| Autor: |
M. E. Neubert, K. Leung, M. R. Jirousek, M. C. Ezenyilimba, S. Sabol-keast, B. Ziemnicka-merchant, R. B. Sharma |
| Rok vydání: |
1991 |
| Předmět: |
|
| Zdroj: |
Molecular Crystals and Liquid Crystals. 197:21-41 |
| ISSN: |
1056-8816 |
| DOI: |
10.1080/00268949108029700 |
| Popis: |
The effect of a (CH2),CO2R' group on the mesomorphic properties of the esters where X= alkyl or alkoxy, Y=(CH2)nCO2R'(R'=C7 and C9) and n = 0–2 has been studied by synthesizing these esters and determining their mesomorphic properties by hot-stage polarizing microscopy. The starting phenols were prepared by esterification of hydroxy protected 4-hydroxybenzoic, phenylacetic or phenylpropionic acids. Both the benzyl and methoxycarbonyl protecting groups were tried with the latter giving higher yields when n = 0 because of better solubility of the protected acid. No mesophases were observed in the esters when n = 1, nematic and smectic A phases occurred when n = 2 and smectic A and C phases when n = 0. A few 1,4-cyclohexane diesters were also prepared using these phenols, The mesomorphic properties of these esters followed the same trend observed in the phenylbenzoates except no C phases were observed. Comparisons of the transition temperatures for these esters with those for Y=R' showed that both s... |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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