• Title/Summary/Keyword: Olefins

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A Mechanistic Study on the Nucleophilic Addition Reactions of Benzylamines to the Activated Olefins

  • Oh, Hyuck-Keun
    • Bulletin of the Korean Chemical Society
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    • v.29 no.6
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    • pp.1195-1198
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    • 2008
  • Kinetic studies of the additions of benzylamines to a noncyclic dicarbonyl group activated olefin, methyl $\alpha$-acetyl-$\beta$ -phenylacrylates (MAP), in acetonitrile at 30.0 ${^{\circ}C}$ are reported. The rates are lower than those for the cyclic dicarbonyl group activated olefins. The addition occurs in a single step with concurrent formation of the $C_\alpha$ -N and $C_\beta$ -H bonds through a four-center hydrogen bonded transition state. The kinetic isotope effects ($k_H/k_D$ > 1.0) measured with deuterated benzylamines ($XC_6H_4CH_2ND_2$) increase with a stronger electron acceptor substituent ($\delta\sigma$ X > 0) which is the same trend as those found for other dicarbonyl group activated series (1-4). The sign and magnitude of the cross-interaction constant, ρXY, is comparable to those for the normal bond formation processes in the $S_N2$ and addition reactions. The relatively low ${\Delta}H^\neq$ and large negative ${\Delta}S^\neq$ values are also consistent with the mechanism proposed.

Conversion of Methanol to Hydrocarbons over Heteropoly Acids(I) (헤테로폴리산 촉매에 의한 탄화수소로의 메탄올 전환반응(I))

  • Hong, Seong-Soo;Lee, Ho-In
    • Applied Chemistry for Engineering
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    • v.2 no.4
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    • pp.363-371
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    • 1991
  • The catalytic performance and availability of heteropoly compounds for the conversion of methanol to hydrocarbons have been studied. The effects of reaction conditions such as reaction temperature, methanol partial pressure and residence time and the effects of ion-exchange of the catalysts were examined for enhancing the yield of hydrocarbons and the selectivity of low olefins. Their acid strength depended on the kind of countercation, and the yield of hydrocarbons and the selectivity for propylene to propane were closely related to the electronegativity of the corresponding countercations. In contrast to the other heteropoly compounds, the ammonium salt showed a considerably high catalytic activity and a high selectivity for paraffins to low olefins.

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Reactive Compatibilization of Amorphous Poly-${\alpha}$-olefins/Amorphous Polyamide Blends (무정형 알파-올레핀 고분자/무정형 폴리아미드 블렌드의 반응 상용화)

  • Yun, Deok-Woo;Choi, Mi-Ju;Hwang, Kyu-Hee;Kim, Geon-Seok;Lee, Kwang-Hee
    • Polymer(Korea)
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    • v.33 no.5
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    • pp.490-495
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    • 2009
  • The reactive compatibilization of amorphous poly-${\alpha}$-olefins (APAO)/amorphous polyamide (aPA) blends was carried out using two kinds of reactive compatibilizers such as maleated polypropylene and ethylene-glycidyl methacrylate-methyl acrylate copolymer. The grafting reaction rates between aPA and the compatibilizers were examined using FT-IR, SEM and rheometer. The effect of the reactive compatibilization on the mechanical property of the blends was investigated with a universal testing machine. The adhesion strength of the blends including a hydrocarbon tackifier resin, C9 was also measured.

Preparation of Copper Nanoparticles in Cellulose Acetate Polymer and the Reaction Chemistry of Copper Complexes in the Polymer

  • Shim, Il-Wun;Noh, Won-Tae;Kwon, Ji-Woon;Jo, Jung-Young;Kim, Kyung-Soo;Kang, Dong-Hee
    • Bulletin of the Korean Chemical Society
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    • v.23 no.4
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    • pp.563-566
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    • 2002
  • Copper complexes have been directly incorporated into cellulose acetate (CA) and the resulting light blue colored homogeneous films of 5-20 wt.% copper acetate complex concentrations are found to be thermally stable up to 200 $^{\circ}C$. The reaction chem istry of Cu in CA has been investigated by reacting them with small gas molecules such as CO, H2, D2, O2, NO, and olefins in the temperature range of 25-160 $^{\circ}C$, and various Cu-hydride, -carbonyl, -nitrosyl, and olefin species coordinated to Cu sites in CA are characterized by IR and UV/Vis spectroscopic study. The reduction of Cu(II) complexes by reacting with H2 gas at the described conditions results in the formation of Cu2O and copper metal nanoparticles in CA, and their sizes in 30-120 nm range are found to be controlled by adjusting metal complex concentration in CA and/or the reduction reaction conditions. These small copper metal particles show various catalytic reactivity in hydrogenation of olefins and CH3CN; CO oxidation; and NO reduction reactions under relatively mild conditions.