| abstract |
Liquid crystal compound satisfying at least one of physical properties such as high stability to heat or light, high maximum temperature, high clearing point, low minimum temperature of liquid crystal phase, small viscosity, suitable optical-anisotropy, large negative dielectric-anisotropy, suitable elastic constant and good compatibility with other liquid crystal compounds; liquid crystal composition containing the compound; and liquid crystal display device including the composition. Compound represented by formula (1), wherein R 1 is alkyl having 1 to 15 carbons; R 2 is alkyl having branched-chain and 3 to 15 carbons; A 1 , A 2 are independently 1,2-cyclopropylene; Z 1 , Z 2 are independently single bond or alkylene having 1 to 15 carbons; L 1 , L 2 are fluorine, chlorine, —OCF 3 or —OCH 2 F; X 1 , X 2 are oxygen or sulfur; and a is 0 or 1, b is 0 or 1, and sum of a and b is 0, 1 or 2. |