• Journal of Environmental Science International
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• v.21 no.4
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• pp.421-435
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• 2012

Novel $N_2O_2$ tetradentate ligands, H-3BPD and H-2BPD were synthesized. Hydrochloric acid salts of Br-3BPD, Cl-3BPD, Br-2BPD and Cl-2BPD having Br and Cl substituents at the $para$ position of the phenol hydroxyl group, were synthesized. The ligands were characterized by C. H. N atomic analysis, $^1H$ NMR, $^{13}C$ NMR, UV-visible, and mass spectra. The proton dissociation constants ($logK_n{^H}$) of the phenol hydroxyl group and secondary amine of the synthesized $N_2O_2$ ligands were shown by four step wise values. The orders of the calculated overall proton dissociation constants ($log{\beta}_p$) were Br-3BPD < Cl-3BPD < H-3BPD in case of 3BPD and Br-2BPD < Cl-2BPD < H-2BPD in case of 2BPD respectively. The order agreed well with that of $para$ Hammett substituent constants(${\delta}_p$). The stability constants($logK_{ML}$) of the complexes between the synthesized ligands and transition metal(II) ions agreed with the order of $log{\beta}_p$ of the ligands. The order of the $logK_{ML}$ value of the each transition metal (II) ion was Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II), which agreed well with that of Iriving-Williams series.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1747-1751
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• 2006

The dinuclear tetraazadiphenol macrocyclic nickel(II) complexes [$Ni_2$([20]-DCHDC)]$Cl_2$ (I), [$Ni_2$([20]-DCHDC)]$(ClO_4)_2{\cdot}2CH_3CN $ (II(b)) and [$Ni_2$([20]-DCHDC)$(NCS)_2$] (III) {$H_2$[20]-DCHDC = 14,29-dimethyl-3,10,18,25-tetraazapentacyclo-[25,3,1,$0^{4,9}$,$1^{12,16}$,$0^{19,24}$]ditriacontane-2,10,12,14,16(32),17,27(31), 28,30-decane-31,32-diol} have been synthesized by self-assembly and characterized by elemental analyses, conductances, FT-IR and FAB-MS spectra, and single crystal X-ray diffraction. The crystal structure of II(b) is determined. It crystallizes in the monoclinic space group P2(1)/c. The coordination geometries around Ni(II) ions in I and II(b) are identical and square planes. In complex III each Ni(II) ion is coordinated to $N_2O_2$ plane from the macrocycle and N atoms of NCS- ions occupying the axial positions, forming a square pyramidal geometry. The nonbonded Ni…Ni intermetallic separation in the complex II(b) is 2.8078(10) $\AA$. The FAB mass spectra of I, II and III display major fragments at m/z 635.1, 699.4 and 662.4 corresponding to [$Ni_2$([20]-DCHDC)(Cl + 2H)]$^+$, [$Ni_2$([20]-DCHDC)$(ClO_4\;+\;2H)]^+$ and [$Ni_2$([20]-DCHDC)(NCS) + 6H]$^+$, respectively.

• Journal of the Korean Chemical Society
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• v.31 no.3
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• pp.231-235
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• 1987

In 10M chloride (4M HCl + 6M LiCl) solution, cobalt, but not nickel, formed complex anion (${CoCl_3}^-$), and this anion was extracted by a liquid anion exchanger with Amberlite LA-2. The ion exchange capacity was 2.175meq of cobalt complex per unit ml of Amberlite LA-2. Upon eluting the resin with 0.4M nitric acid, the cobalt complex was stripped and transfered into eluate quantitatively. By using this separation method in the chloride solution dissolved with 50mg of cobalt (II) and 500mg of nikel(II), recovery of cobalt were 99.6 percent.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.775-782
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• 2009

PP-g-AA-Am nonwoven fabric, which possess anionic exchangeable function, was prepared by chemical modification of carboxyl (-COOH) group of PP-g-AA nonwoven fabric to amine ($-NH_2$) group using diethylene triamine (DETA). Its adsorption characteristics for anionic nutrients including isotherm, kinetics and co-anions were studied by batch adsorption experiments. Adsorption equilibriums of $PO_4$-P on PP-g-AA-Am fabric were well described by the Langmuir isotherm model, and their adsorption energies were ranged 10.3 kJ/mol indicating an ion-exchange process as primary adsorption mechanism. The adsorption selectivity of PP-g-AA-Am nonwoven fabric for anions under competition with each other was in following order: $SO_4\;^{2-}$>$PO_4\;^{3-}$>$NO_3\;^-$>$NO_2\;^-$. Also, all results obtained from this study indicate that the $PO_4$-P removal capacity of PP-g-AA-Am nonwoven fabric was extremely superior to that of PA308 anion-exchange resin.

• Polymer(Korea)
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• v.25 no.5
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• pp.642-648
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• 2001

An attempt was made to synthesize an ammonia adsorbent by the photo-induced grafting of styrene (St) onto polypropylene (PP) nonwoven using benzoin ethyl ether (BEE) as a photosensitizer with urea and trimethylol propane triacrylate in methanol medium. As styrene concentration was increased, the graft yield was increased. It was also found that the graft yield increased with reaction time. The polypropylene grafted with styrene (PP-g-St) was sulfonated by chlorosulfonic acid in dichloroethane and complexed with several metal ion, such as $cO^{+2}$, $nI^{+2}$, $cU^{+2}$, $Zn^{+2}$. The amount of ammonia gas adsorbed by these sample was dependent on the degree of sulfonation, adsorption time, and ammonia gas pressure. The adsorption capacity of ammonia gas by the sulfonated PP-g-St(SPP-g-St) nonwoven with 4. 25 mmol $H^+$/g was 6.61 mmol/g. Metal ion complexed SPP-g-St nonwovens had higher adsorption capacity than SPP-g-St nonwoven and the $Co^{+2}$ complexed SPP-g-St showed 9.90 mmol $NH_3$/g, which was much higher than that of active carbon or silica gel.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2303-2308
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• 2009

A thiocyanate poly(vinyl chloride) (PVC) membrane electrode based on [1,2-bis(diphenylphosphino)ethane]dihalopalladium( II), [(dppe)$PdX_2$, X = Cl ($L^1$), X = I ($L^2$)] as active sensor has been developed. The diiodopalladium complex, [(dppe)$PdI_2](L^2$) displays an anti-Hofmeister selectivity sequence: $SCN^-\;>\;I^-\;>\;{ClO_4}^-\;>\;Sal^-\;>\;Br^-\;>\;{NO_2}^-\;>\;{HPO_4}^-\;>\;AcO^-\;>\;{NO_3}^-\;>\;{H_2PO_4}^-\;>\;{CO_3}^{2-}$. The electrode exhibits a Nernstian response (-59.8 mV/decade) over a wide linear concentration range of thiocyanate ($(1.0\;{\times}\;10^{-1}\;to\;5.0\;{\times}\;10^{-6}$ M), low detection limit ($(1.1\;{\times}\;10^{-6}$ M), fast response $(t_{90%}$ = 24 s), and applicability over a wide pH range (3.5∼11). Addition of anionic sites, potassium tetrakis[p-chlorophenyl] borate (KTpClPB) is shown to improve potentiometric anion selectivity, suggesting that the palladium complex may operate as a partially charged carrier-type ionophore within the polymer membrane phase. The reaction mechanism is discussed with respect to UV-Vis and IR spectroscopy. Application of the electrode to the potentiometric titration of thiocyanate ion with silver nitrate is reported.

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.330-334
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• 2013

Mixtures of poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) and silica nanoparticles are coated on the surface of a silk fabrics separator. The coated separators are finally prepared by injecting an electrolyte solution and then characterized for use of lithium-ion battery separator/electrolyte. In the preparation, various contents of dibutylphthalate (DBP) as a plasticizer are used to enhance the formation of micropores within the coated membrane. The coated silk fabrics separators are characterized in terms of ionic conductivity, drenching rate, and electrochemical stability, and the charge-discharge profiles of lithium-ion batteries adopting the coated separators are also examined. As a result, the coated silk fabrics separator prepared using DBP 40~50 wt% and silica shows the superior separator properties and high-rate capability. This is due to (i) high sustainability of silk fabrics, (ii) the formation of micropores with the coated layer membrane by DBP, (iii) increase in drenching rate by silica nanoparticles to involve great enhancements in specific surface area and ionic conductivity.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.484-488
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• 1988

Two forms of extracellular endo-inulinase, designated as PIand P II were resolved from a species of Pseudomonas isolated from soil. Both enzymes were glycoproteins with their carbohydrate content of 15% for PIand 2.4% for P II inulinase. Tryptophan residue was proved to be an essential amino acid for their catalytic activity. The molecular weights of PIand P II were estimated to be 210, 000 and 170, 000, respectively. The activity of the two enzymes was strongly inhibited by p-chloromercuribenzoate but the inhibition was nearly completely offset by the addition of the reducing agents such as cysteine or dithiothreitol. On the other hand, the two enzymes were activated about 50-60% of their activities by the presence of Co$^{+2}$ ion, and quite stable at pH values ranging from pH 4.0 to 1.5. They also appeared to be relatively thermostable, and no appreciable inactivation was observed after incubation at 55$^{\circ}C$ for 2 hours. About 70 % hydrolysis rate with PIand 56 % with P II were achieved when inulin was hydrolyzed at 5$0^{\circ}C$ for 12 hours with 60 units of the enzymes in 2 % inulin solution.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.709-714
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• 2014

Protein tyrosine nitration is considered as an important indicator of nitrosative stresses and as one of the main factors for pathogenesis of inflammation and neuronal degeneration. In this study, we investigated various nitrosative modifications of bovine carbonic anhydrase II (CAII) through qualitative and semi-quantitative analysis using the combined strategy of Fourier transformation ion cyclotron resonance mass spectrometry (FT-ICR MS) and ion-trap tandem mass spectrometry (IT-MS/MS). FT-ICR MS and its spectra were used for the search of the pattern of nitrosative modifications. Identification of nitrosatively modified tyrosine sites were executed through IT-MS/MS. In addition, we also tried to infer the reason for the site-specific nitrosative modifications in CAII. In view of the above purpose, we have explored- i) the side chain accessibility, ii) the electrostatic environment originated from the acidic/basic amino acid residues neighboring to the nitrosatively modified site and iii) the existence of competing amino acid residues for nitration.

• Journal of the Korean Chemical Society
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• v.47 no.4
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• pp.334-338
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• 2003

The crystal structure of $[Co(phen)_2(Cl)(H_2O)] Clㆍ2H_2O$(phen=1,10-phenanthroline) has been determined by X-ray crystallography. It crystallizes in the triclinic system, space group P1, with lattice parameters a=9.662(2), b=11.445(1), c=13.037(2)${\AA}$ ${\alpha}$=64.02(1), ${\beta}$=86.364(9), ${\gamma}=78.58(2)^°$, and Z=2. The coordinated cations contain a six-coordinated cobalt atom chelated by two phen ligands and one chloride anion and one water ligand in cis arrangement. In addition to the chloride coordinated to the cobalt, there are one chloride ion and four water molecules which complete the crystal structure. In the solid state, the title compound forms three dimensional network structure through hydrogen bonds, within which exists the strongest hydrogen bond (O(3)-O(4)=2.33${\AA}$). The intermolecular hydrogen bonds connect the $[Co(phen)_2(Cl)(H_2O)]1+,\;H_2O$ moieties and chloride ion.