• Analytical Science and Technology
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• v.13 no.6
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• pp.810-814
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• 2000

The open-chain hexadentate $N_4$, $O_2$ ligands 1, 15-bis(2-hydroxybenzyl)-2, 6, 10, 14-tetraazapentadecane (BSATPD. 4HCl) has been synthesized as its tetrahydro-chloride salt and characterized by EA, IR, NMR, and Mass spectrum. Its protonation constants ($logK_n{^H}$) and stability constants ($logK_{ML}$) for $Cu^{2+}$, $Ni^{2+}$, $Co^{2+}$ and $Zn^{2+}$ ions were determined in aqueous solution by potentiometry and compared with those of analogous $N_4$, $O_2$ ligands contain ethtylenic spacers or propylenic spacers, which make six-membered chelate rings between the aliphatic nitrogen atoms.

• Journal of Environmental Science International
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• v.15 no.8
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• pp.799-809
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• 2006

Hydrobromic acid salts of new N, N, O tridentate ligands containing phenol, 2-[(2-Methylamino- ethyl- amino)-methyl]-phenol(H-MMP. 2HBr), 5-Bromo-2-[(2-Methylamino-ethylamino)-methyl]-phenol (Br- MMP. 2HBr), 5-Chloro-2-[(2-Methylamino-ethylamino)-methyl]-phenol(Cl-MMP. 2HBr), 5-Methyl-2-[(2-Methylamino-ethylamino)-methyl]-phenol(Me-MMP. 2HBr), 5-Methoxy-2-I(2-Methylamino-ethylamino)- methyl]-phenol(MeO- MMP. 2HBr) and. 1-[(2-Methylamino-ethylamino)- methyl]-naphthalen-2-ol(Nap- MMP. 2HBr) were synthesized. The synthesized ligands were confirmed by C. H. N. atomic analysis, UV-visible and IR spectroscopies, $^1$H NMR, $^{13}$C NMR and mass analysis. The potentiometry study revealed that the proton dissociation constants(logK$_n^H$) of the synthesized ligands and stability constants (logK$_{ML}$, logK$_{LM2}$) of transition metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) ions occurred in three steps and the order of the calculated overall proton dissociation constants(log$\beta_p$) and stability constants (logK$_{ML}$) of ligands was Br-MMP. 2HBr < Cl-MMP 2HBr < H-MMP. 2HBr < Nap-MMP. 2HBr < Me-MMP. 2HBr < MeO-MMP. 2HBr. The order showed a similar trend to that of Hammett substituent constants($\delta_p$). The synthesized ligands usually form 2:1(ML$_2$) complexes with transition metal ions. The order of the stability constants of each transition metal ions was Co(II) < Ni(II) < Cu(II) ;> Zn(II) ;> Cd(II) ;> Pb(II).

• Journal of the Korean Chemical Society
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• v.35 no.2
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• pp.119-127
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• 1991

The protonation and the metal ion complexation of 15 to 18 membered diaza crown ether such as 1,12-diaza-3, 4 : 9, 10-dibenzo-5, 8-dioxacyclopentadecane(NtnOenH$_4$), 1,13-diaza-3,4 : 10,11-dibenzo-hydroxy-5,9-dioxacyclohexadecane(NtnOtnH$_4$), 1,13-diaza-3,4 : 10,11-dibenzo-15-hydroxy-5,9-dioxacyclohexadecane(Ntn(OH)OtnH$_4$), 1,15-diaza-3,4 : 12,13-dibenzo-5,8,11-trioxacycloheptadecane (NenOdienH$_4$) and 1,15-diaza-3,4 : 12,13-dibenzo-5,8,11-trioxacyclooctadecane(NtnOdienH$_4$) were studlied by potentiometry and NMR spectroscopy. The protonation constants were used to predict basicity of crown ethers. The sequence of the basicity was NenOdienH$_4$ < Ntn(OH)OtnH$_4$ < NtnOenH$_4$ < NtnOtnH$_4$ < NtnOdienH$_4$. Changes on the basicity were explained in terms of the effects of substituents and the degree of twistness of the macrocyclic ring. The sequence of the complex stabilities were Co(II) < Ni(II) < Cu(II) < Zn(II) for the transition metal complexes and Cd(II) < pb(II) < Hg(II) for the post-transition metal complexes. These changes on the stabilities were dependent on the basicity of the ligand and cavity size of the ring. For the heavy post-transiton metal complexes and Zn(Ⅱ) complex, the former factor was predominent and for the other transition metal complexes, the latter was affected on the stabilities. $^1$H and $^{13}$C-NMR studies for heavy post-transition metal complexes indicated that the nitrogen atom has greater affinity on metal ions than oxygen atom and the planarity of the rings was losed by the complexation with metal ions.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.2
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• pp.165-170
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• 2005

Al-Zn alloy/$MnO_2$, seawater cell was considered as a primary aqueous cell with an average voltage range from 1.0 to 1.1V, and the electrolyte of seawater was uptaken into the cell. Eventually, the capacity of its usage will be used for long-term. However, the more use of this cell, the higher corrosion phenomenon of the electrode occurred. Due to its corrosion phenomenon, one main default has been observed with gradual decrease during a discharge process. In this research, a common-used active material for anode was $LiNiO_2$. An active material for cathode, $Zn_{X}FeS_2$ was synthesized in high temperature by uptaken a small amount of 1.3 wt% of ZnS into $FeS_2$, one of the transition-metal dichalcogenides in high temperature. Consequently, based on their usages shown above, this secondary aqueous lithium cell could be more developed. This cell was shown as remarkable charge/discharge performance during the charge/discharge processes. This cathode with active material was given a considerable efficiency of inserting $Li^+$ ions. Moreever, in accordance with the characteristic of the crystal structure for $Zn_{x}FeS_2$, a small amount of ZnS was added which made it possible to reduce prominently velocity of corrosion during the charge/discharge cycle. By applying those merits, Al-Zn alloy/$MnO_2$ seawater cell will be used as a fundamental data in order to transform into a secondary aqueous cell.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.541-550
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• 2010

A new $N_4O_3$ heptadentate ligand, N,N'-Bis(2-hydroxybenzyl)-1,3-bis[(2-aminoethyl)amino]-2-propanol(H-BAP 4HCl)was synthesized. The hydrochloric acid salts of Br-BAP 4HCl, Cl-BAP 4HCl, $CH_3O$-BAP 4HCl and $CH_3$-BAP 4HCl containing Br-, Cl-, H-, $CH_3O-$ and $CH_{3^-}$ groups at the para-site of the phenol group of the H-BAP were synthesized. The structures of the ligands were confirmed by C. H. N. atomic analysis and $^1H$ NMR, $^{13}C$ NMR, UV-visible and mass spectra. The elemental stepwise protonation constants(${logK_n}^H$) of the synthesized $N_4O_3$ ligands showed six steps of the proton dissociation. The orders of the overall dissociation constants($log{\beta}_p$) of the ligands were Br-BAP < Cl-BAP < H-BAP < $CH_3O$-BAP < $CH_3$-BAP. The orders agreed well with that of Hammett substituent constants($\sigma_p$). The calculated stability constants($logK_{ML}$) between the ligands and transition metal ions agreed well with the order of the overall proton dissociation constants of the ligands but they showed a reverse order in Hammestt substituent constants($\sigma_p$). The order of the stability constants between the transition metal ions with the ligands were Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II).

• Analytical Science and Technology
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• v.9 no.1
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• pp.78-83
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• 1996

Hydrogen ion-selective membrane electrodes based on tribenzylamine(TBA), tetrabenzylethylenediamine(TBEDA), pentabenzyldiethylenetriamine(PBDETA) as neutral carriers were shown good selectivity and linearity in the range of pH 1~pH 9, pH 2~pH 12, pH 4~pH 12. The pH selectivity of this membrane electrodes have nothing relation with the numbers of unshared electron pair in TBA, TBEDA, PBDETA and were shown a slope of 43.8mV/pH, 46.9mV/pH, 43.6mV/pH respectively. The selectivity coefficients were determined by the separate solution method for alkali($Li^+$, $Na^+$, $K^+$), alkaline earth metal($Ba^{2+}$, $Ca^{2+}$, $Mg^{2+}$) and transition metal ions($Mn^{2+}$, $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$, $Zn^{2+}$). The membrane electrode based on TBEDA appeared the best results as hydrogen ion electrode.

• Journal of the Korean Chemical Society
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• v.17 no.6
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• pp.434-438
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• 1973

Distribution coefficients (C) of some transition metal ions such as Ni(II), Cu(II), Cd(II), Zn(II), and Hg(II) have been determined in methanol-, ethanol-, isopropanol-, acetone-, and dimethylsulfoxide-water mixtures by using Rexyn 101 (Na-form) resin and 0.2 M sodium chloride solution. The log C values of the metallic ions decrease almost straightly with the increase in reciprocal values of the dielectric constants of the mixed solvents. In the solvents having the same dielectric constants, the distribution coefficients of the metallic ions decrease with the increase in the basicity of the aprotic organic molecule and with the decrease in the molecular size of the protic organic molecule. The separation of the metallic ions has been accomplished with the eluting agent suggested by the C values.

• Analytical Science and Technology
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• v.9 no.4
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• pp.406-410
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• 1996

The adsorption behaviors of transition metal ions on the poly(N,N'-bispalmitoyl-1, 12-diaza-3, 4;9,10-dibenzo-5,8-cyclopentadecane) has been determined by adsorption process in aqueous solution. The order of concentration factor(CF) and the amount of adsorption were Cu(II)

• Journal of Environmental Science International
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• v.18 no.7
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• pp.735-746
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• 2009

Hydrochloric acid salt of a new $N_2O_3$ pentadentate ligand, N,N'-Bis(2-Hydroxybenzyl)-1,3-diamino-2-propanol(H-BHDP 2HCl) was synthesized. Br-BHDP 2HCl, CI-BHDP 2HCl, $CH_3-BHDP$ 2HCl and $CH_3O$-BHDP 2HCl having Br, Cl, $CH_3$ and $CH_3O$ substituents at 5-position of the phenol group of H-BHDP 2HCl were also synthesized. The potentiometry study in aqueous solution revealed that the proton dissociations of the synthesized ligands occurred in four steps and their order of the calculated overall proton dissociation constants($log{\beta}_p$) was Br-BHDP < Cl-BHDP < H-BHDP < $CH_3O-BHDP$ < $CH_3-BHDP$. The order showed a similar trend to that of Hammett substituent constants(${\delta}_p$). The order of the stability constants($logK_{ML}$) was Co(II) < Ni(II) < Cu(II) < Zn(II) < Cd(II) < Pb(II). The order in their stability constants ($logK_{ML}$) of each transition metal complex agreed with that of the overall proton dissociation constants ($log{\beta}_p$).

• Korean Journal of Microbiology
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• v.35 no.4
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• pp.315-321
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• 1999

This study has been performed to deveope a yeast strain having high ${\alpha}$-amylase production ability using nuclear transfer method. Hybrids formed between the strains of Saccharomyces fiburigera KCTC 7393 and Saccharomyces cerevisiae KCTC 7049 (tyr-, ura-)were obtained by nuclear transfer technique. Nuclei isolated from the wild type S. fiburigera strain were transfered into auxotrophic mutants S. cerevisiae and selected the hybrids showing an increased starch degrading capability were selected (MN-16). This transformant grew best and produced maximal ${\alpha}$-amylase activity on the medium containing 2% (V/V) soluble starch. ${\alpha}$-Amylase from MN-16 was purified electrophoretically homogenety and its properties were investigated. The enzyme was purified about 10.6 fold with an overall yield 9.7% from the culture medium by ammonium sulfate fractionation. DEAE-Sephacel column chromatography, and Sephacryl S-200 column chromatography. The purified enzyme showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight of the ${\alpha}$-amylase was estimated to be 53,000 daltons by SDS-PAGE and by gel permeation chromatography on Sephacryl S-200. The purified enzyme showed the maximum activity at pH 5.5 and 40${\circ}C$. The km value for soluble starch was 2.5㎎/㎖. The enzyme activity increased in the presence of $Ca^{2+}, Co^{2+}, EDTA, Mg^{2+}, Mn^{2+}, Zn^{2+}$, but inhibited by $Cu^{2+}, Fe^{2+}$, and $Ni^{2+}$