Patent ID: 7544400

Claim:
A bimesogenic compound of formula I R 1 -MG 1 -X 1 -Sp-X 2 -MG 2 -R 2 I wherein R 1 and R 2 are each independently F, Cl, CN, NCS or a straight-chain or branched alkyl group with 1 to 25 C atoms which may be unsubstituted, mono- or polysubstituted by halogen or CN, it being also possible for one or more non-adjacent CH 2 groups to be replaced, in each case independently from one another, by —O—, —S—, —NH—, —N(CH 3 )—, —CO—, —COO—, —OCO—, —O—CO—O—, —S—CO—, —CO—S—, —CH═CH—, —CH═CF—, —CF═CF— or —C≡C— in such a manner that oxygen atoms are not linked directly to one another, MG 1 and MG 2 are each independently a mesogenic group, Sp is a spacer group comprising 4 to 40 C atoms, wherein one or more non-adjacent CH 2 groups may also be replaced by —O—, —S—, —NH—, —N(CH 3 )—, —CO—, —O—CO—, —S—CO—, —O—COO—, —CO—S—, —CO—O—, —CH(halogen)-, —CH(CN)—, —CH═CH— or —-C≡C—, and X 1 and X 2 are each independently —O—, —S—, —CO—, —COO—, —OCO—, —O—CO—O—, —CO—NH—, —NH—CO—, —CH 2 CH 2 —, —OCH 2 —, —CH 2 O—, —SCH 2 —, —CH 2 S—, —CH═CH—, —CH═CH—COO—, —OCO—CH═CH—, —C≡C — or a single bond, wherein at least one of the mesogenic groups MG 1 and MG 2 comprises one or more linking groups selected from —CF 2 O— and —OCF 2 —.