| 摘要 |
The invention relates to liquid-crystalline compounds of the formula Iin whichR<1>, R<2>, A<1>, A<2>, A<3>, A<4>, Z<1>, Z<2>, a, b and c are as defined in claim 1, and to liquid-crystalline media comprising at least compound of the formula I and to electro-optical displays containing a liquid-crystalline medium of this type. |
