• Bulletin of the Korean Chemical Society
• /
• v.30 no.10
• /
• pp.2213-2216
• /
• 2009

A novel carbazole functionalized bis-$\beta$-diketone type organic ligand, 1,1′-(2,6-bispyridyl)bis-3-(9-ethylcarbazole- 3-yl)-1,3-propanedione ($H_2L$) and its corresponding lanthanide complexes $Eu_2(L)_3\;and\;Tb_2(L)_3$ were successfully prepared. The ligand and complexes were characterized in detail based on FT-IR spectra, $^1H$ NMR and elemental analysis. The observed UV-Vis absorption and photoluminescence properties of the complexes were investigated, it shows that the Eu(III) and Tb(III) ions can be sensitized efficiently by the ligand ($H_2L$) to some extent, in particular, the complex $Tb_2(L)_3$ exhibits a more excellent luminescence property than the Eu(III) complex. Meanwhile, the introduction of the carbazole moiety can enlarge the $\Pi$-conjugated system of the ligand and enhance the luminescent intensity of the complexes. The results show that the complexes would be used as excellent luminescent materials.

• Preventive Nutrition and Food Science
• /
• v.10 no.2
• /
• pp.118-121
• /
• 2005

Methanol extracts were prepared from loquat leaves (2 kg) and successively fractionated with hexane, chloroform, ethyl acetate, butanol, and water solvents. The ethyl acetate fraction exhibited the highest antioxidative and, antimicrobial activities. Therefore, the ethyl acetate fraction was purified and a chemical structure was identified by $^1H$ and $^{13}C-NMR$ spectra, FT-IR and EI/MS spectroscopies. The isolated antioxidative and antimicrobial substance was identified as epicatechin.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.651-654
• /
• 2009

Novel compounds with rod and disc mesogens were synthesized and characterized. The molecular structures were confirmed by FT-IR, $^1H$-NMR spectroscopy and elemental analysis. The optical properties of these molecules were investigated by UV-vis absorption spectroscopy and photo-luminescence spectroscopy. We found that they are a novel series of blue light-emitting molecules. The absorption spectra peaks of these compounds varied from 336 nm-341 nm, while the maximum emissions centered form 410 nm-450 nm in chloroform solution. However, unexpectedly we could not found their biaxiality and mesomorphic properties by POM, conoscopy and DSC method.

• Bulletin of the Korean Chemical Society
• /
• v.24 no.9
• /
• pp.1303-1307
• /
• 2003

The low molecular water-soluble chitosan nanoparticles (LMWSC-NPs) were prepared, which was modified with hydrophilic and hydrophobic moieties to evaluate the potential for pharmaceutics application. The synthesis of LMWSC-NPs was identified by FT-IR and $^1H$-NMR spectra. Also, we measured the photon correlation spectroscopy (PCS), transmission electron microscope (TEM) and atomic force microscope (AFM) to investigate the characteristics and morphology of the LMWSC-NPs. At the PCS measurement, the more increase the number of substitutive group, the more decrease the positive charge of LMWSC-NP surface. From the results of TEM and AFM, spherical morphologies were observed, and their sizes were 30-150 nm. Resultantly, LMWSC-NPs prepared in this experiment will be expected as a suitable device for the drug targeting system.

• Journal of the Korean Chemical Society
• /
• v.59 no.3
• /
• pp.215-224
• /
• 2015

Unsymmetrical tetradentate Schiff base N-(2-hydroxy-5-methylacetophenone)-N'-(2-hydroxy acetophenone) ethylene diamine (H₂L) and its complexes with Cr(III), Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) have been synthesized and characterized by elemental analyses, magnetic susceptibility measurements, IR, electronic spectra and thermogravimetric analyses. ¹H, ¹³C-NMR and FAB Mass spectra of ligand clearly indicate the presence of OH and azomethine groups. Elemental analyses of the complexes indicate that the metal to ligand ratio is 1:1 in all complexes. Infrared spectra of complexes indicate a dibasic quadridentate nature of the ligand and its coordination to metal ions through phenolic oxygen and azomethine nitrogen atoms. The thermal behavior of these complexes showed the loss of lattice water in the first step followed by decomposition of the ligand in subsequent steps. The thermal data have also been analyzed for the kinetic parameters by using Horowitz-Metzger method. The dependence of the electrical conductivity on the temperature has been studied over the temperature range 313-403 K and the complexes are found to show semiconducting behavior. XRD and SEM images of some representative complexes have been recorded. The antimicrobial activity of the ligand and its complexes has been screened against various microorganisms and all of them were found to be active against the test organisms. The Fe(III) and Ni(II) complex have been tested for the catalytic oxidation of styrene.

• Journal of the Korean Chemical Society
• /
• v.56 no.6
• /
• pp.679-691
• /
• 2012

New series of metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Pt(II) with 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide (HCPTS) have been synthesized and characterized by elemental analyses, magnetic moment, spectra (IR, UV-Vis, $^1H$ NMR, mass and ESR) and thermal studies. The IR data suggest different coordination modes for HCPTS which behaves as a monobasic bidentate with all metal ions except Cu(II) and Zn(II) which acts as a monobasic tridentate. Based on the electronic and magnetic studies, Co(II), Cu(II), Pd(II) and Pt(II) complexes have square - planner, Ni(II) has mixed stereochemistry (tetrahedral + square planar), while Zn(II) is tetrahedral. Molar conductance in DMF solution indicates the non-ionic nature of the complexes. The ESR spectra of solid copper(II) complex show $g_{\parallel}$ (2.2221) > $g_{\perp}$ (2.0899) > 2.0023 indicating square-planar structure and the presence of the unpaired electron in the $d_x2_{-y}2$ orbital with significant covalent bond character. The thermal stability and degradation kinetics of the ligand and its metal complexes were studied by TGA and DTA and the kinetic parameters were calculated using Coats-Redfern and Horowitz-Metzger methods. The complexes have more antibacterial activity against some bacteria than the free ligand. However, the ligand has high anticancer activities against HCT116 (human colon carcinoma cell line) and HEPG2 (human liver hepatocellular carcinoma cell line) compared with its complexes.

• Journal of the Korean Chemical Society
• /
• v.35 no.6
• /
• pp.725-729
• /
• 1991

Unsaturated all-cis-5,8,11,14-eicosatetraenoic(arachidonic), 7,10,13-hexadecatrienoic, 10, 13-octadecadienoic acid ethyl ester and a lot of chimyl alcohol were isolated along with common 9-hexadecenoic acid ethyl ester from marine mollusca Bullacta exarata collected from sangnackworl island in the Korea sea. In addition, cholesterol and its fatty acid ester were obtained. Their structures were deduced from $^1H-$and $^{13}C$-NMR, GC-ms, and FT-IR spectra.

• Journal of the Korean Applied Science and Technology
• /
• v.12 no.2
• /
• pp.99-105
• /
• 1995

Phenylvinylsulfone derivatives were synthesized by Kirners condition. The structure of these compounds were ascertained by means of ultraviolet, melting point, IR and $^1H-NMR$ spectra. The nucleophilic addtion reaction kinetics of L-cysteiene for phenylvinylsulfone was investigated by ultraviolet spectrophotometery in 40% $EtOH-H_2O$ at $25^{\circ}C$. The rate equations which were applied over a wide pH $1.0{\sim}13.0$ range. On the basis of general base catalysis and confirmation of addtion reaction product, the nucleophilic addtion reaction kinetics of L-cysteiene for phenylvinylsulfone were measured by the pH change. From the result of the above caption, a plausible nucleophilic addtion reaction mechanism of L-cysteiene for phenylvinylsulfone was proposed. These compounds may by used ad the starting materials for the preparation of the engineering plastics or the germicide.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.9
• /
• pp.2791-2796
• /
• 2014

The capture of $SO_2$ at or close to the temperatures of real flue gas is much more attractive in application. In this work, two kinds of ionic liquids (ILs) based on lactate anion were used to absorb $SO_2$ at high temperatures from 100 to $120^{\circ}C$. The ILs show high absorption capacities of over one mol $SO_2$ per mol IL at $110^{\circ}C$. The absorption of $SO_2$ by the ILs based on lactate anion is reversible and the ILs can be reused for the capture of $SO_2$ at high temperatures with high absorption capacity and thermal stability. Furthermore, the absorption mechanism of $SO_2$ by the ILs was studied by FT-IR, $^1H$ NMR and $^{13}C$ NMR spectra. It has been found that there are strong chemical interactions between the ILs and $SO_2$. Also the absorption mechanism is different when there is water present in ILs compared to when there is not.

• Korean Journal of Pharmacognosy
• /
• v.13 no.3
• /
• pp.106-111
• /
• 1982

Melampyrum roseum Max. is an annual herb in Scrophulariaceae plants. The materials were collected in Kyeongi-Do in 1980. The BuOH extract was evaporated under reduced pressure. The residue was column chromatographed over silica gel with benzene-MeOH (8 : 1) as an eluent and it gave the amorphus powder. Compound I has a molecular formula $C_{17}H_{26}O_{10}$ and it was identified as mussaenoside by chemical data, UV, IR, NMR spectra and compared with the authentic sample of mussaenoside tetraacetate.