Phase transition behaviour of amphiphilic supermolecules possessing a semiperfluorinated alkyl chain

Recently we have found that a novel amphiphilic compound, 1H, 1H, 2H, 2H-heptadecafluoro-1-decyl 3, 4,5-tris[6-(4'-cyanobiphenyl-4-yloxy)hexyloxy]benzoate, exhibited the phase sequence of isotropic liquid -smectic A-bicontinuous cubic-crystal. In this study, we have prepared compounds possessing biphenyl groups or alkyl chains instead of the cyanobiphenyl groups of the amphiphilic compound and investigated their liquid-crystalline properties using optical microscopy and differential scanning calorimetry. The compound possessing the biphenyl groups was found to exhibit a columnar phase, however, the compound possessing the alkyl chains did not show any liquid-crystalline phase. We discuss the structure-property relationship in the amphiphilic oligomers.