Synthesis and mesomorphic properties of 6-methoxy- and 6-ethoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles
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. St...
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| Format: | Article |
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Taylor & Francis Group, LLC
2010
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| _version_ | 1796856236200689664 |
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| author | Ha, Sie Tiong Koh, Teck Ming Yeap, Guan Yeow Lin, Hong Cheu Lee, Siew Ling Win, Yip Foo Ong, Siew Teng |
| author_facet | Ha, Sie Tiong Koh, Teck Ming Yeap, Guan Yeow Lin, Hong Cheu Lee, Siew Ling Win, Yip Foo Ong, Siew Teng |
| author_sort | Ha, Sie Tiong |
| collection | ePrints |
| description | 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. |
| first_indexed | 2024-03-05T18:40:28Z |
| format | Article |
| id | utm.eprints-26650 |
| institution | Universiti Teknologi Malaysia - ePrints |
| last_indexed | 2024-03-05T18:40:28Z |
| publishDate | 2010 |
| publisher | Taylor & Francis Group, LLC |
| record_format | dspace |
| spelling | utm.eprints-266502018-11-30T07:07:09Z http://eprints.utm.my/26650/ Synthesis and mesomorphic properties of 6-methoxy- and 6-ethoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles Ha, Sie Tiong Koh, Teck Ming Yeap, Guan Yeow Lin, Hong Cheu Lee, Siew Ling Win, Yip Foo Ong, Siew Teng Q Science 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. Taylor & Francis Group, LLC 2010 Article PeerReviewed Ha, Sie Tiong and Koh, Teck Ming and Yeap, Guan Yeow and Lin, Hong Cheu and Lee, Siew Ling and Win, Yip Foo and Ong, Siew Teng (2010) Synthesis and mesomorphic properties of 6-methoxy- and 6-ethoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles. Molecular Crystals And Liquid Crystals, 528 (1). pp. 10-22. ISSN 1542-1406 http://dx.doi.org/10.1080/15421406.2010.504510 DOI:10.1080/15421406.2010.504510 |
| spellingShingle | Q Science Ha, Sie Tiong Koh, Teck Ming Yeap, Guan Yeow Lin, Hong Cheu Lee, Siew Ling Win, Yip Foo Ong, Siew Teng Synthesis and mesomorphic properties of 6-methoxy- and 6-ethoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles |
| title | Synthesis and mesomorphic properties of 6-methoxy- and 6-ethoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles |
| title_full | Synthesis and mesomorphic properties of 6-methoxy- and 6-ethoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles |
| title_fullStr | Synthesis and mesomorphic properties of 6-methoxy- and 6-ethoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles |
| title_full_unstemmed | Synthesis and mesomorphic properties of 6-methoxy- and 6-ethoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles |
| title_short | Synthesis and mesomorphic properties of 6-methoxy- and 6-ethoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles |
| title_sort | synthesis and mesomorphic properties of 6 methoxy and 6 ethoxy 2 2 hydroxy 4 alkanoyloxybenzylidenamino benzothiazoles |
| topic | Q Science |
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