Liquid Crystal and Crystal Structure of Octahomotetraoxacalix[4]arenes

Octahomotetraoxacalix[4]arenes bearing long alkyl chains on their lower rim were prepared. Ester 4a
existed in a 1,2-alternate conformation in its crystal structure, which was examined by single-crystal
X-ray diffraction analysis. To prepare liquid crystalline materials possessing calixarene moieties by self-assembling, carboxylic acid derivatives 5 were synthesized. Among them, 5c, the octadecyloxy derivative,
showed smectic liquid crystal phase. Homooxacalixarenes 5 also formed liquid crystal phases with longer
layer distances when two equivalent moles of 1,2-ethylenediamine were added as a linker. These phases
were investigated with X-ray diffraction, differential scanning calorimetry, and polarized optical
microscopy.