Compound comprising a group terminal group of formula wherein: A 1 and A 2 each independently are a ring system of 5 to 40 atoms, wherein each ring system includes at least one unsaturation directly connected via electron conjugation (π-π bonding) to the double bond shown in formula; and wherein and A 2 is linked to a polymerizable group by a single bond or at least one spacer unit; R 1 is hydrogen, a substituent L, wherein L is halogen, hydroxy nitro, cyano or carboxy, and/or acryloyloxy, alkoxy, alkylcarbonyloxy, alkyloxocarbonyloxy, methacryloyloxy, vinyl, vinyloxy, allyl, allyloxy, and/or a cyclic, straight-chain or branched alkyl residue, which is unsubstituted, mono- or poly-substituted by fluorine and/or chlorine, and/or a silane group, and/or a siloxane group, wherein the alkyl residue has from 1 to 20 C-atoms, wherein one or more, preferably non-adjacent, -CH 2 - groups independently may be replaced by a group, preferably selected from -O-, -S-, -NH-, -N(C 1 -C 6)alkyl, -CO-, -COO-, -OCO-, -C=C-, -C≡C-, -Si(CH 3) 2 -, -Si(CH 3) 2 -O-Si(CH 3) 2 -, and wherein if W is hydrogen and Z is an electron withdrawing group, then R 4, R 5 are hydrogen, and R 2 and R 3 form together the residue of an electron-donating ring which is condensed to ring A 1; or if W is hydrogen and Z is an electron withdrawing group, then R 4, R 5 are independently from each other a substituent L, which is halogen, hydroxy and/or a polar group; or an electron-donating single substituent, or R 4, R 5 form together the residue of an electron-donating ring which is condensed to ring A 2, then R 2 and R 3 form together the residue of an electron-donating ring which is condensed to ring A 1; or if W is an electron withdrawing group and Z is hydrogen, then R 4, R 5 are independently from each other hydrogen, a substituent L, wherein L is halogen, hydroxy nitro, cyano or carboxy, and/or acryloyloxy, alkoxy, alkylcarbonyloxy, alkyloxocarbonyloxy, methacryloyloxy, vinyl, vinyloxy, allyl, allyloxy, and/or a cyclic, straight-chain or branched alkyl residue, which is unsubstituted, mono- or poly-substituted by fluorine and/or chlorine, and/or a silane group, and/or a siloxane group, wherein the alkyl residue has from 1 to 20 C-atoms, wherein one or more, preferably non-adjacent, -CH 2 - groups independently may be replaced by a group, preferably selected from -O-, -S-, -NH-, -N(C 1 -C 6)alkyl, -CO-, -COO-, -OCO-, -C=C-, -C≡C-, -Si(CH 3) 2 -, -Si(CH 3) 2 -O-Si(CH 3) 2 -; an electron-donating single substituent, or R 4, R 5 form together the residue of an electron-donating ring which is condensed to ring A 2 or hydrogen, and R 2 and R 3 are independently from each other an electron-donating single substituent, or form together the residue of an electron-donating ring which is condensed to ring A 1. A 1 and A 2 each independently are a ring system of 5 to 40 atoms, wherein each ring system includes at least one unsaturation directly connected via electron conjugation (π-π bonding) to the double bond shown in formula; and wherein and A 2 is linked to a polymerizable group by a single bond or at least one spacer unit; R 1 is hydrogen, a substituent L, wherein L is halogen, hydroxy nitro, cyano or carboxy, and/or acryloyloxy, alkoxy, alkylcarbonyloxy, alkyloxocarbonyloxy, methacryloyloxy, vinyl, vinyloxy, allyl, allyloxy, and/or a cyclic, straight-chain or branched alkyl residue, which is unsubstituted, mono- or poly-substituted by fluorine and/or chlorine, and/or a silane group, and/or a siloxane group, wherein the alkyl residue has from 1 to 20 C-atoms, wherein one or more, preferably non-adjacent, -CH 2 - groups independently may be replaced by a group, preferably selected from -O-, -S-, -NH-, -N(C 1 -C 6)alkyl, -CO-, -COO-, -OCO-, -C=C-, -C≡C-, -Si(CH 3) 2 -, -Si(CH 3) 2 -O-Si(CH 3) 2 -,