• 제목/요약/키워드: Diacetylenes

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Diacetylene Polymerize in Amorphous State? Free Radical Initiated Polymerization of Aromatic Diacetylenes.

  • Beristain Miriam F.;Ogawa Takeshi
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.321-321
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    • 2006
  • Aromatic diacetylenes form stable oligomeric diradicals when irradiated with UV light or heated at temperatures above their melting points. In this paper, the formation of stable diradicals is discussed, and the mechanism of polymerization in the presence of peroxide in solution, is discussed. The diphenyldiacetylene undergoes polymerization through coupling of diradicals, and not by the successive addition of radical species.

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THE PHOTOHYDRATION OF 1-(NITROPHENYL)-5,5-DIMETHYL-1,3-HEXADIYNES: THE NITRO SUBSTITUENT EFFECT ON THE EXCITED STATES OF DIACETYLENES

  • Baek, Eun-Kyung
    • Journal of Photoscience
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    • 제2권2호
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    • pp.73-76
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    • 1995
  • The photohydration of 1-(m-nitrophenyl)-5, 5-dimethyl-1, 3-hexadiyne (m-NDHD) affords allenyl ketone compound (1) via triplet excited state which is converted into $\beta$-dicarbonyl compound (2) through thermal hydration. The allenyl ketone is formed by the synchronous addition of water with protonation at C$_1$ indicating that m-NDHD has the reverse polarization and greater electron withdrawing effect in the triplet excited state in comparison with p-NDHD.

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Self-Assembly and Photopolymerization of Diacetylene Molecules on Surface of Magnetite Nanoparticles

  • Vinod, T.P.;Chang, Ji-Hoon;Kim, Jin-Kwon;Rhee, Seog-Woo
    • Bulletin of the Korean Chemical Society
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    • 제29권4호
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    • pp.799-804
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    • 2008
  • An amphiphilic diacetylene compound was deposited on the surface of nano sized magnetite particles ($Fe_3O_4$) using a self-assembly method. The diacetylene molecular assembly formed on the surface of nanoparticle was subjected to photopolymerization. This resulted in the formation of a polymeric assembly on the surface of the nanoparticles in which the adjacent diacetylene molecules were connected through conjugated covalent networks. The presence of immobilized polymer species on the surface of nanoparticles is expected to protect them from agglomeration and ripening, thereby stabilizing their physical properties. In this work, $Fe_3O_4$ nanoparticles were prepared by chemical coprecipitation method and the diacetylene molecule 10,12- pentacosadiynoic acid (PCDA) was anchored to the surface of $Fe_3O_4$ nanoparticles through its carboxylate head group. Irradiation of UV light on the nanoparticles containing immobilized diacetylenes resulted in the formation of a polymeric assembly. Presence of diacetylene molecules on the surface of nanoparticles was confirmed by X-ray photoelectron spectroscopy and FT-IR measurements. Photopolymerization of the diacetylene assembly was detected by UV-Visible spectroscopy. Magnetic properties of the nanoparticles coated with polymeric assembly were investigated with SQUID and magnetic hysteresis showed superparamagnetic behaviors. The results put forward a simple and effective method for achieving polymer coating on the surface of magnetic nanoparticle.

The Solid-Phase Synthesis of Amino Acid-Derived Diacetylene Lipids

  • Kim Jong-Man;Park Bum Jun;Chang Eun-Ju;Yi Sung Chul;Suh Dong Hack;Ahn Dong June
    • Macromolecular Research
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    • 제13권3호
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    • pp.253-256
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    • 2005
  • We prepared amino acid-derived diacetylene monomers using solid-phase organic synthesis. The solid-phase synthetic method allowed for the rapid and efficient preparation of functional diacetylenes. Amino acids having hydrophobic sidechains such as alanine, leucine, and phenylalanine, as well as hydrophilic sidechains such as aspartic acid and lysine, were successfully coupled to the diacetylene lipid. The diacetylene monomers prepared in this way were subjected to routine procedures for the generation of polydiacetylene vesicles. Depending on the nature of the side-chains, pink to blue colored polydiacetylenes were generated.