Polymerizable compounds and their use in liquid-crystal displays

A polymerisable compound selected from formula I:

• Ra—(C≡C)p-(A1-Z1)m-A2-(C≡C)q—Rb I
• in which the individual radicals have the following meanings:
• Ra, Rb each, independently of one another, denote P-Sp-, H, F, Cl, Br, I, —CN, —NO2, —NCO, —NCS, —OCN, —SCN, SF5, straight-chain or branched alkyl having 1 to 25 C atoms, in which, in addition, one or more non-adjacent CH2 groups may each be replaced, independently of one another, by arylene, —C(R0)═C(R00)—, —C≡C—, —N(R0)—, —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O— in such a way that O and/or S atoms are not linked directly to one another and in which, in addition, one or more H atoms may be replaced by F, Cl, Br, I, CN or P-Sp-, or aryl or heteroaryl which may also contain two or more fused rings and which is optionally mono- or polysubstituted by L,
• where at least one of the radicals Ra and Rb denotes or contains a group P-Sp-,
• P on each occurrence, identically or differently, denotes a polymerisable group,
• Sp on each occurrence, identically or differently, denotes a spacer group or a single bond,
• A1, A2 each, independently of one another, denote an aromatic, heteroaromatic, alicyclic or heterocyclic group, preferably having 4 to 25 C atoms, which may also contain fused rings and which is optionally mono- or polysubstituted by L,
• L on each occurrence, identically or differently, denotes P-Sp-, H, OH, CH2OH, halogen, SF5, NO2, a carbon group or hydrocarbon group,
• Z1 denotes —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, —OCH2—, —CH2O—, —SCH2—, —CH2S—, —CF2O—, —OCF2—, —CF2S—, —SCF2—, —(CH2)n—, —CF2CH2—, —CH2CF2—, —(CF2)n—, —CH═CH—, —CF═CF—, —CH═CF—, —CF═CH—, —C≡C—, —CH═CH—CO—O—, —O—CO—CH═CH—, —CH2—CH2—CO—O—, —O—CO—CH2—CH2—, —C(R0R00)—, —C(RyRz)- or a single bond,
• R0, R00 each, independently of one another and identically or differently on each occurrence, denote H or alkyl having 1 to 12 C atoms,
• Ry, Rz each, independently of one another, denote H, F, CH3 or CF3,
• m denotes 0, 1, 2, 3 or 4,
• n on each occurrence, identically or differently, denotes 1, 2, 3 or 4, and
• p, q each, independently of one another, denote 0 or 1, where p+q is 1 or 2;
• with the provisos that:
• in the case where p=q=1, then -(A1-Z1)m-A2- is other than biphenyl, terphenyl, fluorene, substituted fluorene, and dibenzofuran;
• and
• in the case where p=q=1, Ra=Rb=P-Sp-, P denotes an acrylate, glycidyl or epoxide group, and Sp denotes alkoxy or oxaalkyl having 1 to 20 C atoms or a single bond, then -(A1-Z1)m-A2- denotes a radical other than the following groups:
• in which X denotes CH2, NH, O, S or SO2.

A compound according to formula II

• G-O-Sp-(C≡C)p-(A1-Z1)m-A2-(C≡C)q-Sp′-O-G′ II
• in which
• A1, A2 each, independently of one another, denote an aromatic, hetero aromatic, alicyclic or heterocyclic group which optionally contains fused rings and which is optionally mono- or polysubstituted by L,
• L on each occurrence, identically or differently, denotes P-Sp-, H, OH, CH2OH, halogen, SF5, NO2, a carbon group or hydrocarbon group,
• Z1 denotes —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, —OCH2—, —CH2O—, —SCH2—, —CH2S—, —CF2O—, —OCF2—, —CF2S—, —SCF2—, —(CH2)n—, —CF2CH2—, —CH2CF2—, —(CF2)n—, —CH═CH—, —CF═CF—, —CH═CF—, —CF═CH—, —C≡C—, —CH═CH—CO—O—, —O—CO—CH═CH—, —CH2—CH2—CO—O—, —O—CO—CH2—CH2—, —C(R0R00)—, —C(RyRz)— or a single bond,
• R0, R00 each, independently of one another and identically or differently on each occurrence, denote H or alkyl having 1 to 12 C atoms,
• Ry, R00 each, independently of one another, denote H, F, CH3 or CF3,
• Sp on each occurrence, identically or differently, denotes a spacer group or a single bond,
• Sp′ on each occurrence, identically or differently, denotes a spacer group or a single bond,
• n on each occurrence, identically or differently, denotes 1, 2, 3 or 4,
• p, q each, independently of one another, denote 0 or 1, where p+q is 1 or 2,
• m denotes 0, 1, 2, 3 or 4, and
• G and G′ each, independently of one another, denote an H atom or a protecting group;
• with the proviso that:
• in the case where p=q=1, then -(A1-Z1)m-A2- is other than biphenyl, terphenyl, fluorene, substituted fluorene, and dibenzofuran.