Liquid crystal composition and liquid crystal display device

A liquid crystal composition comprising:

• at least one compound selected from compounds represented by formula (1A) as a first component;
• and
• at least one compound selected from compounds represented by formula (2) as a second component, and the liquid crystal composition has a nematic phase,
• wherein R1 is an alkyl having a carbon number from 1 to 12 or an alkenyl having a carbon number from 2 to 12, and in these groups at least one —CH2— may be substituted by —O—;
• R2 and R3 are each an alkyl having a carbon number from 1 to 12, an alkoxy having a carbon number from 1 to 12, an alkenyl having a carbon number from 2 to 12, an alkyl having a carbon number from 1 to 12 in which at least one hydrogen may be substituted by fluorine or chlorine, or an alkenyl having a carbon number from 2 to 12 in which at least one hydrogen may be substituted by fluorine or chlorine;
• ring A is 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, or 1,3-dioxane-2,5-diyl;
• ring B is an independent 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-, 4-phenylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl;
• Z1 and Z2 are each a single bond, ethylene, methyleneoxy, carbonyloxy, or difluoromethyleneoxy;
• X1 and X2 are each either hydrogen or fluorine;
• Y1 is fluorine, chlorine, an alkyl having a carbon number from 1 to 12 in which at least one hydrogen may be substituted by fluorine or chlorine, an alkoxy having a carbon number from 1 to 12 in which at least one hydrogen may be substituted by fluorine or chlorine, or an alkenyloxy having a carbon number from 2 to 12 in which at least one hydrogen may be substituted by fluorine or chlorine;
• a has a value of 0, 1, 2, or 3;
• n has a value of 0, 1, 2, or 3.