• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.347-349
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• 2007

지구 온난화를 일으키는 온실 가스 중의 하나인 이산화탄소($CO_2$)를 Epoxide와 Tetrabutylammonium bromide를 촉매로 하여 합성하여, 초임계 $CO_2$ 상태($Tc=31.06^{\circ}C$, Pc=7.38MPa)에서 반응하여 그에 따른 수율을 측정한 결과 초임계하에서는 현저한 수율의 증가를 확인하였다.

• Bulletin of the Korean Chemical Society
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• v.18 no.7
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• pp.730-733
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• 1997

Monofluoroiron(Ⅲ) tetraphenylporphyrin, Fe(TPP)F, and difluoroiron(Ⅲ) tetraphenylporphyrin, [Fe(TPP)F2]- were generated in a various non-aqueous solvents by the reaction between Fe(TPP)Cl and tetrabutylammonium fluoride TBAF 3H2O. Formation of the these complexes was detected by the appearance of the ν(F-Fe) (ν, stretching vibration) at 506 cm-1 for Fe(TPP)F and the ν(F-Fe-F) at 448 cm-1 for [Fe(TPP)F2]-, simultaneously, with 441.6 nm excitation by Resonance Raman (RR) spectroscopy. These assignments were confirmed by observed frequency shifts due to 56Fe/54Fe and TPP/TPP-d8/TPP-N15 isotopic substitutions. Difluoroiron complex is an iron(Ⅲ) high-spin complex with the oxidation sensitive band at 1347 cm-1 for ν4 and core size/spin state sensitive band at 1541 cm-1 for ν2.

• Bulletin of the Korean Chemical Society
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• v.12 no.5
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• pp.487-490
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• 1991

Electrochemical studies of alkali metal cations $(Na^+, K^+, Rb^+, Cs^+)$ were performed in methanolic solutions of 18-crown-6 and tetrabutylammonium salts at dropping mercury electrodes (DME) and thin mercury film electrodes (TMFE). All the cations investigated were reduced reversibly at DME in the absence and presence of 18-crown-6, and in the latter the limiting currents were decreased and the reduction potentials shifted to the negative direction. The reduction potentials of the metal ions (0.2 mM) in the presence of the crown (10 mM) were - 2.14 $(Na^+)$, - 2.26 $(K^+)$, - 2.20 $(Rb^+) and - 2.14 $(Cs^+)$ V vs. SCE, respectively. The measured potentials were rationalized with ion recognition of the cations by the crown. Electroreduction at TMFE were highly irreversible. A new representation method of ion recognition is presented. In aqueous solutions, electroreduction of the alkali metal ions were characterized by adsorption.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.2
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• pp.33-39
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• 2015

$BaTiO_3$ is typical ferromagnetic materials with dielectric constant of above 200. $BaTiO_3$ nanoparticles applications are available for multiple purposes such as nanocapacitors, ferroelectric random access memories, and so on. Applications are is diverse from the dispersion of nanoparticles depending on the route of synthesis. In this study, $BaTiO_3$ nanoparticles were synthesized by two different methods such as oxalate method and sol-gel process (ambient condition sol method). Particle size and dispersion condition were studied according to the preparation method and capping agent. Poly vinyl pyrrolidone (PVP) was used as a capping agent in oxalate method and tetrabutylammonium hydroxide (TBAH) used as a capping agent in sol-gel process each. Cubic crystal structure of $BaTiO_3$ phase could be confirmed by X-ray diffraction analysis. Fourier transform-infrared spectroscopy was employed for the confirmation of the capping agent and $BaTiO_3$ nanoparticles. The particle size and distribution analysis was also performed by particles size analyzer and scanning electron microscope.

• Analytical Science and Technology
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• v.13 no.2
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• pp.173-178
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• 2000

A new open-chain ligand containing two phenol groups, 1, 14-Bis (2-hydroxybenzyl)-2, 6, 9, 12-tetraazatetradecane(bsated) was synthesized as its tetrahydrochloride salt and characterized by elemental analysis, mass, infrared and NMR. Its proton dissociation constants ($logK^n{_H}$) and stability constants ($logK_{ML}$) toward $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$ and $Zn^{2+}$ were determined at $25^{\circ}C$ and 0.10M($KNO_3$) ionic strength in aqueous solution by potentiometry. The X-ray structure of its copper (II) complex [Cu(bsated)]$(ClO_4)_2$ was reported: Monoclinic space group $P2_1/n$, $a=17.856(4){\AA}$, $b=17.709(1){\AA}$, $c=8.539(2){\AA}$, $V=2700(2){\AA}$ with Z=4. Electrochemical studies of [Cu(bsated)]$(ClO_4)_2$ complex in dimethyl sulfoxide (DMSO) solution containing tetrabutylammonium perchlorate (supporting electrolyte) were carried out by cyclic voltammograms (CV) and normal pulse voltammetry (NPV).

• Analytical Science and Technology
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• v.19 no.5
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• pp.433-440
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• 2006

A HPLC/UV method was developed and validated for the rapid and simultaneous determination of urinary metabolites of organic solvents, mandelic acid, hippuric acid, phenylglyoxylic acid, ortho-, meta- and para-methylhippuric acid, using a monolithic column. The mobile phase was composed of tetrabutylammonium bromide as ion-pairing reagent with a flow rate of 2.4 mL/min. The total run time was less than 2.5 min for all six analytes. Good linearities were obtained for all the metabolites with correlation coefficients above 0.9993. Intra-day precision, accuracy and inter-day precision was 0.01~7.32%, 83.9~116.3% and 0.01~7.16%, respectively. The method was validated and confirmed by quantification of the quality assurance samples of Industrial Safety and Health Research Institute, Korea Occupational Safety and Health Agency.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2041-2043
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• 2013

A layered perovskite of Dion-Jacobson phase, $RbLaTa_2O_7$, was successfully exfoliated into colloidal suspension via successive ion-exchange and intercalation reaction. The pristine perovskite $RbLaTa_2O_7$ was synthesized by conventional solid-state reaction, and then, it was ion-exchanged with hydrochloric acid to obtain a protonic form of perovskite. The resulting proton-exchanged perovskite was reacted with ethylamine to increase interlayer spaces for further intercalation reaction. Finally, the ethylamine-intercalated form was exfoliated into nanosheets via an intercalation of bulky organic cations (tetrabutylammonium). According to X-ray diffraction (XRD) analysis, the TBA-intercalated form showed remarkably increased interlayer spacing (${\Delta}d$ = 1.67 nm) in comparison with that of the pristine material. Transmission electron microscopic image of exfoliated perovskite clearly revealed that the present exfoliated perovskite were composed of very thin layers. This exfoliated perovskite nanosheets could be applicable as building blocks for fabricating functional nanocomposites.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.2
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• pp.158-162
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• 2019

[¹¹C]GR205171, a Neurokinin 1 (NK1) radioligand, has been known as such a promising PET probe for quantitation of NK1 receptors in the brain by positron emission tomography (PET) imaging. First trial to synthesis of [¹¹C]GR205171 was to use methylene chloride and tetrabutylammonium hydroxide for preactivation of precursor, but the result was not successful in radiochemical yield (0~25%) and unreliable. 7 years later, inorganic base (Cs₂CO₃) was tried to achieve higher radiochemical yield, and they showed higher yield (~53%). We have tried to repeat the same synthesis method, but it did not work properly, because there were the lack of the detail procedure and still reproducibility in radiochemical yield. Here we report the improved synthesis protocol to produce [¹¹C]GR205171 in high yield via commercial automated synthesizer. The sonicator which combines water heating bath was used to activate desmethyl-GR205171, and this method showed high efficiency and reasonable yields (4.7 ± 0.6%, non-decay corrected from molecular sieve trap) with >95% radiochemical purity.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1341-1345
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• 2011

A novel ruthenium(II) complex, [$RuCl_2(DMSO)_2$(PhenTPy)] has been synthesized by the condensation of $RuCl_2(DMSO)_4$ with (1-(1,10-phenanthrolinyl)-2,5-di(2-thienyl)-1H-pyrrole)[PhenTPy] in $CHCl_3$ solution. The [$RuCl_2(DMSO)_2$(PhenTPy)] complex modified electrode was fabricated through the electropolymerization of the monomer in a 0.1 M tetrabutylammonium perchlorate (TBAP)/$CH_2Cl_2$ solution, to take advantage of the electronic communication between metal ion center by the conjugated backbone. The UV-visible spectroscopy (UV), mass spectrometry (MS), and cyclic voltammetry (CV) were employed to characterize the [$RuCl_2(DMSO)_2$(PhenTPy)] complex and its polymer (poly-Ru(II)Phen complex). The poly-Ru(II)Phen complex modified electrode exhibited an electrocatalytic activity to the oxidation of acetaminophen and the catalytic property was used for the analysis of acetaminophen at the concentration range between 0.09 and 0.01 mM in a phosphate buffer solution (pH 7.0).

• The Korean Journal of Pesticide Science
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• v.10 no.1
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• pp.66-68
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• 2006

New synthetic method of 2-mercaptobenzoxazoles and 2-mercaptobenzimidazoles was established using elemental sulfur, dichloromethane, inorganic base and catalysts in alcohol solvents. This reaction condition gave products in high yields.