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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 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
Selecting the target year
A Decanuclear Lithium Niobium(V) Heterometallic Oxo Phenoxide Complex : The Synthesis and Structural Characterization of [
]LL'(THF=tetrahydrofuran, L = 1/2hexane, L = 1/2
박승규 ; 구상만 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1111~1111
A Decanuclear Lithium Niobium(V) Heterometallic Oxo Phenoxide Complex : The Synthesis and Structural Characterization of [
]LL'(THF=tetrahydrofuran, L = 1/2hexane, L = 1/2
박승규 ; 구상만 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1115~1117
Binding Properties of an Allosteric Activator Site for Aspartase from Hafnia alvei
이민섭 ; 김정림 ; 윤문영 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1118~1120
2-O-(α-D-Glucopyranosyl)glycerol, A New Glycerol Glycoside from the Marine Blue-green Alga Oscillatoria sp.
최진숙 ; 이동익 ; 이원갑 ; 김동수 ; 최홍대 ; 손병화 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1121~1122
Synthetic Studies toward Dideoxynojirimycin Derivatives via Dehydroamino Acid as a Key Intermediate
최지아 ; 신정남 ; 전근호 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1123~1125
A Single Amino Acid Substitution Alters Substrate Sequence Specificity of the Yeast Protein Tyrosine Phosphatase YPTP1
양동기 ; 최미숙 ; 박준서 ; 전황근 ; 최희영 ; 이선명 ; 강재승 ; 조형진 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1126~1128
Alkali Metal Cation Selectivity of [
]Ketonand in Methanol: Free Energy Perturbation and Molecular Dynamics Simulation Studies
황선구 ; 장윤희 ; 유진하 ; 정두수 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1129~1135
Free energy perturbation and molecular dynamics simulations were carried out to investigate the relative binding affinities of  ketonand (1) toward alkali metal cations in methanol. The binding affinities of 1 toward the alkali metal cations were calculated to be in the order Li+ > Na+ > K+ > Rb+ > Cs+, whereas our recent theoretically predicted and experimentally observed binding affinities for starand (2) were in the order K+ > Rb+ > Cs+ > Na+ > Li+. The extremely different affinities of 1 and 2 toward smaller cations, Li + and Na+ , were explained in terms of the differences in their ability to change the conformation to accommodate cations of different sizes. The carbonyl groups constituting the central cavity of 1 can reorganize to form a cavity with the optimal M+ -O distance, even for the smallest Li+, without imposing serious strain on 1. The highest affinity of 1 for Li+ was predominantly due to the highest Coulombic attraction between the smallest Li+ and the carbonyl oxygens of 1.
Dynamics of Gas-phase Hydrogen Atom Reaction with Chemisorbed Hydrogen Atoms on a Silicon Surface
임선희 ; 이종백 ; 김유항 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1136~1144
The collision-induced reaction of gas-phase atomic hydrogen with hydrogen atoms chemisorbed on a silicon (001)-(2×1) surface is studied by use of the classical trajectory approach. The model is based on reaction zone atoms interacting with a finite number of primary system silicon atoms, which then are coupled to the heat bath, i.e., the bulk solid phase. The potential energy of the Hads‥Hgas interaction is the primary driver of the reaction, and in all reactive collisions, there is an efficient flow of energy from this interaction to the Hads-Si bond. All reactive events occur on a subpicosecond scale, following the Eley-Rideal mechanism. These events occur in a localized region around the adatom site on the surface. The reaction probability shows the maximum near 700K as the gas temperature increases, but it is nearly independent of the surface temperature up to 700 K. Over the surface temperature range of 0-700 K and gas temperature range of 300 to 2500 K, the reaction probability lies at about 0.1. The reaction energy available for the product states is small, and most of this energy is carried away by the desorbing H2 in its translational and vibrational motions. The Langevin equation is used to consider energy exchange between the reaction zone and the bulk solid phase.
NMR Spectra of Some Amines Coordinated to the Paramagnetic Polyoxometalate,
김병안 ; 소현수 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1145~1148
1H NMR spectra of methyl-, ethyl-, propyl-, isopropyl-, butyl-, N-methylethyl-, N-methylpropyl-, and N-methylisopropylamine coordinated to the paramagnetic 11-tungstocobalto(II)silicate anion (SiW11Co) in dimethylsulfoxide-d6 or dimethylformamide-d7 are reported. For these complexes the ligand exchange is slow on the NMR time scale and pure 1H NMR signals have been observed at room temperature. No complex is detected in D2O. From the pseudocontact shifts of the CH2 and CH3 groups in ethylamine the energy of the gauche conformers with respect to the anti conformer is estimated. Two diastereotopic protons in the CH2 group of N-methylethylamine have quite different chemical shifts especially at low temperatures (e.g. 48.5 vs. 19.4 ppm at -10℃). This may be attributed mainly to the different positions of the two protons in the most stable (gauche) conformer.
NMR Study of 4-Aminopyrimidine Coordinated to the Paramagnetic Undecatung-stocobalto(Ⅱ)silicate Anion: Rates of Internal Rotation of the Amine Group
김병안 ; 소현수 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1149~1152
1H NMR spectrum of a DMF-d7 solution containing 4-aminopyrimidine and [SiW11CoIIO39]6- (SiW11Co) shows separate peaks from two linkage isomers, a and b, in which N(1) and N(3) of the pyrimidine ring are coordinated to SiW11Co, respectively. The signal from the amine group in the isomer a exhibits temperature dependence that is characteristic of a two-site exchange problem. Rates of internal rotation of the amine group were determined by simulating the NMR spectra at 5-35℃. The amine group of free 4-aminopyrimidine also shows temperature-dependent spectra at lower temperatures; rates of internal rotation at (-25)-25℃ were determined. The internal rotation of the amine group in the complex is much slower than that for free 4-aminopyrimidine, indicating that π-character of the C-N bond increases on coordination to SiW11Co. The amine group in the isomer b does not show such behavior. It is probable that hydrogen bonding between N-H and a bridging oxygen atom of SiW11Co prevents it from rotating at low temperatures.
Determination of Relative Reactivities of Free Hydroxyl Groups in β-Cyclodextrin, Amylose, and Cellulose by Reductive-Cleavage Method
이창규 ; 김은주 ; 전중호 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1153~1158
β-Cyclodextrin, amylose, and cellulose were partially methylated and acetylated in order to examine the relative reactivities of 2-, 3-, and 6-OH groups to alkylation and acylation. The partially methylated samples of the polysaccharides were treated with excess of ethyl iodide and sodium hydroxide in dimethyl sulfoxide to convert all of the free hydroxyl groups to ethyl ether groups. The partially O-ethylated and O-methylated polysaccharides were reductively cleaved with triethylsilane in the presence of trimethylsilyl methanesulfonate and borontrifluoride etherate (5 : 1 by mole) and the resulting 4-OH group was acetylated and benzoylated to form mixtures of eight 4-O-acyl-1,5-anhydroalditols. The relative ratio of the alditol esters were analyzed by gas chromatography to determine the degree of substitution at each position. A similar sequence of reactions was carried out with partially acetylated polysaccharides. The results indicated that the order of relative reactivities for methylation are 2-OH > 6-OH > 3-OH and for acylation are 6-OH > 2-OH > 3-OH regardless of the anomeric configuration.
Retention Characteristics of Various Proteins in Flow Field-Flow Fractionation : Effects of pH, Ionic Strength, and Denaturation
송종희 ; 김원숙 ; 박영훈 ; 유의경 ; 이대운 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1159~1164
The study investigated the effect of carrier composition (ionic strength and pH) on the retention of various proteins in flow field-flow fractionation (Flow FFF) as well as the conformational change of Bovine Serum Albumin (BSA) with urea concentration, storage time and temperature. The study found that the retention of protein in Flow FFF increased with the ionic strength of the carrier liquid. Most proteins were well solubilized at pH = 7-8. The hydrodynamic diameters obtained from Flow FFF retention data agree well with theoretical values. The retention increased and the peak shape became distorted at extreme pH conditions of the carrier solution. The selected carrier composition for comparison between the literature value of proteins was 0.05 M tris buffer solution with a pH of 8. Storing BSA at 4 ±2℃ over a period of three months resulted in slow dimerization. Also, in case of the storage of BSA at 37 ±5℃ for one week, the retention of both BSA monomer and dimer increased with the urea concentration. Finally, the structural composition of specific enzymes: malonyl-CoA decarboxylase (MCDC) and malonyl-CoA synthesis (MCS) was determined by using Flow FFF at specific carrier solutions. The molecular weight of the natural MCDC was determined to be 208 kDa, which means it is a homotetramer, while that of the MCS was determined to be 47 kDa, which means it is a monomer.
Preconcentration and Detection of Herbicides in Water by Using the On-line SPE-HPLC System and Photochemical Reaction
이승호 ; 이성광 ; 박영훈 ; 김현주 ; 이대운 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1165~1171
The analysis of trace herbicides using the on-line SPE-HPLC system and a photochemical reaction was studied. 18 compounds of herbicides including eight triazines, six phenoxy acids and esters, and four other herbicides were examined. The on-line SPE-HPLC system developed for selection of eluting solvent improved chromatographic efficiency. The recoveries of herbicides were higher than 77%. With 100 mL tap water samples, the detection limits for all analytes were in the 0.1-2.3×10-10 M range. Detection was done by a UV or fluorescence spectrometer after photochemical reaction at the end of the column with 2W or 450W mercury lamp. Without a photochemical reaction, all compounds responded to 230 nm UV detector, but phenoxy acids and esters were weakly detected. However, with a photochemical reaction, these compounds were selectively detected at 320 nm wavelength of UV absorption and 400 nm emission of the fluorescence detectors. This method can be used for the analysis of environmental water containing herbicides at trace levels.
Kinetics and Mechanism of the Pyridinolysis of Benzyl Bromides in Dimethyl Sulfoxide
홍성완 ; 고한중 ; 이혜황 ; 이익춘 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1172~1176
Nucleophilic substitution reaction of Y-benzyl bromide with X-pyridines are investigated in DMSO at 45.0℃. Biphasic rate dependence is observed on varying the substituents in the substrate (Y) as well as in the nucleophile (X). The two well-defined straight lines in the Hammett (ρy) and Bronsted ( βx) plots are interpreted to indicate the changes in transition-state structure, a decrease in bond cleavage as the substituent on the substrate is changed from electron-donors ( ρy < 0) to electron-acceptors ( ρy > 0), and an increase in the extent of bond formation with the corresponding changes of the substituent on the pyridine. A Jencks' type analysis of separate polar (ρ) and resonance (ρr) effects can also be accounted for by the change of the transition-state structure, not by the variable combination of polar and resonance effects.
Density Functional Theory Studies on the Electrophilic versus Electron Transfer Mechanisms of Aryl Vinyl Ethers
김왕기 ; 손창국 ; 임선희 ; 이순기 ; 김창곤 ; 이익춘 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1177~1180
The ab initio SCF MO and density functional theory (DFT) studies are carried out on the electrophilic (1a) and electron transfer (1b) addition reactions to the vinyl double bond of aryl vinyl sulfides and ethers. In the electrophilic addition processes, a double bond shift from C3 = C4 to X = C3 occurs with occupation number (1.97) close to the normal two. Due to this shift direct conjugation between the cationic center, X = S or O, and the para electron-donor substituent becomes impossible so that the reaction energies (or log K) are correlated with σ rather than σ+. By contrast, radical cation formation leads to delocalization of the SOMO, a lone-pair πorbital on X, with four major resonance structures in which cationic charge as well as spin density is delocalized over C4 , X and C7 atoms. As a result, partial πbonds are formed over C1 -X and C3 - C4 with occupation numbers (0.82) lower than one. In two of the cannonical structures, III(Ⅹ) and III(X+), direct conjugation between the cationic center, X, and the para substituent is achieved so that a better correlation with σ+ rather than σis obtained. The SCF MO energies at the HF/3-21G* and HF/6-31G* levels lead to very much inferior Hammett correlations in the σ/ σ+ diagnostic criterion. In contrast, the ρvalues evaluated with the DFT energies can give reliable diagnostic distinction between the two addition mechanisms.
Ion with Neutral Ferrocene: The Dependence of Reaction Pathways on Its Internal Energy
김병주 ; 소훈영 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1181~1185
The reaction of FeC5H5+ ion with ferrocene molecule is investigated using FT-ICR mass spectrometry. FeC5H5+ ions are generated by dissociative ionization of ferrocenes using an electron beam. The reaction gives rise to the formation of the adduct ion, Fe2(C5H5)3+, in competition with charge transfer reaction leading to the formation of ferrocene molecular ion, Fe(C5H5)2+·. The branching ratio of the adduct ion increases as the internal energy of the reactant ion decreases and correspondingly the branching ratio for the charge transfer reaction product decreases. The observed rate of the addition reaction channel is slower than that of the charge transfer reaction. The observation of the stable adduct ions in the low-pressure ICR cell is attributed to the radiative cooling of the activated ion-molecule complex. The mechanism of the reaction is presented to account for the observed experimental results.
Dynamic Behavior of Photoinduced Birefringence of Copolymers Containing Aminonitro Azobenzene Chromophore in the Side Chain
최동훈 ; 강석훈 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1186~1194
Photoresponsive side chain polymers containing aminonitro azobenzene were synthesized for studying optically induced birefringence. Four different copolymers were prepared using methacrylate, a-methylstyrene, and itaconate monomer. Two copolymers are totally amorphous and the other two are liquid crystalline in nature. Trans-to-cis photoisomerization was observed under the exposure of UV light with UV-VIS absorption spectroscopy. Reorientation of polar azobenzene molecules induced optical anisotropy under a linearly polarized light at 532 nm. The dynamic parameters of optically induced birefringence let us compare the effect of polymeric structure on the rate of growth and decay of the birefringence. Besides the effect of glass transition temperature on the dynamics of photoinduced birefringence, we focused our interests on the geometrical hindrance of polar azobenzene molecules and cooperative motion of environmental mesogenic molecules in the vicinity of polar azobenzene moiety.
2-(Multimethoxy)phenyl-4-methylene-1,3-dioxolane: Ⅱ. Preparation and Cationic Polymerization of 2-(x,y,z- Trimethoxyphenyl)-4-methylene-1,3-dioxolane Derivatives
장원철 ; 공명선 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1195~1199
2-(2,4,5-Trimethoxyphenyl)-4-methylene-1,3-dioxolane (1b), 2-(2,4,6-trimethoxyphenyl)-4-methylene-1,3-di-oxolane (2b), and 2-(3,4,5-trimethoxyphenyl)-4-methylene-1,3-dioxolane (3b) were prepared and polymerized with boron trifluoride. Boron trifluoride catalyzed reaction proceeded via mainly ring-opening polymerization and cyclization reaction to yield poly(keto ether) and 3(2H)-dihydrofuranone. The yields of polymer and cyclized product exhibited a dependency on the position of the methoxy substituents in the benzene ring of 2-phenyl-4-methylene-1,3-dioxolane derivatives. Electrophilic attack of methylene or oxygen atom on 4-meth-ylene-1,3-dioxolane ring were suggested for the polymerization and cyclization.
Reaction of Ru(tpy)
with N,N,C-Terdentates, 3,2'-Annulated-6-(2"-pyridyl)-2-phenylpyridines
장영동 ; 박재규 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1200~1204
The reactions of Ru(tpy)Cl3 (tpy = 2,2';6',2"-terpyridine) with new N,N,C-terdentate ligands, 3,2'-annulated-6-(2"-pyridyl)-2-phenylpyridines (1, HL) and the properties of their Ru(II) complexes are described. The distribution ratio of the two possible Ru(II) complexes, a pentaaza-coordinated complex [Ru(tpy)(1-N,N')Cl]+ and a cycloruthenated complex [Ru(tpy)(La-N,N',C)]+ are highly dependent on the length of the polymethylene unit. The trimethylene bridge of the N,N,C-terdentate in pentaaza-coordinated complex is rigid enough to induce an asymmetry in the complex.
NMR Study of Corundum α-
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1205~1208
27Al NMR chemical shielding, quadrupolar coupling, and dipolar coupling interactions for corundum (α-Al2O3) are determined from the single-crystal 27 Al NMR spectra according to the rotation about three orthogonal axis. 27 Al NMR parameters obtained in this work with high accuracy are as follows: δiso = 7.4(4) ppm, QCC = 2.30(4) MHz, h = 0.08(3), and R = 2.0(3) kHz. This work appears to be the first NMR measurement of an aluminum-aluminum dipolar coupling interaction in α-Al2O3 crystals.
Calculation of the Entropies and Chemical Potentials of Hard-Sphere Solutes Solvated in Hard-Sphere Solids Using the Radial Free-Space Distribution Function
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1209~1212
The entropies and chemical potentials of hard-sphere solutes solvated in hard-sphere solids were calculated by Monte Carlo method using the radial free-space distribution function. This method is based on calculating the entropy by comparing the free volume of a molecule with that of an ideal gas, and is applicable even when the size of solute is very large and the solvent is a solid. When the diameter of hard-sphere solute is small the solute molecule behaves as like as a fluid in solid structures, but when the diameter of solute becomes large, a fluid-to-solid phase transition takes place. The fluid-to-solid phase transition occurs at the region of the smaller size of solute with the more increase of solvent density. The least square fit values of analytical form of the radial free-space distribution functions of solute molecules are presented for future uses.
Mechanism of the Hydrolysis of 2-Phenyl-4H,5H,6H-3-methyl-3-thiazinium Perchlorate Derivatives
김태린 ; 이소영 ; 변상용 ; 김주창 ; 한만소 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1213~1217
Hydrolysis reactions of 2-phenyl-4H,5H,6H-3-methyl-3-thiazinium perchlorate (PTP) and its derivatives at various pH have been investigated kinetically. The hydrolysis is quantitative, producing N-3-mercaptopropyl-N-methylbenzamide as the only product in the all pH ranges. The observed rate of hydrolysis of PTP was always of the first-order. For hydrolysis from PTP, Hammett ρvalues were 0.53, 0.84 and 1.13 for pH 5.0, 8.0, and 10.0, respectively. Bronsted βvalue was 0.53 for general base catalysis. This reaction is catalyzed by general w acetate concentration. However, as the amount of base becomes larger, the rate of hydrolysis reaction approaches the limiting values. The plot of log k vs. pH shows that the rate constants (kt) are two different regions in the profile; one part is directly proportional to hydroxide ion concentration and the other is not. On the bases of these result, the plausible hydrolysis mechanism and a reaction equation were proposed: Below pH 4.5, the hydrolysis was initiated by the addition of water to α-carbon. Above pH 9.0, the hydrolysis was proceeded by the addition of hydroxide ion to α-carbon. However, in the range of pH 4.5-8.0, these two reactions occured competitively.
Trifluoromethyl Group Effect in Chlorination of Dihydro-1,4-oxathiin-3-carboxanilide : Unusual Non-Stereospecific Addition
한호규 ; 장기혁 ; 남기달 ; 전종윤 ; 마혜덕 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1218~1220
Deletion of the Last Five Amino Acid Residues in Human Dihydrolipoamide Dehydrogenase
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1221~1224
Crystal Structure of Mangenese(Ⅲ) Complex with 2-Salicylideneamino-4-t-butylphenol and Salicylaldehyde
모성종 ; 구본권 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1225~1228
The Reaction of Ninhydrin with Polymethylbenzenes in the Presence of Acid Catalyst: Formation of 2-Aryl-1,3-indanedione and Indenoindanone Derivatives
송현남 ; 이홍정 ; 김태이 ; 김재녕 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1229~1231
Electrochemistry and Anion Binding of Urea Functionalized Calixmonoquinone
정해상 ; 최은미 ; 강성옥 ; 남계준 ; 전승원 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1232~1234
Synthesis and Charactrization of Ferric Complex of Biomimetic Tripodal Ligand, Bis(2-Benzimidazolymethyl)ethanolamine
광병훈 ; 이학준 ; 라명수 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1235~1237
On the Isomerism of [
]Ketonand and [
황선구 ; 유진하 ; 장윤희 ; 정두수 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1238~1240
Synthetic, Spectroscopic, and X-ray Crystallographic Studies on Manganese (Ⅲ) Complexes with a 14-Membered Tetraaza Macrocyclic Ligand
김주창 ; Alan J. Lough ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1241~1244
Resolution of Atropisomers of Hindered Naphthamides on an Improved HPLC Chiral Stationary Phase Derived from (S)-Leucine
현명호 ; 이길수 ; 한상철 ;
Bulletin of the Korean Chemical Society, volume 20, issue 10, 1999, Pages 1245~1247