Rahman, Md Lutfor and Jahimin Asik @ Abd. Rashid and Kumar, Sandeep P. and Sidik Silong and M. Z A Rahman (2009) Synthesis and mesomorphic properties of nonsymmetric liquid crystalline dimers containing azobenzene groups. Phase Transitions, 82 (3). pp. 228-239. ISSN 0141-1594
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Abstract
Four novel nonsymmetric dimers containing azobenzene mesogenic groups were synthesized. The nonsymmetric dimers compounds namely, ethyl 4-[(4-{4-(4-((4-nitrophenyl)diazenyl)phenoxy)alkyloxy}phenyl)diazenyl]benzoate were obtained from the alkylation of ethyl 4-[(4-(4-bromoalkyloxy)phenyl) diazenyl]benzoate with 4-[(4-nitrophenyl)diazenyl]phenol. The mesomorphic properties of the compounds were determined by DSC and polarizing optical microscopy. The first member of the series was nonliquid crystalline while all other homologues display nematic and smectic A phases. The trans-azobenzene groups of the dimers display a high-intensity -* transition at about 365 nm and a low-intensity n-* transition at around 465 nm, therefore, photochromism can be achieved by the introduction of the azo linkage to the dimeric liquid crystalline molecules.
| Item Type: | Article |
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| Keyword: | Azobenzene, Cis-trans isomers, Mesophase, Nematic, Nonsymmetric dimmers, Smectic |
| Subjects: | Q Science > QD Chemistry > QD1-999 Chemistry > QD901-999 Crystallography |
| Department: | SCHOOL > School of Science and Technology |
| Depositing User: | ADMIN ADMIN |
| Date Deposited: | 17 Mar 2011 12:14 |
| Last Modified: | 19 Oct 2017 14:50 |
| URI: | https://eprints.ums.edu.my/id/eprint/1540 |
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