• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.315-318
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• 1998

Organic light-emitting diodes(OLEDs) or electroluminescent devices have attracted much attention because of their possible application as large-area light-emitting displays. Their structure was based on employing a multilayer device structure containing an emitting layer and a carrier transporting layer of suitable organic materials. In this study, several Tb complexes such as Tb(ACAC)$_3$(Phen), Tb(ACAC)$_3$(Phen-Cl) and Tb(TPB)$_3$(Phen) were synthesized and the photoluminescence(PL) and electroluminescence (EL) characteristics of their thin films were investigated by fabricating the devices having a structure of anode/HTL/terbium-oomplex/ETL/cathode, where TPD was used as an hole transporting and Alq$_3$ and TAZ-Si were used as an electron transporting materials. It was found that the photoluminescence(PL) and electroluminescence(EL) characteristics of these terbium complexes were dependent upon the ligands coordinated to terbium metal. Details on the explanation of electrical transport phenomena of the structure with I-V characteristics of the OLEDs using the trapped-charge-limited current(TCLC) model will be discussed.

• The Korean Journal of Mycology
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• 제13권2호
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• pp.75-78
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• 1985

Mutagenesis of protoplast could serve a great potential tool for improvement of strains and genetics in higher fungi. For the isolation of auxotrophic mutants from protoplasts of Pleurotus ostreatus and Pleurotus florida, viability levels of ultraviolet lights were determined. Seven auxotrophs were obtained from protoplasts irradiating UV to give $0.83{\sim}15%$ survival. The mutants showed a single requirement for each of Arg, Ribo-l, Ribo-2 or Phen for growth. Some of them showed two or three kinds of requirements, Gly Ser, Ade Hypo or Ala Om Tryp for growth.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2006년도 영호남 합동 학술대회 및 춘계학술대회 논문집 센서 박막 기술교육
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• pp.23-24
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• 2006

We have synthesized electroluminescence materials. including [2-(2-hydroxyphenyl)benzoxazole] (Zn(HPB)$_2$), [(2-(2-hydroxyphenyl)benzoxazole)(8-hydoxyquinoline)] (Zn(HPB)q) and [(1, 10-phenanthroline)(8-hydroxyquinoline)] Zn(phen)q. The ionization potential (IP) and electron affinity (EA) of each Zn-complex was measured using cyclic-voltammetry (C-V). Basing on the consideration of matched in the energy levels of the materials. We investigated the electron transporting properties of Zn(HPB)q and Zn(phen)q compared with $Alq_3$, and also we investigated the hole blocking properties of Zn(HPB)$_2$, compared with BCP. As a result, we used Zn-complex to enhance the performance of OLED. Therefore, we demonstrate that Zn(HPB)q and Zn(phen)q are useful as an electron transporting material. Zn(HPB)$_2$ is also good a hole blocking material.

• Bulletin of the Korean Chemical Society
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• 제18권10호
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• pp.1109-1112
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• 1997

• Journal of the Korean Applied Science and Technology
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• 제15권3호
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• pp.85-90
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• 1998

In this study, organic electroluminescent devices(OELD) with a structure of a glass $substrate/ITO/TPD/Tb(ACAC)_3(Phen-Cl)/Alq_3/Al$ was fabricated by vacuum evaporation method, where Tb complex was known to have green light emitting property. Electroluminescent(EL) and I-V characteristics of this structure were investigated. This triple-layer structure shows the green EL spectrum at the wavelwngth of 546nm, which is almost the same as the PL spectrum of $Pb(ACAC)_3(Phen_Cl)$. It was found in current-voltage(I-V) characteristics of the devices that the operating voltage was about 12V.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2617-2622
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• 2011

Two new Zn(II) complexes, $[Zn_2(dpa)_2(phen)_2(H_2O)_2]{\cdot}H_2O$ (1) (dpa = dephenate, phen = 1,10-phenanthroline) and [$Zn_2(dpa)_2(bpy)_2(H_2O)_2$] (2) (bpy = 2,2'-bipyridine) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. The X-ray analysis reveals that the structures of 1 and 2 are dinuclear zinc(II) complexes bridged by dpa dianions, respectively. The zinc ions in 1 exhibit a distorted square pyramidal environments, while the zinc ions in 2 exhibit a trigonal bipyramid geometry. In each complex, the dpa ligand is coordinated to zinc ions as a bis-monodentate.

• Journal of the Korean Chemical Society
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• 제57권4호
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• pp.425-431
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• 2013

Oxidation of glutamic acid is performed in aqueous acid media at $30^{\circ}C$ under the kinetic condition [glutamic acid]$_T{\gg}[Cr(VI)]_T$. Effect of combination of micellar catalyst (SDS, TX-100) and promoter (PA, bpy, phen) has been studied. Among the promoters phen accelerates the reaction most in aqueous media. But the rate acceleration is small in the case. Combination of promoter and catalyst produces much better result. Maximum rate enhancement occurs in presence of the combination of bpy and SDS.

• Bulletin of the Korean Chemical Society
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• 제19권10호
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• pp.1084-1090
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• 1998

The oxidation of triphenylphosphine by [(tpy)(phen)RuⅣ(O)]2+ and [(bpy)(p-tert-butylpy)RuⅣ(0)]2+ (tpy is 2,2': 6',2"-terpyridine, phen is 1,10-phenanthroline, bpy is 2,2'-bipyridine, and p-tert-butylpy is para-tertbutylpyridine) in CH3CN has been studied. Experiments using 18O-labeled complex show the oxyl group transfer from [RuⅣ=O]2+ to triphenylphosphine occured quantitatively within experimental error. Kinetic data were fit to a second-order for [RuⅣ=O]2+ and [PPh3]. The initial product, [RuⅡ-OPPh3]2+, was formed as an observable intermediate and then underwent slow solvolysis. The reaction proceeded as endothermic in activation enthalpy and a decrease in activation entropy. The oxidative reactivity of four representative ruthenium mono-oxo oxidants against triphenylphosphine was compared. These systems have been utilized as electrochemical oxidative catalysts.

• Analytical Science and Technology
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• 제24권6호
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• pp.451-459
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• 2011

Eight coordinated terbium(III) complexes, tris (2-pyrazinecarboxylato)(phenanthroline) terbium(III) [$Tb(pzc)_3$(phen)], tris (5-methyl-2-pyrazinecarboxylato) (phenanthroline) terbium(III) [$Tb(mpzc)_3$(phen)] and tris(2-picolinato) (phenanthroline) terbium(III) [$Tb(pic)_3$(phen)], have been synthesized and characterized by Fourier transform infrared (FT-IR), UV-Visible and X-ray photoelectron spectroscopy. Photoluminescence (PL) spectroscopy shows that these complexes emitted strong green luminescence. When powder samples of the $Tb^{3+}$ complexes are examined using time-resolved spectroscopic analysis, the luminescence lifetimes are found to be 0.87 ms and 1.0 ms, respectively. Thermogravimetric analysis reveals the terbium complexes to have good thermal stability up to $333-379^{\circ}C$. Cyclic voltammetry shows that HOMO-LUMO energy gap of the $Tb^{3+}$ complexes ranges from 4.26~4.41 eV. These values are similar to those obtained from the UV-visible spectra. Overall, the synthesized $Tb^{3+}$ complexes may be useful advanced materials for green light emitting devices.

• Bulletin of the Korean Chemical Society
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• 제28권6호
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• pp.965-969
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• 2007

The spectral properties, namely the circular dichroism, electric absorption and luminescence properties, of Λ- and Δ-[Ru(II)(1,10-phenanthroline)2benzodipyrido[b:3,2-h:2',3'-j]phenazine]2+ ([Ru(phen)2BDPPZ]2+) in the presence and absence of single stranded poly(dA) and poly(dT) were compared in this work. In the presence of single stranded DNAs, hypochromism in the absorption spectrum and significant changes in the circular dichroism spectrum in the ligand absorption band were apparent, indicating the strong interaction of the [Ru(phen)2BDPPZ]2+ complex with the single stranded DNAs. The luminescence intensity of the Ru(II) complex decreased stoichiometrically with increasing concentrations of the single stranded DNAs. All of these spectral changes were independent of the configuration of the Ru(II) complex and the nature of the DNA bases. Therefore, it is conceivable that both enantiomers of the [Ru(phen)2BDPPZ]2+ complex interact electrostatically with the negatively charged phosphate groups of DNA. However, the spectral properties of [Ru(II)(1,10-phenanthroline)3]2+ were not altered even in the presence of single stranded DNAs. Therefore, the size of the ligand involved in the interaction of the metal complex with the phosphate group of DNA may play an important role, even when the nature of the interaction is electrostatic.