| 主权项 |
1. Mesogenic medium comprising
a first component, component A, consisting of bimesogenic compounds selected from the group of compounds of formulae A-I to A-III wherein R11 and R12, R21 and R22 and R31 and R32 are each independently H, 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 CH2 groups to be replaced, in each occurrence independently from one another, by —O—, —S—, —NH—, —N(CH3)—, —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, MG11 and MG12, MG21 and MG22 and MG31 and MG32 are each independently a mesogenic group, Sp1, Sp2 and Sp3 are each independently a spacer group comprising 5 to 40 C atoms, wherein one or more non-adjacent CH2 groups, with the exception of the CH2 groups of Sp1 linked to O-MG11 and/or O-MG12, of Sp2 linked to MG21 and/or MG22 and of Sp3 linked to X31 and X32, may also be replaced by —O—, —S—, —NH—, —N(CH3)—, —CO—, —O—CO—, —S—CO—, —O—COO—, —CO—S—, —CO—O—, —CH(halogen)-, —CH(CN)—, —CH═CH— or —C≡C—, however in such a way that (in the molecules) no two O-atoms are adjacent to one another, no two —CH═CH— groups are adjacent to each other, and no two groups selected from —O—CO—, —S—CO—, —O—COO—, —CO—S—, —CO—O— and —CH═CH— are adjacent to each other and X31 and X32 are independently from one another a linking group selected from —CO—O—, —O—CO—, —CH═CH—, —C≡C— or —S—, and, alternatively, one of them may also be either —O— or a single bond, and, again alternatively, one of them may be —O— and the other one a single bond, a second component, component B, consisting of nematogenic compounds, preferably selected from the group of compounds of formulae B-I to B-III wherein RB1, RB21 and RB22 and RB31 and RB32 are each independently H, 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 CH2 groups to be replaced, in each occurrence independently from one another, by —O—, —S—, —NH—, —N(CH3)—, —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, XB1 is F, Cl, CN, NCS, preferably CN, ZB1, ZB2 and ZB3 are in each occurrence independently —CH2—CH2—, —CO—O—, —O—CO—, —CF2—O—, —O—CF2—, —CH═CH— or a single bond,andare in each occurrence independentlyoralternatively one or more ofareand
n is 1, 2 or 3, and a third component, component C, consisting of one or more chiral molecules. |
