Patent ID: 7291367

Claim:
A liquid-crystalline compound of the formula I: in which R 1 and R 2 each, independently of one another, denote H, halogen, a halogenated or unsubstituted alkyl or alkoxy radical having 1 to 15 C atoms, where one or more CH 2 groups in these radicals, independently of one another, are optionally replaced by —C≡C—, —CH═CH—, —O—, —CO—O— or —O—CO— in such a way that O atoms are not linked directly to one another, and where one of the radicals R 1 and R 2 is optionally CN, OCN, SCN, NCS or SF 5 , A 1 , A 2 , A 3 and A 4 each, independently of one another, denote Z 1 , Z 2 and Z 3 each, independently of one another, denote —CO—O—, —O—CO—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CH 2 CH 2 —, —(CH 2 ) 4 —, —C 2 F 4 —, —CH 2 CF 2 —, —CF 2 CH 2 —, —CF═CF—, —CH═CH—, —C≡C— or a single bond, and a, b and c each, independently of one another, denote 0, 1, 2 or 3, where a+b+c≦3.