Liquid-crystalline medium

A liquid-crystalline medium comprising a mixture of polar compounds, containing at least one compound of Formula I

• in which
• R11 and R12 each, independently of one another, denote an alkyl or alkenyl radical having up to 15 C atoms which is unsubstituted, where, in addition, one or more CH2 groups in these radicals may be replaced by —O—, —S—,
• , —C≡C—, —OC—O— or —O—CO— in such a way that O atoms are not linked directly to one another, with the proviso that at least one of the radicals R11 and R12 denotes alkenyl having 2 to 6 C atoms, and
• Z1 denotes —CH═CH— or a single bond,
• and
• one or more compounds of Formula IIA and/or IIB:
• R2 denotes 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—, —OC—O— or —O—CO— in such a way that O atoms are not linked directly to one another,
• Z2 denotes a single bond, —CH═CH— or —CH2CH2—,
• p denotes 1 or 2, and
• L1 and L2 each, independently of one another, denote F, Cl, OCF3, CF3, CH3, CH2F, CHF2, and
• v denotes 1 to 6.