• Title/Summary/Keyword: bent-core mesogens

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Synthesis and Characterization of New Azomethine Polymers Containing Bent-Core Mesogen with Sharp Bend Angle

  • Kim, Eun-Chol;Choi, E-Joon;Ok, Chang-Woo;Zin, Wang-Choel
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.553-555
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    • 2007
  • Six azomethine polymers containing bent-core mesogen were synthesized with variation of a bent structure of central core (1,2-dioxyphenylene or 2,3-dioxynaphthylene), and a lateral halogen substituent (X = H, F or Cl ). The properties of the polymers were characterized by FT-IR, NMR spectroscopy, DSC, polarizing optical microscopy, and X-ray diffractometry.

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Importance of the Role of Flexible Spacers in Liquid Crystal Formation by Bent Dimesogenic and Star-Shaped Trimesogenic Compounds

  • Jung-Il Jin;Bong Young Chung;Jae-Kon Choi;Byung-Wook Jo
    • Bulletin of the Korean Chemical Society
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    • v.12 no.2
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    • pp.189-193
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    • 1991
  • A series of compounds that contain varying numbers of the same mesogenic structure, biphenyl p-oxybenzoate unit, attached through a pentamethylene spacer to the central benzene ring were prepared and their liquid crystallinity was studied. The mesophase-forming ability of a dimesogenic compound was found to be greatly dependent on whether or not its geometric shape is linear and also on the existence of the pentamethylene spacer between the mesogen and the central core. The presence of the spacer enhanced the capacity of a compound to form a mesophase. In the trimesogenic compound the mesogens were linked to the 1,3,5-positions of the core benzene ring through the spacer. The compound was found to be enantiotropically nematic.

Chiral Mesophase Derived from Achiral Polymers with Banana-Shaped Mesogens and Their Model Compounds

  • Choi, E-Joon;Kim, Eun-Chul;Kwon, Myung-Hun;Zin, Wang-Cheol;Kim, Young-Chul;Paek, Sang-Hyon
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.242-243
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    • 2006
  • In this work, we report the synthesis and characterization of azomethineester polymers that consist of banana-shaped mesogen in their backbone. Two parts of the key structure of five-ring bent-core mesogen were modified by connecting different angle of central unit (Ar), and introducing lateral substituent into the outer ring (X). The synthetic details includes (1) placing the dioxydodecamethylene unit as a flexible spacer, (2) possessing 2,3- or 2,7-naphthylene, or 1,2-phenylene connection on the central unit, and (3) introducing fluorine or chlorine substituent (X = F or Cl) into the outer phenylene unit.

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Synthesis and Mesomorphism of Polymers with Banana-Shaped Mesogens in the Main Chain

  • Choi, E-Joon;Zin, Wang-Cheol;Kim, Young-Chul;Paek, Sang-Hyon;Chien, Liang-Chy;Samulski, Edward T.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.171-174
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    • 2006
  • In this work, we report the synthesis and characterization of azomethine-ester polymers that consist of banana-shaped mesogen in their backbone. Two parts of the key structure of five-ring bent-core mesogen were modified by connecting different angle of central unit (Ar), and introducing lateral substituent into the outer ring (X). The synthetic details includes (1) placing the dioxydodecamethylene unit as a flexible spacer, (2) possessing 2,3- or 2,7-naphthylene, or 1,2-phenylene connection on the central unit, and (3) introducing fluorine or chlorine substituent (X = F or Cl) into the outer phenylene unit.

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