한국정보디스플레이학회:학술대회논문집

The Korean Infomation Display Society (한국정보디스플레이학회)
권호 표지

Synthesis and Characterization of banana-shaped achiral molecules

  • Lee, Chong-Kwang (Department of Chemistry, College of Natural Science Gyeong sang National University) ;
  • Lee, Chong-Kwang (Dept. of Chemistry, Gyeongsang National University) ;
  • Kwon, Soon-Sik (Dept. of Chemistry, Gyeongsang National University) ;
  • Kim, Tae-Sung (Dept. of Chemistry, Gyeongsang National University) ;
  • Shin, Sung-Tae (Dept. of Physics, Korea University) ;
  • Choi, Suk (Dept. of Physics, Korea University) ;
  • Choi, E-Joon (Dept. of Polymer Science and Engineering, Kumoh National University of Technology) ;
  • Kim, Sea-Yun (Dept. of Polymer Science and Engineering, Kumoh National University of Technology) ;
  • Kim, Jae-Hoon (Dept. of Physics, Hallym University) ;
  • Zin, Wang-Choel (Dept. of Materials Science and Engineering, Pohang University of Science and Technology) ;
  • Kim, Dae-Cheol (Dept. of Materials Science and Engineering, Pohang University of Science and Technology) ;
  • Chien, Liang-Chy (Liquid Crystal Institute, Kent State University)
  • Published : 2003.07.09
Download PDF
⟨ Previous Next ⟩

Abstract

New banana-shaped achiral compounds, 4-chloro-1,3-phenylene bis [4-4(3-fluoro-9-alkenyloxy) phenyl-iminomethylbenzoate]s and 4-chloro-1,3-phenylene bis [4-4-(3-fluoro-10-alkanyloxy) phenyliminomethyl benzoate]s were synthesized by varying the substituent (X=H, F, or Cl); their electrooptical properties are described. The smectic phases, including a switchable chiral smectic C ($SmC^{\ast}$) phase, were characterized by differential scanning calorimetry, polarizing optical microscopy, and triangular method. The presence of vinyl end group at the terminals of linear side wings in the banana-shaped molecules induced a decrease in melting temperature. The smectic phase having the undecenyloxy group such $as-(CH_2)_9CH=CH_2$ showed ferroelectric switching, and its value of spontaneous polarization on reversal of an applied electric field was 2250 $nC/cm^2$, while the value of spontaneous polarization of the smectic phase having the decanyloxy group such as $-(CH2)_9CH_3$ was 3700 $nC/cm^2$. We could obtain the ferroelectric phase with low isotropic temperature by varying the end group at the terminals of linear side wings in the banana-shaped achiral molecules.

Keywords