Go to the main menu
Skip to content
Go to bottom
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 17, Issue 12 - Dec 1996
Volume 17, Issue 11 - Nov 1996
Volume 17, Issue 10 - Oct 1996
Volume 17, Issue 9 - Sep 1996
Volume 17, Issue 8 - Aug 1996
Volume 17, Issue 7 - Jul 1996
Volume 17, Issue 6 - Jun 1996
Volume 17, Issue 5 - May 1996
Volume 17, Issue 4 - Apr 1996
Volume 17, Issue 3 - Mar 1996
Volume 17, Issue 2 - Feb 1996
Volume 17, Issue 1 - Jan 1996
Selecting the target year
Study toward the Total Synthesis of Forskolin (Ⅰ) Synthesis of the Trien 13 as a Key Intermediate Utilizing KF-Alumina Mediated Alkylation
이경혜 ; 이철혜 ; 김홍범 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 773~775
Oxidation of Aromatic Ketone Hydrazones by Thianthrene Cation Radical
이대원 ; 박영숙 ; 이왕근 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 775~777
Preparation of Polyenes with an Allylsilane Moiety Using 2-(Phenylsulfonylmethyl)-3-(trimethylsilyl)propene and Their Cyclization Reactions
강경태 ; 박동경 ; 이승진 ; 성태명 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 777~778
Rearrangement of 2,4-bisalkylpyrrole Unit to 2,5-bisalkylpyrrole Unit in the Ligand-Modified Porphyrinogens
허필연 ; 이창희 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 778~780
Electrochemical Reactions of
Films in the Presence of Water : An Electrochemical Quartz Crystal Microbalance Study
서경자 ; 신명순 ; 전일철 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 781~786
Mass transport behavior of C60 films on electrodes with different thicknesses has been studied by an Electrochemical Quartz Crystal Microbalance (EQCM) during electrochemical reduction-oxidation processes in the presence of water. C60 films were found to be reduced in the presence of water and they remains quite stable. In thin films, the mass on electrode decreased after a complete cycle while X-ray Photoelectron Spectroscopy (XPS) study does not support the existence or formation of C60-epoxides during electrochemical reduction processes in the presence of water or oxygen.
Cobalt(Ⅲ) Complexes of N,N'-Bis(2(S)-aminopropyl)-1(R),2(R)-trans-1,2-diaminocyclohexane
이동일 ; 전무진 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 786~790
A novel optically active tetraamine ligand possessing four asymmetric centers, N,N'-bis(2(S)-aminopropyl)-1(R),2(R)-trans-1,2-diaminocyclohexane (SRRS-apchxn) and its cobalt(Ⅲ) complexes, [Co(SRRS-apchxn)X2]n+ (X=Cl-, H2O, X2=CO32-) have been synthesized. This ligand has coordinated stereospecifically to the cobalt(Ⅲ) ion to give only the Λ-uns-cis-(SS) isomer. A trans dichloro complex has been obtained via the stereospecific isomerization of Λ-uns-cis-(SS)-[Co(SRRS-apchxn)Cl2]+ to trans-(SS)-[Co(SRRS-apchxn) Cl2]+ in CH3OH-HCl medium. Ligand and complexes have been characterized by electronic absorption, 1H NMR, CD spectra, and also by elemental analysis. It is of interest that this is one of the few CoⅢ(N4)X2 type complex preparations, which produces such an uns-cis isomer with stereospecificity.
Stability Constants of Divalent Transition and Trivalent Lanthanide Metal Ion Complexes of Macrocyclic Triazatri(Methylacetic Acid)
김동원 ; 홍춘표 ; 최기영 ; 김창숙 ; 이남수 ; 장영훈 ; 이재국 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 790~793
The azacrown compound, 1,7-dioxa-4,10,13-triazacyclopentadecane-N,N',N"-tri(methyl-acetic acid)(N3O2-tri(methylacetic acid)) was synthesized by modified procedure of Krespan. Potentiometric method has been used to determine the protonation constants of N3O2-tri(methylacetic acid) and stability constants of complexes on the divalent transition metal ions (Co2+, Ni2+, Cu2+, and Zn2+) and trivalent metal ions (Ce3+, Eu3+, Gd3+, and Yb3+) with N3O2-tri(methylacetic acid). The stability constants for the complexes of the divalent transition metal ions studied in the present work with N3O2-tri(methylacetic acid) were 11.4 for Co2+, 11.63 for Ni2+, 13.51 for Cu2+, and 11.65 for Zn2+, respectively. Thus, the order of the stability constants for complexes on the transition metal ions with N3O2-tri(methylacetic acid) was shown Co2+ < Ni2+ < Cu2+ > Zn2+ as same as the order of Irving-Williams series. The stability constants of Ce3+, Eu3+, Gd3+, and Yb3+ trivalent lanthanide metal ion complexes of N3O2-tri(methylacetic acid) were, respectively, 11.26 for Ce3+, 11.56 for Eu3+, 11.49 for Gd3+, and 11.80 for Yb3+. The values of the stability constants on trivalent metal ions with the ligand are increasing according to increase atomic number, due to increase acidity. But the value of stability constant of Gd3+ ion is less than the value of Eu3+ ion. This disordered behavior is also reported by Moeller.
Physical Properties of the Nonstoichiometric Perovskite
정수경 ; 김민규 ; 김규홍 ; 여철현 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 794~798
Solid solutions of the nonstoichiometric Dy1-xSrxCoO3-y system with the compositions of x=0.00, 0.25, 0.50, 0.75, and 1.00 have been synthesized by the solid state reaction at 1000 ℃ under atmospheric air pressure. The crystallographic structures of the solid solutions are analyzed by the powder X-ray diffraction patterns at room temperature. The analyses assign the compositions of x=0.00 and 0.25 to the orthorhombic system with space group of Pbnm/D2h16, the compositions of x=0.50 and 0.75 to the tetragonal system like a typical SrCoO2.86, and the composition of x=l.00 or SrCoO2.50 to the brownmillerite type system with space group of I**a. The reduced lattice volumes increase with x value due to the larger radius of Sr2+ ion than that of Dy3+ ion. The mole ratio of Co4+ ion to total Co ion with mixed valence state between Co3+ and Co4+ ions at B sites or τ value has been determined by an iodometric titration. All the samples except for the DyCoO3 compound show the mixed valnce state and thus the composition of x=0.50 has the maximum τ value in the system. The oxygen vacancies increasing with x value are randomly distributed over the crystal lattice except for the composition of x=l.00 which have the ordering of the oxygen vacancies. The nonstoichiometric chemical formulas of the Dy1-xSrxCo3+1-τCo4+τO3-(x-τ)/2 system are formulated from the x, τ, and y values. The electrical conductivity in the temperature range of 100 to 900 K increases with τ value linearly because of positive holes of the Co4+ ions in π* band as a conducting carrier. The activation energy of the x=0.50 as Ea=0.17 eV is minimum among other compouds. Broad and high order transition due to the overlap between σ* and π* bands broadened by the thermal activation is observed near 1000 K and shows a low temperature-semiconducting behavior. Magnetic properties following the Currie-Weiss law show the low to high spin transition in the cobaltate perovskite. Especially, the composition of x=0.75 presents weak ferromagnetic behavior due to the Co3+-O2--Co4+ indirect superexchange interaction.
Photolysis of Aqueous Ammonia in the Absence and the Presence of O₂
박형련 ; 김희정 ; 성아영 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 798~802
The photochemical decomposition of aqueous ammonia in the absence (saturated with argon) and the presence of O2 (saturated with air or oxygen) has been investigated using 184.9 nm UV light. The decomposition of ammonia depended on the concentration of oxygen in the solution. With increasing the concentration of oxygen, the decomposition of ammonia diminishes. Hydrazine is found the major product from the irradiation. In the presence of oxygen, hydrogenperoxide was also produced. The product yields depended also on the concentration of oxygen in the solution. The initial quantum yield of the products and of the ammonia decomposed were determined. Probable reaction mechanisms for the reaction were presented from the products analysis.
A Mechanistic Study on Reactions of Aryl Benzoates with Ethoxide, Aryloxides and Acetophenone oximates in Absolute Ethanol
엄익환 ; 오수진 ; 권동숙 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 802~807
Second-order rate constants have been measured spectrophotometrically for the reactions of aryl benzoates (X-C6H4CO2C6H4-Y) with EtO-, Z-C6H4O- and Z-C6H4C(Me)=NO- in absolute ethanol at 25.0 ℃. All the reactions have been performed in the presence of excess 18-crown-6 ether in order to eliminate the catalytic effect shown by alkali metal ion. A good Hammett correlation has been obtained with a large ρ- value (-1.96) when σ- (Z) constant was used for the reaction of p-nitrophenyl benzoate (PNPB) with Z-C6H4O-. Surprisingly, the one for the reaction of PNPB with Z-C6H4C(Me)=NO- gives a small but definitely positive ρ- value (＋0.09). However, for reactions of C6H5CO2C6H4-Y with EtO-, correlation of log k with σ- (Y) constant gives very poor Hammett correlation. A significantly improved linearity has been obtained when σ0 (Y) constant was used, indicating that the leaving group departure is little advanced at the TS of the RDS. For reactions of X-C6H4CO2C6H4-4-NO2 with EtO-, C6H5O- and C6H5C(Me)=NO-, correlations of log k with σ (X) constants for all the three nucleophile systems give good linearity with large positive ρ values, e.g. 2.95, 2.81 and 3.06 for EtO-, C6H5O- and C6H5C(Me)=NO-, respectively. The large ρ values clearly suggest that the present reaction proceeds via a stepwise mechanism in which the formation of the addition intermediate is the RDS.
A Lattice Model Study of Native Contact Restraints in Protein Folding
오원석 ; 신재민 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 808~813
To explore protein folding mechanism, we simulated a folding pathway in a simplified 3×3×3 cubic lattice. In the lattice folding Monte Carlo simulations, each of the 28 possible native packing pairs that exist in the native conformation was used as a conformational restraint. The native packing restraints in the lattice model could be considered as a disulfide linkage restraint in a real protein. The results suggest that proteins denatured with a small disulfide loop can, but not always, fold faster than proteins without any disulfide linkage and than proteins with a larger disulfide loop. The results also suggest that there is a rough correlation between loop size of the native packing restraint and folding time. That is, the order of native residue-residue packing interaction in protein folding is likely dependent on the residue-residue distance in primary sequence. The strength of monomer-monomer pairwise interaction is not important in the determination of the packing order in lattice folding. From the folding simulations of five strong folding lattice sequences, it was also found that the context encoded in the primary sequence, which we do not yet clearly understand, plays more crucial role in the determination of detailed folding kinetics. Our restrained lattice model approach would provide a useful strategy to the future protein folding experiments by suggesting a protein engineering for the fast or slow folding research.
Effective Uranyl Binding by a Dihydroxyazobenzene Derivative. Ionization of Uranium-Bound Water
이관표 ; 장보빈 ; 서정훈 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 814~819
In search of simple host molecules for uranyl ion which form 1: 1-type complexes with high formation constants that can be used either in extraction of uranium from seawater or in catalysis of biologically important organic reactions, the uranophile activities of dihydroxyazobenzene derivative 1 were studied. Uranyl ion and 1 form a 1: 1-type complex with a very large formation constant. The formation constant was measured at pH 7-11.6 by competition experiments with carbonate ion. From the resulting pH dependence, ionization constants of the two aquo ligands coordinated to the uranium of the uranyl complex of 1 were calculated. The ionization constants were also measured by potentiometric titration of the uranyl complex of 1. Based on these results, the pKa values of the two aquo ligands were estimated as 7.1 and 11.0, respectively. At pH 7.5-9.5, therefore, the complex exists mostly as monohydroxo species. Under the conditions of seawater, 1 possesses greater affinity toward uranyl ion compared with other uranophiles such as carbonate ion, calixarene derivatives, or a macrocyclic octacarboxylate. In addition, complexation of 1 with uranyl ion is much faster than that of the calixarene or octacarboxylate uranophiles.
Effects of Ionizable Groups on the Redox Potentials of Cytochrome c₃from D. vulgaris Miyazaki F
박장수 ; 강신원 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 820~826
The p2H dependence of the NMR chemical shifts of the proton signals of heme methyl groups and ionizable groups in the vicinity of the heme were investigated. The p2H titration of heme methyl signals in four macroscopic oxidation states by saturation tranfer method was performed in the range between p2H 5.2 and 9.0. While the p2H dependence of the heme methyl resonance in fully oxidized state was small, most resonances in the intermediate oxidation states showed certain shifts. Particularly, methyl resonances of heme 1 (sequential heme numbering) exhibited sharp p2H dependence in acidic range. β-CH2 of the propionate of hemes 1 and 4 were titrated in the range of p2H 4.5-9.0. Only the 6-propionate group of heme 1 was protonated in this p2H range and its titration curve was similar to those of methyl resonances of heme 1 in intermediate oxidation states. Analysis of the microscopic redox potentials showed that they change depending on p2H. The ionizable groups responsible for the p2H dependence of these potentials are 6-propionate of heme 1 in acidic range and His 67 in basic range.
Chemical Reactions in Solid State Complexes of 1,2-Polybutadiene and Palladium Chloride : High Temperature Infrared Study
Lee, Joon Y. ; Laurence A. Belfiore ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 826~830
Fourier transform infrared (FTIR) temperature studies were performed to examine the microstructural changes that occur in annealing process of the thin films of 1,2-polybutadiene (1,2-PBu)/palladium chloride (PdCl2) complex. The disappearance of the infrared absorption intensities at 1640, 1418, 994 and 910 cm-1 signifies the consumption of 1,2-vinyl groups of 1,2-PBu. The progressive loss of unsaturation and production of methyl groups as a function of temperature were identified by the enhanced infrared absorption intensities at 1447 and 1375 cm-1. The loss of pendent carbon-carbon double bond is considered to involve both palladium-catalyzed addition reaction and thermally induced cyclization.
Synthesis and Reaction of Novel Tricyclic Dynemicin A Models with Methyl Group
류훈한 ; 홍용표 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 831~835
New dynemicin A mimics with methyl group 2a and 2b were synthesized, and acid-induced hydrolyzed to see an electronic effect of substituent for epoxide opening. The model 2a with methyl group at C3 position was more rapidly transformed to diol 16a than 2b with methyl group at C2. This result suggests that any substituent at C3 position plays more important role than any substituent at C2 position in the dynemicin A mimic activation.
Synthesis and Characterization of Copper(Ⅱ) Complex Containing 2,2'-dipyridylbenzamide
이동환 ; 김병순 ; 오영희 ; 라명수 ; 장원길 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 836~839
A new copper complex containing 2,2'-dipyridylbenzamide(dpba), Cu(dpba)(NO3)2(CH3CN), has been synthesized and characterized. The crystal structure has been determined. Crystal data: space group P212121, Z=8, a=13.911(3) Å, b=16.813(3) Å, c=18.932(3) Å, V=4427.9(1) Å3 and R=0.0674 for 1716 reflections. The copper environment is square pyramidal containing acetonitrile in axial site. Spectroscopic properties has been characterized in solution state. The redox property of the Cu(dpba)(NO3)2 complex is different from that of corresponding copper-dpa complex.
The Effect of Alkali Metal Ions on Nucleophilic Substitution Reactions of p- and m-Nitrophenyl 2-Thiophenenates with Alkali Metal Ethoxides in Absolute Ethanol
엄익환 ; 남정현 ; 이윤정 ; 권동숙 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 840~845
Rate constants have been measured spectrophotometrically for the reactions of p-and m-nitrophenyl 2-thiophenecarboxylate (5a and 5b, respectively) with alkali metal ethoxides (EtO-M+) in absolute ethanol at 25.0±0.1 ℃. The reactivity of EtO-M+ exhibits dependence on the size of alkali metal ions, i.e. the reactivity of EtO-M+ toward 5a decreases in the order EtO-K+ ≥ EtO-Na+ > EtO-Li+ > EtO-, while the one toward 5b does in the order EtO-Na+ ≥ EtO-K+ > EtO-Li+ > EtO-. This result indicates that ion paired EtO-M+ is more reactive than dissociated EtO-, and alkali metal ions form complexes with the substrate more strongly at the transition state than at the ground state. The catalytic effect shown by alkali metal ions appears to be less significant in the reaction of 5 than in the corresponding reaction of 4, indicating that complexation of alkali metal ions with 5 is not as strong as the one with 4.
Synthesis and Characterization of Bis(N,N-dimethyl-2-aminomethylthiophenium)Tetrahalocuprate(Ⅱ)
정찬규 ; 김영인 ; 최성낙 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 845~849
Bis(N,N-dimethyl-2-aminomethylthiophenium)tetrahalocuprate(Ⅱ) salt, (dmamtH)2CuCl4 and (dmamtH)2CuBr4 were prepared and characterized by spectroscopic (IR, UV-Vis, EPR, XPS), electrochemical method, and magnetic susceptibility measurement. The experimental results reveal that the compounds have pseudotetrahedral symmetry around copper(Ⅱ) site due to the steric hinderance of the bulky 2-(dimethylaminomethyl)thiophene in the complex. The N-H…Cl type hydrogen bonding is expected in (dmamtH)2CuCl4 from the XPS and IR data. Magnetic susceptibility data show that both of the compounds follow Curie-Weiss law in the range of 77-300 K with negative Weiss constant exhibiting antiferromagnetic interaction between copper(Ⅱ) ions in solid state.
Ab initio Studies on the Hetero Diels-Alder Cycloaddition
이본수 ; 김찬경 ; 최정욱 ; 이익준 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 849~853
Hetero Dieis-Alder reactions containing phosphorus atom at various positions of diene and dienophile as well as standard Dieis-Alder reaction between ethylene and cis-l,3-butadiene have been studied using ab initio method. Activation energy showed a good linear relationship with the FMO energy gap between diene and dienophile, which can be normally used to explain Dieis-Alder reactivity. Since π-bond cleavage and σ-bonds formation occur concertedly at the TS, geometrical distortion of diene and dienophile from the reactant to the transition state is the source of barrier. Based on the linear correlations between activation barrier and deformation energy, and between deformation energy and π-bond order change, it was concluded that the activation barrier arises mainly from the breakage of π-bonds in diene and dienophile. Stabilization due to favorable orbital interaction is relatively small. The geometrical distortions raise MO levels of the TS, which is the origin of the activation energy. The lower barrier for the reactions of phosphorus containing dienophile (reactions C, D, and E) can be explained by the electronegativity effect of the phosphorus atom.
Absorption and Lumiescence Spectra of Eu(Ⅲ) Complexes with Oxydiacetate and Dipicolinate in Aqueous Solution
김종구 ; 윤수경 ; 강준길 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 854~857
Absorption and luminescence spectra of Eu3+ (aquo) and the two different 1: 3 Eu3+: ligand systems in aqueous solutions are measured under mild acidic pH condition. The oxydiacetate (ODA) and dipicolinate (DPA) ligands, forming the similar geometric complexes, are used in this work. The three intensity parameters, Ωλ (λ=2, 4, and 6) are empirically determined by applying the Judd-Ofelt theorem to the oscillator strengths of the six absorption bands arising from the ground 7F0 state. Among the three intensity parameters, the Ω2 is found to response markedly to a miner change in the ligand environment via the 7F0→5D0 transition. In addition, the relative oscillator strengths of the four luminescence bands in the visible region, assigned to the 5D0→7FJ (J=1, 2, 3 and 4) transitions are obtained to investigate their sensitivity to the ligand environment. Among the four bands, the 610 nm band, attributed to the 5D0→7F2 transition, shows hypersensitivity in the luminescence.
A Study on the Relationships between Molecular Structure and Antitumor Activity Ⅰ:1-(2-chloroethyl)-3-(2,6-dioxo-3-piperidyl)-1-nitrosourea (PCNU) and 3-(N-phenylacetylamino)-2,6-piperidinedione (Antineoplaston A10)
이민주 ; 이삼규 ; 김성훈 ; 김유항 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 858~861
Synthesis and Electrochemical Characteristics of Pitch Coke Carbon Material for Lithium Ion Battery
도칠훈 ; 문성인 ; 김우식 ; 윤문수 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 861~863
Cyclic Dimerization of 2-Piperidylglycine
정규현 ; 이동렬 ; 김형요 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 863~865
Thermal Bleaching Reactions of Spirooxazine in Ethanol and PMMA
이인자 ; 허영득 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 865~868
A Facile Preparation of α-Amino-β-Methoxydiazines through, the Lithianation Followed by Amination
이정일 ; 조성혜 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 868~869
Calixarene : An Efficient ynthesis of 5-tert-Butyl-11-methyl-17,23-diphenyl-25,26,27,28-tetrahydroxycalixarene
노광현 ; 김종은 ; 김수진 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 869~872
Structure of Unique N,N-Dimethylformamide Solvate of Cobalt(Ⅱ) Chloride
정옥상 ; 이영아 ; 김관묵 ; 조양하 ; 손윤수 ;
Bulletin of the Korean Chemical Society, volume 17, issue 9, 1996, Pages 872~874