| abstract |
Liquid-crystalline a, based on a mixture of polar compounds having positive dielectric anisotropy, are disclosed which are characterized in that they comprise one or more compounds of the general formula I and simultaneously one or more compounds of the general formula I' in which R<SP>1</SP> and R<SP>2</SP> are each, independently of one another, an alkenyl radical having 2 to 7 carbon atoms, R<SP>0</SP>' is n-alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 12 carbon atoms, Y<SP>2</SP>' is H or F, and, X<SP>0</SP>' is F or Cl, or X<SP>0</SP>' is alkyl, alkenyl, alkoxy, alkenyloxy or oxaalkyl each of which is preferably halogenated (especially fluorinated). Such media are useful for electro-optical liquid-crystal displays, particularly for MLC, TN or STN displays. |