• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
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• pp.132.1-132
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• 2000

No Abstract, See Full Text

• Journal of Photoscience
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• 제10권1호
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• pp.105-119
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• 2003

Fullerenes, $C_{60}$ and $C_{70}$, display interesting physicochemical properties in solutions, especially due to their unique chemical structures and their good electron accepting abilities. Solubility of fullerenes in different organic solvents and their unusual solvatochromic behavior, the ability of the fullerenes to form aggregates in solutions, and their electron transfer and charge transfer interactions with variety of electron donors, are the subjects of extensive research activities for more than one decade. Many research groups including ours have contributed substantially in the understanding of the solvatochromism, aggregation behavior, and the photoinduced electron transfer and charge transfer chemistry of fullerenes, in condensed phase. Present article is aimed to summarize the important results reported on the above aspects of fullerenes, subsequent to the earlier report from our group (D.K. Palit and J.P. Mittal, Full. Sci. & Tech. 3, 1995, 643-659).)., 643-659)..

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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• pp.53-56
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• 2001

The degradation of tetrachloroethene (PCE) and trichloroethene (TCE) by vitamin B$_{12}$, an electron mediator was examined when zero valent metals (ZVMs) were used as built electron donors. Dechlorination of PCE and TCE by iron and zinc in the presence of vitamin B$_{12}$ showed that the zinc and vitamin B$_{12}$ combination greatly enhances the reaction rates for both PCE and TCE, but iron and vitamin B$_{12}$ result in an increase in reactivity only for PCE degradation, not for TCE degradation in comparing with meta]s only. This result indicates vitamin B$_{12}$(I) Is active towards both PCE and TCE degradation while vitamin B$_{12}$(II) is active towards both PCE. Calculated activation energies for the dechlorination of PCE in the presence of Vitamin B$_{12}$ showed that vitamin B$_{12}$ lowered the activation energy about 40-60 kJ/㏖ for the both metals.the both metals.

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1190-1198
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• 2012

Three hydroquinone dimethyl ether derivatives have been synthesized and characterized by X-ray diffraction. The electron donating properties were evaluated by using UV-vis spectroscopy, cyclic voltammetry and by ESR spectroscopy. The microcrystalline cation-radical salts of the three donor molecules were also isolated by using antimony pentachloride, a single electron Lewis acid oxidant.

• 통합자연과학논문집
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• 제5권3호
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• pp.195-197
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• 2012

Halogen atoms in a molecule are traditionally considered as electron donors, since they have unshared electrons. Normally when they are bonded, there are three lone pair electrons. These lone pairs can function as Lewis bases. However, when they are bound to electron withdrawing groups, they can act as Lewis acids. Since the situation is similar hydrogen bonding (HB), this type of interaction is named as halogen bonding (XB). This mainly comes from the uneven distribution of electron density around the halogen atoms. Since the electron density around halogen atom opposite to ${\sigma}$-bond is depleted, its electropositive region is called ${\sigma}$-hole. This ${\sigma}$-hole can attract halogen bond acceptors, requiring more stringent directionality compared to HB. Since this interaction mainly comes from electrostatic origin, the geometry tends to be linear. Since the XB energy is comparable to corresponding HB. Still in its infancy, XB shows a broad range of applicability, with potentially more useful properties, compared to corresponding HB.

• 미생물학회지
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• 제38권2호
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• pp.133-138
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• 2002

금속 이온 환훤 세균에 의한 철(III)환원은 생물지구화학적 물질순환(biogeochemical cycle)에 무척 중요하다. 이는 크롬(Ⅵ)이나 우라늄(Ⅵ)과 같은 독성 중금속 물질의 환원과 유기물질의 산화에 모텔이 되기 때문이다. 총 37균주의 Fe (III)환원 세균을 소양호와 천호지의 저질토에서 각각 분리하였다. 두 정점 중 초기 Fe (II)의 함유량이 가장 높았던 것은 소양호의 저질토였으나 Fe (III)환훤능은 반대로 가장 낮은 Fe (II)함유량을 보여 주었던 천호지가 높게 나타났다. 또한 분리한 균주 중 천호지에서 분리한 균주 C2와 C3가 가장 높은 Fe (III) 환훤능을 보여 주었으며 이 균주를 이용하여 다양한 전자 공여체의 이용 여부를 실험하였다. Glucose, yeast extract, acetate, ethanol, toluene등을 이용하여 실험한 결과 두 균주 모두 glucose와 yeast extract만을 전자 공여체로 이용하였다. 또한 전자 수용체로 토양에 광범위하게 존재하는 humid acid와 nitrate를 이용하였으며 수율이 높은 nitrate reduction에 의해 환원되었던 humic acid가 다시 재 산화되는 것을 관촬할수 있었다. 활성능이 우수한 균주 C2와C3의 165S rRNA유전자 분석 결과에 의하면 Aeromonas hydrophila와 95%의 유사성을 보여주었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권10호
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• pp.564-569
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• 2000

This paper analyzed single AlGaAs/GaAa heterojunction energy band structures by solving Schr dinger's equation and Poisson's equation self-consistently. Four different concentrations, positively ionized donors, holes in the valence band, free electrons in the conduction band and 2DEG are taken into account for the whole system. 2DEG from both of the structures are obtained and compared with the date available in the literatures. Differential capacitances are also calculated from the concentration profiles obtained to prove the validity of the single AlGaAs/GaAs system. Finally, theoretical predictions for both of 2DEGs and the capacitances show good agreement with the experimental data referred in this study. It has only an error of les than 10 percent.

• 분석과학
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• 제8권4호
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• pp.481-486
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• 1995

Quenching experiments by photoinduced electron transfer between a charged donor and a neutral acceptor were carried out in acetonitrile, dichloromethane and mixed solvents of acetonitrile and dichloromethane. Tris(2, 2'-bipyridine) ruthenium(II) ($[Ru(bpy)_3]^{2+}$) which has 2+ charge and dicyanobis (2, 2'-bipyridine) ruthenium(II) ($Ru(bpy)_2(CN)_2$) which has no charge were used as electron donors, and a series of tris(${\beta}$-diketonato) ruthenium (III) was used as acceptor. In dichloromethane, $[Ru(bpy)_3]^{2+}$ and its counter ions ($ClO{_4}^-$) form ion pair. In the estimate of ${\Delta}G$ of electron transfer, the electrostatic potential between counter ions and product ion pair produced by electron transfer must be taken into account. A similar effect of counter ions was found in mixed solvents of 10, 30, 50, 70 and 90% acetonitrile ratio in volume. The effect of counter ion on ${\Delta}G$ became smaller with the increase in acetonitrile ratio. The result in mixed solvents suggests that $[Ru(bpy)_3]^{2+}$ and its counter ions form ion pair even in 90% acetonitrile solution.

• Rapid Communication in Photoscience
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• 제3권3호
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• pp.56-58
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• 2014

Single-walled carbon nanotubes (SWNTs) catalyzed hydrogen production from water containing various electron donors under visible light (${\lambda}$ > 420 nm). As-received SWNTs were effective for hydrogen production, yet the effect vanished when they underwent surface chemical treatments. Upon coupling with CdSe particles, however, the surface treated SWNTs were far superior to non-treated SWNTs by a factor of ~30 for hydrogen production.

• Journal of Photoscience
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• 제12권3호
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• pp.155-162
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• 2005

Results of studies of SET-promoted dipole-forming photochemical group transfer reactions of phthalimide and ${\alpha}-ketoamide$ derivatives are discussed. Azomethine ylide forming photochemical reactions, which are initiated by intramolecular SET from tethered silylmethyl-, carboxymethyl-, and ${\beta}-hydroxyethyl$ containing electron donors to excited states of phthalimides, related maleimides, and conjugated imides, are presented first. Following this, investigations of regioselective 1,4-dipole forming photochemical reactions of N-trialkylsilylmethyl- and N-trialkylstannyl-${\alpha}$-ketoamides are described.