• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.259-264
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• 2006

The separation and purification of $TaCl_5$is indispensable in the synthetic process of $TaCl_5$by chlorination of tantalum oxide. The reaction products are mainly $TaCl_5$, $NbCl_5$, $TiCl_4$ and $FeCl_2$. However, we need to separate $TaCl_5/NbCl_5$ mixture from the reaction product, because $TaCl_5$ and $NbCl_5$ are easily separated each other by distillation or hydrogen reduction process. In this work, a comparison study was carried out between direct sequence and indirect sequence to obtain $TaCl_5/NbCl_5$ mixture from the reaction product by removing light component, $TiCl_4$ and heavy component, $FeCl_2$ using two distillation columns. It was concluded that the direct sequence gave better results than indirect sequence in the aspect of initial capital costs and the associative operating costs.

• Food Science and Preservation
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• v.20 no.6
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• pp.871-876
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• 2013

The purpose of this study was to investigate antimicrobial effectiveness of Omija (Schizandra chinensis Baillon) treated with $ClO_2$ (chlorine dioxide) concentration (10, 15, 20, 25 and 30 ppm), washing time (30, 60 and 90 sec) and multiple proportion (x1, x2, x3 and x4). The seven groups were divided into control (Omija without washing water treatment), W-T (Omija treated by tap water ($20{\pm}1^{\circ}C$) for 30 seconds), $ClO_2$-10 (Omija treated by 10 ppm $ClO_2$), $ClO_2$-15 (Omija treated by 15 ppm $ClO_2$), $ClO_2$-20 (Omija treated by 20 ppm $ClO_2$), $ClO_2$-25 (Omija treated by 25 ppm $ClO_2$), $ClO_2$-30 (Omija treated by 30 ppm $ClO_2$), and then they were detected number of total aerobic bacteria, yeast and mold. The rate of inactivation was found, for microorganisms of total aerobic bacteria, yeast and mold, to increase with a increase of $ClO_2$ treatment concentration and multiple proportion. No total aerobic bacteria, yeast and mold in $ClO_2$-30 sample treated for 30 sec, $ClO_2$-15 treated for 60 sec and $ClO_2$-10 treated for 90 sec were detected, and in $ClO_2$-30 Omija with multiple proportion ${\times}1$ (Omija : 30 ppm $ClO_2$ solution ratio was 1:1 (w/w)), $ClO_2$-20 with ${\times}2$ (Omija : 20 ppm $ClO_2$ solution ratio was 1:2 (w/w)) and $ClO_2$-15 with ${\times}4$ (Omija : 15 ppm $ClO_2$ solution ratio was 1:4 (w/w)) respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.5
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• pp.388-392
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• 2002

In this work, the etching of $CeO_2$ thin films has been performed in an inductively coupled $Ar/CF_4/Cl_2$ plasma. The highest etch rate of the $CeO_2$ thin film ws 250 ${\AA}/min$ and the selectivity of CeO$_2$to SBT was 0.4 at a 10% additive $Cl_2$ into Ar/($Ar+CF_4$)gas mixing ratio of 0.8. From result of X-ray photoelectron spectroscopy (XPS) analysis, there are Ce-Cl and Ce-F bonding by chemical reaction between Cl, F and Ce. During the etching of $CeO_2$ thin films in $Ar/CF_4/Cl_2$ plama, Ce-Cl and Ce-F bond is formed, and these prodcuts can be removed by the physical bombardment of Ar ions. The 10% additive $Cl_2$ into the Ar/($Ar+CF_4$)gas mixing ratio of 0.8 could enhance the reaction between Cl, F and Ce.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.679-684
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• 1992

New Pd(IV) complexes have been prepared through the reactions of $trans-[Pd(en)_2Cl_2](ClO_4)_2 $(en = ethylenediamine) with Guanine, Adenine, or Uracil anion as purine and pyrimidine base. We identified the ratio of central metal versus ligands by $C{\cdot}H{\cdot}N$ elemental analysis and proposed the coordinating site of the base by infrared spectrum, $^1H-NMR,\; and\; ^{13}C$-NMR spectrum. Guanine or Adenine ligand coordinated at N7 site and an en ligand exchanged for $ClO_4^-$ counter ions of the starting material . As these results, the complexes showed the formula $[Pd(en)L_2(ClO_4)_2](ClO_4)_2{\cdot}(en)$, (L = Guanine, Adenine). But in the Uracil complex no exchange of the en ligand and $ClO_4^-$ occured and Uracil anion preferred the N1 to N3 as coordinating site, the complex $[Pd(en)_2(Urac)_2](ClO_4)_2(Urac = Uracil anion).$

• Journal of the Korean Chemical Society
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• v.38 no.7
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• pp.485-495
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• 1994

Several new symmetric and asymmetric homo and hetero dinuclear complexes of the type $[Cl(dppp)(NO)_2M({\mu}-pyz)M'(NO)_2(dppp)Cl][ClO_4]_2$ and $[Cl(phen)(NO)_2M({\mu}-pyz)M'(NO)_2(dppp)Cl][ClO_4]_2$(M,M'= Mo or W; phen = 1,10-phenanthroline; dppp = 1,3-bis(diphenylphosphino)propane; pyz = 1,4-pyrazine) were synthesized in three-steps starting from $[M(NO)_2Cl_2]_n(M = Mo, W)$. The final products were purified by eluting it through silica gel column ($2{\times}20$ cm) with acetone as the eluent. Characterization of these complexes and some related complexes was accomplished through UV-vis., $^1H$-NMR, $^{13}C$-NMR and IR spectroscopies as well as elemental analysis. The infrared spectra indicate that the NO groups occupy cis-positions of the octahedral. The $^1H$ and $^{13}C-NMR$ data for the new compounds revealed a dimeric structures with bridged pyz.

• Journal of the Korean Chemical Society
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• v.37 no.7
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• pp.648-654
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• 1993

$[M(cyclam)X_2]Y(M=Co^{3+},\;Fe^{3+},\;Mn^{3+}\;:\;X=Cl-^,\;Br^-,\;NCS^-\;:\;Y=Cl^-,\;Br^-,\;NCS^-),\;[Co(trans-14-diene)X_2]Y(X=Cl^-,\;Br^-\;:\;Y=ClO_4^-)\;and\;[Co(trans-14-diene)](ClO_4)_2$ were able to activate an molecular oxygen under sodium borohydride. 2,4-di-tert-butylphenol and 2,6-di-tert-butylphenol reacted with activated molecular oxygen to give 2,4-tert-butyl-1,6-benzoquinone(BQ) and 3,5,3',5'-tetra-tert-butyldiphenoquinone(DPQ). The saturated tetraazamacrocyclic complexes, $[Co(cyclam)X_2]Y$, were more an effective catalyst than $[Co(trans-14-diene)X_2]Y$ the unsaturated complexes in the formation of BQ and DPQ. The mole ratio of $O_2$ vs. catalyst $(O_2/M)$ for $[Co(cyclam)X_2]Y$ and [Co(trans-14-diene)X_2]Y$ was 1/1, while it was 1/2 for $[M(cyclam)Cl_2]Cl(M=Fe(III),\;Mn(III))$. The results suggested that Co(III)-macrocyclic complexes activated molecular oxygen as superoxolike ${O_2}^-$ and $[M(cyclam)Cl_2]Cl(M=Fe(III),\;Mn(III))$ activated that as peroxolike $O_2^{2-}$.

• Journal of the Korean Chemical Society
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• v.39 no.3
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• pp.191-197
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• 1995

The reactions of [${Mo(NO)_2Cl_2}_n$] with unidentate ligands in $CH_2Cl_2$ solvent afforded monomeric complexes [$Mo(NO)_2L_2Cl_2$]. $[Mo(NO)_2L_4](ClO_4)_2$ was obtained by reaction of unidentate with $[Mo(NO)_2L_2Cl_2]$ in aceton solvent. 4-Dimethylaminopyridine(dmap), pyridine(py), and isoquinoline(isoq) were used as coordinating ligands. These dinitrosylmolybdenum complexes are prepared and characterized by elemental analysis, $^1H$ NMR, infrared, and UV-Visible spectroscopy. The infrared spectra indicate that the NO groups occupy cis-positions of the octahedral.

• Advances in materials Research
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• v.6 no.3
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• pp.303-316
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• 2017

In this article, novel olefin polymerization catalyst with lower cost and simple synthetic process were developed, $ArOTiCl_3$ complexes [$(2-OMeC_6H_4O)TiCl_3(C1)$, $(2,4-Me_2C_6H_3O)TiCl_3(C2)$, $TiCl_3(1,4-OC_6H_4O)TiCl_3(C3)$, $TiCl_3(1,4-OC_6H_2O-Me_2-2,5)$ $TiCl_3(C4)$] and corresponding $(ArO)_2TiCl_2$ complexes [$TiCl_2(OC_6H_4-OMe-2)_2(C5)$ and $TiCl_2(OC_6H_3-Me_2-2,6)_2(C6)$] have been synthesized by the reaction of $TiCl_4$ with phenol, all these complexes were well characterized with $^1H$ NMR, $^{13}C$ NMR, MASS and EA. When combined with methylaluminoxane (MAO), the $ArOTiCl_3/MAO$ system shows high activity for ethylene copolymerization with 1-octene and copolymer was obtained with broaden molecular weight distribution (MWD). The $^{13}C$ NMR result of polymer indicates that the 1-octene incorporation in polymer reached up to 8.29 mol%. The effects of polymerization temperature, concentration of polymerization monomer and polymerization time on the catalytic activity have been investigated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.340-350
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• 1995

This study was conducted to obtain the basic information for the salt stress of Italian Ryegrass. Fourteen cultivars including 7 diploid and 7 tetraploid were subjected to eight levels of NaCl treatments during germination and early seedling stages. Germination percentage decreased remarkably over 300mM of NaCl concentration. The NaCl concentration that inhibited germination of 50% of the viable seeds in the cultivars was 344mM. The decreasing degree of germination percentage was higher in tetraploid type than in diploid type. The varietal difference of germination percentage was shown to be very conspicuous as the NaCl concentration increased. Top dry weight in 166 mM NaCl was decreased by 50% compared with that of control. Inhibition of NaCl appeared to be more in early seedling stage than in germination stage. Top dry weight of cultivars in NaCl stress was not related with germination capacity. Root dry weight in 148mM NaCl decreased by 50% compared with that of control. Root dry weight of cultivars was significantly correlated with top dry weight in NaCl treatment. Top dry weight and root dry weight was higher in diploid type than in tetraploid type at each 8 levels of NaCl concentration. Total chlorophyll content increased with the increase of NaCl concentration and the degree of increase in chlorophyll a was higher than that in chlorophyll b. Chlorophyll a was higher in tetraploid type than in diploid type. But chlorophyll b was higher in diploid type than in tetraploid type. There were significant correlation between chlorophyll a and top dry weight of cultivars over 150mM of NaCl concentration. Free proline content accumulated remarkably in NaCl treatment compared with control and was not difference between diploid type and tetraploid type. Free proline content of cultivars was not related with top dry weight in NaCl treatment.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.215-219
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• 1998

This experiment was conducted to investigate effects of NaCl concentration on photosynthetic rate, free proline content and ion content in tobacco. As NaCl concentration was increased growth was retarded. The decrease growth characteristics(shoot/root ratio was 2.0) at 90mM NaCl indicated that this concentration could be a limiting level. As NaCl concentration was increased photosynthetic rate, transpiration rate, and water use efficiency were decreased. Photosynthetic rate was highly decreased at 60mM NaCl. There was no significant difference between transpiration rate and water use efficiency. Leaf water potential was decreased as NaCl concentration was increased, in that twice lower at 30mM than that of control and drop largely at 120mM NaCl. Free proline content was increased as NaCl increased until 120mM NaCl and drop at 150mM NaCl. The $Ca^{2+}$, $Mg^{2+}$, and $K^+$ contents were increased until NaCl concentration was 120mM. The $Na^{2+}$ content was slowly increased as NaCl concentration increased until 120mM NaCl, and largely increased at 150mM NaCl. There was no significant difference between $Cl^-$ and NaCl treatments except 30 mM NaCl in which $Cl^-$ content was higher than that of control. As NaCl concentration was increased $K^+/Na^+$ ratio was decreased. The negative correlation between $K^+$ and $Na^+$, and positive correlation between $K^+/Na^+$ and protein content were found.