Mesomorphic behaviour of N,N-dialkanoyl-3,4,5,6-tetramethylbenzene-1,2-diamines and related compounds
Autor: | Tomoyuki Akutagawa, Yoshio Matsunaga, K. Iuchi |
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Rok vydání: | 2000 |
Předmět: | |
Zdroj: | Liquid Crystals. 27:1399-1403 |
ISSN: | 1366-5855 0267-8292 |
DOI: | 10.1080/026782900750018537 |
Popis: | DSC, X-ray, broad-line proton NMR, and microscopy studies on several series of N,N' -dialkanoylbenzene-1,2-diamines are presented. The melting point and associated enthalpy are not much affected by methylation of the aromatic nucleus. While the dimethyl compounds carrying heptanoyl-to-hexadecanoyl groups generate metastable mesophases below 111oC, the 3,4,5,6- tetramethyl compounds carrying propionyl-to-hexadecanoyl groups produce stable hexagonal columnar mesophases appearing mostly above 200oC. N,N'-dialkylbenzene-1,2-carboxamides are transformed into birefringent viscous fluids exhibiting a focal-conic texture at a temperature between 76 and 99oC when the alkyl groups are decyl, undecyl, dodecyl, and tetradecyl. |
Databáze: | OpenAIRE |
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