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| Autor: | Yu-Shiuan Li, 黎宇軒 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 Series I A novel system of symmetric dimers containing quinoxaline units has been synthesized and their mesomorphic behavior investigated. All compounds were characterized by 1H, 13C-NMR spectroscopy and the mesomorphic behavior of these compounds investigated by polarized optical microscopy, differential scanning calorimetry and powder x-ray diffraction. The formation of mesophases was found to be sensitive to the number of carbon length of the side chains and/or the spacer. The results indicated that compound 1a, 1c and 1d exhibited hexagonal columnar phases. Packing studies indicated that a single molecule was required to generate a disc-like correlated structure in the columnar phases. The UV and PL spectra were also studied for their light-emitting properties. Series II A new system of 1,3,4-oxa(thia)diazoles contaning quinoxaline exhibiting mesomorphic properties was synthesized and their mesomorphic properties examined. These molecules exhibited hexagonal columnar phases. A change of alkoxy chains and oxygen/sulfur atoms incorporated was amied to their difference or effect on the formation of mesophases. The formation of columnar phases was strongly sensitive to the central heteroatoms and/or their positions incorporated. Packing studies indicated that two molecules laid side-by-side to required to generate a more disc-like correlated structure in the columnar phases. However, these materials show great potential for electronic devices. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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