Compounds having a difluorocyclohexane ring, liquid crystal compositions and liquid crystal display devices

A compound represented by formula (1):

• in formula (1),
• R1 and R2 is hydrogen, fluorine, chlorine or alkyl having 1 to 20 carbons, and in the alkyl at least one —CH2— may be replaced by —O—, at least one —CH2CH2— may be replaced by —CH═CH—, and in these groups at least one hydrogen may be replaced by fluorine;
• wherein L1 is either fluorine or hydrogen, wherein L2 is either fluorine or hydrogen, and wherein L1 is fluorine, both L1s are fluorine and wherein when L2 is fluorine, both L2s are fluorine and wherein when both L1s are fluorine, both L2s are hydrogen and wherein when both L2s are fluorine both L1s are hydrogen;
• and
• Z1 and Z2 are independently a single bond, —COO—, —OCO—, —OCH2—, —CH2O—, —CF2O—, —OCF2—, —CH2CH2—, —CH═CH—, —C≡C—, —CF2CF2—, —CF═CF—, —CH2CH2CH2CH2—, —CH═CHCH2CH2— or —CH2CH═CHCH2—;
• where at least one of Z1 and Z2 is —COO—, —OCO—, —OCH2—, —CH2O—, —CF2O—, —OCF2—, —CH2CH2—, —CH═CH—, —C≡C—, —CF2CF2—, —CF═CF—, —CH2CH2CH2CH2—, —CH═CHCH2CH2— or —CH2CH═CHCH2—, when both R1 and R2 is alkyl having 1 to 20 carbons and L1 is fluorine;
• where at least one of Z1 and Z2 is —COO—, —OCO—, —OCH2—, —CH2O—, —CF2O—, —OCF2—, —CH2CH2—, —CH═CH—, —C≡C—, —CF2CF2—, —CF═CF—, —CH2CH2CH2CH2—, —CH═CHCH2CH2— or —CH2CH═CHCH2—, when R1 is alkyl having 1 to 20 carbons, R2 is alkoxy having 1 to 19 carbons, and L2 is fluorine.