Polymers containing substituted triarylamine units and electroluminescent devices containing said polymers

A polymer comprising at least one structural unit of the following formula (I):

• wherein the at least one structural unit of the formula (I) is selected from the structural unit of formula (Ia):
• where
• Ar1 to Ar3 is on each occurrence, in each case identically or differently, a mono- or polycyclic, aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R;
• R is on each occurrence, identically or differently, H, D, F, Cl, Br, I, N(R1)2, CN, NO2, Si(R1)3, B(OR1)2, C(═O)R1, P(═O)(R1)2, S(═O)R1, S(═O)2R1, OSO2R1, 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 may be substituted by one or more radicals R1, where one or more non-adjacent CH2 groups may be replaced by R1C═CR1, C≡C, Si(R1)2, C═O, C═S, C═NR1, P(═O)(R1), SO, SO2, NR1, O, S or CONR1 and where one or more H atoms may be replaced by D, F, Cl, Br, I or CN, or a mono- or polycyclic, aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R1, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R1, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R1, or a diarylamino group, diheteroarylamino group or arylheteroarylamino group having 10 to 40 aromatic ring atoms, which may be substituted by one or more radicals R1, or a crosslinkable group Q, where two or more radicals R may also form a mono- or polycyclic, aliphatic, aromatic and/or benzo-fused ring system with one another;
• R1 is on each occurrence, identically or differently, H, D, F or an aliphatic hydrocarbon radical having 1 to 20 C atoms, an aromatic and/or a heteroaromatic hydrocarbon radical having 5 to 20 C atoms, in which, in addition, one or more H atoms may be replaced by F;
• where two or more substituents R1 may also form a mono- or polycyclic, aliphatic or aromatic ring system with one another;
• and
• the dashed lines represent bonds to adjacent structural units in the polymer,
• characterised in that Ar3 is substituted by Ar4 in at least one, preferably in one of the two ortho-positions, where Ar4 is a mono- or polycyclic, aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R,
• q=0, 1, 2, 3, 4, 5 or 6,
• X═CR2, NR, SiR2, O, S, C═O or P═O, and
• r=0 or 1.