Patent ID: 7442475

Claim:
A liquid crystalline medium, comprising at least two liquid crystalline compounds, wherein at least one of said compounds comprises a 5-cyanophridon-2-yl group is of formula I wherein R 1 , R 2 and R 3 are independently of each other H or an optionally substituted aliphatic, cycloaliphatic or aromatic group with up to 20 C atoms that optionally comprises one or more hetero atoms and optionally comprises fused rings, A 1 and A 2 are independently of each other an aromatic or alicyclic ring, or a group comprising two or more fused aromatic or alicyclic rings, wherein these rings optionally contain one or more hetero atoms selected from N, O, and S, and are optionally mono- or polysubstituted by R, Z 1 and Z 2 are independently of each other —O—, —S—, —CO—, —COO—, —OCO—, —S—CO—, —CO—S—, —O—COO—, —CO—NR 0 —, —NR 0 —CO—, —OCH 2 —, —CH 2 O—, —SCH 2 —, —CH 2 S—, —CF 2 O—, —OCF 2 —, —CF 2 S—, —SCF 2 —, —CH 2 CH 2 —, —CF 2 CH 2 —, —CH 2 CF 2 —, —CF 2 CF 2 —, —CH═N—, —N═CH—, —N═N—, —CH═CR 0 —, —CY 1 ═CY 2 —, —C≡C—, —CH═CH—COO—, —OCO—CH═CH— or a single bond, Y 1 and Y 2 are independently of each other H, F, CI or CN, R is H, F, Cl, Br, I, CN, NO 2 , NCS, SF 5 or alkyl which is straight chain or branched, has 1 to 20 C-atoms, is unsubstituted, mono- or poly-substituted by F, CI, Br, I or CN, and in which one or more non-adjacent CH 2 groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NH—, NR 0 —, —SiR 0 R 00 —, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO—, —CO—S—, —CY 1 ═CY 2 — or —C═C— in such a manner that O and/or S atoms are not linked directly to one another, or R denotes P-Sp R 0 and R 00 are independently of each other H or alkyl with 1 to 12 C-atoms, P is a polymerisable or reactive group, Sp is a spacer group or a single bond, and m is 0, 1 or 2.