Compound of formulae (I-A') or (I-A"-2) wherein one of R 10, R 11, R 12, R 13 and R 14 is a group of formula R 6 -Sp-[X 1] a - ∗ and R 6 is a group of formula (IV-A) and provided that at least one of R 10, R 11, R 12, R 13 and R 14 is R 15; wherein a is 0 or 1; R 1, R 2 and R 3 are at each occurrence independently selected from the group consisting of H, F, Cl, Br, I, alkyl having from 1 to 20 carbon atoms, partially or completely halogenated alkyl having from 1 to 20 carbon atoms, aryl and heteroaryl; R 4 is H and R 5 is a group of formula R 6 is a group of formula (IV-A) Sp is selected from the group consisting of alkanediyl, alkenediyl and alkyndiyl; X 1, X 2 are independently of each other selected from the group consisting of O, S and N-R 17; X 3 is N-R 17, R 10, R 11, R 12, R 13 and R 14 are at each occurrence independently of each other selected from the group consisting of H, F, Cl, Br, I, R 6 -Sp-[X 1] a - ∗, alkyl having from 1 to 20 carbon atoms, partially or completely halogenated alkyl having from 1 to 20 carbon atoms, aryl and heteroaryl, provided that at least one of R 10, R 11, R 12, R 13 and R 14 is R 15; R 15 is at each occurrence independently selected from the group consisting of alkyl having from 1 to 20 carbon atoms and partially or completely halogenated alkyl having from 1 to 20 carbon atoms; and R 17 is at each occurrence independently selected from the group consisting of H, alkyl having from 1 to 20 carbon atoms, partially or completely halogenated alkyl having from 1 to 20 carbon atoms and aryl, X 4 is selected from the group consisting of O, S, C(=O), C(=O)O and N-R 17; c is 0 or 1; and R 20, R 21 and R 22 are at each occurrence independently of each other selected from the group consisting of H, F, alkyl having from 1 to 20 carbon atoms, partially or completely halogenated alkyl having from 1 to 20 carbon atoms, aryl and heteroaryl. wherein one of R 10, R 11, R 12, R 13 and R 14 is a group of formula R 6 -Sp-[X 1] a - ∗ and R 6 is a group of formula (IV-A) and provided that at least one of R 10, R 11, R 12, R 13 and R 14 is R 15; wherein a is 0 or 1; R 1, R 2 and R 3 are at each occurrence independently selected from the group consisting of H, F, Cl, Br, I, alkyl having from 1 to 20 carbon atoms, partially or completely halogenated alkyl having from 1 to 20 carbon atoms, aryl and heteroaryl; R 4 is H and R 5 is a group of formula R 6 is a group of formula (IV-A) Sp is selected from the group consisting of alkanediyl, alkenediyl and alkyndiyl; X 1, X 2 are independently of each other selected from the group consisting of O, S and N-R 17; X 3 is N-R 17, R 10, R 11, R 12, R 13 and R 14 are at each occurrence independently of each other selected from the group consisting of H, F, Cl, Br, I, R 6 -Sp-[X 1] a - ∗, alkyl having from 1 to 20 carbon atoms, partially or completely halogenated alkyl having from 1 to 20 carbon atoms, aryl and heteroaryl, provided that at least one of R 10, R 11, R 12, R 13 and R 14 is R 15; R 15 is at each occurrence independently selected from the group consisting of alkyl having from 1 to 20 carbon atoms and partially or completely halogenated alkyl having from 1 to 20 carbon atoms; and R 17 is at each occurrence independently selected from the group consisting of H, alkyl having from 1 to 20 carbon atoms, partially or completely halogenated alkyl having from 1 to 20 carbon atoms and aryl, X 4 is selected from the group consisting of O, S, C(=O), C(=O)O and N-R 17; c is 0 or 1; and R 20, R 21 and R 22 are at each occurrence independently of each other selected from the group consisting of H, F, alkyl having from 1 to 20 carbon atoms, partially or completely halogenated alkyl having from 1 to 20 carbon atoms, aryl and heteroaryl.