Abstract: A liquid crystal (LC) compound having generally required physical properties, low viscosity, proper optical anisotropy, proper dielectric anisotropy and good compatibility with other LC compounds is described. An LC composition including the compound and an LCD device including the composition are also described. The compound is expressed by formula (1a): wherein the ring A1 and the ring A2 are independently 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl or naphthalene-2,6-diyl, in which any hydrogen can be replaced by halogen; Z1, Z2 and Z3 are independently a single bond, —(CH2)2—, —(CH2)4—, —CH?CH—, —C?C—, —CF2O—, —OCF2—, —COO— or —OCO—; Xa, Xb, Xc, Xd, Xe and Xf are independently hydrogen or fluorine; Y is —OCH2F, —OCHF2, —OCF3, —SCH2F, —SCHF2, —SCF3, —CH2F, —CHF2, —CF3, fluorine or chlorine; La and Lb are independently hydrogen or fluorine; and “l” and “m” are independently equal to 0 or 1.

Abstract: A liquid crystal compound is provided that has stability to heat and an ultraviolet ray, a small viscosity, a suitable refractive index anisotropy, a suitable dielectric anisotropy, a nematic phase within a wide temperature range and favorable compatibility with other liquid crystal compounds, and a liquid crystal composition is also provided that has a particularly small viscosity. The liquid crystal compound is a compound represented by formula (1): wherein in formula (1), R1 is hydrogen or alkyl having 1 to 5 carbons; one of X1 and X2 is hydrogen, and the other thereof is fluorine; and R2 is hydrogen or methyl.

Abstract: A liquid crystal compound is provided that has stability to heat and an ultraviolet ray, a small viscosity, a suitable refractive index anisotropy, a suitable dielectric anisotropy, a nematic phase within a wide temperature range and favorable compatibility with other liquid crystal compounds, and a liquid crystal composition is also provided that has a particularly small viscosity. The liquid crystal compound is a compound represented by formula (1): wherein in formula (1), R1 is hydrogen or alkyl having 1 to 5 carbons; one of X1 and X2 is hydrogen, and the other thereof is fluorine; and R2 is hydrogen or methyl.

Abstract: A liquid crystal (LC) compound having generally required physical properties, low viscosity, proper optical anisotropy, proper dielectric anisotropy and good compatibility with other LC compounds is described. An LC composition including the compound and an LCD device including the composition are also described. The compound is expressed by formula (1a): wherein the ring A1 and the ring A2 are independently 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl or naphthalene-2,6-diyl, in which any hydrogen can be replaced by halogen; Z1, Z2 and Z3 are independently a single bond, —(CH2 )2—, —(CH2 )4—, —CH?CH—, —C?C—, —CF2O—, —OCF2—, —COO— or —OCO—; Xa, Xb, Xc, Xd, Xe and Xf are independently hydrogen or fluorine; Y is —OCH2F, —OCHF2, —OCF3, —SCH2F, —SCHF2, —SCF3, —CH2F, —CHF2, —CF3, fluorine or chlorine; La and Lb are independently hydrogen or fluorine; and “l” and “m” are independently equal to 0 or 1.

Abstract: The present invention provides liquid crystalline compounds having a high voltage holding ratio and a low threshold voltage, little variation of these properties with temperature change, high &Dgr;n, and good compatibility with other liquid crystal materials particularly under a low temperature; liquid crystal compositions containing these crystalline compounds; and liquid crystal display devices made using these liquid crystal compositions.

Abstract: The present invention provides liquid crystalline compounds having a high voltage holding ratio and a low threshold voltage, little variation of these properties with temperature change, high &Dgr;n, and good compatibility with other liquid crystal materials particularly under a low temperature; liquid crystal compositions containing these crystalline compounds; and liquid crystal display devices made using these liquid crystal compositions.

Abstract: The present invention provides liquid crystalline compounds having a high voltage holding ratio and a low threshold voltage, little variation of these properties depending on temperature change, high &Dgr;n, and good compatibility with other liquid crystal materials particularly under a low temperature; liquid crystal compositions containing these crystalline compounds; and liquid crystal display devices comprising these liquid crystal compositions.

Abstract: The present invention provides liquid crystalline compounds having a high voltage holding ratio and a low threshold voltage, little variation of these properties with temperature change, high An, and good compatibility with other liquid crystal materials particularly under a low temperature; liquid crystal compositions containing these crystalline compounds; and liquid crystal display devices made using these liquid crystal compositions.

Abstract: The present invention provides liquid crystalline compounds having a high voltage holding ratio and a low threshold voltage, little variation of these properties with temperature change, high &Dgr;n, and good compatibility with other liquid crystal materials particularly under a low temperature; liquid crystal compositions containing these crystalline compounds; and liquid crystal display devices made using these liquid crystal compositions.

Abstract: The present invention provides liquid crystalline compounds having a very high voltage holding ratio, very little variation of these properties depending on temperature, high &Dgr;n, and good compatibility in the other liquid crystal materials particularly under a low temperature, liquid crystal compositions containing these crystalline compounds, and liquid crystal display devices constituted by using the liquid crystal compositions.

Abstract: The present invention provides liquid crystalline compounds having a high voltage holding ratio and a remarkably high &Dgr;&egr; value, electric and chemical stability, and having good compatibility with known liquid crystalline compounds, liquid crystal compositions containing the compound, and liquid crystal display devices constituted by using the compounds. The liquid crystalline compounds of the present invention are particular dioxane derivatives represented by general formula (1). Further, the present invention relates to liquid crystal compositions characterized in that the compositions comprise at least one of the derivatives, and liquid crystal display devices constituted by using the compositions.