Liquid-crystalline medium

A liquid-crystalline medium, comprising at least one compound of formula IA-31, IA-32, IA-33, IA-34, IA-35, IA-36, IA-37, IA-38, IA-39, IA-40, IA-41 and/or IA-42

• and at least one compound of formulae IB, IC and/or ID
• in which
• R1B denotes an alkenyl radical having up to 6 C atoms which is unsubstituted, monosubstituted by CN or CF3 or at least monosubstituted by halogen, in which optionally, one or more CH2 groups are, each independently of one another, 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,
• R2B, R1C,
• R1D and R2D each, independently of one another, denote an alkyl or alkenyl radical having up to 6 C atoms which is unsubstituted, monosubstituted by CN or CF3 or at least monosubstituted by halogen, in which optionally, one or more CH2 groups are, each independently of one another, 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,
• Y1, Y2, Y4
• and Y5 each, independently of one another, denote F, Cl, CF3, CHF2, CH2F, OCF3, OCH2F, OCHF2 or CN,
• alkyl denotes a straight-chain alkyl radical having 1-6 C atoms
• R2C denotes H or F,
• R3C denotes H, CH3, C2H5 or n-C3H7,
• c denotes 1 or 2, and
• d denotes 0 or 1.