In this study, we prepared Alkylamine-tropolone hydrogen bonding complexes and evaluated their characterization. The complex was found to show a thermotropic liquid-crystalline behavior. This liquid-crystalline property was caused from intermolecular and intramolecular hydrogen-bond interaction which derived from tropolone hydroxyl group. We attempted to measure ionic conductivity of hydrogen-bonding complexes, which basis of orderly structure.

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Side-end LCPs, in which mesogens are linked to the backbone by one of their end groups, show large ER effect. However, the response time for applied electric field is slow, because of their high inherent viscosity due to the smectic phase. On the other hands, side-on LCPs, in which mesogens are laterally attached to the backbone, exhibit nematic phase. In this work, side-on liquid crystalline polysiloxane was prepared in order to study phase transition behavior and ER effect. And it was found that side-on liquid crystalline polysiloxane shows large ER effect with quick response in nematic phase.

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We synthesized terthiophene derivatives as mesogens. These mesogenic groups were introduced to polysiloxane backbones by hydrosilylation. We investigated the hole transporting properties of the polymers.

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ER properties of polymeric and monomeric liquid crystalline compounds have been studied by many researchers. In such materials, the liquid crystalline polymers showed a remarkable ER effect [1]. However, the response time of polymeric liquid crystalline compounds is generally quite long. On the other hand, monomeric liquid crystalline compounds show relatively quick response, but small viscosity change under the electric field. Therefore, our attention is focused on oligomeric liquid crystalline compounds of which molecular weights are intermediate between polymeric and monomeric liquid crystalline compounds. In this study, the pentaerythritol derivative and the dipentaerythritol derivative have been newly synthesized. The phase transition behavior and the dynamic viscoelastic properties of the objective compounds have been studied, and the ER effect has been also investigated.

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Electro-Rheological(ER) fluids have been widely studied as smart materials for industrial utilities, because the viscosity is controlled by an applied electric field strength. On the other hand, silsesquioxane has a cubic structure which consists of a siloxane framework. A siloxane linkage is very flexible. Therefore silsesquioxane derivatives are expected to exhibit a high generated shear stress and a quick response. In this work, liquid crystalline silsesquioxane derivatives have been prepared in order to study the phase transition behavior. In addition, the ER effect and the dynamic viscoelastic behavior of the derivatives have been also investigated by using a rotational rheometer.

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In this study, 1,3-disubstituted ferrocene derivatives, 1,3-bis[ω-[4-(4-methoxyphenoxycarbonyl)phenoxy]alkyloxycarbonyl]ferrocene, were prepared. The phase transition behavior of these compounds are compared with that of 1,1 '-disubstitution ferrocene derivatives including the same substituent. The result obtained here is discussed from a viewpoint of liquid crystallinity influence by the positions introduced the substituents.

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The mono-substituted ferrocene derivatives containing biphenyl group in mesogenic one, ω- [4-(4-methoxybiphenoxy carbonyl) phenoxycarbonyl] alkyl 4-ferrocenylbenzoate, has been synthesized. Furthermore, the analogous compounds have been prepared with systematically changing the number of the carbon atoms in the flexible methylene unit. Their phase transition behavior has been studied by a differential scanning calorimeter and a polarizing microscope. The effect of an existence of the biphenyl group on their phase transition behavior and a comparison of the phase transition phenomena with that of ω-[4-(4-methoxyphenoxy carbonyl) phenoxycarbonyl] alkyl4-ferrocenylbenzoate will be discussed.

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Various liquid crystalline ferrocene derivatives have been synthesized hitherto as one of the typical metallomesogens, and most of the derivatives are symmetrically 1,1'- or 1,3-disubsitituted ones. The liquid crystalline phases of such compounds are stable enantiotropic phases, but are observed at relatively high temperature region. We previously designed some unsymmetrically and symmetrically 1,1'-disubstituted derivatives. In the case of unsymmetrical derivatives which have two different substituents at 1 and 1' positions, although the enantiotropic liquid crystalline phase was observed, the temperature range of the phase was not in the vicinity of ambient temperature. To obtain the compounds which show stable liquid crystalline phases near ambient temperature, we newly designed unsymmetrically 1,1'-disubstituted derivatives.

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We have investigated the molecular mechanism of the spontaneous and reversible deformation of smectic elastomers during the isotropic-to-smectic phase transformation, by observing the shape change as well as an X-ray image of the elastomers for two different types of crosslinker, namely, a rod-like crosslinker and a hydroquinone-type crosslinker. The elastomer crosslinked by the rod-like crosslinker exhibits elongation corresponding to the change in the order parameter S during the isotropic-to-smectic phase transformation. As for another elastomer crosslinked by the hydroquinone-type crosslinker, which is too flexible to work as mesogen, the shape change is weakly coupled with the orientational order of mesogens. We conclude that the crosslinking topology attributed to the chemical constitution of the crosslinker predominantly controls the chain anisotropy of polymer network as well as the deformation behavior of smectic elastomers during the isotropic-to-smectic phase transformation.

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In this paper, we have investigated piezoelectric properties of a SmC* elastomer, focusing on the mechanical response to electric excitation in the chiral smectic phases. In order to study some details of their piezoelectric properties, both of uniaxially and biaxially deformed samples of the SmC* elastomer were prepared for the measurements. Sample observation was carried out under rectangular electric waves which were applied parallel to the smectic layer between electrodes of silver conductive grease. Elongation and shrinkage along the layer normal (Dz) were estimated by a CCD camera system attached to a polarizing optical microscope. Fig. 1 shows the temperature dependence of the electric-field-induced deformation (Dz) in the uniformly aligned SmC* elastomer prepared by biaxially mechanical field. While Dz is smaller than 2.5 micron in a higher ordered smectic phase (SmX*), it is estimated at more than 10 micron in the SmC* phase because of the ferroelectricity. Additionally, we recognize a small Dz even in the isotropic phase, because the ordered structure is fixed by crosslinks.

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In order to align the director and the smectic layers a biaxial mechanical field consistent with the phase symmetry has to be used to achieve a macroscopically uniform orientation of untwisted smectic C* structure. So far, we succeeded in obtaining the monodomain SmC* elastomers by two successive uniaxial-deformation processes and by mechanical shear deformation. In addition, we have recently demonstrated that the monodomain SmC* elastomer obtained by a mechanical shear field exhibits a biaxial shape memory effect, which means spontaneous and reversible shear deformation occurs in a heating and cooling process where the successive phase transitions take place. In this paper, reversible deformation of another monodomain C* elastomer by two successive uniaxial-deformation processes has been investigated. By comparing deformation behavior between two monodomain SmC* elastomers, we recognize that the elastomers remember their deformation process in sample preparation.

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We prepared a novel lambda-shaped liquid crystal oligomer 1 possessing two phenylpyrimidine cores and a semiperfluorinated alkyl chain. The lambda-shaped compound exhibited an SmA phase, whereas the corresponding linear-shaped compound 2 showed an SmC phase. Then we investigated phase transition behavior of binary mixtures of compound 1 and lambda-shaped compound 3 possessing two cyanobiphenyl moieties.

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Poly(fumarate)s carrying tolane-based mesogenic side chains were obtained by radical polymerization of the corresponding fumarate monomers. The phase behaviors were comprehensively inverstigated by DSC, polarized optical microscopy, and X-ray diffraction analysis.

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A polymerizable benzoic acid derivative, 3,5-bis(propenoyloxymethyl)-4-hexadecyloxy benzoic acid was synthesized and complexed with dipyridyl compounds, 4,4'-bipyridyl, 1,2-dipyridylethane, 1,2-dipyridylethene, and 1,3-dipyridyl propane in the molar ratio of 2:1. All of the 2:1 complexes exhibited a monotropic smectic A liquid crystal phase. Their thermotropic behaviors and superstructures were investigated by polarized optical microscopy and X-ray diffraction. The complexes in the liquid crystal phase were photo polymerized by UV irradiation. after the polymerization, it was cofirmed that the multi layered structure was maintained.

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This is the first report that helical conjugated polymer, such as poly(meta-phenylene) derivative bearing chiral alkyl group in the side chain, serves as a chiral template to induce a chirality in nematic liquid crystal (N-LC). The N-LC dispersed on the chiral polymer substrate showed striped (finger-print) texture and cholesteric Grandjean texture, indicating a formation of chiral nematic LC (N*-LC). This means that the interfacial chirality transcription has occurred between the chiral polymer and the achiral N-LC. The N*-LC thus prepared enabled us to synthesize a helical polyacetylene, when it was used as an asymmetric solvent for acetylene polymerization.

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We report the synthesis and behaviors of achiral rodlike molecules possessing a bipenyl core at the center of molecule. The biphenyl part generates a twist conformation. We expected that a helical super structure was constructed by aggregation of the molecules with one chirality. Compound 3 exhibited enantiotropic nematic(N) and smectic C phases. Furthermore, formation of defect-lines was observed in the SmC phase. This suggested that a helical super structure was built spontaneously in the SmC phase.

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We have developed photoresponsive surface (liquid crystalline film) having azobenzene compounds in terms of micro manipulation, irradiation of light on the film caused the movement of solid particles placed on it. Then cholesteric liquid crystal, compensated nematic liquid crystal, and nematic liquid crystal having azobenzene compound induced by light were prepared. Under irradiation of ultraviolet light (366nm) or visible light (420 nm~), we could observed rotational motion, translational motion and both rotational and translational motion of micro particles on the surface of the cholesteric LC, the nematic LC and the compensated nematic LC films, respectively.

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Since a dynamic viscoelastic measurement is very sensitive to a structural change, this method can be utilized to a study on phase transition phenomena of low molecular weight liquid crystals. Previously, we reported on the dynamic viscoelastic properties of liquid crystalline ferrocene derivatives1) and those of biphenyl ones2). In addition, the dynamic viscoelastic properties of cholesteryl alkanoates (abbreviated hereafter to ChA-n, where n is the number of carbon atoms in the alkyl group, n=8-14) which are well-known liquid crystalline compounds have been measured as a function of temperature3). In this study, dynamic viscoelastic measurements of dicholesteryl alkanedioates (abbreviated hereafter to diChA-n, where n is the number of carbon atoms in the methylene chain, n=8-14) were performed in order to compare to those of ChA-n.

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Effect of the alignment condition on the electric field response was investigated.

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The chiral dopants having a spiro structure were synthesized from optically active 3,3'-(4H,4'H)-spirobi(2H-naphtho[1,2-b]pyran)-6,6'-dicarboxylic acid for nematic liquid crystals, and their helical twisting power (HTP) values were determined. It was found that the novel ester-linked spiro chiral dopants showed large HTP values. On the other hand, the ether-linked chiral dopants showed relatively small HTP values.

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Molecular realignments during the successive phase transformations of a binary mixture of smectogenic and aliphatic compounds has been studied. The layer spacing d, which is about 38 A in the crystal phase, abruptly increases up to 54 A during the phase transformation from the crystal phase to the smectic phase, because the aliphatic molecules are taken into the smectic structure during the transformation. A myelinic texture is observed in the smectic phase. In addition, the quadrupolar splitting is observed in the 2H-NMR spectra of the aliphatic compound (d8-octane) in the smectic phase, where the aliphatic molecules are averagely oriented in the direction parallel to the layer normal.

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The non-symmetrical dimeric liquid crystals containing two lateral fluorine atoms in the mesogenic group, 4-(4-fluorobenzoyloxy)phenyl 4-(4-n-hexyloxybenzoyloxy)-2,3-difluorophenyl decanedioate (abbreviated to 4FdiF-8) had been synthesized and discussed the phase transition behavior. In this study, the homologous compounds with systematically changing the length of the flexible methylene chain were prepared in order to discuss the effect of the spacer length on their phase transition behavior. In addition, we determined the molecular and crystal structures of 4FdiF-8 and its analogous compound, 4-(4-fluorobenzoyloxy)phenyl 4-(4-n-hexyloxybenzoyloxy)-2,3,5,6-tetrafluorophenyl decanedioate (abbreviated to 4FtF-8) by single-crystal X-ray diffraction method.

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Intermolecular ferromagnetic interactions in all-organic magnetic materials were observed only in the solid state at low temperatures. To investigate the intermolecular magnetic interactions in the liquid crystalline (LC) state of all-organic magnetic materials, we synthesized radical compounds 1 and 2 which contain a polar and chiral cyclic-nitroxide unit in the mesogen core and show an achiral or chiral nematic (N or N*) phase and an achiral or chiral smectic A (SmA or SmA*) phase, respectively, at higer temperatures. Here we report the unusual magnetic behavior of 1 and 2 in the LC phases.

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We report on the synthesis and self-assembly of novel supramolecular compounds composed of 3,4,5-trialkylbenzyloxybenzoic acid derivative and amino alcohol. The complexes showed hexagonal columnar and micellar cubic phases whose super structures were controlled by their alkyl-chain volumes and core compounds. The properties of their thermotropic liquid-crystalline phases were investigated by means of polarized optical microscopy, differential scanning calorimetry, and X-ray diffraction. Furthermore, nano-ball structures are prepared by photo polymerization of the monomer molecules in the micellar cubic mesophases.

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Liquid crystalline bolaamphiphiles were synthesized. Their thermal and orientational properties were examined. The liquid crystalline bolaamphiphiles exhibited smectic A, C, and F phases, due to the formation of hydrogen bonding networks.

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We synthesized single- or double-tail anionic surfactants having mesogen groups as a hydrophobic part, and studied their liquid crystal behavior as functions of temperature and solvent concentration. The surfactants with a cyanobiphenyl group formed a columnar or lamella liquid crystal under presence of water. Interestingly, the double-tail type of those surfactants showed myelin figures in water, that is, a tubular lamella liquid crystal having double helix.

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Six kinds of tetrapyrroles having C[SUB]5[/SUB]H[SUB]11[/SUB], C[SUB]8[/SUB]H[SUB]17[/SUB], or C[SUB]11[/SUB]H[SUB]23[/SUB] at the [I]meso[/I]-positions or the [I]beta[/I]-positions were synthesized. Self-assembly and alignment onto glass substrates of these tetrapyrroles were characterized by DSC, UV-vis spectrum, and XRD.As the alkyl chains are longer, the melting points of these compounds are lower. The [I]meso[/I]-substituted porphyrins are stacked in a [I]head-to-tail [/I]fashion, while the [I]beta[/I]-substituted ones are stacked in a [I]face-to-face[/I] fashion. These results help the design of self-assembled molecules for molecular devices.

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A pyrene derivative showing a shear-induced cubic-columnar phase transition is developed. On this liquid-crystalline phase transition, the photoluminescent color of the compound changes from yellow to blue-green under UV irradiation.

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Bistable [2]rotaxanes having mesogenic moieties at both ends were designed and synthesized. The [2]rotaxanes exhibited smectic liquid-crystalline phases over wide temperature ranges. The redox and spectroscopic properties of the [2]rotaxanes were studied.

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(1-Cyclohexenyl)phenyldiazene(CPD) undergoes the trans-cis photoisomerization as the well-known photochromic compound of azobenzene. In this study, we newly synthesized a CPD derivative possessing a cyano group and an alkyl chain. This compound exhibited a nematic liquid crystal phase at 35-60 degree C. Optical properties and photoresponse behavior will be presented.

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The mechanism on the photorefractive effect of ferroelectric liquid crystals was investigated through two-beam coupling experiments.

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We have developed new protecting agents for metal nanoparticles based on cyanobiphenyl compounds with various ligand groups, aiming at an improvement of metal nanoparticle-doped LC displays. Pd nanoparticles capped with these protecting agents have been prepared. The size distribution of nanoparticles was examined by an electron microscopy. Dispersibility in common organic solvents was also studied by light scattering behavior and microscopic observation. Moreover, the nanoparticles have been added to various liquid crystals such as 5CB and other practical LC materials. Properties of the LC composite such as miscibility and phase transition have been examined.

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Recently, organic-inorganic hybrid liquid crystals consist of monodispersed rod-like inorganic particles and organic liquid crystals have been reported. In this study, as monodispersed rod-like inorganic particles, we have synthesized titanium oxide nanoparticles. The organic-inorganic hybrid liquid crystals have been fabricated by hybridization of the nanoparticles with liquid-crystalline amines. To investigate the possibilities of the hybrid liquid crystals for the applications as optical materials, we have observed phase transition behaviors and have performed optical measurements such as transmittance and optical retardation. We will report the details including the orientation of the hybrid liquid crystals.

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we prepare the liquid crystal elastomers having macroscopic twist nematic orientation by cross-linkig in the presence of the nonreactive chiral dopant. Globally anisotropic deformation results from phase transition between the random and twist nematic oriented states.

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Dielectric properties of liquid crystal elastomers and liquid crystalline polymer were examined. The imaginary part of normalized dielectric constant of liquid crystal elastomer formed in nematic phase and in isotropic phase showed similar frequency dependence at higher than nematic-isotropic transition temperature. However they revealed distinct temperature dependence.

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Recently there have been some attempts to expand a temperature range of blue phases which is typically a few K. We have investigated a novel approach for expanding the stable temperature range of blue phases by using the liquid crystal mixtures with a broad coexisting temperature range of a nematic and isotropic phases. When two types of liquid crystal molecules with different molecular core length were mixed to each other, the mixture showed a broad coexisting temperature range of a nematic and isotropic phases. The temperature of induced blue phase by doping with a chiral molecule showed broader temperature range as the coexisting temperature range of the host mixture increased. However, a critical concentration inducing the blue phase decreased with increasing the fraction of liquid crystal molecule with a long core.

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The three dimensional structure of polymer-stabilized blue phase with the order of optical wavelength was non-destrutively investigated by confocal laser scanning microscope. The periodical patterns corresponding to the bcc lattice were observed not only surface but also internal region. The visualization mechanism was expected to be back scattering caused from liquid crystal order.

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Blue Phases (BPs) have three dimensionally ordered molecular alignments. Because of peculiar characteristics originating from these structures of BPs, they are expected to be applied for electro-optical devices and high-speed response display devices. However, an electric field-induced phase transition from BPs to a chiral nematic phase must be suppressed for such applications. The physical mechanism and dominating factors of the electric field-induced phase transition have not been much investigated so far. In this study, we investigated behavior of electric field-induced phase transition in BP by polarizing optical microscope observations, reflection spectra measurements and electric capacitance measurements.

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Blue phases (BPs) are known to exhibit optical stop bands in a visible range because they have a three-dimensional cubic structure with lattice periods of several 100 nm. Furthermore, since the diffracted wavelength of BPs can be shifted by external electric fields. BPs are expected to be applied for tunable photonic crystals. We have succeeded in expanding a temperature range of BPs from generally ca. 1 ^oC to 11 ^oC on heating when an asymmetric dimer with mesogenic- and nonmesogenic-groups was added to BP. In this study, we investigated structural analyses and electric-field response behaviors of BPs with an extended temperature range.

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A few years ago, Nishiyama et al. synthesized new chiral twin molecules exhibiting two anomalous mesophases. The mesophase at the higher temperature region (MSUB>1 phase) exhibits optical isotropy and shows the diffraction peak suggesting the layer structure in the X-ray measurement. On the other hand, the parquet-like texture was observed in the mesophase at the lower temperature region (M₂ phase). The M₂ phase also shows clear spot-like diffraction patterns suggesting 3D periodicity similar to the SmQ phase. In this study, we more precisely discuss structures of these liquid crystalline phases by using X-ray diffraction experiment.

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When we add some perfluorinated terminal chain to usual thermotropic liquid crystals, some new phase behavior appears with micro phase separation. We synthesized a liquid crystal BI which is a cyanobiphenyl liquid crystal with perfluorinated terminal chain. BI shows Smectic-A phase and Smectic-C phase. When we diluted BI with perfluorinated oil, we found that the layer spacing can extremely swell and reaches about three times length of pure BI. And surprisingly SmC phase of BI is maintained in that hyper swollen phases.

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Ferroelectric liquid crystals (FLC) have attracted considerable attention in the field of electrooptic devices because of quick electrooptic response. So far electrooptic effects of a free-standing film of FLC in air have been reported(1). In this study, a FLC film underwater is prepared successfully. The SmC* phases are observed in the FLC film underwater, and the electrooptic effect can be observed. The cell is minimum unit of living things, and has certain electric potential difference between inside and outside of membrane. It is called a cell membrane potential. We are trying to measure the potential by the electrooptical effect of the FLC film.

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Tetraarylethylenes display interesting chemical and physical properties. Tetraarylethylene has a flat aromatic core whose derivatives exhibit discotic columnar phase because of intermolecular pi-pi interaction between aromatic cores. In addition, microsegration of the polar cores from non-polar alkyl side chains also contributes to show mesophase. In this study, amphiphilic molecules with tetraarylethylene were newly synthesized and then the phase behavior and the electrochemical property were investigated.

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We examined the molecular assembled structures and ion-conductive properties of cellulose derivatives having imidazolium moieties. Alignment of the polymer chain was achieved by mechanical shearing, resulting in the enhancement of ionic conductivities.

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We have designed and synthesized fan-shaped ammonium salts. Self-assembly of these molecules through nanosegregation and ionic interaction leads to the induction of liquid-crystalline (LC) bicontinuous cubic phase forming continuous ionic channels. The ion-conductive behavior of these samples reveals that these ionic LC having interconnected ion-channels function as efficient ion transporting materials.

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It has been reported that CT complexes showed different liquid crystal phases depending on the strength of CT interactions using disk-shaped molecules. It is therefore expected that liquid crystal phases can be controlled by changing strength of CT interaction with redox reaction. In this study, we investigated CT interaction of rod-shaped molecules in which an electron donor and an electron acceptor are linked by a flexible chain.

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Three kinds of 2-oxo-2H-chromen-6-yl 4'-Alkoxy-biphenyl-4-carboxylates were prepared and their physico-chemical properties are investigated. These compounds exhibit smectic A and/or nematic phase in bulk state, and can gelatinize several organic electrolyte solutions containing lithium perchlorate (LiClO₄) as a supporting salt. The organic gel electrolytes are thermo-reversible and the sol-gel transition temperatures depend on the physical properties of the electrolyte solutions.

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(Polymer/liquid crystal) composite films in which a liquid crystal is filled as a continuous phase in a three-dimensional spongy polymer matrix show the light scattering-light transmission switching by the external electric field. In general, the light switching of the (polymer/liquid crystal) composite films is performed in the visible region. In this study, we investigated electro-optical properties of (polymer/liquid crystal) composite films including a dichroic dye which absorb the infrared light in the near infrared region. The high contrast switching was actually observed for the dichroic dyes doped (polymer/liquid crystal) composite films in the wavelength of 1300-1500 nm.

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We prepared some amphiphilic compounds possessing a cyanobiphenyl moiety, and investigated their liquid-crystallinity and anticancer activity. The compounds were tested against A549 human lung carcinoma cell lines. The compounds with a nematic phase showed inhibition of cell proliferation. The anticancer activity was found to depend on the alkyl chain length. We discuss relationship between liquid-crystallinity and anticancer activity for the amphiphilic compounds.

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Amphiphilic mesogenic compounds were evaluated regarding their potential for platelet production from mature megakaryocytes by culturing of CD34+cells derived from normal human prepheral blood. 4-(4-Octylphenyl)benzoic acid and 5-hydroxy-2-{4-(4-hexyloxyphenyl)phenyl}pyrimidine led to a significant increase in platelets. We discuss their promorting activity on thrombopoiesis.

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