• 제목/요약/키워드: Chemical Reaction Mechanism

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벤조산유도체 I, Nitrone 유도체에 대한 Thiourea의 친핵성 첨가반응메카니즘과 그 반응속도론적 연구 (Benzoic Acid Derivatives I, The Kinetics and Mechanism of the Nucleopilic Addition of Thiourea to Nitrone Derivatives)

  • 김동환;이기창;류정욱;최봉종
    • 한국응용과학기술학회지
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    • 제8권1호
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    • pp.21-26
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    • 1991

  • The rate constants for the addition reaction of thiourea to nitrone derivatives were determind at various pH and reaction rate equation which could be applied over a wide pH were obtained. The substituent effects and general base catalysis for the addition of thiourea to nitrone derivatives were observed. On the basis of these findings, a plausible reaction mechanism for the nucleophilic addition of thiourea to nitrone was proposed.

  • https://doi.org/10.12925/jkocs.1991.8.1.3 인용 PDF

Mechanism of Alcohol Decrease by Acid Hydrolsis of Hovenia dulcis Extract

  • Kang, Sung-Hee;Kim, Sung-Mun;Kim, Jin-Hyun
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2005년도 생물공학의 동향(XVII)
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    • pp.530-534
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    • 2005

  • This work was a method that used an acid hydrolysis for increasing the efficacy of decreasing alcohol concentration from Hovenia dulcis extract. The best pH was 2.0 to obtain a maximum alcohol dehydrogenase activity at fixed reaction temperature and time. At pH 2.0, reaction temperature $80^{\circ}C$ and reaction time 4hr gave the highest activity which was 124% of control. The bioactive compound, (+)-dihydromyricetin, content increased to 30% after acid hydrolysis. This is very simple and efficient method to increase the efficacy of decreasing alcohol concentration from Hovenia dulcis extract. The mechanism that increase the efficiency of alcohol decrease be examined through hydrolysis.

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Morphologically Controlled Growth of Aluminum Nitride Nanostructures by the Carbothermal Reduction and Nitridation Method

  • Jung, Woo-Sik
    • Bulletin of the Korean Chemical Society
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    • 제30권7호
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    • pp.1563-1566
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    • 2009

  • One-dimensional aluminum nitride (AlN) nanostructures were synthesized by calcining an Al(OH)(succinate) complex, which contained a very small amount of iron as a catalyst, under a mixed gas flow of nitrogen and CO (1 vol%). The complex decomposed into a homogeneous mixture of alumina and carbon at the molecular level, resulting in the lowering of the formation temperature of the AlN nanostructures. The morphology of the nanostructures such as nanocone, nanoneedle, nanowire, and nanobamboo was controlled by varying the reaction conditions, including the reaction atmosphere, reaction temperature, duration time, and ramping rate. Iron droplets were observed on the tips of the AlN nanostructures, strongly supporting that the nanostructures grow through the vapor-liquid-solid mechanism. The variation in the morphology of the nanostructures was well explained in terms of the relationship between the diffusion rate of AlN vapor into the iron droplets and the growth rate of the nanostructures.

  • https://doi.org/10.5012/bkcs.2009.30.7.1563 인용 PDF KSCI

Very Efficient Nucleophilic Aromatic Fluorination Reaction in Molten Salts: A Mechanistic Study

  • Jang, Sung-Woo;Park, Sung-Woo;Lee, Byoung-Se;Chi, Dae-Yoon;Song, Choong-Eui;Lee, Sung-Yul
    • Bulletin of the Korean Chemical Society
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    • 제33권3호
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    • pp.881-884
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    • 2012

  • We report a quantum chemical study of an extremely efficient nucleophilic aromatic fluorination in molten salts. We describe that the mechanism involves solvent anion interacting with the ion pair nucleophile $M^+F^-$(M = Na, K, Rb, Cs) to accelerate the reaction. We show that our proposed mechanism may well explain the excellent efficiency of molten salts for SNAr reactions, the relative efficacy of the metal cations, and also the observed large difference in rate constants in two molten salts $(n-C_4H_9)_4N^+\;CX_3SO_3^-$, (X=H, F) with slightly different sidechain ($-CH_3$ vs. $-CF_3$).

  • https://doi.org/10.5012/bkcs.2012.33.3.881 인용 PDF KSCI