Abstract: Provided is a liquid crystal compound having general physical properties necessary for a compound, stability to heat, light or the like, a wide liquid crystal phase temperature range, a high clearing point, an excellent compatibility with other liquid crystal compounds, a large refractive index anisotropy and a large dielectric anisotropy. Provided are a liquid crystal composition including the liquid crystal compound, and a liquid crystal display device containing the liquid crystal composition. The compound is represented by formula (1): wherein, for example, R1 is alkyl having 1 to 20 carbons; at least one of the rings A1 to A6 is pyrimidine-2,5-diyl or pyridine-2,5-diyl and the others are 1,4-cyclohexylene or 1,4-phenylene; Z1 to Z6 are a single bond; L1 to L4 is hydrogen or halogen; X1 is hydrogen, halogen, —C?N or alkyl having 1 to 10 carbons; and l, m, n, o, p and q are 0 or 1 and l+m+n+o+p+q=3.

Abstract: A liquid crystal compound with branched alkyl or branched alkenyl as represented by formula (1), a liquid crystal medium (a liquid crystal composition or a polymer/liquid crystal composite material) containing the liquid crystal compound, and an optical element containing the liquid crystal medium are described. In formula (1), R1 is branched alkyl of C3-20 or branched alkenyl of C3-20. The ring A1, A2, A3, A4 or A5 is 1,4-phenylene or 1,3-dioxane-2,5-diyl, for example. Z1, Z2, Z3 and Z4 are independently a single bond or C1-4 alkylene, for example. Y1 is fluorine, for example, m, n and p are independently 0 or 1, and 1?m+n+p?3.

Abstract: A liquid crystal compound is to be obtained that has stability to heat, light and so forth, a high clearing point, a suitable optical anisotropy, a large negative dielectric anisotropy, and excellent compatibility with other liquid crystal compounds. A liquid crystal composition containing the compound is also to be obtained that has a low viscosity, a suitable optical anisotropy, a suitable negative dielectric anisotropy, a low threshold voltage, a high maximum temperature of a nematic phase (phase transition temperature from a nematic phase to an isotropic phase), and a low minimum temperature of a nematic phase. A compound having a hydrocoumarin skeleton is synthesized, and a liquid crystal composition containing the compound is produced.

Abstract: The subject is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a suitable optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light, a high stability to heat and a large elastic constant, or that is suitably balanced regarding at least two of the characteristics. The subject is to provide an AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The invention provides a liquid crystal composition that has a nematic phase and includes a specific four-ring compound having a high maximum temperature and a large dielectric anisotropy as a first component and a specific compound having a small dielectric anisotropy as a second component, and also provides a liquid crystal display device containing this composition.

Abstract: The invention provides a liquid crystal composition that satisfies at least one characteristic among the characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a large optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light, and a high stability to heat, or that is suitably balanced regarding two or more characteristics. The invention provides an AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. A liquid crystal display device contains the liquid crystal composition having a nematic phase that includes two components, wherein the first component is a specific compound having a large optical anisotropy and a large dielectric anisotropy and the second component is a specific compound having a small viscosity or a large maximum temperature.

Abstract: A liquid crystal compound is to be obtained that has stability to heat, light and so forth, a high clearing point, a suitable optical anisotropy, a large negative dielectric anisotropy, and excellent compatibility with other liquid crystal compounds. A liquid crystal composition containing the compound is also to be obtained that has a low viscosity, a suitable optical anisotropy, a suitable negative dielectric anisotropy, a low threshold voltage, a high maximum temperature of a nematic phase (phase transition temperature from a nematic phase to an isotropic phase), and a low minimum temperature of a nematic phase. A compound having a hydrocoumarin skeleton is synthesized, and a liquid crystal composition containing the compound is produced.

Abstract: Provided is a liquid crystal compound having general physical properties necessary for a compound, stability to heat, light or the like, a wide liquid crystal phase temperature range, a high clearing point, an excellent compatibility with other liquid crystal compounds, a large refractive index anisotropy and a large dielectric anisotropy. Provided are a liquid crystal composition including the liquid crystal compound, and a liquid crystal display device containing the liquid crystal composition. The compound is represented by formula (1): wherein, for example, R1 is alkyl having 1 to 20 carbons; at least one of the rings A1 to A6 is pyrimidine-2,5-diyl or pyridine-2,5-diyl and the others are 1,4-cyclohexylene or 1,4-phenylene; Z1 to Z6 are a single bond; L1 to L4 is hydrogen or halogen; X1 is hydrogen, halogen, —C?N or alkyl having 1 to 10 carbons; and l, m, n, o, p and q are 0 or 1 and l+m+n+o+p+q=3.

Abstract: The subject is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a suitable optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light, a high stability to heat and a large elastic constant, or that is suitably balanced regarding at least two of the characteristics. The subject is to provide an AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The invention provides a liquid crystal composition that has a nematic phase and includes a specific four-ring compound having a high maximum temperature and a large dielectric anisotropy as a first component and a specific compound having a small dielectric anisotropy as a second component, and also provides a liquid crystal display device containing this composition.

Abstract: A liquid crystal compound is to be obtained that has stability to heat, light and so forth, a high clearing point, a suitable optical anisotropy, a large negative dielectric anisotropy, and excellent compatibility with other liquid crystal compounds. A liquid crystal composition containing the compound is also to be obtained that has a low viscosity, a suitable optical anisotropy, a suitable negative dielectric anisotropy, a low threshold voltage, a high maximum temperature of a nematic phase (phase transition temperature from a nematic phase to an isotropic phase), and a low minimum temperature of a nematic phase. A compound having a hydrocoumarin skeleton is synthesized, and a liquid crystal composition containing the compound is produced.

Abstract: The invention provides a liquid crystal composition that satisfies at least one characteristic among the characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a large optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light, and a high stability to heat, or that is suitably balanced regarding two or more characteristics. The invention provides an AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. A liquid crystal display device contains the liquid crystal composition having a nematic phase that includes two components, wherein the first component is a specific compound having a large optical anisotropy and a large dielectric anisotropy and the second component is a specific compound having a small viscosity or a large maximum temperature.

Abstract: A liquid crystal compound is to be obtained that has stability to heat, light and so forth, a high clearing point, a suitable optical anisotropy, a large negative dielectric anisotropy, and excellent compatibility with other liquid crystal compounds. A liquid crystal composition containing the compound is also to be obtained that has a low viscosity, a suitable optical anisotropy, a suitable negative dielectric anisotropy, a low threshold voltage, a high maximum temperature of a nematic phase (phase transition temperature from a nematic phase to an isotropic phase), and a low minimum temperature of a nematic phase. A compound having a hydrocoumarin skeleton is synthesized, and a liquid crystal composition containing the compound is produced.

Abstract: The present invention relates to a compound having a chroman ring, which has good thermal and optical stability, adequate optical anisotropy, adequate dielectric anisotropy and superior compatibility with other liquid crystal compounds, a liquid crystal composition comprising the compound, and a liquid crystal device comprising the composition.

Abstract: The present invention relates to a compound having a chroman ring, which has good thermal and optical stability, adequate optical anisotropy, adequate dielectric anisotropy and superior compatibility with other liquid crystal compounds, a liquid crystal composition comprising the compound, and a liquid crystal device comprising the composition.

Abstract: The present invention provides a process for producing a difluoromethyl ether derivative simple and efficient process for producing the difluoromethyl ether derivative represented by Formula (1d?) or a difluoromethyl ether derivative represented by Formula (1c?): wherein all the variables are defined in the specification.

Abstract: A liquid crystalline compound represented by Formula (1c′): wherein R1 and R2, rings A1, A2, A3, A4 and A5, Z1, Z2, Z3 and Z4, Y1, Y2, Y3 and Y4, and k, l, m and n are as defined in the specification. Also provided is a liquid crystal composition containing at least one of these liquid crystalline compounds.

Abstract: The present invention provides a difluoromethyl ether derivative which shows various suitable physical properties as a liquid crystal compound, a liquid crystal composition comprising the compound and a liquid crystal display element containing the composition, and also provides a simple and efficient process for producing the difluoromethyl ether derivative.

Abstract: The present invention provides a difluoromethyl ether derivative which shows various suitable physical properties as a liquid crystal compound, a liquid crystal composition comprising the compound and a liquid crystal display element containing the composition, and also provides a simple and efficient process for producing the difluoromethyl ether derivative.

Abstract: The present invention provides a difluoromethyl ether derivative which shows various suitable physical properties as a liquid crystal compound, a liquid crystal composition comprising the compound and a liquid crystal display element containing the composition, and also provides a simple and efficient process for producing the difluoromethyl ether derivative. According to the present invention, a process for producing a difluoromethyl ether derivative represented by Formula (1d): wherein the variables are defined in the specification, is characterized by using an &agr;&agr;-difluorocyclohexylidene derivative represented by Formula (1a): wherein R1, rings A1 and A2, Z1, Z2, k and l have the same meanings as defined in the specification, as a starting material.

Abstract: The present invention provides a difluoromethyl ether derivative which shows various suitable physical properties as a liquid crystal compound, a liquid crystal composition comprising the compound and a liquid crystal display element containing the composition, and also provides a simple and efficient process for producing the difluoromethyl ether derivative.

Abstract: Liquid crystalline compounds which have large dielectric anisotropy, high electrical insulation properties (high specific resistance or high voltage holding ratio), small temperature dependence, broad liquid crystal phase temperature range, excellent compatibility and low viscosity and which are represented by formula (1) 1