pISSN : 0253-2964 / eISSN : 1229-5949
About BKCS
A Message from our Editor-in-Chief
Papers since 2015 are available from Wiley.
(Bulletin of the Korean Chemical Society: List of Issues - Wiley Online Library)
The Bulletin of the Korean Chemical Society (BKCS) is a monthly journal and publishes communications, articles, accounts and reviews in all fields of chemistry, including analytical, electro-, industrial, inorganic, life-science, macromolecular, organic, physical and materials chemistry. The BKCS is published on behalf of the Korean Chemical Society (KCS).
A Message from our Editor-in-Chief
Prof. Wonwoo Nam is the Editor-in-Chief of the flagship journal of the Korean Chemical Society, which provides the opportunity to share new findings in all chemical sciences.
Our BKCS editorial teams also continue our publishing services. Thus, if you have any concerns about the publishing process, please contact the corresponding editorial office without hesitation.
Papers since 2015 are available from Wiley.
(Bulletin of the Korean Chemical Society: List of Issues - Wiley Online Library)
Latest Publication (Vol. 35, No. 12, Dec. 2014)
Molecular Dynamics Simulation Study of Transport Properties of Diatomic Gases
Song Hi Lee Jahun Kim
In this paper, we report thermodynamic and transport properties (diffusion coefficient, viscosity, and thermal conductivity) of diatomic gases (H2, N2, O2, and Cl2) at 273.15 K and 1.00 atm by performing molecular dynamics simulations using Lennard-Jones intermolecular potential and modified Green-Kubo formulas. The results of self-diffusion coefficients of diatomic gases obtained from velocity auto-correlation functions by Green-Kubo relation are in good agreement with those obtained from mean square displacements by Einstein relation. While the results for viscosities of diatomic gases obtained from stress auto-correlation functions underestimate the experimental results, those for thermal conductivities obtained from heat flux autocorrelation functions overestimate the experimental data except H2.
Temperature and Electric Field Effect on Proton Transfer in Adenine-thymine
Guiqing Zhang Shijie Xie
In theoretical simulations of proton transfer in DNA, environmental factors nearly have not been considered. In our calculations, using QM/MM method on the basis of CP2K, proton transfer on adenine-thymine base pair is studied in water, at wide scope temperature, and under the external electric field. Our results indicate that the external electric field induces the proton transfer at room temperature, and its intensity and temperature have some effect on hole localization and proton transfer.
SBA-15 Supported Fe, Ni, Fe-Ni Bimetallic Catalysts for Wet Oxidation of Bisphenol-A
Suranjana V. Mayani Vishal J. Mayani Sang Wook Kim
Bisphenol A is considered as pollutant, because it is toxic and hazardous to living organisms even at very low concentrations. Biological oxidation used for removing this organic from waste water is not suitable and consequently application of catalytic wet oxidation has been considered as one of the best options for treating bisphenol A. We have developed Fe/SBA-15, Ni/SBA-15 and Fe-Ni/SBA-15 as heterogeneous catalysts using the advanced impregnation method for oxidation of bisphenol A in water. The catalysts were characterized with physico-chemical characterization methods such as, powder X-ray diffraction (PXRD), FT-IR measurements, N2 adsorption–desorption isotherm, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICPOES) analysis. This work illustrates activity of the catalysts for heterogeneous catalytic degradation reaction revealed with excellent conversion and recyclability. The degradation products identified were not persistent pollutants. GC-MS analysis identified the products: 2,4-hexadienedioic acid, 2,4-pentadienic acid and isopropanol or acetic acid. The leachability study indicated that the catalysts release very little metals to water. Therefore, the possibility of water contamination through metal leaching was almost negligible.
End-to-end Structural Restriction of α-Synuclein and Its Influence on Amyloid Fibril Formation
Chul-Suk Hong Jae Hyung Park Young-Jun Choe Seung R. Paik
Relationship between molecular freedom of amyloidogenic protein and its self-assembly into amyloid fibrils has been evaluated with α-synuclein, an intrinsically unfolded protein related to Parkinson’s disease, by restricting its structural plasticity through an end-to-end disulfide bond formation between two newly introduced cysteine residues on the N- and C-termini. Although the resulting circular form of α-synuclein exhibited an impaired fibrillation propensity, the restriction did not completely block the protein’s interactive core since co-incubation with wild-type α-synuclein dramatically facilitated the fibrillation by producing distinctive forms of amyloid fibrils. The suppressed fibrillation propensity was instantly restored as the structural restriction was unleashed with β-mercaptoethanol. Conformational flexibility of the accreting amyloidogenic protein to pre-existing seeds has been demonstrated to be critical for fibrillar extension process by exerting structural adjustment to a complementary structure for the assembly.
Nanosecond Gated Raman Spectroscopy for Standoff Detection of Hazardous Materials
Jin Hyuk Chung Soo Gyeong Cho
Laser Raman spectroscopy is one of the most powerful technologies for standoff detection of hazardous materials including explosives. Supported by recent development of laser and sensitive ICCD camera, the technology can identify trace amount of unknown substances in a distance. Using this concept, we built a standoff detection system, in which nanosecond pulse laser and nanosecond gating ICCD technique were delicately devised to avoid the large background noise which suppressed weak Raman signals from the target sample. In standoff detection of explosives which have large kill radius, one of the most important technical issues is the detection distance from the target. Hence, we focused to increase the detection distance up to 54 m by careful optimization of optics and laser settings. The Raman spectra of hazardous materials observed at the distance of 54 m were fully identifiable. We succeeded to detect and identify eleven hazardous materials of liquid or solid particles, which were either explosives or chemical substances used frequently in chemical plants. We also performed experiments to establish the limit of detection (LOD) of HMX at 10 m, which was estimated to be 6 mg.
Synthesis and Electrochemical Performance of Reduced Graphene Oxide/AlPO4-coated LiMn1.5Ni0.5O4 for Lithium-ion Batteries
Jaehyun Hur Il Tae Kim
The reduced graphene oxide(rGO)/aluminum phosphate(AlPO4)-coated LiMn1.5Ni0.5O4 (LMNO) cathode material has been developed by hydroxide precursor method for LMNO and by a facile solution based process for the coating with GO/AlPO4 on the surface of LMNO, followed by annealing process. The amount of AlPO4 has been varied from 0.5 wt % to 1.0 wt %, while the amount of rGO is maintained at 1.0 wt %. The samples have been characterized by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. The rGO/AlPO4-coated LMNO electrodes exhibit better cyclic performance compared to that of pristine LMNO electrode. Specifically, rGO(1%)/AlPO4(0.5%)- and rGO(1%)/AlPO4(1%)-coated electrodes deliver a discharge capacity of, respectively, 123 mAh g−1 and 122 mAh g−1 at C/6 rate, with a capacity retention of, respectively, 96% and 98% at 100 cycles. Furthermore, the surface-modified LMNO electrodes demonstrate higher-rate capability. The rGO(1%)/AlPO4(0.5%)-coated LMNO electrode shows the highest rate performance demonstrating a capacity retention of 91% at 10 C rate. The enhanced electrochemical performance can be attributed to (1) the suppression of the direct contact of electrode surface with the electrolyte, resulting in side reactions with the electrolyte due to the high cut-off voltage, and (2) smaller surface resistance and charge transfer resistance, which is confirmed by total polarization resistance and electrochemical impedance spectroscopy.
Study on Anharmonic Effect of the Unimolecular Reaction of CH2(D2)FO
Jingjun Zhong Qian Li Ji Luo Wenwen Xia Li Yao S. H. Lin
Study on the unimolecular reaction for CH2FO and CD2FO is carried out. The structures, energy barriers and zero point energy of the three channels in the title unimolecular reactions are computed with the MP2/6- 311++G(3df, 3pd) method. RRKM theory is used to calculate the rate constants of canonical case at temperature range of 500–5000 K and microcanonical system at total energy of 19.05–71.68 kcal/mol. The results indicate that the anharmonic effect and isotope effect are very small for the three channels, and the anharmonic rate constants, around 109–1011 s−1, are close to the experimental prediction reasonably.
The Study of Adsorption Structures of 3-Methyl-5-Pyrazolone on the Ge(100) Surface
Myungjin Lee Hangil Lee
The most stable adsorption structures and energies of four tautomers of 3-methyl-5-pyrazolone (keto-1, enol-1, keto-2, and enol-2) on Ge(100) surfaces were investigated using density functional theory (DFT) calculations. The enol-1, keto-2, and enol-2 tautomers, but not the keto-1 tautomer, were found to exhibit stable adsorption structures on the Ge(100)-2 × 1 surface. Of these three adsorption structures, that of enol-2 is the most stable.
Synthesis and Biological Evaluation of Tetrapeptide Ketones as Reversible 20S Proteasome Inhibitors
Muhammad Latif Myoung Eun Jung Kwangho Lee Gildon Choi
Proteasome, a multicatalytic protease complex, has been validated as a promising therapeutic target in oncology. Carfilzomib (Kyprolis®), a tetrapeptide epoxyketone, irreversibly inhibits the chymotrypsin-like (CT-L) activity of the proteasome and has been recently approved for multiple myeloma treatment by FDA. A chemistry effort was initiated to discover the compounds that are reversibly inhibit the proteasome by replacing the epoxyketone moiety of carfilzomib with a variety of ketones as reversible and covalent warheads at the Cterminus. The newly synthesized compounds exhibited significant inhibitory activity against CT-L activity of the human 20S proteasome. When the compounds were tested for cancer cell viability, 14-8 was found to be most potent in inhibiting Molt-4 acute lymphoblastic leukemia cell line with a GI50 of 4.4 μM. Cytotoxic effects of 14-8 were further evaluated by cell cycle analysis and Western blotting, demonstrating activation of apoptotic pathways.
Electrochemical Behavior of Pt-Ru Catalysts on Zeolite-templated Carbon Supports for Direct Methanol Fuel Cells
Tae-Jin Lim Seul-Yi Lee Yoon-Jong Yoo Soo-Jin Park
Zeolite-templated carbons (ZTCs), which have high specific surface area, were prepared by a conventional templating method using microporous zeolite-Y for catalyst supports in direct methanol fuel cells. The ZTCs were synthesized at different temperatures to investigate the characteristics of the surface produced and their electrochemical properties. Thereafter, Pt-Ru was deposited at different carbonization temperatures by a chemical reduction method. The crystalline and structural features were investigated using X-ray diffraction and scanning electron microscopy. The textural properties of the ZTCs were investigated by analyzing N2/77 K adsorption isotherms using the Brunauer-Emmett-Teller equation, while the micro- and meso-pore size distributions were analyzed using the Barrett-Joyner-Halenda and Harvarth-Kawazoe methods, respectively. The surface morphology was characterized using transmission electron microscopy and inductively coupled plasma-mass spectrometry. The electrochemical properties of the Pt-Ru/ZTCs catalysts were also analyzed by cyclic voltammetry measurements. From the results, the ZTCs carbonized at 900 °C show the highest specific surface areas. In addition, ZTC900-PR led to uniform dispersion of Pt-Ru on the ZTCs, which enhanced the electro-catalytic activity of the Pt-Ru catalysts. The particle size of ZTC900-PR catalyst is about 3.4 nm, also peak current density from the CV plot is 12.5 mA/cm2. Therefore, electro-catalytic activity of the ZTC900-PR catalyst is higher than those of ZTC1000-PR catalyst.
ISSN(Print) 0253-2964
ISSN(Online) 1229-5949
