A compound comprising two or more repeating units, at least one of which is selected of formula I wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings R 1, R 2 straight-chain, branched or cyclic alkyl with 1 to 30, preferably 1 to 20, C atoms, in which one or more CH 2 groups are optionally replaced by -O-, -S-, -C(=O)-, -C(=S)-,-C(=O)-O-, -O-C(=O)-, -NR 0 -, -SiR 0 R 00 -, -CF 2 -, -CR 0 =CR 00 -,-CY 1 =CY 2 - or -C≡C- in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, C!, Br, I or CN, and in which one or more CH 2 or CH 3 groups are optionally replaced by a cationic or anionic group, or aryl, heteroaryl, arylalkyl or heteroarylalkyl, wherein each of the aforementioned cyclic groups has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, and is unsubstituted or substituted by one or more identical or different groups L, R 3-6 H, F, Cl, CN, or straight-chain, branched or cyclic alkyl with 1 to 30, preferably 1 to 20, C atoms, in which one or more CH 2 groups are optionally replaced by -O-, -S-, -C(=O)-, -C(=S)-,-C(=O)-O-, -O-C(=O)-, -NR 0 -, -SiR 0 R 00 -, -CF 2 -, -CR 0 =CR 00 -,-CY 1 =CY 2 - or -C≡C- in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, C!, Br, I or CN, and in which one or more CH 2 or CH 3 groups are optionally replaced by a cationic or anionic group, or aryl, heteroaryl, arylalkyl, heteroarylalkyl, aryloxy or heteroaryloxy, wherein each of the aforementioned cyclic groups has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, and is unsubstituted or substituted by one or more identical or different groups L, L F, C!, -CN, -NC, -NCO, -NCS, -OCN, -SCN, R 0, OR 0, SR 0,-C(=O)X 0, -C(=O)R 0, -C(=O)-OR 0, -O-C(=O)-R 0, -NH 2, -NHR 0, -NR 0 R 00, -C(=O)NHR 0, -C(=O)NR 0 R 00, -SO 3 R 0, -SO 2 R 0, -OH, -NO 2, -CF 3, -SF 5, or optionally substituted silyl, or carbyl or hydrocarbyl with with 1 to 30, preferably 1 to 20 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, preferably F, -CN, R 0, -OR 0, -SR 0,-C(=O)-R°, -C(=O)-OR 0, -O-C(=O)-R 0, -O-C(=O)-OR°, -C(=O)-NHR 0, -C(=O)-NR 0 R 00, Y 1, Y 2 H, F, Cl or CN, X 0 halogen, preferably F or CI, R 0, R 00 H or straight-chain or branched alkyl with 1 to 20, preferably 1 to 12, C atoms that is optionally fluorinated, a1, b1 0, 1 or 2, wherein a1+b1>0, c1, d1 0, 1 or 2, wherein a1+c1≤3 and b1+d1≤3. R 1, R 2 straight-chain, branched or cyclic alkyl with 1 to 30, preferably 1 to 20, C atoms, in which one or more CH 2 groups are optionally replaced by -O-, -S-, -C(=O)-, -C(=S)-,-C(=O)-O-, -O-C(=O)-, -NR 0 -, -SiR 0 R 00 -, -CF 2 -, -CR 0 =CR 00 -,-CY 1 =CY 2 - or -C≡C- in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, C!, Br, I or CN, and in which one or more CH 2 or CH 3 groups are optionally replaced by a cationic or anionic group, or aryl, heteroaryl, arylalkyl or heteroarylalkyl, wherein each of the aforementioned cyclic groups has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, and is unsubstituted or substituted by one or more identical or different groups L, R 3-6 H, F, Cl, CN, or straight-chain, branched or cyclic alkyl with 1 to 30, preferably 1 to 20, C atoms, in which one or more CH 2 groups are optionally replaced by -O-, -S-, -C(=O)-, -C(=S)-,-C(=O)-O-, -O-C(=O)-, -NR 0 -, -SiR 0 R 00 -, -CF 2 -, -CR 0 =CR 00 -,-CY 1 =CY 2 - or -C≡C- in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, C!, Br, I or CN, and in which one or more CH 2 or CH 3 groups are optionally replaced by a cationic or anionic group, or aryl, heteroaryl, arylalkyl, heteroarylalkyl, aryloxy or heteroaryloxy, wherein each of the aforementioned cyclic groups has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, and is unsubstituted or substituted by one or more identical or different groups L, L F, C!, -CN, -NC, -NCO, -NCS, -OCN, -SCN, R 0, OR 0, SR 0,-C(=O)X 0, -C(=O)R 0, -C(=O)-OR 0, -O-C(=O)-R 0, -NH 2, -NHR 0, -NR 0 R 00, -C(=O)NHR 0, -C(=O)NR 0 R 00, -SO 3 R 0, -SO 2 R 0, -OH, -NO 2, -CF 3, -SF 5, or optionally substituted silyl, or carbyl or hydrocarbyl with with 1 to 30, preferably 1 to 20 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, preferably F, -CN, R 0, -OR 0, -SR 0,-C(=O)-R°, -C(=O)-OR 0, -O-C(=O)-R 0, -O-C(=O)-OR°, -C(=O)-NHR 0, -C(=O)-NR 0 R 00, Y 1, Y 2 H, F, Cl or CN, X 0 halogen, preferably F or CI, R 0, R 00 H or straight-chain or branched alkyl with 1 to 20, preferably 1 to 12, C atoms that is optionally fluorinated, a1, b1 0, 1 or 2, wherein a1+b1>0, c1, d1 0, 1 or 2, wherein a1+c1≤3 and b1+d1≤3.