| abstract |
The invention provides a liquid crystal compound having the stability to heat, light or the like, a wide temperature range of a nematic phase, a small viscosity, a large optical anisotropy, a suitable elastic constant K 3 3 , a large negative dielectric anisotropy and an excellent compatibility with other liquid crystal compounds. The invention also provides a liquid crystal composition including this compound and a liquid crystal display device containing this composition. n A liquid crystal compound represented by formula (1-1).n nFor example, R 1 and R 2 are independently hydrogen, alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, alkoxy having 1 to 9 carbons, alkoxyalkyl having 2 to 9 carbons or alkenyloxy having 2 to 9 carbons; the ring A 1 is trans-1,4-cyclohexylene, 1,4-cyclohexenylene, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2, 5-diyl; L 1 and L 2 are independently hydrogen or fluorine, and at least one of them is fluorine; and Z 1 , Z 2 and Z 3 are independently a single bond, -(CH 2 ) 2 -, -CH=CH-, -C≡C-, -CH 2 O-, -OCH 2 -, -COO- or -OCO-. |