| abstract |
This invention provides a liquid-crystalline compound which has stabilities in reaction to light and heat, lower viscosity, bigger optical anisotropy, and a proper elastic constant K33, is in a nematic phase in a wider temperature range, and further has proper negative dielectric anisotropy and excellent compatibility with other liquid crystal compounds. Moreover, this invention provides a liquid crystal composition including the liquid-crystalline compound and a liquid crystal device including the liquid crystal composition. The liquid-crystalline compound of this invention is shown by formula (a): R1 and R2 are C1-10 alkyl, C2-10 alkenyl or C1-9 alkoxyl; ring A1 and A2 are 1,4-phenylene or trans-1,4-cyclohexylene; L1 and L2 are hydrogen or fluorine, and at least one of L1 and L2 is fluorine; and Z1 and Z2 are single bond, -(CH2)2-, -CH=CH-, -CH2O-, or -OCH2-. |