Polymerizable liquid crystal having a carbazole core

An anisotropic compound of formula (I)

• wherein R1, R2 and R3 are independently from each other selected from the group consisting of hydrogen, C1-C12 straight alkyl chain, C3-C12 branched alkyl chain, C3-C12 alkenyl, C1-C12 alkoxy, C3-C12 alkenyloxy —(CH2)m, —C(CH3)3, NO2, CN, COR, —COOR, —OCOR, —CONR′R, —NR′COR, OCOOR, —OCONR′R, —NR′COOR, —F, —Cl, —CF3 and —OCF3;
• in which
• m is an integer between 0 and 12;
• R is selected from the group consisting of hydrogen, an C1-18 alkyl group, an C3-18 alkenyl group, (CH2)p—C—(CF3)3, CN, and unsubstituted or substituted phenyl ring, wherein the substituent of the phenyl ring is selected from the group consisting of C1-C6 straight alkyl chain, C3-C6 branched alkyl chain, C1-C6 alkoxy, —C—(CH3)3, halogen, —CF3, NO2, CN, COR′″, —COOR′″, —OCOR′″, —CONR″R′″, —NR″COR′″, OCOOR′″, —OCONR″R′″, —NR″COOR′″, —F, —Cl, —CF3 and —OCF3 in which
• R″ is selected from the group consisting of hydrogen, a lower alkyl group and a lower alkenyl group;
• R′″ is selected from the group consisting of hydrogen, an C1-18 alkyl group and an C3-18 alkenyl group;
• p is an integer between 0 and 12;
• R′ is selected from the group consisting of hydrogen, lower alkyl, lower alkenyl and lower alkoxy;
• n is 0, 1, 2 or 3;
• Y is selected from the group consisting of H, or substituted or unsubstituted alkyl group having 1 to 12 carbon atoms;
• rings C and D are independently from each other selected from the group consisting of phenyl, biphenyl, naphthyl, cycloalkyl, bicycloalkyl,
• with the proviso that at least one of rings C or D is an aromatic ring;
• ring E is selected from the group consisting of phenyl, biphenyl and naphthyl
• X1 and X2 are independently from each other selected from the group consisting of hydrogen, C1-C12 substituted or unsubstituted straight alkyl chain, C3-C12 substituted or unsubstituted branched alkyl chain, C3-C12 substituted or unsubstituted straight chain or branched alkenyl chain and C1-C12 alkoxy, wherein one or more carbon atoms may be replaced by —O—, —COO—, —OCO—, —OOC—, —O(CO)O—, —N—, —NRa—, —CON—, wherein Ra is a C1-C12 alkyl group;
• or
• X1 and X2 independently from each other are represented by the group of formula (II)
• wherein
• n is an integer between 0 and 24, and wherein one or more C atoms may be replaced by —O—, —COO—, —OCO—, —OOC—, —O(CO)O—, —N—, —NRa—, —CON—, wherein Ra is a C1-C12 alkyl group;
• and
• PG represents a polymerisable group selected from the group consisting of CH2═C(Ph)-, CH2═CW—COO—, CH2═CH—COO-Ph-, CH2═CW—CO—NH—, CH2═CH—O—, CH2═CH—OOC—, Ph-CH═CH—, CH2═CH-Ph-, CH2═CH-Ph-O—, Rb-Ph-CH═CH—COO—, Rb—OOC—CH═CH-Ph-O— and 2-W-epoxyethyl;
• in which
• W represents H, Cl, Ph or a lower alkyl,
• Rb represents a lower alkyl with the proviso that when Rb is attached to a phenylene group (-Ph-) it may also represent hydrogen or a lower alkoxy.