Mesomorphic properties of achiral halogen-substituted banana-shaped compounds |
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Authors: | Chong-Kwang Lee Soon-Sik Kwon Wang-Choel Zin Dae-Cheol Kim Sung-Tae Shin Joon-Ho Song |
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Institution: | 1. Department of Chemistry, Gyeongsang National University, Chinju 660-701, Korea;2. Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea;3. Department of Physics, Korea University, Chungnam 339-700, Korea |
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Abstract: | Three banana-shaped achiral compounds, derivatives of 4,6-dichloro-1,3-phenylene bis-4-(4-n-octyloxyphenyliminomethyl) benzoate], were synthesized by varying the substituent (X = H, F and Cl). Their mesomorphic properties were investigated by differential scanning calorimetry, polarizing optical microscopy, and X-ray analysis. The compound with X = H exhibited an enantiomeric nematic phase. The compounds with X = F and Cl formed a nematic phase on heating, while on cooling they formed a nematic phase at high temperature and a smectic A phase at a lower temperature (monotropic). A schematic representation of the mesophase structures for the compound with X = F is also illustrated. |
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Keywords: | textural analysis homogeneity histogram peak detection algorithm image processing liquid crystals |
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