• Analytical Science and Technology
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• v.8 no.4
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• pp.617-622
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• 1995

Electrocatalytic reduction of dioxygen has been investigated by cyclic voltammetry at glassy carbon electrode modified with new Co(II)-Schiff base complexes in aqueous solutions of various pH. The reduction potentials of dioxygen at chemically adsorbed electrodes show the dependence of pH between pH 4 and 14. The catalytic effect is large and the reaction occurs via two or four electron transfer in various pH solution.

• Journal of the Korean Chemical Society
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• v.13 no.1
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• pp.29-36
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• 1969

lnorganic polymers, which are composed of metal (Ⅱ) ions and Schiff's Base of quinizarin-ethylenediamine, have been prepared. In order to find out proper conditions for the reaction, some investigations have been carried out to test the effect of pH, kind of solvent and the state of reagent. As a result, the highest yield occurred near pH 7 and it was found that there were not great difference in the kind of solvent and the state of reagent we had used. Most of the polymers are seemed not to be those we have attempted to prepare. They are found to be coordination polymers which have rather low molecular weight.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1583-1587
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• 2009

The four dentate $N_2O_2$ Schiff base ligand of bis(2-hydroxyacetophenone)-1,2-propanediimine (BHAPN) and its manganese (III) complex were synthesized and identified by microanalysis, spectral data ($^1H$ NMR, MS, FT-IR and UV-Visible) and molar conductivity measurement. The mild and efficient homogeneous oxidative decarboxylation of some carboxylic acids by catalytic amount of this manganese (III) complex, using tetrabutylamonium periodate as a mild oxidant in chloroform at room temperature is reported. The catalyst used in this study showed good activity for the decarboxylation of the titled compounds.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1121-1127
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• 2014

The design, synthesis, and structural characterization of two new palladium complexes based on Schiff base ligands is reported; $[Pd(L1)_2]$ (1) and $[Pd(L2)_2]$ (2), [HL1 = 2-((E)-(2,6-diethylphenylimino)methyl)-4,6-dibromophenol, L2 = (E)-N-benzylidene-2,6-diethylbenzenamine], which are obtained by functionalizing Schiff base ligands with or without electron-withdrawing groups. Both compounds are mononuclear structures. Comparisons are made to the compounds 1 and 2 to analyze and understand the effect of electron-withdrawing groups. Antibacterial activity studies indicate the electron-withdrawing groups on Schiff base ligands enhance antibacterial activity. Catalytic activity, however, is reduced due to the enhanced steric-hindrance of the electron-withdrawing groups. Electronic absorption and emission properties of HL1, L2, 1 and 2 are also reported.

• Journal of the Korean Chemical Society
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• v.57 no.5
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• pp.560-567
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• 2013

A series of new Iron(II) Schiff base amino acid complexes derived from the condensation of amino acid and sodium 2-hydroxybenzaldehyde-5-sulfonate have been synthesized. The complexes were characterized by elemental, electronic, IR spectral analyses and conductance measurements. The stability and solubility of the prepared complexes were determined. Two spectral methods used to determine the stoichiometry of the prepared complexes which exhibited divalent tridentate coordination and formed chelates of octahedral structures. The antibacterial activity of the prepared complexes has been tested against Bacillus cereus, Pseudomonas aeruginosa and Micrococcus bacteria. The effect of HCl on investigated complexes studied spectrophotometrically.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.402-410
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• 2010

New complexes cis-[$Mo_2O_5(Hapdhba)_2$], trans-[$UO_2(Hapdhba)_2$], [Pd(Hapdhba)Cl($H_2O$)], [Pd(bpy)(Hapdhba)]Cl, [Ag(bpy)(Hapdhba)], [$Ru(Hapdhba)_2(H_2O)_2$], [$Rh(Hapdhba)_2Cl(H_2O)$] and [Au(Hapdhba)$Cl_2$] are reported, where $H_2$apdhba is the Schiff-base derived from 2-aminopyrimidine and 2,4-dihydroxy benzaldehyde. The complexes were characterized by IR, electronic, $^1H$ NMR and mass spectra, conductivity, magnetic and thermal measurements. The inhibitive effect of $H_2$apdhba for the corrosion of copper in 0.5 M HCl was also determined by potentiodynamic polarization measurements.

• Journal of Microbiology and Biotechnology
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• v.24 no.8
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• pp.1059-1064
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• 2014

Staphylococcus aureus is a major human pathogen, implicated in both community and hospital acquired infections. The therapy for methicillin-resistant Staphylococcus aureus (MRSA) infections is becoming more difficult because of multidrug resistance and strong biofilm-forming properties. Schiff bases have attracted attention as promising antibacterial agents. In this study, we investigated the in vitro activity of taurine-5-bromosalicylaldehyde Schiff base (TBSSB) against MRSA. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) were determined using a microtiter broth dilution method. TBSSB effectively inhibited planktonic MRSA, with an MIC of $32{\mu}g/ml$. The time-kill curve confirmed that TBSSB exhibited bactericidal activity against MRSA. TBSSB was also found to significantly inhibit MRSA biofilm formation at 24 h, especially at $1{\times}MIC$ and sub-MIC levels. Furthermore, scanning electron microscopy and transmission electron microscopy showed remarkable morphological and ultrastructural changes on the MRSA cell surface, due to exposure to TBSSB. This study indicated that TBSSB may be an effective bactericidal agent against MRSA.

• Journal of the Korean Chemical Society
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• v.33 no.3
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• pp.295-303
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• 1989

Tetradentate Schiff base cobalt(II) complex; Co(SND) and Co(SOPD) were synthesized, and these complexes were allowed to react with dry oxygen to form oxygen adducts cobalt(III) complexes such as $[Co(SND)(Py)]_2O_2$ and $[Co(SOPD)(Py)]_2O_2$ in pyridine. These complexes have been identified by IR specta, T.G.A., magnetic susceptibilities measurements and elemental analysis. It has been found that the oxygen adducts coblat(III) complexes have hexacoordinated octahedral configuration with tetradentate Schiff base cobalt(II), pyridine and oxygen, and the mole ratio of oxygen to cobalt(II) complexes are 1;2. The redox reaction processes of $Co(SND)(Py)_2$ and $Co(SOPD)(Py)_2$ complexes were investigated by cyclic voltammetry with glassy carbon electrode in 0.1M TEAP pyridine. The result of redox reaction processes of Co(III)/Co(II) and Co(II)/Co(I) for $Co(SND)(Py)_2$ and $Co(SOPD)(Py)_2$ complexes are reversible or quasi reversible process but oxygen adducts complexes are irreversible processes. Redox process for oxygen of oxygen adducts complexes was quasi reversible and redox range of potential was $E_{pc}\;=\;-0.96{\sim}-1.03V$ and $E_{pa}\;=\;-0.78{\sim}-0.80V.$

• Journal of the Korean Chemical Society
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• v.31 no.6
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• pp.542-554
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• 1987

Tetradentate schiff base cobalt(II) complexes; Co(SED), Co(SND) and Co(SOPD) have been prepared, these complexes have react with dry oxygen in DMSO to form oxygen adducts cobalt(III) complexes; $[Co(SED)(DMSO)]_2O_2,\;[Co(SND)(DMSO)]_2O_2$ and $[Co(SOPD)(DMSO)]_2O_2$. It seems to be that the oxygen adducts cobalt(Ⅲ) complexes have heexa coordinated octahedral configration with tetradentate schiff base cobalt (III), DMSO and oxygen, and the mole ratio of oxygen to cobalt(II) complexes are 1 : 2, these complexes have been identified by IR-Spectra, T.G.A., magnetic susceptibilitis and elemental analysis of C.H.N. and Cobalt. The redox reaction process of Co(SED), Co(SND) and Co(SOPD) complexes was investigated by cyclic voltammetry with glassy carbon electrode in 0.1M TEAP-DMSO. The results of redox reaction process of Co(II) / Co(III) and Co(II) / Co(I) for cobalt(SED) and cobalt(SOPD) complexes and Co(II) / Co(III) process for cobalt(SND) complex are reversible process but Co(II) / Co(I) process of Cobalt(SND) complex is irreversible, and oxygen adduct complexes to quasi reversibly with oxygen should be very closed related to the redox potentials of range, $E_{pc}$ = -0.80~-0.89V and $E_{pa}$ = -0.70~-0.76V.

• Bulletin of the Korean Chemical Society
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• v.27 no.6
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• pp.925-928
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• 2006