• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2009.11a
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• pp.115-116
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• 2009

In this study, near-infrared absorbing dyes, namely, new rigidified heptamethine cyanine dyes were synthesized and investigated their properties. The cyanine dyes have been synthesized by a condensation reaction between a quanternary salt containing as activated methyl group and an unsaturated bisaldehyde or its equivalent. We were investigated the synthesis of new rigidified heptamethine cyanine and related the compounds with near infrared absorption. The full spectroscopic characterization of all cyanine were described. Absorption properties in the near-infrared region may cause these dyes to the potential used in bio-probe, optical recording media materials.

• Journal of Integrative Natural Science
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• v.3 no.1
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• pp.19-23
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• 2010

A simple and rapid method is described for detecting nitroaromatic explosives in air or seawater with the use of photoluminescent organosilicon compounds. The synthesis, spectroscopic characterization, and fluorescence quenching efficiency of silafluorenes are reported. Silafluorenes were synthesized from the reduction of dilithiobiphenyl with dichlorosilanes. Two silafluorenes were used for the detection of nitroaromatic compounds. Detection of nitroaromatic molecules, such as 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), and picric acid (PA), has been explored. A linear Stern-Volmer relationship was observed for the first three analytes. Fluorescence spectra of silafluorenes obtained in either toluene solutions or thin films displayed no shift in the maximum of the emission wavelength. The photoluminescence quenching occurs by a static mechanism.

• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1715-1718
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• 2009

A series of sitting-atop (SAT) complexes, [(ZrO)$H_2t(X)pp(NO_3)_2$], have been prepared via the reactions of free base meso-tetraarylporphyrins, $H_2$t(X)pp, with zirconyl nitrate hydrate, ZrO(N$O_3)_2{\cdot}xH_2$O. The products have been characterized by a variety of methods including $^1H\;NMR,\;^{13}C$ NMR, IR and UV-Vis spectroscopies, elemental analysis and conductance measurements. The data indicate that the meso-tetraarylporphyrins coordinate with two pyrrolenine nitrogen atoms to the zirconyl cation located above the distorted porphyrin plane and two protons remain on the pyrrole nitrogens. Such half sandwich-type sitting-atop complexes may be considered as models for the initial steps of the metallation of the macrocycles.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1535-1542
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• 2010

Spectrophotometric micro determination of allopurinol (ALP) via charge-transfer formation is described. This includes the utility of some $\pi$-acceptors such as 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 3,6-dichloro-2,5-dihydroxy-p-benzoquinone (p-CLA) for estimation of ALP drug (act as $\grave{e}$-donor). These reactions are applied for determination of ALP in its pharmaceutical preparations coming from different companies. Elucidation of the chemical structure of the solid CT complexes formed via reaction between drugs under study and $\pi$-acceptors, using elemental analyses (C, H, N), I. R., $^1H$ NMR and mass spectrometry.

• KSBB Journal
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• v.9 no.2
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• pp.174-179
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• 1994

Chitin was isolated from crab shell wastes and characterized for its chemical and physical properties. White powdered chitin was obtained through demineralizaticn, deproteinization and decoloration process. The contents of inorganics was less than 0.5%, whereas protein and lipid were almost removed. The results of IR spectroscopic analysis for the isolated chitin showed similar characteristics with that of Sigma product. Degree of deacetylation of purified chitin was significantly higher than Sigma product and viscosity average molecular weights was $2.3{\times}10^5~3.2{\times}10^5$. SEM analysis showed that the obtained chitin had the fibril shaped morphology.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.2895-2898
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• 2009

The complete structural characterization of dehydrodivanillin, an important natural product of interest to the food, cosmetics and aroma industries, has been carried out using multi-dimensional NMR spectroscopic techniques, and its previously $reported^{13}$C-NMR values have been reassigned. Dense and granular thin films of dehydrodivanillin have been grown by sublimation under high vacuum and studied using Scanning Electron Microscopy (SEM), electrical and optical techniques. The transmittance spectra of the films indicate a wide optical band gap of more than 3 eV. Typical J-V characteristics of Glass/ITO/dehydrodivanillin/Al structure exhibited moderate current densities ${\sim}10^{-4}\;A/cm^2$ at voltages > 25 V with an appreciable SCLC mobility of the order of $10^{-6}\;cm^2$/V-s.

• Journal of the Korean Chemical Society
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• v.62 no.3
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• pp.187-190
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• 2018

A three-component coupling reaction of phenylacetylene, p-toluenesulfonyl azide, and water through copper catalysis is described to provide knowledge of spectroscopy and catalytic reactions and to introduce current research topics in organic chemistry for second-year undergraduate students. In the presence of stoichiometric amounts of phenylacetylene, p-toluenesulfonyl azide, and triethylamine, the reaction was performed with 4 mol% CuCl in water as the sole solvent and was completed in 1.5 h. A practical purification method and recrystallization of the crude reaction mixture resulted in the rapid isolation of the desired product with yields of 42~65%. Students characterized 4-methyl-N-(phenylacetyl)benzenesulfonamide by using melting-point determination, infrared spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. This experimental procedure and spectroscopic data analysis will serve as a platform for students to apply classroom knowledge in practical state-of-the-art research.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1900-1906
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• 2012

Three carbazole chromophores featuring dicyano, cyano, ethyl acetate and dimethyl acetate groups as an acceptor moiety with a ${\pi}$-conjugated spacer and $N$-methyl dibenzo[$b$]pyrole as donor were synthesized by Knovenagel condensation and characterized by IR, $^1HNMR$, $^{13}CNMR$, UV-vis, fluorescence spectroscopy, electrochemistry and theoretical B3LYP/6-$311G^*$ level whilst NLO properties and spectroscopic quantities were calculated. Calculations showed remarkable trend with HOMO located on the donor moiety and LUMO on the acceptors dicyano methylene, cyano, ethyl acetate methylene and dimethyl acetate methylene. In agreement with the calculations, solvatochromic, behavior intramolecular charge transfer band was observed in the visible region.

• Journal of the Korean Chemical Society
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• v.57 no.3
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• pp.341-351
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• 2013

Zn(II), Cd(II) and Hg(II) complexes with a general composition[$M(L)_2(X)_2$], where L=4-aminopyridine (4AP) and $X=NO_2{^-}$ were prepared under microwave irradiation. The metal complexes were characterized by elemental analyses, molar conductance, IR, Far-IR, electronic, NMR ($^1H$, $^{13}C$), XPS spectral and thermal studies. The spectroscopic studies reveal the composition, different modes of bonding, electronic transition, different chemical environment of C and H atoms and the electronic state of the metal atoms. On the basis of the characterization data, tetrahedral geometry is suggested for all the complexes. The free ligand (4-aminopyridine) and their metal complexes were screened against phytopathogenic fungi and bacteria in vitro and the activities were compared.

• Journal of the Semiconductor & Display Technology
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• v.10 no.2
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• pp.83-89
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• 2011

In this study, we investigated the effects of shutter control by Reactive Magnetron Sputtering using Inductively-Coupled Plasma(ICP) for obtaining ZnO thin films with high purity. The surface morphologies and structure of deposited ZnO thin films were characterized using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-ray Diffractometer (XRD). Also, optical and chemical properties of ZnO thin films were analyzed by Spectroscopic Ellipsometer (SE) and X-ray Photoelectron spectroscopy (XPS). As a result, it observed that ZnO thin films grown at reactive sputtering using shutter control and ICP were higher density, lower surface roughness, better crystallinity than other conventional sputtering deposition methods. For obtaining better quality deposition ZnO thin films, we will investigate the effects of substrate temperature and RF power on shutter control by a reactive magnetron sputtering using inductively-coupled plasma.