• 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 Society of Cosmetic Scientists of Korea
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• v.19 no.1
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• pp.77-84
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• 1993

Two acardic acids showing antimicrobial activity against Propionibacterium acnes ATCC 6919, were isolated from Galla Rhois. They were identified as 6-pentadec-8-enyl salicylic acid and 6-pentadecyl aslicylic acid on the base of spectroscopic evidence.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.11
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• pp.609-615
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• 2000

A prototype electrodeless sulfur lamp was developed and investigated the spectroscopic characteristics. The emission spectra of $S_2$ in the microwave-discharged eletrodeless sulfur lamp (ESL) were studied at various input power. The emission spectra of the ESL shift to longer wavelength with increasing of the input power. We have shown that this is due to the self reversal effect in the high pressure gas discharge. We also show that the self reversal effect increases as the rotation of the discharged bulb. The spectral distribution of the ESL shifts about 45 nm toward visible region from UV region due to the rotation of the lamp bulb.

• Journal of the Korean Ceramic Society
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• v.54 no.3
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• pp.205-210
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• 2017

In this study, we examined the photo-degradation efficiency of $CoSe_2$-Graphene-$TiO_2$ ($CoSe_2-G-TiO_2$) nanocomposites under visible light irradiation using rhodamine B (RhB) as standard dye. $CoSe_2-G-TiO_2$ nanocomposites were synthesized by ultrasonication and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopic analysis and UV-Vis absorbance spectra analysis. Our results show that the $CoSe_2-G-TiO_2$ nanocomposite exhibited significant photo degradation efficiency compared to pure $TiO_2$ and $CoSe_2-G$, approximately 85.2% of the rhodamine (Rh B) degraded after 2.5 h. It is concluded that the $CoSe_2-G-TiO_2$ nanocomposite is a promising candidate for use in dye pollutants.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.05a
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• pp.193-194
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• 2001

To determine for the hybridization, we have investigated by UV spectroscopic method. This complex behavior as nonelectrolytes in polar aprotic solution with molar conductivities. The technoques of pulse and cyclic voltammetry have been applied to the determination of $(E_{1/2})_{2}$-$(E_{1/2})_{1}$ for two-step electrochemical charge transfers. A simple amplitude has been derived for the dependence of the differential-pulse response on $(E_{1/2})_{1}$ and $(E_{1/2})_{2}$. The use of the peak-to-peak separation in cyclic voltammetry has also been evaluated. Comparison with a differential pulse and cyclic voltammetry methods shows agreement of comproportionation constant$(K_{c})$ within 50%.

• Bulletin of the Korean Chemical Society
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• v.15 no.2
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• pp.145-150
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• 1994

The low temperature luminescence and excitation, room-temperature UV-visible and infrared spectra of [Cr(${\pm})chxn_3]Cl_3$ (chxn=trans-1,2-cyclohexanediamine) have been measured. It is found that the zero-phonon line in the excitation spectrum splits into two components by $47\;cm^{-1}$. The eight electronic transitions due to spin-allowed and spin-forbidden are assigned. As expected, nitrogen atoms of chxn ligand have strong ${\sigma}-donor $properties toward chromium(Ⅲ). The positions and splittings of sharp-line transitions are analyzed as a function of the Cartesian bite (${\alpha}$) and twist (${\beta}$) angles to predict the metal-ligand geometry.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.845-849
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• 1996

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.

• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.1022-1028
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• 1997

The reaction between Ni(Ⅱ) and sodium salt of 5,6-dihydro-1,4-dithiin-2,3-dithiolate (DDDT2-) in the presence of oxygen results in the formation of Ni(Ⅲ) species, Ni(DDDT)2-, which is isolated as tetraalkylammonium salt. The same reaction performed in the absence of oxygen yields dianionic Ni(Ⅱ) species, Ni(DDDT)22-, which is also isolated as the tetraethylammonium salt. The bis(5,6-dihydro-1,4-dithiin-2,3-dithiolato) nickelate (Ⅱ) dianion, Ni(DDDT)22-, reacts with methyl iodide to yield unusually stable bis(methylthio)dithiolene complex, Ni(CH3)2C8H8S8. All the isolated dithiolato-nickel(Ⅱ) and nickel(Ⅲ) complexes are characterized by 1H NMR, UV/Vis, IR and mass spectroscopic methods. The internal redox reaction of the nickel(Ⅱ)-dithiolate has been studied by spectro-electrochemical method and the results were compared with those of other metal-dithiolenes. The alkylated nickel(dithiolene) complex presumably undergoes cis-trans isomerization reaction in solution, judging from the experimental results of variable-temperature 1H NMR measurements.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.1-4
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• 1998

In continued studies on cultivated Korean rhubarb rhizomes, three additional stilbene compounds were isolated from water extract by column chromatographic separation using Sepha dex LH-20, ODS-gel. Compound I, desoxyrhapontigenin(3,5-dihydroxy-4`-methoxystilbene), Compound II, rhapontigenin(3,3`,5-trihydroxy-4`-methoxystilbene), and compound III, piceatannol(3,3`,4`,5-tetrahydroxystilbene) were elucidated based on physico-chemical and spectroscopic evidences(UV, IR, $^1H$-NMR, $^13C$-NMR and Mass).

• Bulletin of the Korean Chemical Society
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• v.9 no.4
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• pp.198-202
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• 1988

Several new palladium(II) complexes of aminophosphines, $(Pd(L)X_2)$, (L = $Ph_2PNH$ ++ $NR_2$; R = $CH_3(L_1)$, $C_2H_5(L_2)$ : X = Cl, Br, I, and NCS) that contain two different donor atoms of nitrogen and phosphorus as ${\pi}$-electron acceptor, were synthesized and characterized by conductivity measurement, ir, and UV/Vis-spectra. For the dithiocyanatopalladium(II) complexes with aminophosphines, it was confirmed that the thiocyanate group trans to phosphorus is coordinated as Pd-NCS mode and the one trans to nitrogen as Pd-SCN mode, and the aminophosphines form six-membered chelate ring. The spectra of dihalogenopalladium(II) complexes with aminophosphines show that the band maxima are shifted to the short wavelengths as the concentration is decreased.