標題: | Synthesis and Mesomorphic Properties of 6-Methoxy- and 6-Ethoxy-2-(2-Hydroxy-4-Alkanoyloxybenzylidenamino)Benzothiazoles |
作者: | Ha, Sie-Tiong Koh, Teck-Ming Yeap, Guan-Yeow Lin, Hong-Cheu Lee, Siew-Ling Win, Yip-Foo Ong, Siew-Teng 材料科學與工程學系 Department of Materials Science and Engineering |
關鍵字: | Benzothiazole liquid crystals;lateral hydroxyl group;nematic;structure-property relationship;terminal group |
公開日期: | 2010 |
摘要: | Two new series of Schiff base thermotropic liquid crystals, 6-methoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles and 6-ethoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles, comprising different terminal groups, a methoxyl and ethoxyl group, respectively, were synthesized. Structural elucidation was carried out using elemental analysis and spectroscopic techniques such as Fourier transform infrared (FTIR), 1H and 13C nuclear magnetic resources (NMR), and mass spectrometry. The mesomorphic properties and thermal stabilities of the title compounds were studied by using differential scanning calorimetry, optical polarizing microscopy, and thermogravimetric analysis. No liquid-crystal phases were observed for the short-chain members (n=2 and 3) in both series, and the remaining members all exhibited nematic phase with Schlieren or marble-like textures. Effects of the lateral hydroxyl group, terminal group, and the length of the terminal alkanoyloxy chain on the mesomorphic properties are discussed. Structure-property relationships were established upon comparison with other structurally related compounds. |
URI: | http://hdl.handle.net/11536/6015 http://dx.doi.org/10.1080/15421406.2010.504510 |
ISSN: | 1542-1406 |
DOI: | 10.1080/15421406.2010.504510 |
期刊: | MOLECULAR CRYSTALS AND LIQUID CRYSTALS |
Volume: | 528 |
起始頁: | 10 |
結束頁: | 22 |
顯示於類別: | 期刊論文 |