• 제목/요약/키워드: Chemical reduction

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트란스-1,2-비스피라질에틸렌의 광화학적 환원 (Photochemical Reduction of trans-1,2-Bispyrazylethylene)

  • 심상철;채정석
    • 대한화학회지
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    • 제21권2호
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    • pp.102-107
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    • 1977
  • 질소를 방향족고리에 포함하고 있는 헤테로 화합물인 트란스-1,2-비스피라질 에틸렌을 쿠멘, 이소프로판올, 시멘용매등에 녹여 빛을 쪼여준 결과 광화학적 환원이 일어나 1,2-비스피라질 에탄이 됨을 알았다. 알칼리 금속염이 이 환원반응에 미치는 영향, 용매효과, 증감제와 아줄렌등의 영향으로 부터 이 환원 반응은 $(n,{\pi}^*)^1$상태로부터 일어남을 알았다.

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Effect of Different Pretreatments on Indium-Tin Oxide Electrodes

  • Choi, Moonjeong;Jo, Kyungmin;Yang, Haesik
    • Bulletin of the Korean Chemical Society
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    • 제34권2호
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    • pp.421-425
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    • 2013
  • The effect of pretreatment on indium-tin oxide (ITO) electrodes has been rarely studied, although that on metal and carbon electrodes has been enormously done. The electrochemical and surface properties of ITO electrodes are investigated after 6 different pretreatments. The electrochemical behaviors for oxygen reduction, $Ru(NH_3){_6}^{3+}$ reduction, $Fe(CN){_6}^{3-}$ reduction, and p-hydroquinone oxidation are compared, and the surface roughness, hydrophilicity, and surface chemical composition are also compared. Oxygen reduction, $Fe(CN){_6}^{3-}$ reduction, and p-hydroquinone oxidation are highly affected by the type of the pretreatment, whereas $Ru(NH_3){_6}^{3+}$ reduction is almost independent of it. Interestingly, oxygen reduction is significantly suppressed by the treatment in an HCl solution. The changes in surface roughness and composition are not high after each pretreatment, but the change in contact angle is substantial in some pretreatments.

화학환원법을 이용한 Ag-Pd 합금 나노분말의 합성 (Synthesis of Ag-Pd Alloy Nanoparticles by Chemical Reduction Method)

  • 서원식;김윤도;정일엽;이호석;송기창
    • 한국세라믹학회지
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    • 제43권4호
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    • pp.224-229
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    • 2006
  • Ag-Pd alloy nanoparticles were prepared by a chemical reduction method using hydrazine $(N_2H_4)$ as a reductant in $AgNO_3\;and\;Pd(NO_3)_2$ aqueous solutions. Characterization of these particles by X-ray powder diffraction revealed a bimetallic and crystalline silver-palladium alloy. The average size of the particles was influenced not by the reductant $(N_2H_4)$ concentration, but the concentration of the starting materials $(AgNO_3\;and\;Pd(NO_3)_2)$.

Preparation of Copper Nanoparticles and Catalytic Properties for the Reduction of Aromatic Nitro Compounds

  • Duan, Zhongyu;Ma, Guoli;Zhang, Wenjun
    • Bulletin of the Korean Chemical Society
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    • 제33권12호
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    • pp.4003-4006
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    • 2012
  • A novel copper nanoparticles were synthesized from cupric sulfate using hydrazine as reducing reagents. A series of aromatic nitro compounds were reacted with sodium borohydride in the presence of the copper nanoparticles catalysts to afford the aromatic amino compounds in high yields. Additionally, the catalysts system can be recycled and maintain a high catalytic effect in the reduction of aromatic nitro compounds.

Preparation and Characterization of Palladium Nanoparticles Supported on Nickel Hexacyanoferrate for Fuel Cell Application

  • Choi, Kwang-Hyun;Shokouhimehr, Mohammadreza;Kang, Yun Sik;Chung, Dong Young;Chung, Young-Hoon;Ahn, Minjeh;Sung, Yung-Eun
    • Bulletin of the Korean Chemical Society
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    • 제34권4호
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    • pp.1195-1198
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    • 2013
  • Nickel hexacyanoferrate supported palladium nanoparticles (Pd-NiHCF NPs) were synthesized and studied for oxygen reduction reactions in direct methanol fuel cell. The NiHCF support was readily synthesized by a comixing of $Ni(OCOCH_3)_2$ and equimolar $K_3[Fe(CN)_6]$ solution into DI water under rigorous stirring. After the preparation of NiHCF support, Pd NPs were loaded on NiHCF via L-ascorbic acid reduction method at $80^{\circ}C$. Pd-NiHCF NPs were electrochemically active for oxygen reduction reaction in 0.1 M $HClO_4$ solution. X-ray absorption near edge structure analysis was conducted to measure the white line intensity of Pd-NiHCF to verify the OH adsorption. As a comparison, carbon supported Pd NPs exhibited same white line intensity. This study provides a general synthetic approach to easily load Pd NPs on porous coordination polymers such as NiHCF and can provide further light to load Pd based alloy NPs on NiHCF framework.

Triphenylphosphine Phenylimide의 전기화학적인 환원 (Electrochemical Reduction of Triphenylphosphine Phenylimide)

  • 박종민
    • 대한화학회지
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    • 제18권5호
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    • pp.341-353
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    • 1974
  • Triphenylphosphine phenylimide의 비수용액에서의 전기화학적인 환원반응을 polarography, cyclic voltammetry, controlled-potential coulometry 및 electron spin resonance 법을 써서 고찰하였다. 이 유기인화합물은 one-electon transfer에 따라서 anion radical이 형성되나 순간일 뿐이고 protonation과 재차 one-electon reduction 결과 인과 질소사이의 이중결합이 끊어진다. 그 결과 아닐린이 주요 반응생성물로서 발견되었다. 또 한편 동반하는 화학반응결과 생긴 주산물의 하나인 triphenylposphine oxide의 환원결과 인과 페닐 사이의 단일결합이 끊어지는 것도 관찰할 수 있었다.

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Selective Reduction of Oximes to N-Monosubstituted Hydroxylamines with Lithium Borohydride

  • Cho, Byung-Tae;Seong, See-Yearl
    • Bulletin of the Korean Chemical Society
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    • 제9권5호
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    • pp.322-324
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    • 1988
  • Selective reduction of aldoximes and ketoximes with lithium borohydride in tetrahydrofuran was investigated. Thus, aldoximes and cyclic ketoximes such as hexanaldoxime, heptanaldoxime, cyclopentanone oxime and cyclohexanone oxime were reduced smoothly to the corresponding N-monosubstituted hydroxylamines at room temperature in 65-93% yield. The reduction of alicyclic ketoxime was very slow, requiring somewhat high reaction temperature ($65^{\circ}C$) for the complete reduction to give the hydroxnylamines. The reduction of aromatic oximes such as benzaldoxime and acetophenone oxime was very sluggish, giving a mixture of the corresponding hydroxylamines and amines at $65^{\circ}C$.