Tomonori Hanasaki

Syntheses and Physical Properties of Ferrocene Derivatives (I) Liquid Crystallinity of Ferrocene Derivatives Containing Cholesteryl Group

Abstract Nine kinds of ferrocene derivatives, [4-[ω-(cholesteryloxy carbonyl)alkoxy carbonyl]phenyl] ferrocene, were synthesized. Polarizing microscopy observations and differential scanning calorimetry measurements of these compounds were made in a wide temperature range. The liquid crystallinity was observed in the derivatives containing 2,4,6, 10, and 11 carbon atoms in the flexible alkyl chain of the compounds. An appearance of the liquid crystallinity was discussed with a conformation of the flexible alkyl chain which exerted a great influence on the molecular shape.

Syntheses and Physical Properties of Ferrocene Derivatives (II) Liquid Crystallinity and Multiple Melting Behavior of Ferrocene Derivatives

Abstract Nine kinds of monosubstituted ferrocene derivatives, ω-[4-(4-methoxyphenoxycarbonyl)phenoxycarbonyllalkyl 4-ferrocenylbenzoate, were prepared. The derivatives containing 4, 6, 10 and 11 carbon atoms in the flexible alkyl chain of the compounds showed liquid crystallinity, and multiple melting behavior was observed in the compounds containing 4, 6 and 11 carbom atoms. An appearance of the liquid crystallinity showed a carbon number dependence on the flexible alkyl chain.

Syntheses and Physical Properties of Ferrocene Derivatives (III) Liquid Crystallinity of Disubstituted Ferrocene Derivatives

A new series of 1,1′-disubstituted ferrocene derivatives, 1,1′-bis[4-[ω-(4′-methoxyphenoxycarbonyl)phenoxy]-alkoxycarbonyl]ferrocene, incorporating a variable carbon number of methylene chain units...

Syntheses and Physical Properties of Ferrocene Derivatives (IV) A Study on the Smectic Structure of Ferrocene Derivatives Containing a Cholesteryl Group

Abstract The smectic structure of ferrocene derivatives, [4-[ω-(cholesteryloxycarbonyl)alkoxycarbonyl]phenyl]-ferrocene (abbreviated to CAPF-n, n = 2, 4, 6, 8, 9, 10, and 11, the carbon number of the frexible alkyl chain), was studied by X-ray diffraction. The structure of CAPF-n having a shorter alkyl chain (n < 9) was different from that of a longer one. The derivatives containing 2, 4, 6, 8, and 10 carbon atoms in the flexible alkyl chain have a double-layer structure, while the derivatives having 9, 10, and 11 carbon atoms in the alkyl chain showed a quasi single-layer structure. CAPF-10 indicated both the double-layer and the quasi single-layer structures.

Syntheses and Physical Properties of Ferrocene Derivatives (VII) PhaseTransition Behavior and Liquid Crystal Structure of 1,1′-Disubstituted Ferrocene Derivatives

Abstract Liquid crystalline 1,1′-disubstituted ferrocene derivatives, 1,1′-bis[ω-[4-(4′-methoxyphenoxycarbonyl)phenoxy]alkoxycarbonyl] ferrocene (abbreviated hereafter to bMAF-n, n = 2∼12, where n is a carbon number of the methylene chain units), were synthesized, and their phase transition behavior was studied using a differential scanning calorimeter and a polarizing microscope. The liquid crystal structures of the compounds were investigated by the X-ray diffraction method. Nine of eleven compounds of the samples showed liquid crystallinity. The liquid crystalline phases were identified as a nematic (n = 3 and 5∼12), a smectic C (n = 5∼12) and a smectic F or I (n = 11 and 12). As a model structure of the smectic phase, a tilted structure with an expanded substituent is presented.

Syntheses and Physical Properties of Ferrocene Derivatives(V) a Study on the Phase Transition of Liquid Crystals Containing Ferrocene by x-ray PSPC System

Abstract The structure changes with the phase transition of liquid crystalline monosubstituted ferrocene derivatives, [4- ω(cholesteryloxycarbonyl)alkoxycarbonyl]phenyl]ferrocene, have been studied using a X-ray PSPC system. The results of the X-ray measurements agreed very closely with those of DSC measurements and polarizing microscopy texture observations. It was suggested that a layer structure existed in a crystal and a liquid crystal phases of the samples. The long spacing values were estimated from the PSPC data. The long spacing value of liquid crystal phase was not so much different from that obtained in our previous work. Consequently, the structure model of the liquid crystal phase previously presented can be applicable to this study. In addition to the liquid crystal structure model, the reasonable models of the crystals will be newly presented in this paper.

The phase transition behaviour and electro-rheological effect of liquid crystalline siloxane dimers

Symmetrical liquid crystalline dimers have been synthesised, composed of rod-like mesogenic units with polar groups and a siloxane core of varying length in the central region. All the dimers containing siloxane units have been shown to exhibit a smectic A phase, confirmed by polarising optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Rheological properties under an applied electric field were investigated by rotational rheometer. The influence of the siloxane core length on rheological properties has been investigated, and in addition the behaviour of the liquid crystalline dimers in the smectic A phase under an applied electric field has been observed by POM.

Syntheses and Physical Properties of Ferrocene Derivatives (XVI): Crystal Structure of a Liquid Crystalline Ferrocene Derivative, 5-[4-(4-Methoxyphenoxycarbonyl) Phenoxycarbonyl] Pentyl4-Ferrocenylbenzoate

The crystal structure of a monosubstituted ferrocene derivative, 5-[4-(4-methoxyphenoxycarbonyl)phenoxycarbonyl]pentyl 4-ferrocenylbenzoate was determined by the X-ray diffraction method using a single crystal. The unit cell of the crystal contained two crystallographically unequivalent molecules, A and B. The C 5 H 10 chain introduced into molecules A and B as a flexible spacer was an all-trans conformation. Both molecules were slightly bent around the ester group located at the nearest neighbor of the ferrocenylbenzoate section, but the shape of the molecules could be regarded as rodlike. This compound was a nonliquid crystalline compound; however, its structure was similar to that of the homologues, which gave rise to smectic liquid crystalline phases.

Syntheses and physical properties of ferrocene derivatives (XIV) dynamic viscoelastic property of liquid crystalline ferrocene derivatives containing cholesteryl group as a mesogenic one

Abstract The dynamic viscoelastic properties for [4-[ω-(cholesteryloxy carbonyl)alkoxycarbonyl]phenyl]ferrocenes with hexyloxy and octyloxy groups as an alkoxyl group were measured as functions of temperature and frequency. These samples showed liquid crystallinity. The results obtained here suggest that a kind of molecular order exists in the temperature range from the clearing point to about 20 degrees above it, in the liquid phase. Furthermore, the values of apparent activation energy in the liquid crystalline phase are as large as those of a primary dispersion of polymers, and its activation energy is not affected by the structural change at the clearing point.

Syntheses and physical properties of ferrocene derivatives (XIII) : Liquid crystallinity of ω-[4-(4-methoxyphenoxycarbonyl)phenoxycarbonyl] alkyl 4-ferrocenylbenzoate with octyl and nonyl groups as an alkyl one

Abstract Two monosubstituted ferrocene derivatives, 8-[4-(4-methoxyphenoxycarbonyl)phenoxycarbonyl]octyl 4-ferrocenylbenzoate (MPAF-8) and 9-[4-(4-methoxyphenoxycarbonyl)phenoxycarbonyl] nonyl 4-ferrocenylbenzoate (MPAF-9), were synthesized and their phase transition behavior was studied using a differential scanning calorimeter, a polarizing microscope and an X-ray diffractometer. MPAF-8 exhibited two liquid crystalline phases in both heating and cooling processes at approximately room temperature. In the heating process, a crystal-crystal phase transition behavior was ascertained. The phase transition behavior of MPAF-9 was very similar to that of MPAF-8 except for the behavior of the crystal-crystal phase transition in the heating process. In MPAF-8, one crystalline phase was transformed into another crystalline phase completely. On the other hand, this transformation was observed in part in MPAF-9, and as a result, the melting behavior was observed two times in the heating process.