• Title/Summary/Keyword: organic molecules

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Highly Efficient Blue-Light-Emitting Diodes Based on Styrylamine Derivatives End-capped with a Diphenylvinyl Group

  • Kim, Seul-Ong;Lee, Kum-Hee;Kang, Sun-Woo;Lee, Jin-Yong;Seo, Ji-Hoon;Kim, Young-Kwan;Yoon, Seung-Soo
    • Bulletin of the Korean Chemical Society
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    • v.31 no.2
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    • pp.389-396
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    • 2010
  • In this paper, we reported the synthesis and electroluminescent properties of blue fluorescent styrylamine derivatives end-capped with a diphenylvinyl group. A new series of styrylamine derivatives have been synthesized via the Horner-Wadsworth-Emmons reaction. To explore electroluminescent properties of these molecules, multilayer organic lighte-mitting devices with the configuration of ITO/NPB/1-5 doped in MADN/Bphen/Liq/Al were fabricated. All devices exhibited blue emissions with good EL performances. Among those reported herein, the device using dopant 5 exhibited a maximum luminance of $24,000\;cd/m^2$ at 11.0 V, a luminous efficiency of 12.5 cd/A at $20\;mA/cm^2$, a power efficiency of 6.50 lm/W at $20\;mA/cm^2$, and $CIE_{x,y}$ coordinates of (x = 0.173, y = 0.306) at 8.0 V, all of which demonstrate the superiority of these materials in blue OLEDs.

Development of Molecular Simulation Software for the Prediction of Thermodynamic Properties (열역학 물성 예측을 위한 분자 시뮬레이션 소프트웨어의 개발)

  • Chang, Jaee-On
    • Korean Chemical Engineering Research
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    • v.49 no.3
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    • pp.361-366
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    • 2011
  • By using Monte Carlo simulation method we developed a new molecular simulation software which can be used to predict the thermodynamic properties of organic compounds. Starting from molecular structure and intermolecular potential function, rigorous statistical mechanical principles give a probability distribution for the behavior of a system containing many molecules, which enables us to calculate macroscopic thermodynamic properties of the system. The software developed in this work, cheMC, is based on Windows platform providing with easy access. One can efficiently administrate simulations by using an intuitive interface equipped with visualization tool and chart generation. It is expected that molecular simulations supplement the equation of state approach and will play a more important role in the study of thermodynamic properties.

녹색형광단백질로 구성된 분자광다이오드의 전자전달 특성

  • Nam, Yun-Seok;Choe, Jeong-U;Lee, Won-Hong
    • 한국생물공학회:학술대회논문집
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    • 2000.04a
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    • pp.149-152
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    • 2000
  • In recent years, various artificial molecular photodiode have been fabricated by mimicking the electron transport function of biological photosynthesis. And now, we have been investigated the protein-organic hetero thin film photodiode using GFP as an sensitizer based on the redox potential difference of functional molecules. In this paper, shows molecular photodiode consisting of green fluorescence protein(GFP). viologen and TCNQ. The TCNQ and viologen were deposited onto ITO coated glass by LB technique. And GFP molecule was adsorption onto the viologen LB film surface by self-assembly method. Finally, The Al deposition onto GFP/viologen/TCNQ film surface was performed to make a top electrode. As a result, The MIM(metal/Insulator/Metal) structured device was constructed. The input light of 460nm wavelength was generated by the xenon lamp system, and then the photocurrent produced from the molecular device was detected through a current-voltage(I-V) measuring unit (SMU Model 236, Keithley, USA). An artificial molecular photodiode using protein(GFP)-adsorbed hetero-LB film is presented as a model system for the bioelectronic device based on the biomimesis.

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Bacterial determinants involved in the induction of systemic resistance ana plant growth promotion in tobacco by Pseudomonas chlororaphis O6.

  • Han, Song-Hee;Cho, Baik-Ho;Kim, Young-Cheol
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.101.2-102
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    • 2003
  • The ability of P. chlororaphis O6 to induce resistance to Erwinia carotovora subsp. carotovara SCCI and to promote growth in tobacco was demonstrated in microtiter assays on plants pre-inoculated at the root level with the bacteria before challenge with the leaf pathogen. To identify th bacterial determinants involved in induced systemic resistance and plant growth promotion, cell culture of O6 grown in King's medium B was fractionated with organic solvents and purified using various columns. in vivo and in vitro assays with samples from successive fractionation steps of the O6 supernatant led to the conclusion that antibacterial compounds were observed in aqueous layer, and to the isolation of fractions containing metabolites that retained most of the resistance-inducing activity (70:30, methanol:water) and the plant growth promotion (80:20 and 90:10, methanol:water) after ODS column chromatography. Although these molecules remain to be purified further and structurally characterized, its isolation is an addition to the range of determinants from plant growth-promoting rhizobacteria known to stimulate plant defence.

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Identification of a Glucokinase that Generates a Major Glucose Phosphorylation Activity in the Cyanobacterium Synechocystis sp. PCC 6803

  • Lee, Jung-Mi;Ryu, Jee-Youn;Kim, Hyong-Ha;Choi, Sang-Bong;de Marsac, Nicole Tandeau;Park, Youn-Il
    • Molecules and Cells
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    • v.19 no.2
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    • pp.256-261
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    • 2005
  • In silico analysis of genome of the cyanobacterium Synechocystis sp. PCC 6803 identified two genes, slr0329 and sll0593, that might participate in glucose (Glc) phosphorylation (www.kazusa.or.jp/cyano). In order to determine the functions of these two genes, we generated deletion mutants, and analyzed their phenotypes and enzymatic activities. In the presence of 10 mM Glc, wild-type (WT) and slr0329 defective strain (M1) grew fast with increased respiratory activity and NADPH production, whereas the sll0593 deletion mutant (M2) failed to show any of the Glc responses. WT and M1 were not significantly different in their glucokinase activity, but M2 had 90% less activity. Therefore, we propose that Sll0593 plays a major role in the phosphorylation of glucose in Synechocystis cells.

Effects of Spacer Inserted Inside the Emission Layer on the Efficiency and Emission Characteristics of Phosphorescent Organic Light-emitting Diodes (발광층 내의 스페이서가 인광 OLED의 효율 및 발광 특성에 미치는 영향)

  • Seo, Yu-Seok;Moon, Dae-Gyu
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.6
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    • pp.377-382
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    • 2014
  • We have investigated the effects of spacer layer inserted between blue and red doped emission layers on the emission and efficiency characteristics of phosphorescent OLEDs. N,N'-di-carbazolyl-3,5-benzene (mCP) was used as a host layer. Iridium(III)bis[(4,6-di-fluorophenyl)- pyridinato-N,$C^2$']picolinate (FIrpic) and tris(1-phenyl-isoquinolinato-$C^2$,N)iridium(III) [Ir(piq)3] were used as blue and red dopants, respectively. The emission layer structure was mCP (1-x) nm/mCP:$Ir(piq)_3$ (5 nm, 10%)/mCP (x nm)/mCP:FIrpic (5 nm, 10%). The thickness of mCP spacer layer was varied from 0 to 15 nm. The emission from $Ir(piq)_3$ and the efficiency of the device were dominated by energy transfer from mCP host and FIrpic molecules, and by diffusion of mCP host triplet excitons.

A New HPLC-analytical Method for Total Sphingosine Contents as an Indirect Index for the Ganglioside Contents of Deer Antlers

  • Choi, Hye-Ok;Kim, Jeung-Won;Jo, Sung-Jun;Kim, Jung-Hwan;Han, Byung-Hoon
    • Natural Product Sciences
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    • v.17 no.4
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    • pp.315-320
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    • 2011
  • Routinely applicable HPLC assay procedures for the ganglioside content in various deer antler preparations were established through the creation of a UV-absorbing chromophoric substance - trans-${\alpha},{\beta}$-unsaturated-hexadecene-aldehyde - from the sphingosine moiety in ganglioside molecules by two step chemical reactions. In order to guarantee the assay's accuracy and sensitivity, the HPLC-assay procedure adopted internal reference procedures by mixing cis-${\alpha},{\beta}$-unsaturated-hexadecene aldehyde[V] or cis-3-heptadecene- 1,2-diol[IV] to assay samples. The internal reference compound [IV] or [V] was synthesized in our laboratory starting from mannitol-diacetonide through three or four step organic reactions. This new HPLC-assay procedure was successfully applied to deer antler extracts with good dose-dependent calibration curves at the picomole level of gangliosides.

Electrodelss Plasma Torch Powered by Microwave and Its Applications (무전극 마이크로웨이브 플라즈마 토치와 응용)

  • Hong, Yong-Cheol;Jun, Hyung-Won;Lho, Tai-Hyeop;Lee, Bong-Ju;Uhm, Han-Sup
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.889-892
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    • 2009
  • A microwave plasma torch at the atmospheric pressure by making use of magnetrons operated at the 2.45 GHz and used in a home microwave oven has been developed. This electrodeless torch can be used to various areas, including industrial, environmental and military applications. Although the microwave plasma torch has many applications, we in the present work focused on the microwave plasma torch operated in pure steam and several applications, which may be used in future and right now. For example, a high-temperature steam microwave plasma torch may have a potential application of the hydrocarbon fuel reforming at one atmospheric pressure. Moreover, the radicals including hydrogen, oxygen and hydroxide molecules are abundantly available in the steam torch, dramatically enhancing the reaction speed. Also, the microwave plasma torch can be used as a high-temperature, large-volume plasma burner by injecting hydrocarbon fuels in gas, liquid, and solid into the plasma flame. Lastly, we briefly report an underway research, which is remediation of soils contaminated with oils, volatile organic compounds, heavy metals, etc.

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Abundant Methanol Ices toward a Massive Young Stellar Object in the Galactic Center

  • An, Deokkeun;Sellgren, Kris;Adwin Boogert, A.C.;Ramirez, Solange V.;Pyo, Tae-Soo
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.57.1-57.1
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    • 2016
  • Methanol ($CH_3OH$) is a key species in the formation of complex organic molecules. We report the first detection of solid $CH_3OH$ in a line of sight toward the Galactic center (GC) region, based on L-band spectra taken with the Subaru telescope, aided by L'-band imaging data and moderate-resolution spectra from NASA/IRTF. It is found toward a background star, ~8000 AU in projected distance from a newly discovered massive young stellar object (YSO). This YSO also exhibits a strong $CO_2$ ice absorption band at ${\sim}15{\mu}m$ in Spitzer/IRS data, which has a prominent long-wavelength wing. It confirms that a high $CH_3OH$ abundance is responsible for the broad $15{\mu}m$ $CO_2$ ice absorption towards massive YSOs in the GC. Clearly, $CH_3OH$ formation in ices is efficient in the GC region, as it is in star-forming regions in the Galactic disk. We discuss implications of our result on the astrochemical processes in the hostile GC molecular clouds.

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The electrical characteristics of pentacene field-effect transistors with polymer gate insulators

  • Kang, Gi-Wook;Kang, Hee-Young;Park, Kyung-Min;Song, Jun-Ho;Lee, Chang-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.675-678
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    • 2003
  • We studied the electrical characteristics of pentacene-based organic field-effect transistors (FETs) with polymethyl methacrylate (PMMA) or poly-4-vinylphenol (PVP) as the gate insulator. PMMA or PVP was spin-coated on the indium tin oxide glass substrate that serves as gate electrodes. The source-drain current dependence on the gate voltage shows the FET characteristics of the hole accumulation type. The transistor with PVP shows a higher field-effect mobility of 0.14 $cm^{2}/Vs$ compared with 0.045 $cm^{2}/Vs$ for the transistor with PMMA. The atomic force microscope (AFM) images indicate that the grain size of the pentacene on PVP is larger than that on PMMA. X-ray diffraction (XRD) patterns for the pentacene deposited on PVP exhibit a new Bragg reflection at $19.5{\pm}0.2^{\circ}$, which is absent for the pentacene on PMMA. This peak corresponds to the flat-lying pentacene molecules with less intermolecular spacing.

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