AnIa3¯dthermotropic cubic phase fromN-alkylpyridinium tetrahalocuprates
Autor: | Marianne Impéror-Clerc, Francesco Neve |
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Rok vydání: | 2004 |
Předmět: | |
Zdroj: | Liquid Crystals. 31:907-912 |
ISSN: | 1366-5855 0267-8292 |
Popis: | The thermotropic liquid crystalline behaviour of two N-alkylpyridinium tetrahalocuprates was investigated. The n-pentadecyl tetrachloro and tetrabromo derivatives (CU15-CL and CU15-BR, respectively) exhibit very similar behaviour on cooling, and specifically, a high temperature smectic phase followed by a cubic phase. We fully elucidated the Ia3¯d space group for the cubic phase from X-ray diffraction on single crystals. The type of cubic phase is still under discussion, but we suggest that it is a direct type of structure based on the known phase sequence of lower and higher homologues. A model for the local organization of CU15-CL and CU15-BR in the cubic and smectic mesophases is also proposed. |
Databáze: | OpenAIRE |
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