Preparation of liquid crystals containing Azobenzene and Alkyl Chains as terminal group
Liquid crystals have long dominated in the display devices, due to their large optical anisotropies and ability to undergo electric-field induced switching. In particular, liquid crystals containing azobenzene offers faster switching times than electric-field induced switching. The synthesis of l...
| Main Author: | |
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| Format: | Academic Exercise |
| Language: | English |
| Published: |
2008
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| Subjects: | |
| Online Access: | https://eprints.ums.edu.my/id/eprint/20138/1/Preparation%20of%20liquid%20crystals%20containing.pdf |
| _version_ | 1796909943984488448 |
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| author | Lee, Swee Ting |
| author_facet | Lee, Swee Ting |
| author_sort | Lee, Swee Ting |
| collection | UMS |
| description | Liquid crystals have long dominated in the display devices, due to their large optical
anisotropies and ability to undergo electric-field induced switching. In particular,
liquid crystals containing azobenzene offers faster switching times than electric-field
induced switching. The synthesis of liquid crystals containing azobenzene and alkyl
chains as terminal groups is studied. The target compounds of ethyl-4-{ 4-
hexyloxyphenylazo )benzoate (compound 2), ethyl-4-{ 4-decyloxyphenylazo )benzoate
(compound 3), and ethyl-4-(4-hexadecyloxyphenylazo)benzoate (compound 4) were
prepared. These liquid crystals were prepared through several organic syntheses steps
which are diazonium coupling and Williamson ether synthesis reactions. The yield
obtained for all the compounds synthesized was in the range 70-80010. Infrared
spectroscopy was used to identify the functional groups of all the intermediates and
target compounds. IH NMR spectroscopy was carried out only for compound 2 in
order to confirm its molecular structure. The mesomorphic behaviours of the target
compounds were investigated using differential scanning calorimetry (DSC). The
DSC thermograms reveal that only compound 2 is a liquid crystalline molecule as it
exhibited mesophase. As for compounds 3 and 4, they are crystalline solids because
no mesophase was discovered. The transition temperatures of these compounds were
influenced by different lengths ofthe alkyl chains. |
| first_indexed | 2024-03-06T02:57:06Z |
| format | Academic Exercise |
| id | ums.eprints-20138 |
| institution | Universiti Malaysia Sabah |
| language | English |
| last_indexed | 2024-03-06T02:57:06Z |
| publishDate | 2008 |
| record_format | dspace |
| spelling | ums.eprints-201382018-06-04T00:16:46Z https://eprints.ums.edu.my/id/eprint/20138/ Preparation of liquid crystals containing Azobenzene and Alkyl Chains as terminal group Lee, Swee Ting QD Chemistry Liquid crystals have long dominated in the display devices, due to their large optical anisotropies and ability to undergo electric-field induced switching. In particular, liquid crystals containing azobenzene offers faster switching times than electric-field induced switching. The synthesis of liquid crystals containing azobenzene and alkyl chains as terminal groups is studied. The target compounds of ethyl-4-{ 4- hexyloxyphenylazo )benzoate (compound 2), ethyl-4-{ 4-decyloxyphenylazo )benzoate (compound 3), and ethyl-4-(4-hexadecyloxyphenylazo)benzoate (compound 4) were prepared. These liquid crystals were prepared through several organic syntheses steps which are diazonium coupling and Williamson ether synthesis reactions. The yield obtained for all the compounds synthesized was in the range 70-80010. Infrared spectroscopy was used to identify the functional groups of all the intermediates and target compounds. IH NMR spectroscopy was carried out only for compound 2 in order to confirm its molecular structure. The mesomorphic behaviours of the target compounds were investigated using differential scanning calorimetry (DSC). The DSC thermograms reveal that only compound 2 is a liquid crystalline molecule as it exhibited mesophase. As for compounds 3 and 4, they are crystalline solids because no mesophase was discovered. The transition temperatures of these compounds were influenced by different lengths ofthe alkyl chains. 2008 Academic Exercise NonPeerReviewed text en https://eprints.ums.edu.my/id/eprint/20138/1/Preparation%20of%20liquid%20crystals%20containing.pdf Lee, Swee Ting (2008) Preparation of liquid crystals containing Azobenzene and Alkyl Chains as terminal group. Universiti Malaysia Sabah. |
| spellingShingle | QD Chemistry Lee, Swee Ting Preparation of liquid crystals containing Azobenzene and Alkyl Chains as terminal group |
| title | Preparation of liquid crystals containing Azobenzene and Alkyl Chains as terminal group |
| title_full | Preparation of liquid crystals containing Azobenzene and Alkyl Chains as terminal group |
| title_fullStr | Preparation of liquid crystals containing Azobenzene and Alkyl Chains as terminal group |
| title_full_unstemmed | Preparation of liquid crystals containing Azobenzene and Alkyl Chains as terminal group |
| title_short | Preparation of liquid crystals containing Azobenzene and Alkyl Chains as terminal group |
| title_sort | preparation of liquid crystals containing azobenzene and alkyl chains as terminal group |
| topic | QD Chemistry |
| url | https://eprints.ums.edu.my/id/eprint/20138/1/Preparation%20of%20liquid%20crystals%20containing.pdf |
| work_keys_str_mv | AT leesweeting preparationofliquidcrystalscontainingazobenzeneandalkylchainsasterminalgroup |