Electro-optical liquid-crystal display

A liquid-crystalline medium of positive dielectric anisotropy having a birefringence Δn of no more than 0.12 comprising at least one compound of the formula I and at least one compound of formula II or III

• in which
• R1, R2 and R3 are each, independent of one another, alkyl or alkoxy having 1 to 7 carbon atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 7 carbon atoms,
• Y11, Y12, Y21, Y22,
• Y31 and Y32 are each, independent of one another, H or F,
• are each, independent of one another,
• and
• Q—X is F, Cl, —OCF2H or —OCF3;
• and at least one compound of the formula:
• in which
• R4 is H, an alkyl or alkenyl radical having 1 to 15 carbon atoms which is monosubstituted by CN or CF3 and one or more CH2 groups in these radicals are, independent of one another, replaceable by
• —O—, —S—,
• —CO—, —CO—O—, —O—CO—, —O—CO—O— or —C≡C— in such a way that O atoms are not linked directly to one another,
• A41, A42
• and A43 are each, independent of one another,
• (a) a trans-1,4-cyclohexylene radical, in which, in addition, one or more non-adjacent CH2 groups may be replaced by —O— and/or —S—,
• (b) a 1,4-phenylene radical, in which, in addition, one or two CH groups may be replaced by N,
• (c) a radical of 1,4-cyclohexenylene, 1,4-bicyclo[2.2.2]octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein the trans-1,4-cyclohexylene and 1,4-phenylene is, optionally, by at least one fluorine atom,
• Z41, Z42
• and Z43 are each, independent of one another, —CO—O—, —O—CO—, —CH2O—, —OCH2—, —CH2CH2—, —CH═CH—, —C≡C— or a single bond, or one of Z41 and Z42 is alternatively —(CH2)4— or —CH═CH—CH2CH2—,
• X4 is F, —OCF2H or —OCF3,
• Y41 and Y42 are each, independent of one another, H or F, and
• n1 and n2 are each, independent of one another, 0 or 1;
• at least one compound of the formula Va:
• wherein at least one of the groups R51 and R52 is alkenyl and the other is alkyl or alkoxy having 1-7 carbon atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2-7 carbon atoms;
• at least one compound of the formula Vc
• wherein R52 is n-alkyl having 1-5 carbon atoms and R51 is 1E-alkenyl having 2-5 carbon atoms.