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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Bulletin of the Korean Chemical Society
Journal Basic Information
Journal DOI :
Korean Chemical Society
Editor in Chief :
Byeong Moon Kim
Volume & Issues
Volume 20, Issue 12 - Dec 1999
Volume 20, Issue 11 - Nov 1999
Volume 20, Issue 10 - Oct 1999
Volume 20, Issue 9 - Sep 1999
Volume 20, Issue 8 - Aug 1999
Volume 20, Issue 7 - Jul 1999
Volume 20, Issue 6 - Jun 1999
Volume 20, Issue 5 - May 1999
Volume 20, Issue 4 - Apr 1999
Volume 20, Issue 3 - Mar 1999
Volume 20, Issue 2 - Feb 1999
Volume 20, Issue 1 - Jan 1999
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SmI₂Mediated Reaction of N-(Haloalkyl)-N-phenylformamide: Homologation
로영해 ; 김중협 ; 김성훈 ; 유병우 ; 윤철민 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 981~981
SmI₂Mediated Reaction of N-(Haloalkyl)-N-phenylformamide: Homologation
로영해 ; 김중협 ; 김성훈 ; 유병우 ; 윤철민 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 985~986
Low Energy Photodissociation of HCI : Theoretical Analysis
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 987~988
Electrochemical Organyl Group Transfer of Triorganylboranes to Carboxylic Acid Chlorides and Carboxylic Acid Anhydrides Using Copper Sacrificial Anode
최정훈 ; 조성욱 ; 김범성 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 989~990
Synthesis of New Soluble Subphthalocyanine Substituted with Crown Ethers
이성은 ; 서홍석 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 991~992
Concurrent Production of Methanol and Dimethyl Ether from Carbon Dioxide Hydrogenation : Investgation of Reaction Conditions
전기원 ; 신원제 ; 이규완 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 993~998
The concurrent production of methanol and dimethyl ether from carbon dioxide hydrogenation has been studied under various reaction conditions. First, the methanol synthesis was compared with the concurrent production method. For the methanol synthesis, the ternary mixed oxide catalyst (CuO/ZnO/Al2O3) was used and for the coproduction of methanol and dimethyl ether, silica-alumina was mixed with the methanol synthesis catalyst to be a hybrid catalyst. The results show that the co-production provides much higher per-pass yield than methanol synthesis even at very short contact time. The effects of temperature, contact time, pressure and catalyst hybrid ratio on the product yields and selectivities were also determined in the co-production.
A Kinetic Study on the Adsorptionof Compact, Water-soluble Proteins onto Aqueous Surfaces
조태철 ; Michel A. Cornec ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 999~1004
Two compact sized globular proteins, β-lactoglobulin and α-lactalbumin were kinetically characterized at the aqueous solution surface with the measurement of surface pressure (π) and surface concentration (Γ) via a radiotracer method. The adsorption kinetics was of diffusion control at early times, the rates of increase of πand Γ being lower at longer times due to growing energy barrier. At low concentrations, an apparent time lag was observed in the evolution of π for β-lactoglobulin but not for α-lactalbumin which was shown to be due to the non-linear nature of the p- G relationship for the former. The area per molecule of an adsorbed β-lactoglobulin during adsorption was smaller than that for spread monolayer since β-lactoglobulin was not fully unfolded during the adsorption. For α-lactalbumin, however, no such difference in the molecular areas for adsorbed and spread monolayer was observed indicating thereby that α-lactalbumin unfolded much more rapidly (has looser tertiary structure) than β-lactoglobulin. Surface excess concentrations of α-lactalbumin was found to evolve in two steps possibly due to the change in the orientation of the adsorbed protein from a side-on to an end-on orientation.
A New Synthetic Route to Wustite
박정철 ; 김돈 ; 이충섭 ; 김동국 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1005~1009
Wustite with NaCl structure is successfully synthesized in a quartz tube sealed under vacuum ( ≒1×10 -3 torr). Hematite in an evacuated quartz tube progressively loses oxide ion at 1373 K. XRD patterns disclose that α-Fe2O3 is transformed into the Fe3O4 after heat treatment at 1373 K for 32 h, and the poorly crystallized FeO is appeared after heat treatment for 48 h. Finally, α-Fe2O3 is completely transformed into the well crystallized Fe 0.935O after heat treatment for 84 h. The electrical resistivity, ac-susceptibility measurement, Mossbauer spectroscopy, and x-ray absorption spectroscopy corroborate the structural phase transition on the iron oxides prepared in a sealed quartz tube depending on the heating time at 1373 K.
Effect of Temperature on Photoinduced Reorientation of Azobenzee Chromophore in the Side Chain Copolymers
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1010~1016
We synthesized the photoresponsive side chain polymers containing aminonitro azobenzene for studying the effect of temperature on photoinduced birefringence. Four different copolymers were prepared using methacrylate, α-methylstyrene, and itaconate monomer. Photoisomerization was observed under the exposure of UV light using UV-VIS absorption spectroscopy. Reorientation of polar azobenzene molecules induced optical anisotropy under a linearly polarized light at 532 nm. The change of the birefringence was observed with increasing the sample temperature under a continuous irradiation of excitation light. We could estimate the activation energy of molecular motion in thermal and photochemical mode. Besides the effect of glass transition temperature on the activation energy, we focused our interests on the effect of geometrical hindrance of polar azobenzene molecules and cooperative motion of environmental mesogenic molecules in the vicinity of polar azobenzene molecules.
Nucleophilic Substitution Reactions of Thiophenyl Phenylacetate with Benzylamines in Acetonitrile
오혁근 ; 김선경 ; 이익춘 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1017~1020
The aminolysis reactions of thiophenyl phenylacetates with benzylamines are investigated in acetonitrile at 55.0℃. Relatively large selectivity parameters, βx≒ 1.5, βz = -1.5~-1.8 and βxz = 0.92 together with the valid reactivity-selectivity principle are consistent with stepwise acyl transfer mechanism with rate limiting expulsion of the leaving group, thiophenolate anion, from the tetrahedral intermediate, T ± . The first order kinetics with respect to the benzylamine concentration and the realtively large secondary kinetic isotope effect (kH / kD = 1.2-1.7) involving deuterated benzylamine nucleophiles suggest a four center type transition state in which concurrent leaving group departure and proton transfer are involved.
Rapid Identification of Petroleum Products by Near-Infrared Spectroscopy
정호일 ; 최혁진 ; 구민식 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1021~1025
Near-infrared (NIR) spectroscopy has been successfully utilized for the rapid identification of six typical petroleum products such as light straight-run (LSR), naphtha, kerosine, light gas oil (LGO), gasoline, and diesel. The spectral features of each product were reasonably differentiated in the NIR region, and the spectral differences provided enough qualitative spectral information for discrimination. For discrimination, principal component analysis (PCA) combined with Mahalanobis distance was used to identify each petroleum product from NIR spectra. The results showed that each product was accurately identified with an accuracy over 95%. Most noticeably, LSR, kerosine, gasoline, and diesel samples were predicted with identification accuracy of 99%. The overall results ensure that a portable NIR instrument combined with a multivariate qualitative discrimination method can be efficiently utilized for rapid and simple identification of petroleum products. This is especially important when local at-site measurements are necessary, such as accidental petroleum leakage and regulation of illegal product blending.
Semiflexible Polymer Brushes: Most Probable Configuration Approach Based on Cotinuous Chain Model
김광규 ; 차국헌 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1026~1030
The properties of semiflexible polymer brushes are studied by applying the classical limit of mean-field approach for chains with marginal chain stiffness. Using the mean-spherical Gaussian model, the most probable configuration for semiflexible chains is obtained, which reduces to the parabolic brush of Milner et al. [Mac-romolecules 1988, 21, 2610] in the flexible limit. From this configuration, equilibrium brush height as well as interactions between semiflexible brushes are estimated.
The Growth Kinetics of Tin Oxide Films from Tetramethyltin
이상운 ; 윤천호 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1031~1034
Tin oxide films have been grown employing the chemical vapor deposition technique under reduced pressure conditions using tetramethyltin as the precursor and oxygen as the oxidant. An activation energy derived for the deposition reaction under representative deposition conditions has a value of 89±3 kJ mol-1, suggesting a typical kinetic control. Deposition rates of tin oxide films exhibit a near first order dependence on tetramethyltin partial pressure and a zeroth order dependence on oxygen partial pressure. This study provides the first quantitative information about the growth kinetics of tin oxide films from tetramethyltin by the cold-wall low-pressure chemical vapor deposition.
Photoluminescence of the Mn-doped ZnGa₂O₄ Phosphors Prepared by Coprecipitation of Metal Salts
고중곤 ; 박희동 ; 김동표 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1035~1039
Manganese-activated zincgallate (Zn1-xMnxGa2O4) phosphor as a green phosphor was readily prepared by coprecipitation in aqueous basic solution of metal salts. The obtained product converted to amorphous zincgallate even at 300℃, followed by crystallization at 1000 ℃. The pyrolyzed phosphor showed fine particle, then reduction treatment at 900 ℃ changed into homogeneous shape with slight grain growth(particle size less than 0.5 mm). The photoluminescence characteristics of the zincgallates have been investigated as a function of dopant concentrations, reducing atmospheres and temperatures. Under UV excitation the phosphors displayed the highest green emission efficiency at 504 nm when the specimen oxidized at 1000 ℃ was reduced at 900 ℃ in a mild hydrogen atmosphere (97% N2, 3% H2) with a flow rate of 100 ml/min.
Application of a Membrane Desolvator to the Analysis of Organic Solvents in Inductively Coupled Plasma Atomic Emission Spectrometry
Lee, J. S. ; Lim, H. B. ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1040~1044
A micro porous PTFE membrane desolvator (MMD) was built and evaluated for the on-line removal of organic solvents to facilitate the determination of trace metal contaminants in the solvents by ICP-AES. Three organic solvents, isopropyl alcohol (IPA), methanol, and dimethy sulfoxide (DMSO) were studied. The MMD reduced organic solvent concentration in the sample aerosol stream by 82% to 89%, as indicated by monitoring C(I) emission. Net signal intensity of Fe, Al, and Cu was increasing with higher organic solvent concentration, with the rate of increase being solvent dependent. The signal intensities for Mg and Pb followed the trend with the C(I) signal. Changing the sweep gas flow rate affected the optimum signal intensity. Wine samples were analyzed by the method of standard addition. The concentrations of B, Al, and Mg were determined with a relative precision of less than 2.3%.
Differences of Structural and Electronic Properties in
(x=0, 0.04, and 0.4)
정동운 ; 최은국 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1045~1048
Electronic structures calculated based upon the extended Huckel tight-binding method for Ba1-xKxBiO3 with x = 0, 0.04, and 0.4 are reported. It is noticed that the commensurate ordering of Bi 3+ and Bi 5+ is responsible for the insulating and semiconducting behavior in BaBiO3 and Ba0.96K0.04BiO4. The band gaps of 3.2 eV and 1.4 eV for the former and the latter compounds, respectively, are consistent with the experimental results. Doping in Bi 6s-block band up to x = 0.4 causes the collapse of the ordering of Bi 3+ and Bi 5+, thereby resulting in the superconductivity in the Ba0.6K0.4BiO3 compound. Strikingly, the character of oxygen contributes to the conducting mechanism than that of the bismuth. This is quite different from the cuprate superconductors in which the character of copper dominates that of oxygen.
In-situ Monitoring of Anodic Oxidation of p-type Si(100) by Electrochemical Impedance Techniques in Nonaqueous and Aqueous Solutions
김민수 ; 김경구 ; 김상열 ; 김영태 ; 원영희 ; 최연익 ; 모선일 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1049~1055
Electrochemical oxidation of silicon (p-type Si(100)) at room temperature in ethylene glycol and in aqueous solutions has been performed by applying constant low current densities for the preparation of thin SiO2 layers. In-situ ac impedance spectroscopic methods have been employed to characterize the interfaces of electrolyte/oxide/semiconductor and to estimate the thickness of the oxide layer. The thicknesses of SiO2 layers calculated from the capacitive impedance were in the range of 25-100Å depending on the experimental conditions. The anodic polarization resistance parallel with the oxide layer capacitance increased continuously to a very large value in ethylene glycol solution. However, it decreased above 4 V in aqueous solutions, where oxygen evolved through the oxidation of water. Interstitially dissolved oxygen molecules in SiO2 layer at above the oxygen evolution potential were expected to facilitate the formation of SiO2 at the interfaces. Thin SiO2 films grew efficiently at a controlled rate during the application of low anodization currents in aqueous solutions.
Electrocatalytic Reduction of Dioxygen by New Water Soluble Cobalt(II) Tetrakis-(1,2,5,6-tetrafluoro-4-NN'N''-trimethylanilinium)-β-octabromoporphyrin in Aqueous Solutions
최은미 ; 정해상 ; 박덕희 ; 최용국 ; 전승원 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1056~1060
New water soluble and highly electron deficient cobalt(II) tetrakis-(1,2,5,6-tertrafluoro-4-NN'N"-trimethyla-nilinium)-β-octabromoporphyrin [Co II (Br8TTFP)(Y)2] was synthesized and used for the electrocatalytic reduction of dioxygen. The first reduction of synthesized [Co II (Br8TTFP)(Y)2] involves one electron process to give metal centered [Co I (Br8TTFP)(Y)2]. The reduction of potential [E1/2 = -0.32 V] of [Co II (Br8TTFP)(Y)2] shifts positively 370 mV compared with that of [Co II (TTFP)(Y)2] due to the substituted bromide to β-pyrrole positions. The electrochemically reduced [Co I (Br8TTFP)(Y)2] binds dioxygen and catalytically reduces it to HOOH by 2e - transfer. Cyclic and hydrodynamic voltammetry at a glassy carbon electrode in dioxygen-saturated aqueous solutions are used to study the electrocatalytic pathway.
The Interaction of CO and W(111) Surface
Lee, S. Y. ; Kim, Y. D. ; Seo, S. N. ; Park, C. Y. ; Kwak, H. T. ; Boo, J. H. ; Lee, S. B. ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1061~1066
The adsorption of CO on W(111) surface in the range of adsorption temperature between 300 K and 1000 K has been studied using AES, LEED, and TDS in an UHV system. After CO saturation at 300 K, four desorption peaks are observed at temperatures (K) of about 400, 850, 1000, and 1100 in thermal desorption spectra, called as α, β1, β2, and β3 state, respectively. The state was attributed to molecular species of CO, which is well known. Because the CO in βstates (especially the β3 state) is still debated as to whether it is dissociative or non-dissociative, the β3 state is mainly discussed. By using the variation method of heating rate in the thermal desorption spectrometry, the desorption energy and pre-exponential factor for the β3 state are evaluated to be 280 kJ/mol and 1.5×10 12 s-1 , respectively. A lateral interaction energy of 5.7 kJ/mol can also be estimated by Bragg-Williams approximation. To interpret the thermal desorption spectra for the β3 state, moreover, those for the model of a first order and a second order desorption are simulated using quasi-chemical approximation. In this study, a model of lying-down CO species is proposed for the β3 state of CO adsorption.
Structures of Ammonia Cluster Cations
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1067~1072
Structures of unprotonated [(NH3)n+(n = 1-6)] and protonated [NH4+(NH3)n-1(n = 1-6)] ammonia cluster cations have been optimized with ab initio Hartree-Fock (HF) and second-order MФller-Plesset (MP2)/6-31+G ** levels and the harmonic vibrational frequencies have also been evaluated. In unprotonated cluster cations, NH3+ forms as a central core of the first ammonia solvation shell. In protonated cluster cations, NH4+ forms as a central core. In unprotonated dimer and trimer cations, there are two types of isomers (hydrogen-bonded and head-to-head interactions). In both cluster cations, the hydrogen-bonded isomers are more stable. In the hydrogen-bonded dimer cation, the proton transfer reaction takes place from (NH3-HN+H2) to (NH4+-NH2). But in the other unprotonated cluster cations, the proton transfer does not take place. In unprotonated pentamer and hexamer, a NH3+ core has both interactions in a complex. On the other hand, in unprotonated tetramer a core has only the hydrogen-bonded type combined with neutral ammonia molecules. With increasing cluster cation size, the bond lengths [R(NN)] between two nitrogen atoms and the distances [R(N ...H)] of the hydrogen-bond increase reg-ularly. In the calculated infra-red absorption bands for ammonia cluster cations, the characteristic peaks of the bridged NH vibration of the hydrogen-bonded clusters appear near 2500 cm-1 . With increasing size, the peaks shift from 2306 cm-1 to 2780 cm-1 .
Synthesis and Antibiotic Activities of CRAMP, a Cathelin-related Antimicrobial Peptide and Its Fragments
하종명 ; 신송엽 ; 강신원 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1073~1077
CRAMP, a 37-amino acid cationic antimicrobial peptide was recently deduced from the cDNA cloned from mouse femoral marrow RNA. In order to investigate the structure-activity relationship and functional region of CRAMP, CRAMP and its 18-mer overlapping peptides were synthesized by the solid phase method. CRAMP showed broad spectrum antibacterial activity against both Gram-positive and Gram-negative bacterial strains (MIC: 3.125-6.25 μM) but had no hemolytic activity until 50 μM. CRAMP was found to have a potent anticancer activity (IC50: 12-23 μM) against two human small cell lung cancer cell lines. Furthermore, CRAMP was found to display faster bactericidal rate in B. subtilis rather than E. coli in the kinetics of bacterial killing. Among 18-meric overlapping fragment peptides, only CRAMP (16-33) displayed potent antibacterial activity (MIC: 12.5-50 μM) against several bacteria with no hemolytic activity. Circular dichroism (CD) spectra anal-ysis indicated that CRAMP and its analogues will form the amphipathic α-helical conformation in the cell membranes similar to other antimicrobial peptides, such as cecropins and magainins.
Influences of Hinge Region of a Systhetic Antimicrobial Peptide, Cecropin A(1-13)-Melittin(1-13) Hybrid on Antibiotic Activity
신송엽 ; 강주현 ; 이동건 ; 장소윤 ; 서무열 ; 김길룡 ; 함경수 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1078~1084
A synthetic cecropin A(1-13)-melittin(1-13) [CA-ME] hybrid peptide was known to be an antimicrobial peptide having strong antibacterial, antifungal and antitumor activity with minimal cytotoxic effect against human erythrocyte. Analogues were synthesized to investigate the influences of the flexible hinge region of CA-ME on the antibiotic activity. Antibiotic activity of the peptides was measured by the growth inhibition against bac-terial, fungal and tumor cells and vesicle-aggregating or disrupting activity. The deletion of Gln-Gly-Ile (P1) or Gly-Gln-Gly-Ile-Gly (P3) from CA-ME brought about a significant decrease on the antibiotic activities. In contrast, Gly-Ile-Gly deletion (P2) from CA-ME or Pro insertion (P5) instead of Gly-Gln-Gly-Ile-Gly of CA-ME retained antibiotic activity. This result indicated that the flexible hinge or β-bend structure provided by Gly-Gln-Gly-Ile-Gly, Gln-Gly, or Pro in the central region of the peptides is requisite for its effective antibiotic activity and may facilitate easily the hydrophobic C-terminal region of the peptide to penetrate the lipid bilayers of the target cell membrane. In contrast, P4 and P6 with Gly-Gln-Gly-Pro-Gly or Gly-Gln-Pro in the central region of the peptide caused a drastic reduction on the antibiotic activities. This result suggested that the con-secutive β-bend structure provided by Gly-Gln-Gly-Pro-Gly or Gly-Gln-Pro in the central hinge region of the peptide seems to interrupt the ion channel/pore formation on the target cell membranes.
Synthesis of Dihexadecyl N-[Monomethoxypoly(ethylene glycol)]-L-glutamate and Its Effect on Liposomes
이윤식 ; 김운정 ; 이국행 ; 유수창 ; 이상희 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1085~1088
Preparation and Structure of trans-Bis(phenylethynyl)bis(triethylphosphine)palladium(II)
김효진 ; Lee, Soon W. ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1089~1092
Correlation between Energy Transfer and Phase Separation in Emissive Polymer Blends
한정희 ; 이윤식 ; 남기숙 ; 조은하 ; 고석범 ; 김철주 ; 전일철 ; 이원희 ; 서은경 ; 이영희 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1093~1096
Rhodium-catalyzed Coupling Reaction of 2-Vinylpyridines with Allyl Ethers
임영권 ; 한종수 ; 구본택 ; 강정부 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1097~1100
Laser Ablation of a YBCO Target at 266 nm and 1064 nm: Reactive Scattering of a YBCO Plume and an Oxygen Jet
문지윤 ; 박승민 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1101~1104
Crystal Structure of Dinuclear Molybdenum(VI) Complex Involving trans-Dioxo
모성종 ; 구본권 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1105~1107
Upper Rim Urea Derivative of Calixarene: Anion Selective Neutral Receptor
남계춘 ; 전종철 ; 강성옥 ; 고승환 ;
Bulletin of the Korean Chemical Society, volume 20, issue 9, 1999, Pages 1108~1110