Materials for organic electroluminescent devices

A blend comprising:

• a) at least one polymer or copolymer or a mixture of a plurality of polymers and/or copolymers, where the at least one polymer or copolymer contains at least one structural unit of the following formula (I) in the side chains
• where the dashed line represents the connection to the polymer or copolymer backbone, and the other symbols and indices used have the following meanings:
• L is on each occurrence, identically or differently, a single covalent bond or a straight-chain alkylene group having 1 to 20 C atoms or a branched or cyclic alkylene group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R1, where one or more non-adjacent CH2 groups is optionally replaced by R2C═CR2, C≡C, Si(R2)2, Ge(R2)2, Sn(R2)2, C═O, C═S, C═Se, C═NR2, P(═O)(R2), SO, SO2, NR2, O, S or CONR2 and where one or more H atoms is optionally replaced by F, Cl, Br, I, CN or NO2;
• Ar1 is on each occurrence, identically or differently, a divalent, mono- or polycyclic, aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R1;
• Ar2 is on each occurrence, identically or differently, a mono- or polycyclic, aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R1;
• Q is a unit selected from the group consisting of a group —X(=A)-, where A=O, S, Se or Te, and mono- or polycyclic aromatic ring systems having 6 to 60 aromatic carbon atoms or mono- or polycyclic heteroaromatic ring systems having 2 to 50 aromatic carbon atoms;
• m is 0, 1, 2 or 3;
• l is 0, 1, 2 or 3;
• s is 1 in the case of Q=—X(=A)-;
• is 1 to 5, in the case where Q is selected from the group consisting of mono- or polycyclic aromatic ring systems having 6 to 60 aromatic carbon atoms or mono- or polycyclic heteroaromatic ring systems having 2 to 50 aromatic carbon atoms;
• and is 1 or 2 in the case m=0;
• R1 is on each occurrence, identically or differently, D, F, Cl, Br, I, N(Ar3)2, CN, NO2, Si(R2)3, B(OR2)2, C(═O)Ar3, P(═O)(Ar3)2, S(═O)Ar3, S(═O)2Ar3, —CR2═CR2(Ar3), a mono- or polycyclic, aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, tosylate, triflate, OSO2R2, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R2, where one or more non-adjacent CH2 groups is optionally replaced by R2C═CR2, C≡C, Si(R2)2, Ge(R2)2, Sn(R2)2, C═O, C═S, C═Se, C═NR2, P(═O)(R2), SO, SO2, NR2, O, S or CONR2 and where one or more H atoms is optionally replaced by F, Cl, Br, I, CN or NO2, or a combination of these systems;
• where two or more adjacent substituents R1 may also be linked to one another via a single covalent bond or a divalent group Z;
• X is selected from the group consisting of C, P(Ar4), S and SO;
• R2 is on each occurrence, identically or differently, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH2 groups is optionally replaced by NH, O or S and where one or more H atoms is optionally replaced by F, or a mono- or polycylic, aromatic or heteroaromatic ring system having 5 to 20 aromatic ring atoms, which may in each case be substituted by one or more radicals R3;
• where two or more substituents R2 may also be linked to one another via a single covalent bond or a divalent group Z;
• R3 is on each occurrence, identically or differently, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH2 groups is optionally replaced by NH, O or S and where one or more H atoms is optionally replaced by F;
• where two or more substituents R3 may also be linked to one another via a single covalent bond or a divalent group Z;
• Ar3 and Ar4 are on each occurrence, identically or differently, a mono- or polycyclic, aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R3;
• Z represents a divalent group —(CR42)q—;
• q is equal to 1, 2, 3, 4 or 5;
• R4 is on each occurrence, identically or differently, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH2 groups is optionally replaced by NH, O or S and where one or more H atoms is optionally replaced by F;
• b) at least one host molecule which has electron- or hole-transporting functionality, and
• c) at least one emitter molecule.