Mitsuo Fukumasa

New Ferroelectric Liquid Crystals Having 2-Fluoro-2-Methyl Alkanoyloxy Group

Abstract We have prepared ferroelectric liquid crystals with newly designed chiral part, 2-fluoro-2-methyl alkanoyloxy group. The physical properties of the ferroelectric liquid crystals having this chiral part are compared with those of other ferroelectric liquid crystals having 2-fluoro alkanoyloxy group, 2-trifluoromethyl alkanoyloxy group, 2-fluoro-2-trifluoromethyl alkanoyloxy group and 2-methyl alkanoyloxy group. The ferroelectric liquid crystals having 2-fluoro-2-methyl alkanoyloxy group show large spontaneous polarization, compared with other fluorinated ferroelectric liquid crystals. We have investigated the effect of the core structures on the spontaneous polarization. Introduction of a pyrimidine ring in the core part extremely enhances spontaneous polarization, over 400 nC/cm2. Moreover, we have also investigated the effect of chiral dopants of the compound having this chiral part.

Trifluoropropene oxide as a trifluoromethyl source. Preparation of optically active alcohols

Abstract Optically active 3,3,3-trifluoropropene oxide(TFPO) was converted to 1,1,1-trifluoro-2-ols via Grignard type or Friedel-Crafts type reaction. The regio-selectivity of the latter reaction was discussed through an MO calculation.

Asymmetric synthesis of α-methyl carboxylic acid derivatives. Stereochemistry in acidic ring opening of epoxides

Abstract Optically active α-methyl carboxylic acid derivatives were prepared via reaction of microbially produced epoxides with trimethylaluminum. Stereochemistry of the ring opening reaction was discussed through an MO calculation.

New ferroelectric liquid crystal having 2-methylalkanoyl group

Abstract A relationship between molecular structure and physical properties of newly prepared ferroelectric liquid crystals having 2-methylalkanoyl group is investigated by observing the phase transition temperatures, the spontaneous polarization, and the bistability. Carbon chain length is proved to play an important role not only in the thermal stability of the SC phase but also in the magnitude of the spontaneous polarization in this phase. A lateral fluoro substituent is efficient at producing more stable SC* phase and reducing the occurrence of higher ordered phases. Especially the lateral fluoro substitution at the ortho position to the chiral tail favors the uniform state and contributes to the bistability.

Poly-linked cyclopentadienide ions. 1. Synthesis and properties of tris(cyclopentadienyl)methane trianion

Abstract Tris(cyclopentadienyl)methane trianion has been synthesized via triferrocenylmethyl derivatives. The dynamic 1H NMR spectroscopy indicates the barrier to internal rotation of cyclopentadienido rings.

Different Effects of Alkyl Chain Length on Rotational Viscosity in Two Types of FLC Mixtures

In order to clarify the role of intermolecular interaction, effects of alkyl chain length on the rotational viscosity are investigated in two types of FLC mixtures: a totally chiral compound system and a chiral-compound-doped system. Only in the case of the chiral-compound-doped system does a long alkyl chain, which can produce the strong intermolecular interaction, provide the low rotational viscosity. In this system, ferroelectrically triggered orientation change of a small amount of chiral molecules induces the orientation change of a large amount of non-chiral molecules. It is suggested that the strong intermolecular interaction between the chiral and non-chiral molecules is required in order to amplify the molecular orientation change efficiently.