Mesomorphic behaviour of four series of compounds derived from N,N′-dialkanoylbenzene-1,3-diamine
Autor: | Yukimasa Harada, Nobuhiko Miyajima, Yoshio Matsunaga, Seiji Sakamoto |
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Rok vydání: | 1995 |
Předmět: | |
Zdroj: | J. Mater. Chem.. 5:2305-2308 |
ISSN: | 1364-5501 0959-9428 |
DOI: | 10.1039/jm9950502305 |
Popis: | Syntheses, differential scanning calorimetric (DSC) and X-ray diffraction (XRD) studies were carried out on the following four series of compounds: the 5-methyl-2-alkanoyloxy, 4,5-dimethyl-2-alkanoyloxy, 2-methyl-5-tert-butyl-4-methoxy and 2,5,6-trimethyl-4-hydroxy derivatives of N,N′-dialkanoylbenzene-1,3-diamine. The high-temperature phases given by the first and second series are viscous fluids. On supercooling of the isotropic liquid, a hexagonal ordered columnar phase appears, as demonstrated by the XRD pattern. This behaviour is in sharp contrast to that of the 2,5-dimethyl-4-alkanoyloxy derivatives, which are isomeric with compounds of the second series and nematogenic. Many homologous members in the third and fourth series exhibit a nematic phase. The methoxy group introduced to the 4-position of the 2-methyl-5-tert-butyl derivative leads to a significant depression of the clearing point relative to the parent compound. |
Databáze: | OpenAIRE |
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