Liquid-crystalline medium

A liquid-crystalline medium, comprising one or more compounds of Formula I

• in which the individual substituents have the following meanings:
• R1 and R2 each, independently of one another, a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by —C≡C—,
• —CF2O—, —OCF2—, —CH═CH—,
• —O—, —CO—O— or —O—CO— in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms,
• and A2 each, independently of one another, denote phenylene-1,4-diyl, in which, in addition, one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH3, CHF2, CH2F, CF3, OCH3, OCHF2 or OCF3, cyclohexane-1,4-diyl, in which, in addition, one or two non-adjacent CH2 groups may be replaced, independently of one another, by O and/or S and one or more H atoms may be replaced by F, cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo-[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioxane-2,5-diyl,
• A0 denotes
• Z1 and Z2 each, independently of one another, denote —CF2O—, —OCF2—, —CH2O—, —OCH2—, —CO—O—, —O—CO—, —C2H4—, —C2F4—, —CF2CH2—, —CH2CF2—, —CFHCFH—, —CFHCH2—, —CH2CFH—, —CF2CFH—, —CFHCF2—, —CH═CH—, —CF═CH—, —CH═CF—, —CF═CF—, —C≡C— or a single bond,
• k and l respectively denotes 1 and 0;
• one or more compounds selected from the group consisting of the following formulae:
• in which
• L1 is H, F or Cl, and
• R1 and R2 each, independently of one another, is a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by —C≡C—,
• —CF2O—, —OCF2—, —CH═CH—
• —O—, —CO—O— or —O—CO— in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms in which one or more H atoms may be replaced by a halogen atom;
• and one or more compounds of the Formula ST
• in which the individual substituents have the following meanings:
• X21, X22 each, independently of one another, —O—, —CH2—, —CHR23— or —N—R23—,
• R21 and R22 each, independently of one another, a H atom or an alkyl- or alkoxy group having 1 to 12 C atoms, an alkenyl, alkynyl, alkenyloxy or alkoxyalkyl group having 2 to 12 C atoms or a cycloalkyl group having 3 to 12 C atoms, in which one or more non-adjacent CH2 groups are optionally substituted by —C≡C—,
• —CF2O—, —OCF2—, —CH═CH—,
• —O—, —CO—O— or —O—CO— in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom,
• R23 denotes a H atom, an alkyl or alkoxy group having 1 to 10 C atoms,
• r denotes 0 or 1.