Monocyclic rod-type liquid crystals; 2,5-dialkanoyloxytropones and 5-alkanoyloxy-2-alkoxytropones |
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| Authors: | Akira Mori Hitoshi Takeshita Ryoji Mori Shinji Takematsu Manabu Takemoto Seiji Ujiie |
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| Institution: | 1. Institute of Advanced Material Study, 86 Kyushu University, Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan;2. Graduate School of Engineering Sciences, 39 Kyushu University, Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan;3. Interdisciplinary Faculty of Science and Engineering, Shimane University, Department of Material Science, Matsue 690-8504, Japan |
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| Abstract: | Two kinds of monocyclic troponoid mesogens, 2,5-dialkanoyloxytropones (4) and 5-alkanoyloxy2-alkoxytropones (5), were prepared. The former showed monotropic smectic A phases and the virtual isotropic liquid-smectic A transitions of the latter were determined by extrapolation of results in a binary phase diagram. Comparing the mesogenic properties between the tropones 4 and the 2-alkanoyloxy-5-alkoxytropones (1), the alkanoyloxy group at C-5 enhances both the melting points and the transition temperatures of the smectic A phases. From the comparison between 5 and 1, the alkanoyloxy group at C-2 lowers the melting points. |
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| Keywords: | cholesteric liquid crystal circularly polarised light wash-out/refill polymer network memory effect |
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