Such a liquid crystal compound is provided that has stability to heat, light and so forth, has a nematic phase in a wide temperature range, has a small viscosity, a suitable optical anisotropy, and suitable elastic constants K33 and K11 (K33: bend elastic constant, K11: splay elastic constant), and has suitable negative dielectric anisotropy and excellent compatibility with other liquid crystal compounds. A liquid crystal composition containing the liquid crystal compound, and a liquid crystal display device containing the liquid crystal composition are also provided.
The liquid crystal compound is represented by one of formulas (a) to (d), the liquid crystal composition contains the liquid crystal compound, and the liquid crystal display device contains the liquid crystal composition:
wherein Ra and Rb are independently linear alkyl or linear alkoxy, rings A1, A2, B and C are independently trans-1,4-cyclohexylene or 1,4-phenylene, Z11, Z12, Z2 and Z3 are independently a single bond or alkylene, and one of X1 and X2 is fluorine, and the other thereof is chlorine.