group $P2_1/n$ with a= 13.099 (1) ${\AA}$, b= 10.930 (1) ${\AA}$, c= 17.859 (1) ${\AA}$, ${\beta}$= 95.315 $(7)^{\circ}$, and Z= 2. The structure was solved by heavy atom methods and refined anisotropically to R values of R= 0.0633 and $R_w$= 0.0702 for 1819 observed reflections with F > $4{\sigma}$ (F) measured with Mo K${\alpha}$ radiation on a CAD-4 diffractometer. The two macrocyclic units are coupled through the bridgehead carbons of ${\beta}$-diimitie moieties by a double bond. The double bonds in each macrocycle unit are localized. The average bond distances of $Fe(II)-N_{imine}$, $Fe(II)-N_{amine}$, and $Fe(II)-N_{MeCN}$ are 1.890 (5), 2.001 (5), and 1.925 (6) ${\AA}$, respectively. The complex is diamagnetic, containing two low spin Fe(II) ions in the molecule. The complex shows extremely intense charge transfer band in the near infrared at 868 nm with ${\varepsilon}$= 25,000 $M^{-1}cm^{-1}$. The complex shows a one-electron oxidation wave at +0.83 volts and two one-electron reduction waves at -0.43 and-0.72 volts vs. Ag/AgCl reference electrode. The complex reacts with carbon monoxide in $MeNO_2$ to form carbonyl adducts, whose $v_{CO}$ value (2010 $cm^{-1}$) indicates the ${\pi}$-accepting property of the present bismacrocyclic ligand.