A lactone monomer having a structure of general formula wherein n is selected from 0, 1 or 2; m is selected from 0, 1 or 2; and m + n is 2; R 1 is selected from CN, COOR 4, CONR 5 R 6, halogen or NO 2; one of R 2 and R 3 is selected from CN, COOR 4, CONR 5 R 6, halogen or NO 2, while the other one is selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted O-alkyl, or substituted or unsubstituted O-aryl; with the condition that if n is 0, R 2 is H, and if m is 0, R 3 is H; R 4 is selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, or substituted or unsubstituted alkyl-aryl; R 5 and R 6 are independently of each other selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted alkyl-aryl, substituted or unsubstituted heterocyclyl, or substituted or unsubstituted alkyl-heterocyclyl, alternatively, R 5 and R 6 taken together with the nitrogen atom to which they are attached, may form a substituted or unsubstituted heterocyclyl, wherein alkyl, alkenyl, alkynyl and O-alkyl if substituted, as well as alkylaryl, alkylheterocycly, alkylcycloalkyl if substituted on the alkyl, is substituted by halogen (F, Cl, Br, I), -NR c R c', -SR c, -S R c, -S 2 R c, -OR c, -C OR c, -CN, -C NR c R c', or a linear or branched, substituted or unsubstituted -OC 1-6 alkyl, with R c and R c' being represented by H or by a linear or branched, substituted or unsubstituted C 1-6 -alkyl; and wherein aryl, cycloalkyl or heterocyclyl if substituted as well as alkyl-aryl, alkyl-cycloalkyl, or alkyl-heterocyclyl, if substituted on the ring-system, substituted by halogen (F, Cl, Br, I), -R c,-OR c, -CN, -NO 2, -NR c R c', -C OR c, NR c C R c', -C NR c R c', -NR c S 2 R c', =O, -OCH 2 CH 2 OR c, -NR c C NR c' R c", -S 2 NR c R c', -NR c S 2 NR c' R c", haloalkyl, haloalkoxy, -SR c, -S R c, -S 2 R c, -C(CH 3)OR c; NR c R c', or linear or branched, substituted or unsubstituted -OC 1-6 alkyl, with R c, R c' and R c" being represented by H or by a linear or branched, substituted or unsubstituted C 1-6 -alkyl. n is selected from 0, 1 or 2; m is selected from 0, 1 or 2; and m + n is 2; R 1 is selected from CN, COOR 4, CONR 5 R 6, halogen or NO 2; one of R 2 and R 3 is selected from CN, COOR 4, CONR 5 R 6, halogen or NO 2, while the other one is selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted O-alkyl, or substituted or unsubstituted O-aryl; with the condition that if n is 0, R 2 is H, and if m is 0, R 3 is H; R 4 is selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, or substituted or unsubstituted alkyl-aryl; R 5 and R 6 are independently of each other selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted alkyl-aryl, substituted or unsubstituted heterocyclyl, or substituted or unsubstituted alkyl-heterocyclyl, alternatively, R 5 and R 6 taken together with the nitrogen atom to which they are attached, may form a substituted or unsubstituted heterocyclyl, wherein alkyl, alkenyl, alkynyl and O-alkyl if substituted, as well as alkylaryl, alkylheterocycly, alkylcycloalkyl if substituted on the alkyl, is substituted by halogen (F, Cl, Br, I), -NR c R c', -SR c, -S R c, -S 2 R c, -OR c, -C OR c, -CN, -C NR c R c', or a linear or branched, substituted or unsubstituted -OC 1-6 alkyl, with R c and R c' being represented by H or by a linear or branched, substituted or unsubstituted C 1-6 -alkyl; and wherein aryl, cycloalkyl or heterocyclyl if substituted as well as alkyl-aryl, alkyl-cycloalkyl, or alkyl-heterocyclyl, if substituted on the ring-system, substituted by halogen (F, Cl, Br, I), -R c,-OR c, -CN, -NO 2, -NR c R c', -C OR c, NR c C R c', -C NR c R c', -NR c S 2 R c', =O, -OCH 2 CH 2 OR c, -NR c C NR c' R c", -S 2 NR c R c', -NR c S 2 NR c' R c", haloalkyl, haloalkoxy, -SR c, -S R c, -S 2 R c, -C(CH 3)OR c; NR c R c', or linear or branched, substituted or unsubstituted -OC 1-6 alkyl, with R c, R c' and R c" being represented by H or by a linear or branched, substituted or unsubstituted C 1-6 -alkyl.