Patent ID: 7258902

Claim:
A chiral compound of the general formula I and diastereomers thereof, where R 1 and R 2 , independently of one another, are P—Y 1 -A 1 -Y 2 -M-Y 3 —(A 2 ) m —Y 4 — groups, wherein A 1 and A 2 are spacers having one to 30 carbon atoms, M is a mesogenic group, Y 1 , Y 2 , Y 3 and Y 4 are, independently of one another, a single chemical bond, —O—, —S—, —CO—, —CO—O—, —O—CO—, —CO—N(R)—, —(R)N—CO—, —O—CO—O—, —O—CO—N(R)—, —(R)N—CO—O— or —(R)N—CO—N(R)—, R is hydrogen or C 1 -C 4 -alkyl, P is hydrogen, C 1 -C 12 -alkyl, a group which is polymerizable or suitable for polymerization, or a radical which carries a group which is polymerizable or suitable for polymerization, and m is a value of 0 or 1, and wherein the variables A 1 , A 2 , Y 1 , Y 2 , Y 3 , Y 4 , M, P and the index m, in the groups R 1 and R 2 , are identical or different, with the proviso that, in the case where the index m is 0, at least one of the variables Y 3 and Y 4 adjacent to A 2 is a single chemical bond.