The lutetium sandwich complexes (n=8-16) in the title were synthesized to obtain discotic liquid crystals showing both spontaneous homeotropic alignment and high mobility. Recycling HPLC effectively separated the double-deckers and triple-deckers. The amount of triple-deckers was too short to study their physical properties. The double-deckers show one Colh, two Cub and one Coltet mesophases under n=13, and a Colr mesophase over n=14 instead of the Colh mesophase. Interestingly, the Coltet mesophases over n=10 exhibit spontaneous homeotropic alignment.

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We have studied positive charge carrier transport in each domain of poly domain texture in discotic hexagonal plastic phase of triphenylene derivative, Hexabutyloxytriphenylene (H4T). We observed transient photocurrent with multi-kinks in polydomain texture having large domains over a few mm, some of which indicated a slower transit than that corresponded to the mobility of 10-2 (cm2/Vs) reported previously. It was clearly shown that the mobility in a perfect homeotropic domain is 10-2 (cm2/Vs), on the other hand, that in a tilted domain is 10-3 or 10-4(cm2/Vs) by proving each domain with a selective illumination technique in time-of-flight experiments.

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The hole transport in smectic phases of phenyl-naphthalene derivatives doped with impurities, i.e., thiophene derivatives, was characterized by time-of-flight(TOF) technique. We discuss the experimental results on the effect of impurities in terms of the trap depth of impurity and its effect in different smectic phases.

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An azimuthal anchoring of the rubbed PVCi film increases by irradiating with the unpolarized UV light. Therefore, we can pattern the LC alignment with different twist angles in the cell which is fabricated using the PVCi surface irradiated with the different amount of UV light dose. The twist angle can also be controlled by irradiating with the film the UV light after the LC cell fabrication. The properties of the anchoring strength increase are discussed in the case where the surfaces in contact with and without the LC are irradiated with the UV light.

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We propose a novel technique for determining the four cell parameters such as cell gap, tilt angle, twist angle of the director alignment, and the angle between the axis of the polarizer and the entrance LC director. Applying renormalized transmission spectroscopic ellipsometry (RTSE), the evaluation of director profile in the case of twisted nematic cell with relatively high pretilt angle were performed. Using these parameters, we detemied the azimuthal anchoring strength.

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One and two-dimensional periodic surface relief grating structures were fabricated on the glass substrates by a photolithography technique in which a negative type photo-resist was used. Stable homeotropic alignment was observed just below an I-N phase transition point in a sandwich cell having surface relief grating structure on surfaces. The molecular alignment in the cell strongly depends on temperature.

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Nematic liquid crystal director orientation in the vicinity of a glass substrate is evaluated in terms of the acoustic phase change of a shear horizontal(SH)wave propagating in a cell structure. The response times of the director orientation change under application and removal of voltage are compared with the results from optical measurement. The decay time of the director change is shorter than that from the optical measurement by two order of magnitude.

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Organic monolayers at the air-water interface show the characteristic surface polarization phenomena, such as spontaneous polarization and non-linear polarization, due to their asymmetric structure. Maxwell displacement current (MDC) and second harmonic generation (SHG) measurement can detect these surface polarization phenomena, thus allows us to analyze the structure of monolayers. In the present study, the liquid crystalline properties of the monolayers, such as flow orientation and the flexoelectric effect, are investigated by MDC and SHG. It is concluded that monolayers at the air-water interface have the liquid crystalline property as well as the crystalline property.

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The zigzag instability coarsening of splay-bend walls formed in a nematic liquid crystal under external fields is investigated experimentally as a study of one-dimensional analog of spinodal decomposition. When the zigzag instability occurs, a sinusoidal modulation appears firstly. Then the higher harmonics of it progressively grow up as time goes on and the shape of wall changes to zigzag. We have analyzed the time evolution of the sinusoidal modulation in the early stage of coarsening and found that the sinusoidal modulation develops exponentially up to an equilibrium value as expected in the theory of spinodal decomposition.

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THz time domain spectroscopy is a newly arising spectroscopic technique for evaluating refractive indexes and absorption coefficients of materials in THz(far infrared) region. Organic molecules posses low frequency vibrational and rotational absorption in this region. These absorptions can reflect the state of aggregation and the dynamical motion of molecules; accordingly THz spectroscopy can be a useful tool of studying molecular packing and motion in liquid crystal phases. We measured polarized THz spectra of MBBA and BBBA in nematic and isotropic phases to confirm the validity of THz spectroscopy in this field. Both materials show polarization dependence in their spectra at the nematic phase. These spectral features suggest the validity of this technique for studying liquid crystals.

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Introduction of the chirality has a fascinating effect on producing various kinds of superstructures. Chiral molecules generally favor to form a helical superstructure, of which the periodicity can be adjusted by changing the degree of chirality. 3D structures can also been seen in some chirality-driven frustrated phases. In this study, chiral twin molecules possessing two chiral centres at both peripheral ends were designed in order to produce strong chirality, of which the core structures were also systematically modified so that the strength of the layered structure can be tuned. Decrease in the layer strength resulted in the emergence of the anomalous SmQ and sponge phases, which showed 3D superstructures.

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We synthesized new chiral dopants having two trifluoromethyl asymmetric frames derived from an optically active 2-(6-methoxy-2-naphthyl)propanoic acid (Naproxen). Some dihydroxy aryl compounds such as dihydroxy benzene, dihydroxy naphthalene and dihydroxy biphenyl were used as the central cores. Their central cores and chiral parts were linked by ester or ether bond. It was found that the helical twisting power (HTP) values of new chiral dopants were affected by the substituted positions of the chiral parts, the central core, and the types of linkage. The dichiral dopants (CDP1,4, CDP1,3, CDP1,2)derived from the benzene core and that (CDN1,4, CDN1,3, CDN2,3)derived from the naphthalene core showed a similar tendency for the HTP values.

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All-organic paramagnetic liquid crystals are of great interest regarding the possibility of reorientation of molecules by low applied magnetic fields. In addition, introduction of chirality to paramagnetic liquid crystals may give rise to ferroelectricity and thereby the cooperative effect between the magnetic and electric anisotropy. To develop chiral paramagnetic liquid crystals, several racemic and enantiomerically enriched nitroxide mesogens have been prepared. EPR spectroscopy indicates that the g values of the racemates showing only a nematic phase decrease after crystal-nematic phase transition upon heating; this should be ascribed to the reorientation of the LC molecules by the external magnetic field. Application of electric fields to the SmC* phases has induced spontaneous polarization bringing about ferroelectricity.

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We have studied metal complexes as a chiral dopant for nematic liquid crystals, aiming also at producing a new type of chiral metallomesophases. In this work, we have looked into the dopant behaviors of a range of homologues of chiral Ru(III) complexes, a prototype complex of which was studied previously and displayed a remarkably high HTP.

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Optically transparent and isotropic liquid crystalline composites were successfully prepared by in-situ photo-polymerization of cross-linking monomers in the isotropic phase of chiral liquid crystals. The electro-optical Kerr constant of the composite steeply increased with decreasing temperature in accordance with a pretransitional behavior expressed by the Landu-de Gennes theory in a temperature range of the isotropic phase. This is due to thermal growth of the coherence length of short-range orientational order of the liquid crystal molecules. Even in a temperature range below the critical temperature where the coherence length grows infinitely and the Kerr effect originating from the pretransitional phenomenon disappears in case of common nematics, the composite showed the remarkable Kerr effect being relatively insensitive to temperature. The results indicate that the growth of the coherence length was effectively suppressed by polymer network and chirality of the liquid crystals below the critical temperature.

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We have investigated manufacturing the color filter for liquid crystal display using cholesteric liquid crystal with photosensitive chiral compounds. We selected the (E)-cinnamates of isosorbide or isomannide as photosensitive chiral compounds because the HTPs(Helical Twisting Power) before photo-irradiation were similarly high. On the other hand, after photo-irradiation, the HTP of isosorbide derivative was lower than the HTP of isomannide derivative. We synthesized all geometric isomers of these compounds and obtained HTPs.

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The cubic (Cub) phase structure of 1,2-bis(4-n-alkoxybenzoyl)hydrazines (BABH-n, where n is the number of carbon atoms in the alkoxy group) was examined. The X-ray diffraction results revealed that, similarly to the n=8 homologue, all Cub phases for n=9-12 are of Ia3d type, with a good linear relationship of the lattice constant (a) with n. The value of (1/a)(da/dT) was positive for n=9-12 except the cooling process of n=12. The infrared spectral studies showed a slight different tendency for the hydrogen bonding dissociation of N-H groups between the homologues with n=9 and 10, and higher. The difference may be explained in terms of the average molecular shape dependence on n.

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The electro-optic Kerr effect caused in optically isotropic substances is known to show extremely fast response as optical shutters. However, the magnitude of the induced birefringence in conventional substances has been too small to be applied to flat-panel displays. We report the large electro-optic Kerr effect in the polymer-stabilized blue phase which exhibits a liquid crystalline blue phase in a wide temperature range. For the flat Kerr cells containing the polymer-stabilized blue phase, micro-second optical switching was demonstrated. The achievements can contribute toward providing new flat-panel liquid crystal displays with high speed response and without rubbing process in the fabrication.

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[in Japanese]

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Thermotropic ionic liquid crystals with a pyridinium skeleton were synthesized and the effects of counter ions for the liquid crystal formation were examined. The liquid crystal formation depended on counter anions. The thermotropic ionic liquid crystal with chloride anion showed columnar, cubic, and smectic A phases. A polyacrylate counter ion enhanced the thermal stability of the cubic phase. A tartrate ion led to the formation of a columnar phase with the enhanced thermal stability.

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Cholesteric blue phases (BPs) are kinds of liquid crystal phase, which have a three dimensional periodic structure of several hundreds nanometers. BPs are applicable to self-assemble photonic crystal. In this study, preparation methods to create large size monodomains of polymer-stabilized cholesteric blue phases were investigated because large single monodomains are required for applying to various optical devices such as a photonic crystal. We examined the effects of surface conditions, electric field and chirality on the cholesteric blue phases.

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The physical properties of LC mixtures containing novel liquid crystalline 1,7,8-trifluoronaphthalenes with negative dielectric anisotropy for VA-LCD were measured. The LC mixtures with different birefringence (0.10-0.12) show low viscosity, and the response time for VA-LCD are discussed.

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Voltage Holding Ratio (VHR) and impurities of liquid crystalline materials recovered from LCD panels have been measured to examine technical feasibility of recycle of the materials. We found that VHR strongly depends on recovery-method of the materials and that the impurities can be eliminated by purifications. The optimized purifications open possibility of the recycle.

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We previously synthesized the octakisdialkoxyphenoxy-substituted phthalocyaninato copper(II) complexes 1 exhibiting seven different mesophases. In this study, we have successfully synthesized novel discotic liquid crystals of the octakisdialkoxyphenoxy-substituted tetrapyrazinophorpyrazinato copper(II) complexes 2. The molecular structural difference between 1 and 2 is very small only on the number of nitrogen atoms in the core. However, the complexes 2 exhibit only one mesophase in contrast to the previous complexes 1. The mesophase of the complexes 2 could be assigned as a novel pseudo-hexagonal columner phase Colrh(C2/m). Very interestingly, each of the complexes 2 changes color of the mesophase from purple to green with elevating temperature.

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A series of the novel triphenylenes with polymeries functional groups in the terimal part of peripheral chains was synthesized to show hexagonal columnar (Colh) mesophase. The charged carrier mobility was evaluated by Time-Of-Flight (TOF) method to reveal that the mobilities are in the order of 10-4cmVs-1.This result is in the same order of the mobility alkoxyl for triphenylene analogues. In the (Colh)phase, the positive carrier mobilities exhibited positive temperature-dependence.

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A disc-shaped triphenylene derivative with terminal functional groups at the adjacent two long chains was synthesized in order to qualitatively investigate on the correlation between hexagonal columnar mesomorphism and rotational dynamics of molecule around the columnar axis. A new behaviour of mesophase with hydrogen bonding interaction was found that. An extraordinary change of Colh mesophase to a more highly ordered mesophase is caused in an isothermal condition by a way of a thermodynamical relaxation process which is strictly affected by the initial state of the Colh mesophase in relation to the intermolecular hydrogen bonding interaction.

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General liquid crystals have a rod-like or disk-like rigid core and flexible long chains in the periphery. However, about 100 years ago, in 1911, Vorlander reported liquid crystalline properties of alkali metal carboxylates having neither a rigid core in the center nor flexible long chains in the surroundings. These liquid crystalline compounds have long been forgotten to clarify the mesophase structures. Here we have revealed these mesophase structures for the first time. The molecular shapes are "flying-seed-like" and they exhibit very unique mesophase structures.

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It is reported that the minimum numbers of rings of the core in polycatenars are required to be four for tetracatenars and at least five for penta- and hexa-catenars. In this paper, we report the mesomorphic properties of a three-ring polycatenar system with seven- and six-membered rings with two ester groups, two amide groups, and one amide and one ester group as connecting groups. Troponoid tetracatenars with two amide groups and an amide and an ester group showed Colh phases and the benzenoids did not. All troponoid hexacatenars and the benzenoid hexacatenars with an amide and an ester group showed Colh phases.

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Alignment change of liquid crystal domains induced by infrared irradiation was investigated for a plastic hexagonal columnar mesophase of a liquid crystalline triphenylene derivative. A uniform and anisotropic alignment change of domains was observed when a polarized infrared light corresponding to the wavelength of the aromatic C-C stretching absorption band of triphenylene core was irradiated. The results strongly imply that the infrared irradiation is a possible technique for device fabrication by use of plastic columnar mesophase as a liquid crystalline semiconductor.

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Anisotropic photoreaction and orientation control in photocrosslinkable polymer liquid crystal film were performed based on axis-selective two-photon excitation and following triplet energy transfer, using a linearly polarized femtosecond pulse laser at a wavelength of 800 nm. Molecular orientation was controlled parallel to the polarization of the laser with in-plane order parameter of +0.75. Superior axis selection for the two-photon excitation of the triplet photosensitizer compared to that for one-photon excitation led to great reorientational value of the film.

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We have prepared novel non-symmetric dimeric liquid crystals where cyanobiphenyl and pheylpyrimidine moieties are connected via a dihydroxybenzene and investigated the transition behavior. A flexible dimeric liquid crystal possessing a 1,3-dihydroxybenzene derivative in the spacer group was found to show an unusual phase sequence of I-N-SmA-SmCanti. Furthermore, a polar non-symmetric bent molecule where the two mesogenic groups are connected via 1,3-dihydroxy-5-methoxy benzene has been prepared. We discuss the structure-property correlations for the flexible bent molecular system.

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A novel U-shaped liquid-crystalline molecule where two polar mesogenic groups are connected via catechol, 1-{6-(3,4-difluorophenyloxy)hexyloxy}-2-{6-[4-(4-fluorophenyl)phenyloxy]hexyloxy}benzene, has been prepared and the electro-optical properties investigated. A threshold voltage of a nematic mixture consisting of a host nematic liquid crystal and 10wt% of the U-shaped compound was found to be markedly lower than that of the host LC. We discuss structure-property correlations of the U-shaped liquid -crystalline system.

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We reported that a novel lambda-shaped molecule in which a cyanobiphenyl and two phenylpyrimidine groups are connected to 3,4-dihydoroxybenzoic acid exibits an incommensurate SmA phase. In the present study, we have investigated effect of the spacer length on the phase transition behaviour. XRD studies indicated that the lambda-shaped compounds having lower spacers showed an interdigitated SmA phase but the compounds having longer spacers an intercalated one, suggesting that appearance of the incommensurate SmA phase results from competition between interdigitated and intercalated layer structures.

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The synthesis and characterization of achiral banana-shaped compounds with a seven-membered ring as a central core are reported. One of the advantages to use a seven-membered ring is to make the bend angle shaper. Further, the seven-membered ring has an electro-withdrawing carbonyl group at the central position, which could play a role to induce a B7 phase. In fact, 1,3-bis[4-(4-alkyloxyphenyliminomethyl)-benzoyloxy]tropones show banana phases. From the observation of the optical texture, the phase at higher temperature is assigned to be B7 phase and the phase at lower temperature SmCsP phase.

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Heat capacity of the title compound was measured by adiabatic calorimetry on bulk sample below 400 K. The as-prepared crystal is metastable around its melting temperature to the cubic phase. The cubic phase is also metastable. There is the other, thermodynamically stable crystalline phase, which undergoes a phase transition below room temperature. The as prepared crystal shows below room temperature a trapezoidal anomaly in temperature dependence of heat capacity. The thermal effects are very small in the Col - SmAd and SmAd - IL phase transitions as previously observed through DSC experiments. An anomalous increase in heat capacity is observed a few K below the SmAd - IL phase transition, around which the layer spacing was reported to start decreasing.

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The homologous series of 3H-benzofuran-2-one-5-yl 4-alkoxybenzoates (1), 4-alkoxybiphenyl-4'-carboxylates (2), and 4-alkylbenzoates (3) are synthesized and their physico-chemical properties are examined. Compounds 1 and 2 show a nematic (N), smectic A (SmA) and/or smectic C (SmC) phases, while 3 are non-mesogenic even in a rapid cooling process. The layer spacing of SmA phase was examined by a small angle X-ray diffraction study, and the results are compared with molecular structures calculated by a semi-empirical molecular orbital calculation.

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A dichiral liquid crystal molecule M7BBM7 is known to show the SmQ three-dimensional liquid crystal phase which has tetragonal symmetry.Quite recently, a novel compound similar to this M7BBM7 was found to show the sponge phase at the higher temperature side to the SmQ phase.In this study, we have tried to approach the three-dimensional structure of the SmQ phase of the M7BBM7 molecule with using molecular simulations.

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A microscopic model for interpreting remarkably high helical twisting power (HTP) of metal complexes as a chiral dopant is proposed. The intermolecular interaction of a triad system consisting of a dopant and two host molecules located near its chiral center has been calculated for this purpose. The dopant molecule studied here is D-[M(acac)2L] (L= dibenzoylmethanate substituted with n octyloxy groups), and the host molecule is N-(4-methoxybenzylidene)-4-n-butylaniline (MBBA). D-[M(acac)2L] is regarded as a modified three-bladed propeller, interacting with host molecules through its bulky ligands. The stable structure has been obtained by geometry optimization using Gaussian 03, and the interaction energy assessed as a function of twisting angle between two host molecules. The results provide a simple explanation for the extremely high HTP as observed for this type of a chiral dopant.

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Anisotropically ion-conductive liquid crystalline (LC) chemical gels have been prepared by photopolymerization for the complexes of ion-conductive liquid crystals, lithium salts and polymerizable compounds. The X-ray diffraction measurements and the field-emission scanning electron micrographs revealed that the LC gels have highly oriented hierarchical phase-segregated structures in nano- and micrometer levels. These organized LC gels have potentials for the application as a new type of ion-active materials. The structural analysis and anisotropic ionic conductivities are discussed.

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The miscibility of main-chain liquid crystalline polymer (LCP) with some amorphous polymers was investigated for the blends prepared by solution casting. It was found that LCP was miscible with styrene-acrylonitrile random copolymers (SAN) which have AN content from 4 to 7 (SAN4~7). Both blends of LCP with PS and with SAN19 were phase-separated via the spinodal decomposition. The immiscible blend system of LCP/SAN19 was applied to the scattered polarizing plate by controlling phase-separated morphology and orientation of LCP molecules, which were aligned parallel to the rubbing direction by applying magnetic field. For the miscible blend system of LCP/SAN6, the control of the birefringence was attempted and it was shown that the wavelength dispersion of birefringence became smaller than that of neat LCP. This result suggests the possibility to a new mono-layer retardation film which has larger birefringence in larger wavelength.

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The liquid crystalline phase of polyolefins was first discovered in poly(methylene-1,3-cyclopentane) (PMCP), obtained by cyclization polymerization of 1,5-hexadiene (HD) using a zirconocene catalyst. PMCPS clearly show fluidity and briefrigence above the glass transition temperature, and the texture derives from nematic liquid crystalline phase. The high cyclization selectivity of HD units and high trans-content of 1,3-cyclopentane unit are needed to induce the liquid crystalline phase.

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Novel 1,7,8-trifluoronaphthalene derivatives were designed for applications with negative dielectric anisotropy and were prepared through the regioselective fluorination and lithiation of fluorinated naphthols. These compounds exhibited large absolute value of dielectric anisotropy and large birefringence, compared with corresponding difluoronaphthalene and difluorotetrahydronaphthalene derivatives.

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Rod-like liquid crystalline compounds 1-3 possessing an amide group and an m- or p-substituted alkoxy chain were synthesized and their thermodynamic behaviors and layer structures were investigated. Molecules in the smectic C phase of 1 were organized partially into a synparallel aggregation with the weak lateral intermolecular hydrogen bonding in the layers. On the other hand, molecules in the smectic Cx phase of 2 were self-assembled into the synparallel organization with the strong intermolecular hydrogen bonding. Additionally in the case of 3 which has a spacer between the amide group and the spinning core, the molecules generated a highly ordered smectic phase (n = 5, SmCx) and a chiral cubic phase (n = 10).

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2H-Chromen-2-one-6-yl 4-alkoxybenzoates(1) and 4-alkoxybiphenyl 4'-calboxylates(2) were synthesized and the LC properties and the gelation abilities were examined. Compounds 1 and 2 reveal smectic A and/or nematic phases, and gelatinize various organic solvents such as cyclohexane, 1-octanol, and acetonitrile. The transition between the gel phase and the isotropic fluid is thermally reversible. The images of gel observed with SEM show fine fibers and small pores which are considered to be occupied with organic solvents. The polar effect of the terminal lactone group and/or solvophobic one between organic solvent and molecule are supposed to play important role for gelation.

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Recently, we have focused on developing supramolecular liquid-crystalline (LC) materials based on biomolecules. Here we report on chiral columnar liquid crystals of oligo(glutamic acid) derivatives having pyrene moieties. One-dimensionally organized columns containing pyrene inside are expected as functional materials with photo- and electronic properties. The compounds form chiral columnar liquid crystals in which helically stacked pyrenes are involved. Charge-transfer complexes of pyrene derivatives and electron acceptor molecules (2,4,7-trinitrofluorenone, TNF) show LC structures over wide temperature ranges by alternate stacking. Intermolecular hydrogen bonds of glutamic acid parts play important roles in stabilizing mesophases, and in transferring supramolecular chirality.

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Preliminary results of dynamics in smectic phases of banana-shaped molecules using Teraherz spectroscopic technique are reported. The terahertz (THz) waves, categorized between millimeter radio- and middle infrared light- waves, and some rapid molecular motion and segmental motion reflecting intermolecular interaction are expected to be obtained in the THz region. In P-8-PIMB, transmittance of the THz region is strongest in the crystal phase, and that in the isotropic liquid and the B2 phases is lower. To our surprise, the transmittance in B3 is almost the same as in B2. Although B3 is said to be one of the crystal states from x-ray results, this result suggests that molecular dynamics of the B3 phase in this time scale is liquid crystal-like.

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A series of 2-(4-alkoxyphenyl)-5-trifuluoromethylpyridine(CnH2n+1OC6H4C5NH3CF3, n=1-8) was prepared and their mesogenicity was observed on POM observation, DSC and X-ray scattering measurements. An enantiotropic SmA phase was observed in n=2-4. Enatiotropic SmA and SmB phases were observed in n=5-8. In the SmA phase of the n=3, obtained layer spacing was 16.8 Å and this value was 1.8 Å larger than the calculated molecular length. This result shows that CF3 groups were separated from the layer in the SmA phase.

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We investigated about the VA cell property and the polar anchoring of the alignement film. We focused on the optical feature, especially response properties, as the cell properties. Polar anchoring strength was evaluated from the measurements of the optical retardation and simulation.As a result, correlation was able to be confirmed between the polar anchoring strength and the response properties. Furthermore, polar anchoring strength was influenced by the chain length of the alignment film.

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The applicability of the previously proposed method for measuring the rotational viscosity of nematic liquid crystals (NLCs) with negative dielectric anisotropy from transient current in homeotropic NLC cells has been examined. It is found that the shapes of transient current in NLCs with negative dielectric anisotropy are different from those with positive dielectric anisotropy and hence the method can not directly be applied to the analysis of the transient current of NLCs with negative dielectric anisotropy. Computer simulation shows that the transient current of NLCs with negative dielectric anisotropy is successfully reproduced by taking into account of flow effects. It is noted that the flow effects play a key role for faster electro-optic response in vertical alignment NLC displays.

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We propose an optical measurement method for simultaneously determining the cell thickness and twist angle in reflective liquid crystal (LC) cells by using an LC polarization controlling device such as a circularly-homogeneously aligned LC (CH-LC) cell and a charge couple device camera. Since the minimum point of the spatial light intensity distribution at two wavelengths from the reflective LC cell is measured through the CH-LC cell, and then both of the cell thickness and twist angle can be derived by the Jones matrix analysis.

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