An aromatic monomer compound of formula I-X: wherein X independently from each other, are Br or I; R a independently of each other are hydrogen or linear or branched or cyclic C 1 -C 30 alkyl, preferably hydrogen or methyl; R b independently of each other, are hydrogen; linear or branched or cyclic C 1 -C 30 alkyl which is unsubstituted or substituted by one or more OH, C 1 -C 4 alkoxy, phenyl, or by CN; C 2 -C 12 alkyl which is interrupted by one or more non-consecutive O; halogen; OH; OR 3 ; SR 3 ; CN; NO 2 ; NR 1 R 2 ; (CO)R 3 ; (CO)OR 3 ; O(CO)OR 3 ; O(CO)NR 1 R 2 ; O(CO)R 3 ; C 1 -C 12 alkoxy; C 1 -C 12 alkylthio; (C 1 -C 6 alkyl)-NR 7 R 8 ; or-O-(C 1 -C 6 alkyl)NR 1 R 2 ; aryl or heteroaryl; wherein aryl is preferably phenyl, biphenyl, naphthyl, or anthryl all of which are unsubstituted or are substituted by one or more C 1 -C 4 -alkyl, CN, OR 3 , SR 3 , CH 2 OR 3 , (CO)OR 3 , (CO)NR 1 R 2 or halogen; R c independently of each other, are hydrogen; linear or branched or cyclic C 1 -C 30 alkyl which is unsubstituted or substituted by one or more OH, C 1 -C 4 alkoxy, phenyl, or by CN; C 2 -C 12 alkyl which is interrupted by one or more non-consecutive O; halogen; OH; OR 3 ; SR 3 ; CN; NO 2 ; NR 1 R 2 ; (CO)R 3 ; (CO)OR 3 ; O(CO)OR 3 ; O(CO)NR 1 R 2 ; O(CO)R 3 ; C 1 -C 12 alkoxy; C 1 -C 12 alkylthio; (C 1 -C 6 alkyl)-NR 7 R 8 ; or-O-(C 1 -C 6 alkyl)NR 1 R 2 ; or two groups R a , R b and R c , may together with the carbon atoms they are attached to, form a 5-8-membered cycle or heterocycle; R 1 and R 2 are, independently of each other, hydrogen, linear or branched C 1 -C 6 alkyl or phenyl, or R 1 and R 2 together with the nitrogen atom to which they are bonded form a group selected from R 3 is selected from H, C 1 -C 30 alkyl and phenyl, which may be unsubstituted or substituted by one or more C 1 -C 4 alkyl, phenyl, halogen, C 1 -C 4 alkoxy or C 1 -C 4 alkylthio. X independently from each other, are Br or I; R a independently of each other are hydrogen or linear or branched or cyclic C 1 -C 30 alkyl, preferably hydrogen or methyl; R b independently of each other, are hydrogen; linear or branched or cyclic C 1 -C 30 alkyl which is unsubstituted or substituted by one or more OH, C 1 -C 4 alkoxy, phenyl, or by CN; C 2 -C 12 alkyl which is interrupted by one or more non-consecutive O; halogen; OH; OR 3 ; SR 3 ; CN; NO 2 ; NR 1 R 2 ; (CO)R 3 ; (CO)OR 3 ; O(CO)OR 3 ; O(CO)NR 1 R 2 ; O(CO)R 3 ; C 1 -C 12 alkoxy; C 1 -C 12 alkylthio; (C 1 -C 6 alkyl)-NR 7 R 8 ; or-O-(C 1 -C 6 alkyl)NR 1 R 2 ; aryl or heteroaryl; wherein aryl is preferably phenyl, biphenyl, naphthyl, or anthryl all of which are unsubstituted or are substituted by one or more C 1 -C 4 -alkyl, CN, OR 3 , SR 3 , CH 2 OR 3 , (CO)OR 3 , (CO)NR 1 R 2 or halogen; R c independently of each other, are hydrogen; linear or branched or cyclic C 1 -C 30 alkyl which is unsubstituted or substituted by one or more OH, C 1 -C 4 alkoxy, phenyl, or by CN; C 2 -C 12 alkyl which is interrupted by one or more non-consecutive O; halogen; OH; OR 3 ; SR 3 ; CN; NO 2 ; NR 1 R 2 ; (CO)R 3 ; (CO)OR 3 ; O(CO)OR 3 ; O(CO)NR 1 R 2 ; O(CO)R 3 ; C 1 -C 12 alkoxy; C 1 -C 12 alkylthio; (C 1 -C 6 alkyl)-NR 7 R 8 ; or-O-(C 1 -C 6 alkyl)NR 1 R 2 ; or two groups R a , R b and R c , may together with the carbon atoms they are attached to, form a 5-8-membered cycle or heterocycle; R 1 and R 2 are, independently of each other, hydrogen, linear or branched C 1 -C 6 alkyl or phenyl, or R 1 and R 2 together with the nitrogen atom to which they are bonded form a group selected from R 3 is selected from H, C 1 -C 30 alkyl and phenyl, which may be unsubstituted or substituted by one or more C 1 -C 4 alkyl, phenyl, halogen, C 1 -C 4 alkoxy or C 1 -C 4 alkylthio. R 3 is selected from H, C 1 -C 30 alkyl and phenyl, which may be unsubstituted or substituted by one or more C 1 -C 4 alkyl, phenyl, halogen, C 1 -C 4 alkoxy or C 1 -C 4 alkylthio. <EOS>