COMPOUNDS AND LIQUID-CRYSTALLINE MEDIUM

The invention relates to compounds of the formula I, and to a liquid- crystalline medium, preferably having a nematic phase and negative dielectric anisotropy, which comprises a one or more compounds of the formula I and b) one or more compounds selected from the group of compounds of formulae II and III in which the parameters have the meanings indicated in Claim 1, to the use thereof in an electro-optical display, particularly in an active-matrix display based on the VA, ECB, PALC, FFS or IPS effect, to displays of this type which contain a liquid-crystalline medium of this type, and to the use of the compounds of the formula I for the stabilisation of a liquid-crystalline medium which comprises one or more compounds of the formula II and one or more compounds selected from the group of the compounds of the formulae 111-1 to III-4 and B.