Diacetylenic Liquid Crystals: A Systematic Investigation of the Homologous Series of 4, 4¹- Dialkanoyloxydiphenyldiacetylenes

Abstract

Abstract The homologous series of 4, 41 -dialkanoyloxydiphenyldiacetylenes with n ranging from zero to ten have been prepared. Optical microscopy, differential scanning calorimetry and X-ray diffraction have been used to study the mesomorphic behavior of these compounds. All homologs with n=1-7 are liquid crystals having nematic phases. In addition to nematic phases, these esters have extensive solid-state polymorphism. The transition enthalpies and entropies have also been calculated.