Fluorovinyl derivative compound, liquid crystal composition, and liquid crystal display device

A liquid crystal composition which comprises at least one fluorovinyl derivative compound represent by the general formula (1)

• wherein R1 is an alkyl group having 1 to 18 carbon atoms, and a methylene group in the alkyl group may be substituted by an oxygen atom, a sulfur atom, —CH═CH— or —C≡C— and a hydrogen atom in the alkyl group may be substituted by a halogen atom or a cyano group;
• rings A, B and C are each independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 1,3-dioxane-2,5-diyl, pyridine-2,5-diyl or pyrimidine-2,5-diyl in which a hydrogen atom in the ring may be substituted by a halogen atom;
• Z1, Z2 and Z3 are each independently a single bond, —CH2CH2—, —CH═CH—,-CH2O, —OCH2—, —(CH2)4—, —(CH2)3—O—, —O—(CH2)3—, —(CH2)2—CH═CH—, —CH═CH—(CH2)2—, CF2O—, OCF2—, —CR2═CH—, —CH═CR2— or —CF═CF—, and R2 is an alkyl group having 1 to 5 carbon atoms;
• X is a hydrogen atom or a fluorine atom;
• p and q are each independently 0 or 1;
• and m is an integer of O to 5;
• except for (1) a compound in which p is 0, q is 0, Z3 is the single bond, —CH2CH2—, —CH2O— or —OCH2—, and the ring C is 1,4-cyclohexylene or 1,4-phenylene, (2) a compound in which p is 0, q is 1, Z2 and Z3are each the single bond, the ring B is 1,4-phenylene, and the ring C is 1,4-cyclohexylene or 1,4-phenylene, and (3) a compound in which p is 0, q is 1, Z2 is a single bond, Z3 is —CH2CH2—, the ring B is 1,4-phenylene, the ring C is 1,4-cyclohexylene, and X is a hydrogen atom;
• and
• at least one optically active compound.

A liquid crystal display device which comprises a liquid crystal composition which comprises at least one fluorovinyl derivative compound repreby the general formula (1)

• wherein R1 is an alkyl group having 1 to 18 carbon atoms, and a methylene group in the alkyl group may be substituted by an oxygen atom, a sulfur atom, —CH═CH— or —C≡C— and a hydrogen atom in the alkyl group may be substituted by a halogen atom or a cyano group;
• rings A, B and C are each independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 1,3-dioxane-2,5-diyl, pyridine-2,5-diyl or pyrimidine-2,5-diyl in which a hydrogen atom in the ring may be substituted by a halogen atom;
• Z1, Z2 and Z3 are each independently a single bond, —CH2CH2—, —CH═CH—, —CH2O—, —OCH2—, —(CH2)4—, —(CH2)3—O—, —O—(CH2)3—, —(CH2)2—CH═CH—, —CH═CH—(CH2)2—, CF2O—, —OCF2—, —CR2═CH—, —CH═CR2— or —CF═CF—, and R2 is an alkyl group having 1 to 5 carbon atoms;
• X is a hydrogen atom or a fluorine atom;
• p and q are each independently 0 or 1;
• and m is an integer of 0 to 5;
• except for (1) a compound in which p is 0, q is 0, Z3 is the single bond, —CH2CH2—, —CH2O— or —OCH2—, and the ring C is 1,4-cyclohexylene or 1,4-phenylene, (2) a compound in which p is 0, q is 1, Z2 and Z3are each the single bond, the ring B is 1,4-phenylene, and the ring C is 1,4-cyclohexylene or 1,4-phenylene, and (3) a compound in which p is 0, q is 1, Z2 is a single bond, Z3 is —CH2CH2—, the ring B is 1,4-phenylene, the ring C is 1,4-cyclohexylene, and X is a hydrogen atom;
• and
• at least one optically active compound.