• 제목/요약/키워드: Organic synthesis

검색결과 1,221건 처리시간 0.033초

A New Approach to Synthesis and Photoluminescence of Silicon Nanoparticles

  • Kim, Beomsuk
    • 통합자연과학논문집
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    • 제2권1호
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    • pp.28-31
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    • 2009
  • We describe the synthesis and characterization of silicon nanoparticles prepared by the soluton reduction of SiCl4. These reactions produce Si nanoparticles with surfaces that are covalently terminated. The resultant organic derivatized Si nanoparticles as well as a probable distribution of Water-soluble Si nanoparticles are observed and characterized by photoluminescence(PL) spectroscopy. This work focuses originally on the organic- and water-soluble silicon nanoparticles in terms of the photoluminescence. Further this work displays probably the first layout of hydrogen terminated Si nanoparticles synthesized in solution at room temperature.

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Synthesis of Triazole-functionalized Phenolic Resin and its Inherent Flame Retardant Property

  • Poduval, Mithrabinda K.K.;Kim, Tae-Hyun
    • Bulletin of the Korean Chemical Society
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    • 제35권11호
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    • pp.3249-3253
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    • 2014
  • A novel triazole-functionalized phenolic resin was developed, and its thermal and flame-retardant properties were investigated. The triazole group was incorporated as a pendant unit on the phenolic resin via copper-mediated click chemistry between propargylated phenolic resin and benzyl azide. The newly-developed triazole-functionalized phenolic resin showed higher thermal stability and char yield, together with a reduced total heat release (THR), than the non-functionalized bare phenolic resin, indicating enhanced flame retardancy for the triazole-functionalized phenolic resin.

Asymmetric Reduction of 3-Ketoproline Ethyl Ester by Modified Borohydrides and Various Vegetables

  • Wibowo, Agustono;Shaameri, Zurina;Mohammat, Mohd Fazli;Hamzah, Ahmad Sazali
    • 대한화학회지
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    • 제61권5호
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    • pp.244-250
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    • 2017
  • Reduction of (${\pm}$)-3-ketoproline ethyl ester (1) by $NaBH_4$ in the presence of $CaCl_2$ and $MgCl_2$ as the chelating agents gave selective products cis-3(R/S)-alcohols, while reduction by $NaBH_4$ alone or chelated with $NiCl_2$ and $AlBr_3$ gave mixtures of cis- and trans-alcohols. The reduction of (${\pm}$)-1 by various vegetables however, gave exclusively the cis-alcohol as the major and trans-alcohol as the minor. On the contrary, reduction of (${\pm}$)-1 by carrot afforded a mixture of cis- and trans-alcohols, in which the trans-alcohol exists as the major product. In addition, we found that this biocatalyst selectively converted S-enantiomer of (${\pm}$)-1 to the cis-alcohol, and R-enantiomer to a mixture of cis- and trans-alcohols with cis-alcohol as the major product. This fact prompted us to use various fresh plant tissues for stereoselective reduction of diverse types of pyrrolidinones, as its stereoselectivity towards racemic mixtures is higher compared to that using chemical reducing agents.

플래시라이트를 이용한 금속나노입자 기반 전극 및 금속유기골격체 합성 전략 (Synthesis Strategy for Electrodes and Metal-Organic Frameworks based on Metal Nanoparticle using Flashlight)

  • 임창용;백새연;박소연;김하민
    • 공업화학
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    • 제31권6호
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    • pp.591-595
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    • 2020
  • Intensive pulsed light (IPL) 기술은 빛을 millisecond 단위의 짧은 시간에 상온, 상압 환경에서 대상 물질에 조사하여 에너지를 전달한다. 이렇게 단시간에 조사되는 특징을 가진 플래시라이트(flashlight)에 대한 관심의 증대로 IPL을 이용한 금속입자의 광소결 연구가 대표적으로 이루어져 왔으며, 최근에는 IPL을 다양한 물질 합성에 적용한 사례가 발표되고 있다. 본 총설 논문은 지금까지 연구되어 밝혀진 IPL을 활용한 다양한 물질 합성 전략들에 대한 것으로 IPL 기술을 이용한 물질 합성에 대한 이해를 증진시키고자 한다. 특히, 금속나노입자의 소결을 이용한 유연 전극제작 및 금속유기골격체(metal-organic framework, MOF) 합성을 다루었다. 전극제작의 핵심 요소인 전극의 산화 저항성과 전기전도도 향상을 위한 과정을 다루었고, 금속기판으로부터 금속유기골격체를 합성하는 과정을 설명하였다. 이를 향후 IPL을 이용한 전극 제작 및 물질 합성 응용에 관한 연구를 하는 연구자에게 이해하기 쉽게 설명하고자 하였다.

Synthesis and Biological Activities of (4-Arylpiperazinyl)piperidines as Nonpeptide BACE 1 Inhibitors

  • Boja, Poojary;Won, Sun-Woo;Suh, Dong-Hoon;Chu, Jeong-Hyun;Park, Woo-Kyu;Lim, Hee-Jong
    • Bulletin of the Korean Chemical Society
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    • 제32권4호
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    • pp.1249-1252
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    • 2011
  • Inhibition of BACE 1 activity is considered as a promising therapeutic target for Alzheimer's Disease (AD). Synthesis and inhibitory activities of (4-arylpiperazinyl)piperidines by bioisosteric replacement of a biaryl group with an arylpiperazine as BACE 1 inhibitors are described. The resulting (4-arylpiperazinyl)piperidines represent novel nonpeptide BACE 1 inhibitors with improved in vitro potency.

An Efficient Synthesis of 2,4,5-Triaryl-1H-Imidazole Derivatives Catalyzed by Boric Acid in Aqueous Media Under Ultrasound-Irradiation

  • Shelke, Kiran F.;Sapkal, Suryakant;Sonal, Swapnil;Madje, Balaji R.;Shingate, Bapurao B.;Shingare, Murlidhar S.
    • Bulletin of the Korean Chemical Society
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    • 제30권5호
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    • pp.1057-1060
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    • 2009
  • Boric acid ($BO_3H_3$) is an inexpensive, efficient and mild catalyst for the synthesis of 2,4,5-triaryl-1H-imidazoles in excellent yields from the one-pot three-component condensation of benzil/benzoin, an aldehydes and ammonium acetate in aqueous media under ultrasound at room temperature. The remarkable advantages offered by this method are green catalyst, mild reaction conditions, simple procedures, much faster reactions and excellent yield of products.