Liquid crystal compounds

A compound of formula (I)

• wherein
• the ring A is an unsubstituted or substituted phenylene group, naphthalene group or biphenylene group,
• AA1 is selected from the groups (a), (b) and (c):
• AA2 is selected from the groups (a), (b), (c), (d) and (e):
• wherein AA1 and AA2 are independently from each other unsubstituted or substituted with one or two substituents selected from the group consisting of F, Cl, Br, I, CN, C1-C6alkyl, C1-C6 alkenyl, C1-C6alkoxy and C1-C6alkenyloxy,
• Q1 is an unsubstituted or substituted homocyclic or heterocyclic group, or
• Q1 is selected from unsubstituted or substituted groups of formulae (Ia), (Ib), (Ic) and (Id):
• —COO—SP2—BB (Ia),
• —OCO—SP2—BB (Ib),
• —CO—SP2—BB (Ic) and
• —O—SP2—BB (Id),
• with the proviso that the substituents of Q1 are selected from the group consisting of F, Cl, Br, I, CN, C1-C6alkyl, C1-C6 alkenyl, C1-C6alkoxy and C1-C6alkenyloxy;
• and
• with the proviso that if the ring A is a naphthalene group Q1 has the above given meaning or is hydrogen;
• SP1, SP2 and SP3 independently from each other represents a single bond or a spacer group of the formula —(CH2) p- in which p is an integer of 1 to 18 and in which one, two, three or four —CH2— groups are unreplaced or replaced by a group selected from the group consisting of —CH═CH—, —O—, —S—, —CO—, —COO—, —CONR′—, —OCOO—, —OCONR′, —NR′—, —CONR′—, —OCOO—, —OCONR′, wherein R′ is selected from the group consisting of hydrogen, a C1-C6 alkyl group and a C1-C6 alkenyl group;
• with the proviso that the spacer group does not contain two adjacent heteroatoms;
• n is 0 or 1,
• BP is a polymerizable group or F, Cl, Br, I, CN, C1-C6alkyl, C1-C6 alkenyl, C1-C6alkoxy or C1-C6alkenyloxy,
• P1 is a polymerizable group,
• with the proviso that if BP and P1 are polymerizable groups, they are identical or different;
• BB is hydrogen or a group of formula (II)
• in which
• A and B independently represent an unsubstituted or substituted six membered homocyclic or heterocyclic group or a naphthalene group;
• C is selected from the group consisting of a five and six membered homocyclic or heterocyclic group or a naphthalene group;
• n1 and n2 are 0 or 1 with the proviso that firstly 1≤n1+n2≤2 and secondly, when C is a naphthalene group 0≤n1+n2≤2;
• Z1 is selected from the group consisting of —O—, —S—, —COO—, —OOC—, —CO—, —CONR′—, —NR′CO—, —OCOO—, —OCONR′—, —NR′COO— and a single bond;
• in which
• R′ is selected from the group consisting of hydrogen, a C1-C6 alkyl group and a C1-C6 alkenyl group;
• with the proviso that the —SP2—Z1— group does not contain two adjacent heteroatoms;
• Z2 and Z3 are independently from each other selected from the group consisting of single bond, —COO—, —OOC—, —CH2—CH2—, —CH2O—, —OCH2—, —CH═CH—, —C≡C—, —(CH2)4— and —(CH2)3O—;
• R1 is selected from the group consisting of H, —CN, —COR, —COOR, —OCOR, —CONR′R, —NR′COR, OCOOR, —OCONR′R, —NR′COOR, —F, —Cl, I, —CF3, —OCF3, —OR, in which
• R′ is selected from the group consisting of hydrogen, a C1-C6 alkyl group and a C1-C6 alkenyl group, and R is selected from the group consisting of hydrogen, a C1-18alkyl group and a C4-18alkenyl group with the double bond at 3-position or higher.