A compound of formula I P-Sp-A 1 -(Z 1 -A 2) z -R I wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings P a polymerisable group, Sp a spacer group that is optionally substituted by one or more groups P or L a, or a single bond, A 1, A 2 an alicyclic, heterocyclic, aromatic or heteroaromatic group with 4 to 30 ring atoms, which may also contain fused rings, and is optionally substituted by one or more groups L or R, Z 1 -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH 2 -, -CH 2 O-, -SCH 2 -, -CH 2 S-, -CF 2 O-, -OCF 2 -, -CF 2 S-, -SCF 2 -, -(CH 2) n1 -, -CF 2 CH 2 -, -CH 2 CF 2 -, -(CF 2) n1 -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH 2 -CH 2 -CO-O-, -O-CO-CH 2 -CH 2 -, -CR 0 R 00 -, or a single bond, R 0, R 00 H or alkyl having 1 to 12 C atoms, R H, L, P-Sp- or L a -Sp-, L F, Cl, -CN, P-Sp-,L a, L a -Sp-, or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P, F, Cl or L a -, L a -C(R aa)(R bb)OH, R aa, R bb straight-chain alkyl with 1 to 20 C atoms, branched alkyl with 3 to 20 C atoms, or cyclic alkyl with 3 to 12, preferably 4 to 6, C atoms, or R aa and R bb together with the C atom to which they are attached form a cyclic alkyl group with 3 to 12, preferably 4 to 6, C atoms, wherein in all aforementioned groups one or more non-adjacent CH 2 -groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F or Cl, z 1, 2 or 3, n1 1, 2, 3 or 4, characterized in that the compound contains at least one group L a or L a -Sp-. P a polymerisable group, Sp a spacer group that is optionally substituted by one or more groups P or L a, or a single bond, A 1, A 2 an alicyclic, heterocyclic, aromatic or heteroaromatic group with 4 to 30 ring atoms, which may also contain fused rings, and is optionally substituted by one or more groups L or R, Z 1 -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH 2 -, -CH 2 O-, -SCH 2 -, -CH 2 S-, -CF 2 O-, -OCF 2 -, -CF 2 S-, -SCF 2 -, -(CH 2) n1 -, -CF 2 CH 2 -, -CH 2 CF 2 -, -(CF 2) n1 -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH 2 -CH 2 -CO-O-, -O-CO-CH 2 -CH 2 -, -CR 0 R 00 -, or a single bond, R 0, R 00 H or alkyl having 1 to 12 C atoms, R H, L, P-Sp- or L a -Sp-, L F, Cl, -CN, P-Sp-,L a, L a -Sp-, or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P, F, Cl or L a -, L a -C(R aa)(R bb)OH, R aa, R bb straight-chain alkyl with 1 to 20 C atoms, branched alkyl with 3 to 20 C atoms, or cyclic alkyl with 3 to 12, preferably 4 to 6, C atoms, or R aa and R bb together with the C atom to which they are attached form a cyclic alkyl group with 3 to 12, preferably 4 to 6, C atoms, wherein in all aforementioned groups one or more non-adjacent CH 2 -groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F or Cl, z 1, 2 or 3, n1 1, 2, 3 or 4,