• Title/Summary/Keyword: IR spectra

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The Ir(PPh$_3)_2\;(CO)OClO_3\;and\;Ir(PPh_3)_3N_2Cl$ Mediated Activation of Aldehyde C-H Bonds via Chelate-Assisted Oxidative Addition

  • Ko, Jae-Jung;Joo, Wan-Chul;Kong, Young-Kun
    • Bulletin of the Korean Chemical Society
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    • v.7 no.5
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    • pp.338-341
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    • 1986
  • Hydrocarbon solution of $Ir(PPh_3)_2(CO)OClO_3$ reacts with $Ph_2PC_6H_4$-o-CHO and 3-methyl-2-aminopyridinyl aldimine to yield ${\bar{Ir(Ph_2PC_6H_4-o-CO)}}\;(PPh_3)_2(CO)(H)ClO_4$(1) and ${\bar{Ir(NC_6H_6NC}}C_6H_5)(PPh_3)_2(CO)(H)ClO_4$(2), respectively. The compound $Ir(PPh_3)_2N_2Cl$ also reacts with $Ph_2PC_6H_4$-o-CHO and 3-methyl-2-aminopyridinyl aldimine to give ${\bar{Ir(Ph_2PC_6H_4-o-C}}O)(PPh_3)_2(H)Cl(3)$ and $Ir(NC_6H_5NCC_6H_5(PPh_3)_2(H)Cl(4)$, respectively. Compounds 1, 2, 3, and 4 were characterized by infrared, $^1H$ NMR, $^{31}p$ NMR, UV spectra, and conductivity measurements.

Discrimination of Cultivars and Cultivation Origins from the Sepals of Dry Persimmon Using FT-IR Spectroscopy Combined with Multivariate Analysis (FT-IR 스펙트럼 데이터의 다변량 통계분석을 이용한 곶감의 원산지 및 품종 식별)

  • Hur, Suel Hye;Kim, Suk Weon;Min, Byung Whan
    • Korean Journal of Food Science and Technology
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    • v.47 no.1
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    • pp.20-26
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    • 2015
  • This study aimed to establish a rapid system for discriminating the cultivation origins and cultivars of dry persimmons, using metabolite fingerprinting by Fourier transform infrared (FT-IR) spectroscopy combined with multivariate analysis. Whole-cell extracts from the sepals of four Korean cultivars and two different Chinese dry persimmons were subjected to FT-IR spectroscopy. Principle component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) of the FT-IR spectral data successfully discriminated six dry persimmons into two groups depending on their cultivation origins. Principal component loading values showed that the 1750-1420 and $1190-950cm^{-1}$ regions of the FT-IR spectra were significantly important for the discrimination of cultivation origins. The accuracy of prediction of the cultivation origins and cultivars by PLS regression was 100% (p<0.01) and 85.9% (p<0.05), respectively. These results clearly show that metabolic fingerprinting of FT-IR spectra can be applied for rapid discrimination of the cultivation origins and cultivars of commercial dry persimmons.

HIGH RESOLUTION NEAR-INFRARED SPECTRA OF NEARBY QUASAR, PG1426+015

  • Le, Huynh Anh Nguyen;Pak, Soo-Jong;Im, Myung-Shin;Ho, Luis C.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.51.1-51.1
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    • 2012
  • We observed low-z quasar PG1426+015 (z=0.086), using the near-IR high resolution echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. Using an Adoptive Optics system, the full width at half maximum of the point spread function was about 0.3 arcsec, which can effectively separate the quasar spectra from the host galaxy spectra. We also maximize the total exposure time up to several hours per target, and develop data reduction methods to increase the signal-to-noise ratios. This poster presents the data reduction processes and sample spectra from the quasar and its host galaxy. These spectral lines will be used to study the physical mechanism of quasars, and the velocity dispersions of the stars in the bugle of the host galaxy.

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A Study of Azo-Hydrazone Tautomerism in 3-Phenyl-4-arylazo-5-isozaolones by $^H-NMR$ spectra of $^{15}N-labeled$ Compounds and HMO Method

  • Shawali, Ahmad S.;Salkaabi, harifia S.;Abdallah, Magda A.
    • Archives of Pharmacal Research
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    • v.14 no.3
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    • pp.237-241
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    • 1991
  • The tautomerism in 3-phenyl-4-arylazo-5-isoxazolones 1 was examined by $^1H-NMR$ spectra of $^15N-labeled$ compound and by HMO method. Both spectra data $(^1H-NMR\;and\;IR)$ and bonding energies are in support of the assignment of the hydrazone structure to such compounds. It is further shown that intermolecular and intramolecular hydrogen bondings favor the hydrazone tautomer.

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Near-IR Spectral Features of Haze Particles in the Atmosphere of Titan

  • Kim, Sang Joon
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.62.1-62.1
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    • 2013
  • The Cassini/Visual Infrared Mapping Spectrometer (VIMS) observed the sun through the atmosphere of Titan, and provided vertically-resolved 63 spectra from 49 km to 987 km for the 1 - 5 micron range (Bellucci, 2008). Bellucci et al. (2009) analyzed selected spectral ranges where the band absorptions of $CH_4$ and CO are strong by constructing synthetic spectra including $CH_4$ and CO lines, but without including haze absorptions in their synthetic spectra. Kim et al. (2011) and Sim et al. (2013) were able to extract detailed spectral features of fundamental (Dv = 1) and overtone (Dv = 2) bands of the haze from the VIMS spectra by excluding the adjacent influences of strong $CH_4$ absorptions using a radiative transfer program, which includes effects of absorption and emission of lines of these molecules, and absorption and scattering of haze particles. In this presentation, we extend our detailed analyses to other remaining wavelengths in order to provide the spectral characteristics of the Titanian haze for the entire 1 - 5 micron range and to identify any additional haze spectral features and an unidentified feature near 4.3 microns reported by Bellucci et al. (2009).

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Synthesis and Properties of Conjugated Polycarbosilanes with 1,4-Bis(thiophene or phenylene)-buta-1,3-diyne

  • 서일권;박영태;김용록
    • Bulletin of the Korean Chemical Society
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    • v.20 no.6
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    • pp.677-682
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    • 1999
  • Conjugated polycarbosilanes with diacetylene and aromatic groups of thiophene or phenylene simultaneously present in the polymer backbone such as poly[[1,4-bis(thiophenyl)buta-1,3-diyne]-alt-(dimethylsilane)], poly[[1,4-bis(thiophenyl)buta-1,3-diyne]-alt-(diphenylsilane)], poly[[1,4-bis(phenyl)buta-1,3-diyne]-alt-(dimethylsilane)],and poly[[1,4-bis(phenyl)buta-1,3-diyne]-alt-(diphenylsilane)] have been prepared. The characteristic C=C stretching frequencies appear at 2177-2179㎝-1 in the IR spectra of the polymers. The molecular weights of these polymers were detemined by GPC. All of these materials are soluble in organic solvents such as THF and chloroform, and thermally stable up to 200℃ in general without any weight loss under nitrogen. The prepared materials in THF solvent show a maximum absorption peak in the range of 334-356 nm with a molar absorptivity of 10³∼10ⁿ(n=5)L/(cm·mol) in the UV-visible absorption spectra. A maximum emission peak in the range of 403-550 nm is also observed in the fluorescence emission spectra. Both absorption and emission spectra strongly indicate that the obtained polycarbosilanes contain the new conjugated systems along the polymer main chain.

High Pressure Vibrational Study of $C_{70}$ Using Diamond Anvil Cell

  • Ahn, Hang-Sun;Jeon, Seung-Joon
    • The Korean Journal of Ceramics
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    • v.3 no.2
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    • pp.82-87
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    • 1997
  • High pressure FTIR and Raman spectra of soild $C_{70}$ were measured at pressure up to 11 GPa and room temperature. The slope (dv/dp) of the frequency-pressure plots for several IR and Raman mode changed around 1.5 GPa, where a solid-solid transition might occur. In IR study, we can observe new mode appeared around 777$cm^{-1}$1 above 5.5 GPa which might indicate another solid-solid transition. Our study showed that this transition might be irreversible.

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Enhancement of Phosphorescence from Organic Fluorescent Materials $Bebq_2$ and $Alq_3$ by Sensitization

  • Tsuboi, Taiju;Jeon, Woo-Sik;Kwon, Jang-Hyuk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1509-1512
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    • 2008
  • Monomer and aggregate of $Bebq_2$ give fluorescence at 492 and 511 nm at 12 K, respectively. Intense T1 emission with vibronic structure was observed from $Bebq_2$ and $Alq_3$ below 70 K by heavily doping with phosphorescent $Ir(ppy)_3$. Energy transfer from $Ir(ppy)_3$ was clarified by photoluminescence excitation spectra.

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Physico-Chemical Properties of Various Oxide Nanoparticles Synthesized with Electron Beam Irradiation System

  • Sin, Won-Gyu
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.437-437
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    • 2014
  • Various oxide particles are synthesized in an ambient condition using an electron beam irradiation system. The formation of oxide particles is confirmed by FT-IR spectra results and the X-ray photoelectron spectrum. It is also shown that the morphology and size of oxide particles are significantly influenced by the type and flowrate of dilution gas. The energy dispersive X-ray (EDX) analysis also confirms that various oxide particles are synthesized.

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