Liquid-crystalline meduim

Liquid-crystalline medium based on a mixture of polar compounds having negative dielectric anisotropy (Δε), characterized in that it contains at least one compound selected from the group of compounds of the formula I, IIA and IIIB

• and at least one compound of the formula I*
• in which
• R0, R1, R2 and R1* each, independently of one another, denote H, an alkyl or alkenyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN or CF3 or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in these radicals may be replaced by —O—, —S—,
• —C≡C—, —CF2O—, —OCF2——OC—O— or —O—CO— in such a way that O atoms are not linked directly to one another,
• A1, A1*, A2* each, independently of each other
• a) denote a 1,4-cyclohexenylene or 1,4-cyclohexylene radical, in which one or two non-adjacent CH2 groups may be replaced by —O— or —S—,
• b) denote a 1,4-phenylene radical, in which one or two CH groups may be replaced by N,
• c) denote a radical from the group consisting of piperidine-1,4-diyl-, 1,4-bicyclo[2.2.2]octylene-, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl and fluorene-2,7-diyl,
• where the radicals a), b) and c) may be mono- or polysubstituted by halogen atoms,
• Z1, Z1* and Z2* each, independently of one another denote —CO—O—, —O—CO—, —CF2O—, —OCF2—, —CH2O—, —OCH2—, —CH2CH2—, —(CH2)4—, —C2F4—, —CH2CF2—, —CF2CH2—, —CF═CF—, —CH═CF—, —CF═CH—, —CH═CH—, —C≡C— or a single bond,
• m and m* each independently of one another denote 0, 1 or 2
• p denotes 1 or 2
• q denotes 0 or 1
• v denotes 1 to 6
• L1* and L2* each independently of one another denote H or F
• X1 and X2 each independently of one another denote, F, Cl, CHF2, CF3, OCHF2 or OCF3
• Q single bond, —CF2—, —CHF—, —OCF2— or —OCHF— and
• Y F or Cl.