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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Bulletin of the Korean Chemical Society
Journal Basic Information
Journal DOI :
Korean Chemical Society
Editor in Chief :
Byeong Moon Kim
Volume & Issues
Volume 16, Issue 12 - Dec 1995
Volume 16, Issue 11 - Nov 1995
Volume 16, Issue 10 - Oct 1995
Volume 16, Issue 9 - Sep 1995
Volume 16, Issue 8 - Aug 1995
Volume 16, Issue 7 - Jul 1995
Volume 16, Issue 6 - Jun 1995
Volume 16, Issue 5 - May 1995
Volume 16, Issue 4 - Apr 1995
Volume 16, Issue 3 - Mar 1995
Volume 16, Issue 2 - Feb 1995
Volume 16, Issue 1 - Jan 1995
Selecting the target year
Synthesis of Perdeuterated RNAs and Its Applications to NMR Studies
Jeong, Chae Jun ; Lee, Cheol Hyeon ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 383~386
Photocycloaddition Reaction of
-(4-Methyl-3-pentenyl)-uracil and -thymine
Choe, Ha Yeong ; Kim, Jeong Uk ; An, Jong Il ; Yun, Ho Seop ; Han, Bo Seop ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 386~387
Prediction of Asymmetric Resonances in the Predissociation of the
State of OH
Lee, Seong Yul ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 387~389
Observation of Charge Transfer in
-Aliphatic Carboxylate Mixtures
Hong, Jin Seop ; Yu, Jeong A ; Kim, Gang Jin ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 389~391
Electropolymerization Mechanism for Poly(o-phenylenediamine) (PPD) and Its Electrocatalytic Behavior for
Jang, Dong Hun ; Yu, Yong Seop ; O, Seung Mo ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 392~397
o-Phenylenediamine (o-PD) was electropolymerized on glassy carbon electrodes under a potential cycling condition. The resulting polymer films mediated electrons for the reduction of molecular oxygen at pH=1.0. It was found from the RDE, RRDE, and cyclic voltammetry experiments that the modified electrodes reduce oxygen to hydrogen peroxide at about 300 mV lower potential than the bare glassy carbon electrode. The polymer film consisted of more than two components. Among those, only one component was active in oxygen reduction, which was formed mainly in the earlier stage of the electropolymerization. 2,3-Diaminophenazine, a cyclic dimer of o-PD, was also active in the oxygen reduction reaction, from which it was suggested that the active polymeric component has a structural unit similar to the cyclic dimer. Finally, the electropolymerization mechanism for the formation of the active and inactive components has been proposed.
Cyclohexane Oxidations by an Iron-Palladium Bicatalytic System; Soluble Catalysts and Polymer Supported Catalysts
Jun, Gi Won ; Sim, Eun Gyeong ; Park, Sang Eon ; Lee, Gyu Wan ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 398~400
Selective oxidation of cyclohexane in acetone solution has been studied using iron catalysts with hydrogen peroxide in-situ produced by palladium catalyst. Iron tetraphenylporphyrin chloride shows the highest activity among the tested chlorides and porphyrin complexes of some metals of the first transiton series. Iron chloride and iron tetraphenylporphyrin chloride were supported on four kinds of 4-vinylpyridine copolymer with styrene or divinyl-benzene. Nitrogen 1s photoelectron spectra give the evidence that pyridyl nitrogens of the 4-vinyl pyridine copolymer act as ligands to bind iron species. The copolymer with styrene is the most efficient support for the binding because its solubility in catalyst preparation solvent (methylene chloride) gives the pyridyl group advantage to contact with the iron catalysts. However, better catalytic activity per iron atom could be obtained with a rigid crosslinked polymer due to active site isolation.
Purification and the Catalytic Site Residues of Pseudonomas fragil Lipase Expressed in Escherichia coli
Kim, Tae Ryeon ; Yang, Cheol Hak ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 401~406
The P. fragi lipase overexpressed in E. coli as a fusion protein of 57 kilodalton (kDa) has been purified through glutathione-agarose affinity chromatography by elution with free glutathione. The general properties of the purified GST-fusion protein were characterized by observing absorbance of released p-nitrophenoxide at 400 nm which was hydrolyzed from the substrate p-nitrophenyl palmitate. The optimum condition was observed at 25
, pH 7.8 with 0.4
of protein and 1.0 mM substrate in 0.6% (v/v) TritonX-100 solution. Also the lipase was activated by Ca+2, Mg+2, Ba+2 and Na+ but it was inhibited by Co+2 and Ni+2. pGEX-2T containing P. fragi lipase gene as expression vector was named pGL191 and used as a template for the site-directed mutagenesis by sequential PCR steps. A Ser-His-Asp catalytic triad similar to that present in serine proteases may be present in Pseudomonas lipase. Therefore, the PCR fragments replacing Asp217 to Arg and His260 to Arg were synthesized, and substituted for original fragment in pGL19. The ligated products were transformed into E. coli NM522, and pGEX-2T harboring mutant lipase genes were screened through digestion with XbaI and StuI sites created by mutagenic primers, respectively. No activity of mutant lipases was observed on the plate containing tributyrin. The purified mutant lipases were not activated on the substrate and affected at pH variation. These results demonstrate that Asp217 and His260 are involved in the catalytic site of Pseudomonas lipase.
A Study on the Complexation of Copper(Ⅱ) Ion with 2,2-Bis(hydroxymethyl)-2,
-nitrilotriethanol in Aqueous Solution
Hong, Gyeong Hui ; Ha, Eun Jong ; Bae, Gyu Seon ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 406~409
The complex formation from Cu(Ⅱ) ion and 2,2-bis(hydroxymethyl)-2,2',2"-nitrilotriethanol (Bistris) in aqueous solution has been studied potentiometrically and spectrophotometrically. Bistris (L) coordinates to Cu(Ⅱ) as tridentate. The complex CuL2+ undergoes deprotonation in neutral and basic media. The deprotonated complexes involve metal-alcoholate coordinate bond in stable chelate structures.
Determination of the Proton Transfer Energies of Glycine and Alanine and the Influence of Water Molecules
Gwon, O Yeong ; Kim, Su Yeon ; No, Gyeong Tae ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 410~416
The proton transfer energies of gas phase glycine and alanine and those of hydrated glycine and alanine were calculated both with Hartree-Fock and
ab initio molecular orbital (MO) calculations with 6-31G** basis set. The transition states of the proton transfer of gas phase glycine was also investigated. For zwitterions, both for glycine and alanine, the water bound to -NH3+ site stabilize the complex more compared with the water bound to -CO2-. The proton transfer energy, ΔEpt, of glycine, alanine, mono-hydrated glycine, mono-hydrated alanine, di-hydrated glycine and di-hydrated alanine were obtained as 30.78 (MP2: 22.57), 31.43, 23.99 (MP2: 17.00), 24.98, 22.87, and 25.63 kcal/mol, respectively. The activation energy for proton transfer from neutral (Nt) glycine to zwitterion (Zw) glycine, Ea, was obtained as 16.13 kcal/mol and that for reverse process, Ear, was obtained as 0.85 kcal/mol. Since the transition state of the proton transfer of gas phase glycine locate near the glycine zwitterion on the potential energy surface and the shape of the potential well of the zwitterion is shallow, the zwitterion easily changed to neutral glycine through the proton transfer.
Reaction of Lithium Gallium Hydride with Selected Organic Compounds Containing Representative Functional Groups
Choe, Jeong Hun ; Yun, Mun Yeong ; Yun, Jong Hun ; Jeong, Dong Won ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 416~421
The approximate rates and stoichiometry of the reaction of excess lithium gallium hydride with selected organic compounds containing representative functional groups were examined under the standard conditions (diethyl ether, 0
in order to compare its reducing characteristics with lithium aluminum hydride and lithium borohydride previously reported, and enlarge the scope of its applicability as a reducing agent. Alcohols, phenol, and amines evolve hydrogen rapidly and quantitatively. However lithium gallium hydride reacts with only one active hydrogen of primary amine. Aldehydes and ketones of diverse structure are rapidly reduced to the corresponding alcohols. Conjugated aldehyde and ketone such as cinnamaldehyde and methyl vinyl ketone are rapidly reduced to the corresponding saturated alcohols. p-Benzoquinone is mainly reduces to hydroquinone. Caproic acid and benzoic acid liberate hydrogen rapidly and quantitatively, but reduction proceeds slowly. The acid chlorides and esters tested are all rapidly reduced to the corresponding alcohols. Alkyl halides and epoxides are reduced rapidly with an uptake of 1 equiv of hydride. Styrene oxide is reduced to give 1-phenylethanol quantitatively. Primary amides are reduced slowly. Benzonitrile consumes 2.0 equiv of hydride rapidly, whereas capronitrile is reduced slowly. Nitro compounds consumed 2.9 equiv of hydride, of which 1.9 equiv is for reduction, whereas azobenzene, and azoxybenzene are inert toward this reagent. Cyclohexanone oxime is reduced consuming 2.0 equiv of hydride for reduction at a moderate rate. Pyridine is inert toward this reagent. Disulfides and sulfoxides are reduced slowly, whereas sulfide, sulfone, and sulfonate are inert under these reaction conditions. Sulfonic acid evolves 1 equiv of hydrogen instantly, but reduction is not proceeded.
A New On-line Coprecipitation Preconcentration Technique for Trace Metal Analysis by ICP-AES
Park, Gyeong Hui ; Park, Yong Nam ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 422~427
In a stream of water sample, trace metal ions are quantitatively coprecipitated with Indium hydroxide and filtered. The filtered precipitate is continuously dissolved in 3 M nitric acid and introduced to ICP directly. The lead, cadmium, and copper are concentrated more than 10-fold and determined with ICP-AES at a sampling frequency of 10/hour. The detection limits are 2.89, 1.43,0.52 ppb for lead, cadmium, and copper respectively. Recoveries of lead, cadmium, and copper are 98.7, 94.3, and 104.5% respectively. The RSD values for three elements are about 3-5% currently.
Multidimensional Frictional Coupling Effect in the Photoisomerization of trans-Stilbene
Gwak, Gi Jeong ; Lee, Sang Yeop ; Sin, Guk Jo ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 427~432
A model based on two coupled generalized Langevin equations is proposed to investigate the trans-stilbene photoisomerization dynamics. In this model, a system which has two independent coordinates is considered and these two system coordinates are coupled to the same harmonic bath. The direct coupling between the system coordinates is assumed negligible and these two coordinates influence each other through the frictional coupling mediated by solvent molecules. From the Hamiltonian which is equivalent to the coupled generalized Langevin equations, we obtain the transition state theory rate constants of the stilbene photoisomerization. The rates obtained from this model are compared to experimental results in n-alkane solvents.
Thermodynamic Properties of Caffeine in Compressed Gas
Kim, Jeong Rim ; Gyeong, Jin Beom ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 432~436
The solubility of caffeine in compressed carbon dioxide has been measured to determine its fugacity coefficient between 330 and 410 K up to 500 bar. The result allows the calculation of the thermodynamic excess functions such as the molar excess enthalpy, the molar excess free energy, and the molar excess entropy. The pressure variations of the molar excess functions of caffeine in the caffeine-CO2 mixture were discussed and also compared them with those in the caffeine-NH3 mixture.
Rotational State Distribution of NO after Collisions with Fast Hydrogen Atom
Kim, Yu Hang ; David A. Micha ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 436~438
Based on the collisional time-correlation function approach a general analytical expression has been derived for the double differential cross-section with respect to the scattering angle and the final rotational energy, which can be applied to molecules with non-zero electronic orbital angular momentum after collision with fast hydrogen atoms. By integrating this expression another very simple expression, which gives the final rotational distribution as a function of the rotational quantum number, has also been derived. When this expression is applied to NO(2Π1/2, v'=1) and NO(2Π3/2, v'=1, 2, 3), it can reproduce the experimental rotational distribution after collision with fast H atom very well. The average rotational quantum number and average rotational energy using this expression are also in good agreement with those deduced from the experimental distributions.
Catalytic Asymmetric Allylic Alkylation with A Novel P-S Bidentate Ligand
Gang, Ja Hyo ; Yu, Seong Hun ; Kim, Ju In ; Jo, Hyeong Geun ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 439~443
Both enantiomers of (S)-(-)-2-(diphenylphosphino)-2'-mercapto-1,1'-binaphthyl and their derivatives were obtained by synthesis from racemic 2,2'-dihydroxy-1,1'-binaphthyl and subsequent resolution. The utilities of these ligands were investigated briefly. And among these, S-methyl derivative 15 has proved to be an effective ligand for Pd-catalyzed allylic alkylation.
Synthesis of Polymers Having N-Hydroxymaleimide Units by Thermolysis of N-(Isopropyloxycarbonyloxy)maleimide Polymers
An, Gwang Deok ; C. Grant Willson ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 443~449
N-(Isopropyloxycarbonyloxy)maleimide (iPOCMI) has been synthesized and polymerized to give both the homopolymer and copolymers with substituted styrenes. These polymers were readily deprotected by thermolysis of the isopropyloxycarbonyl (iPOC) groups to provide the corresponding N-hydroxymaleimide (HOMI) polymers. The homopolymer and styrenic copolymers of iPOCMI were radically obtained in higher conversion and higher molecular weight than those obtained by direct polymerizations of N-hydroxymaleimide. The homopolymer of iPOCMI was transformed into poly(N-hydroxymaleimide)P(HOMI) by thermolysis of iPOC groups at 205
with concurrent release of propene and carbon dioxide. The copolymer of iPOCMI and styrene was thermally deprotected to the copolymer of HOMI and styrene at 235
The mass loss was 28% and the Tg of the resulting copolymer was 250
The thermal deprotection readily provided the desired, polar HOMI polymers which have Tgs above 240
The deprotection was accompanied by large changes in aqueous base solubility.
A Theoretical Treatment of the Resonances in the Predissociation of Lower Rovibrational Levels of the
State of OH
Lee, Seong Yul ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 449~453
An exact quantum mechanical theory is employed to treat predissociation process of the
state of OH. The widths and positions of the lower (v= 2 and v= 3) rovibrational levels are calculated. Energy shifts of the resonances from the zeroth order (pure Hund'scase (b)) positions are shown to be small for N
10, indicating that the
state can be described as case (b) very well for low N. Due to the differential interactions of the
states, small splittings between the
levels are predicted. Calculated lifetimes of the resonances agree with experimental results reasonably well.
Corrosion Inhibitors For Zinc in 2 M HCI Solution
A. S. Fouda ; L. H. Madkour ; A. A. El-Shafel ; S. A. Abd ElMaksoud ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 454~458
Inhibiting action of semicarbazide, thiosemicarbazide, sym. diphenylcarbazide towards corrosion of zinc in hydrochloric acid has been investigated. The rate of corrosion depends on the nature of the inhibitor and its concentration. The values of inhibition efficiency from, weight loss, thermometric measurements are in good agreement with those obtained from polarization studies. From the polarization studies, the inhibitors used act as mixed absorption type inhibitors, increased adsorption resulting from an increase in the electron density at the reactive C=S and C=O groups and N-atoms. The thermodynamic parameters of adsorption obtained using Bockris-Swinkels adsorption isotherm reveal a strong interaction of these carbazides on zinc surface.
The Influence of Simple Electrolyte on the Behaviour of Some Acid Dyes in Aqueous Media
M. M. El-Fass ; N. A. Badawy ; A. A. El-Bayaa ; N. S. Moursy ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 458~461
The influence of adding counter-ion such as Na+ on the dimerization of the two sulphonated azo dyes, C.I. Acid Red 14 and C.I. Acid Red 17 in aqueous media has been studied spectrophotometrically. The observed hypochromic effect on increasing the amount of salt has been described. The dye concentration range where the dimerization equilibrium is applicable was chosen. No metachromatic behaviour was observed on changing the dye concentration and the amount of salt. This behaviour was attributed to the ability of the counter-ion to disrupt the structure of water as well as reducing the electrostatic repulsion forces between dye anions which will lead to the increase of aggregation tendency of the dye species.
Stereoselective Complexation of Poly(glutamic acid) with Poly(L-proline) in Aqueous Solution
Jang, Chun Hak ; Kim, Hyeon Don ; Jo, Byeong Gi ; Lee, Jang U ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 462~464
Convenient Synthesis of 20(Chloromethyl)-3-(trimethylsilyl)propene and Allylsilane Based Bifunctional Reagents
Gang, Gyeong Tae ; U, Jong Seon ; Park, Dong Gyeong ; Kim, Jun Geun ; Kim, Won Jeon ;
Bulletin of the Korean Chemical Society, volume 16, issue 5, 1995, Pages 464~466