Layer structures, 13. Chiral sanidic polyesters derived from 2,5-bis(alkylthio)terephthalic acids

Abstract

SUMMARY: Two chiral terephthalic acids were synthesized from (S)-2-methylbutane-1-thiol and bromoterephthalic acid or 2,5-dibromoterephthalic acid. A series of chiral polyesters was then prepared by polycondensation of silylated 4,49-dihydroxybiphenyl and mixtures of 2,5-bis(dodecylthio)terephthaloyl chloride and 2,5-bis((S)-2-methylbutylthio)terephthaloyl chloride. The copolyesters were characterized by elemental analyses, viscosity, DSC and X-ray measurements, and optical microscopy. Depending on the reaction conditions low and high molecular weights were obtained. In addition to a solid sanidic phase these polyesters form a chiral sanidic LC-phase and a chiral nematic LC-phase. However, in contrast to a normal cholesteric melt, these polyesters did not form a Grandjean texture but display the unusual "sausage texture".

Advances in synthetic optically active condensation polymers - A review

“…Sanidic PEs are PEs forming a layered supramolecular structure with the layer planes parallel to the main chain in contrast to the smectic systems where the layer planes are more or less perpendicular. Kricheldorf and coworkers [137] also synthesized a series of chiral PEs by polycondensation of silylated 4,4!-dihydroxybiphenyl and mixtures of 2,5-bis(dodecylthio)terephthaloyl chloride and 2,5-bis((S)-2-methylbutylthio)terephthaloyl chloride. The resulting coPEs were characterized by elemental analyses, viscosity, DSC and X-ray measurements, and optical microscopy.…”