• Title/Summary/Keyword: Dehydrohalogenation

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Dehydrohalogenation Reactions Induced by Sodamide Containing Complex Bases (I). Mechanistic Studies on Dehydrohalogenation from trans-1,2-Dihalocyclohexanes (소다아미드를 포함하는 복합염기에 의한 탈할로겐화수소반응 (제1보). 트란스-1,2-디할로시클로헥산의 탈할로겐화수소 반응의 메카니즘 연구)

  • Jong Gun Lee;Kyung-Tae Kang;Euk-Suk Lee
    • Journal of the Korean Chemical Society
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    • v.28 no.1
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    • pp.20-25
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    • 1984
  • Sodamide-containing complex base induced dehydrohalogenations from trans-1,2-dihalocyclohexanes were investigated. Isomerization, deuterium isotope effect along with element effect and others provided strong evidence in favor of E2 reaction mechanism.

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Synthesis and Light-emitting Properties of Random Copolymers Composed of Phenylsilyl- and Alkoxy-Sustituted Phenylenevinylene

  • Ahn, Taek
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.5
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    • pp.263-267
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    • 2013
  • New random copolymers of phenylsilyl- and alkoxy-substituted phenylenevinylene, DMPS(9)-MEH(1)-PPV, DMPS(5)- MEH(5)-PPV and DMPS(1)-MEH(9)-PPV, have been synthesized by the Gilch dehydrohalogenation route, and the light-emitting properties of these polymers have been studied. The synthesized polymers were completely soluble in common organic solvents, and exhibited good thermal stability, almost up to $380^{\circ}C$. They showed UV-visible absorbance and photoluminescence (PL) in the ranges of 422-510 and 513-590 nm, respectively, according to their feed ratios. Electroluminescent devices were fabricated with these polymers as emitting layers, and ITO and Al as anode and cathode, respectively. DMPS(1)-MEH(9)-PPV, DMPS(5)-MEH(5)-PPV and DMPS(9)-MEH(1)-PPV exhibited EL emission maxima at 575 nm, 565 nm, and 541 nm, respectively.

Improved Antimicrobial Efficacy of m-Aramid

  • Kim, Sam-Soo;Park, Jeong-Eun;Jung, Da-Un;Seo, Byeong-Joo;Huh, Man-Woo;Lee, Jae-Woong
    • Textile Coloration and Finishing
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    • v.21 no.5
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    • pp.58-62
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    • 2009
  • Poly(m-phenyleneisophthalamide), m-aramid has no adjacent $\alpha$-hydrogen of a nitrogen-halogen bond causes dehydrohalogenation. This fact proposes that m-aramid is one of good antimicrobial precursors. To enhance the surface area of m-aramid, electrospinning was employed. Scanning electron microscopy(SEM) was conducted to inspect the morphology change of m-aramid. The surface area of regular and electrospun m-aramid was calculated. Swatch test was applied to measure antimicrobial activity of the samples. The results showed that within 10 min contact time the electrospun m-aramid inactivated Escherichia coli KCTC 1039 (Gram-negative bacteria) with 8 log reductions.

Synthesis of 7-[p-(Methylthio)benzoyl]-5-benzofurancetic Acid

  • Choi, Hong-Dae;Geum, Dek-Hyun;Kowan, Youn-Sil;Son, Byeng-Wha
    • Archives of Pharmacal Research
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    • v.16 no.4
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    • pp.343-346
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    • 1993
  • A new method was described for the preparation of 7-[p-(methylthio)benzoyl]-5-benzofuranacetic acid 6, which is an analgestic agent. Methyl 5-(2, 3-di-hydobenzofuran)acetate 3 was obtained by Friedel-Crafts reaction of 2, 3-dihydrobenzofuran with methyl .alpha.-chloro-.alpha.(methylthio)actate 1 and desulfurization of 2. Tifurac 6 was synthesized from acylation of 3 with p-(methythio)benzoyl chioride followed by bromination of 4, dehydrohalogenation, and hydrolysis of 5.

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Synthesis and Characterization of Oligomers Composed of Alternating 2,5-Bis(ethynylenedimethylsilylene)thienylene and Arylene Units

  • Kwak, Young-Woo;Lee, Kyung-Koo;Cha, Seung-Hun;Lee, Sang-Koo;Lee, In-Sook;Park, Yong-Tae;Lee, Jae-Keun;Yoh, Soo-Dong;Kim, Woo-Sik
    • Bulletin of the Korean Chemical Society
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    • v.24 no.4
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    • pp.479-483
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    • 2003
  • The reactions of 2,5-bis(ethynyldimethylsilyl)thiophene (1) with aromatic dihalides(1,4-dibromobenzene, 4,4'- dibromobiphenyl, 9,10-dibromoanthracene, 2,5-dibromopyridine, 2,5-dibromothiophene, and 2,6-diiodo-4- nitroaniline) were carried out in the presence of a $[(PPh_3)_2PdCl_2]$-CuI catalyst in refluxing triethylamine to give poly{[2,5-bis(ethynylenedimethylsilylene)thienylene](arylene)} (2-7) with molecular weights of 2200-7400. The oligomers reveal characteristic absorption in the UV/visible region. The thermal behavior of 2-7 was examined by thermogravimetric analysis in an argon atmosphere.

A Study for Reductive Degradation and Surface Characteristics of Hexachloroethane by Iron Sulfide ($FeS,\;FeS_{2}$) (황화철($FeS,\;FeS_{2}$)을 이용한 헥사클로로에탄의 환원적 분해반응과 표면특성에 관한 연구)

  • Park Sang-Won;Kim Sung-Kuk;Heo Jae-Eun
    • Journal of Soil and Groundwater Environment
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    • v.11 no.5
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    • pp.35-42
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    • 2006
  • The following results were obtained in the reductive degradation of hexachloroethane (HCA), and surface characteristics by using iron sulfide ($FeS,\;FeS_{2}$) mediators. HCA was degraded to pentachloroethane (PCA), tetrachloroethylene(PCE), trichloroethylene(TCE) and cis-l,2-dichloroethylene (cis-1,2-DCE) by complicated pathways such as hydrogenolysis, dehaloelimination and dehydrohalogenation. FeS had more rapid degradation rates of organic solvent than $FeS_{2}$. In liquidsolid reaction, the reaction rates of organic solvents were investigated to explain surface characteristics of FeS and $FeS_{2}$.. To determine surface characteristics of FeS and $FeS_{2}$, the specific surface area and surface potential of each mineral was determined and the hydrophilic site ($N_{s}$) was calculated. The specific surface area ($107.0470m^{2}/g\;and\;92.6374m^{2}/g$) and the $pH_{ZPC}$ of minerals ($FeS\;PH_{ZPC}=7.42,\;FeS_{2},\;PH_{ZPC}=7.80$) were measured. The results showed that the Ns of FeS and $FeS_{2}$ were $0.053\;site/mm^{2}\;and\;0.205\;site/mm^{2}$, respectively. $FeS_{2}$ had more hydrophilic surface than FeS. In other words, FeS have more hydrophobic surface site than $FeS_{2}$.

Reductive degradation of Chlorinated compounds by using Iron Minerals (철 광물에 의한 염소계 유기화합물의 환원적분해)

  • Kim, Sung-Kuk;Park, Sang-Won
    • Journal of Soil and Groundwater Environment
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    • v.9 no.2
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    • pp.11-19
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    • 2004
  • Chlorinated and nitroaromatic compounds are non-degradable substances that are extremely toxic and are known to be carcinogens and mutation causing agents. Moreover, the half-lives of substances such as carbon tetrachloride, hexachloroethane and nitroaromatic compounds are several decades. In this study, the optimal conditions to detoxify chlorinated compounds by the reductive degradation were investigated. The following results were obtained in the reductive degradation of CCl$_4$, C$_2$Cl$\_$6/, C$_2$HCl$\_$5/, C$_2$Cl$_4$, and C$_2$HCl$\_$5/ by using Fe, FeS and FeS$_2$ as mediators. CCl$_4$ was reduced to CH$_2$Cl$_3$ and CH$_2$Cl$_2$in anaerobic conditions when FeS was used as a mediator. While the reduction of CCl$_4$ to CHCl$_3$ was rapidly proceeded, the reduction of CHCl$_3$ to CH$_2$Cl$_2$ was occurred slowly. Further reduction to CH$_3$Cl was not observed. Unlike CCl$_4$, C$_2$Cl$\_$6/ was degraded to C$_2$HCl$\_$5/, C$_2$Cl$_4$. C$_2$HCl$_3$ and cis-1,2-C$_2$H$_2$Cl$_2$ by complicated pathways such as hydrogenolysis, dehalo-elimination and dehydrohalogenation. A small amount of C$_2$HCl$\_$5/ was detected only in the early stages of the reduction. However, majority of the C$_2$Cl$\_$6/ was reduced to C$_2$Cl$_4$. cis-1,2-C$_2$H$_2$C1$_2$ was the only product among other possible isomers.