• Journal of the Korean Chemical Society
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• v.48 no.2
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• pp.215-219
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• 2004

• 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.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.709-719
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• 1992

We synthesized the binuclear tetradentate Schiff base cobalt(II), nickel(II) and copper(II) complexes such as [Co(II)_2(TSBP)(L)_4], [Ni(II)_2(TSBP)(II)_4] and [Cu(II)_2(TSBP)] (TSBP: 3,3',4,4'-tetra(salicylideneimino)-1,1'-biphenyl, L: Py, DMSO and DMF). We identified the binucleated structure of these complexes by elemental analysis, IR-spectrum, UV-visible spectrum, T.G.A. and D.S.C. According to the results for cyclic voltammogram and differential pulse polarogram of 1 mM complexes in nonaqueous solvents included 0.1M TEAP-L (L; Py, DMSO and DMF) as supporting electrolyte, it was found that diffusionally controlled redox processes of four steps through with one electron for binucleated Schiff base Cobalt(II) complex was Co(III)_2 {^\longrightarrow \\_\longleftarrow^e^-}Co(III)Co(II)_2{^\longrightarrow \\_\longleftarrow^e^-}Co(II){^\longrightarrow \\_\longleftarrow^e^-}Co(I){^\longrightarrow \\_\longleftarrow^e^-}Co(I)_2 and two steps with one electron for Nickel(II) and Copper(II) complexes were M(II)_2 {^\longrightarrow \\_\longleftarrow^e^-}M(I)M(I){^\longrightarrow \\_\longleftarrow^e^-}M(I)_2 (M; Ni and Cu) in nonaqueous solvents.

• Journal of the Korean Chemical Society
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• v.36 no.3
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• pp.428-441
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• 1992

We synthesized a series of binuclear pentadentate Schiff base complexes such as $Co(Ⅱ)_2$ (BSPP)($H_2O)_2$, $Co(Ⅱ)_2$ (BSPD)($H_2O)_2$, $Mn(Ⅱ)_2$ (BSPP)($H_2O)_2$ and $Mn(Ⅱ)_2$ (BSPD)($H_2O)_2$, mononuclear pentadentate Schiff base complexes such as Co(Ⅱ)(BSP)($H_2O)$ and Mn(Ⅱ)(BSP)($H_2O)$. The composition of these complexes identified by IR, UV-visible spectrum, T.G.A., DSC, and elemental analysis. The electrochemical redox processes have been examined by cyclic voltammetry and differential pulse polarography with glassy carbon electrode in 0.1M TEAP-Py(-DMSO and -DMF) as a supporting electrolyte solution. As a result of electrochemical measurements, the reduction processes for pentadentate binuclear Schiff base cobalt(Ⅱ) and manganese(Ⅱ) complexes occurred to four steps in $M(Ⅲ)_2$ / $Mn(Ⅱ)_2$ and $Mn(Ⅱ)_2$ / $M(Ⅰ)_2$ (M; Co, Mn) two processes through each two reduction steps with one electron, by contrast, the mononuclear pentadentate Schiff base cobalt(Ⅱ) and manganese(Ⅱ) complexes occurred to two steps in M(Ⅲ) / M(Ⅱ) and M(Ⅱ) / M(Ⅰ) (M; Co, Mn) two processes with one electron reduction steps.

• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.24-37
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• 1991

We synthesized the binuclear Tetradentate Schiff base nickel(II) and copper(II) complexes ; [Ni(II)$_2$(SMPO)$_2$(L)$_2$], [Ni(II)$_2$(SPPD)$_2$(L)$_2$] and [Cu(II)$_2$(SMPD)$_2$] and [Cu(II)$_2$(SPPD)$_2$] (where, L : Py, DMSO and DMF). We identified the structure of these complexes by elemental analysis, IR-spectrum, T.G.A, D.S.C and ESR measurements. According to the results of cyclic voltammetry and DPP measurements in aprotic solvent included 0.1M TEAP as supporting electrolyte, we knew that diffusional controlled redox process of one step with one electron was irreversible process in 0.1M TEAP-Py solution. Also it was reversible or quasi reversible process in 0.1M TEAP-DMSO solution and reversible or E.C reaction mechanism in 0.1M TEAP-DMF solution at mononuclear complexes ; [Cu(II)(SOPD)] and [Ni(II)(SOPD)(L)$_2$]. But, we knew that diffusional controlled redox process of two step for one electron of binuclear complexes was as follows. The values of redox potential for dimeric complexes in 0.1M TEAP-L solution (where, L ; Py, DMSO and DMF) with scan rate 100mV/sec.

• Journal of the Korean Chemical Society
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• v.35 no.4
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• pp.379-388
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• 1991

We synthesized the binuclear Tetradentate Schiff base cobalt (II) complexes; [Co(II)$_2$(SMPD)$_2$(L)$_2$] and [Co(II)$_2$(SPPD)$_2$(L)$_2$] (where, SMPD: N,N'-bis(salicylaldehyde)-m-phenylenediimine, SPPD: N,N'-bis(salicylaldehyde)-p-phenylenediimine, L: Py, DMSO and DMF). We identified the binuclear structure of these complexes by elemental analysis, IR-spectrum, and T. G. A. According to the results of cyclic voltammetry and DPP measurements in aprotic solvents containing 0.1M TEAP as supporting electrolyte, it was found that diffusionally controlled redox process of two step for one electron was reversible or quasi reversible process in 0.1M TEAP-pyridine and 0.1M TEAP-DMSO solution at mononuclear complexes; [Co(II)(SOPD)(L)$_2$]. But, we knew that diffusionally controlled reduction processes of four steps with one electron for binuclear [Co(II)$_2$(SMPD)$_2$(L)$_2$] and [Co(II)$_2$(SPPD)$_2$(L)$_2$] complexes was Co(III)$_2\;{\longrightarrow^e}$ Co(III)Co(II) ${\longrightarrow^e}$ Co(II)$_2\;{\longrightarrow^e}$ Co(II)Co(I) ${\longrightarrow^e}$ Co(I)$_2$ in aprotic solvents.

• Journal of the Korean Chemical Society
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• v.37 no.8
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• pp.702-710
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• 1993

Electrochemical reduction of thionyl chloride has been carried out at glassy carbon and molybdenum electrodes, the surface of which is modified by binuclear tetradentate schiff base Co(II), Ni(II),Cu(II) and Fe(II) complexes. The catalyst molecules of transition metal(II) complexes were adsorbed on the electrode surface and reduced thionyl chloride resulting in a generation of oxidized catalyst molecules. There was an optimum concentration for each catalyst compound. The catalytic effects of SOCl$_2$ reduction were larger on glassy carbon electrodes compared to molybdenum electrodes and enhancements in reduction current of up to 120${\%}$ at the glassy carbon electrodes. The reduction currents of thionyl chloride were increased and the reduction potentials were shifted to the negative potential when scan rates became faster. The reduction of thionyl chloride was proceed to diffusion controlled reaction.