Shogo Kobayashi

Optically active ketones with intramolecular hydrogen bond

Abstract New ferroelectric liquid crystal compounds having an optically active alkanoyl group on one side and a chiral group derived from lactic acid on the other side of the core were synthesized. The new compounds with a three-ring core exhibit very large spontaneous polarization, when the signs of the spontaneous polarization due to the two chiral groups are the same. In particular, the compounds with an intramolecular hydrogen bond show larger spontaneous polarization as high as 1130 nC/cm2. The spontaneous polarization values are much greater than the sums of the spontaneous polarization for corresponding compounds having one of the two chiral groups. The dopant properties of the new compounds were also studied.

New Polymeric Ferroelectric Liquid Crystal with Two Chiral Groups

Abstract A new polymeric ferroelectric liquid crystal (PFLC) with an optically active alkanoyl group and a chiral group derived from lactic acid has been synthesized. The PFLC shows the smectic A phase, chiral smectic C phase and higher-order smectic phase, and exhibits large spontaneous polarization.

Polymeric ferroelectric liquid crystals with a 2-methylalkanoyl group-effect of substitution in the core benzene ring

Polymeric ferroelectric liquid crystals with a 2-methylalkanoyl group in their mesogenic side chains exhibit large spontaneous polarization and are expected to respond quickly to an electric field. We prepared and examined novel polymeric liquid crystals. They contained a 2-methylbutanoyl or a 2-methyloctanoyl group, in which the ortho position to the alkanoyl group on the core was replaced by a fluorine atom, a hydroxy group, or a methyl group. We studied the effect of the substitutions on their properties and found that they lower the clearing points. The low spontaneous polarizaion of the polymer that underwent the fluorine substitution can be explained by the electronegativity of the fluorine atom. IR analysis verified that the substituted hydroxy group formed an intramolecular hydrogen bond with the adjacent alkanoyl carbonyl group. The steric hindrance introduced by the methyl substitution increased the tilt angle and slightly increased the intermolecular distance between the mesogens.