Materials for organic electroluminescent devices

A compound of the formula (1) to formula (4)

• wherein
• Y is on each occurrence, identically or differently, CR1 or N;
• Z is equal to C if a bridge X is bonded to the group Z and is equal to Y if no bridge X is bonded to the group Z;
• X is on each occurrence, identically or differently, a divalent bridge selected from B(R1), C(R1)2, Si(R1)2, C═O, C═NR1, C═C(R1)2, O, S, S═O, SO2, N(R1), P(R1) and P(═O)R1;
• R1 is on each occurrence, identically or differently, H, F, Cl, Br, T, N(Ar)2, C(═O)Ar, P(═O)Ar2, S(═O)Ar, S(═O)2Ar, CR2═CR2Ar, CN, NO2, Si(R2)3, B(OR2)2, 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 may be substituted by one or more radicals R2 and in which one or more non-adjacent CH2 groups may be 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 in which one or more H atoms is optionally replaced by F, Cl, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which optionally in each case be substituted by one or more radicals R2, or an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R2, or a combination of these systems;
• two or more adjacent substituents R1 here optionally form a mono- or polycyclic aliphatic or aromatic ring system with one another;
• Ar is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5-30 aromatic ring atoms, which is optionally substituted by one or more non-aromatic radicals R1;
• two radicals Ar here on the same nitrogen or phosphorus atom are optionally linked to one another by a single bond or a bridge X;
• R2 is on each occurrence, identically or differently, H or an aliphatic, aromatic and/or heteroaromatic hydrocarbon radical having 1 to 20 C atoms, in which, in addition, H atoms is optionally replaced by F;
• two or more adjacent substituents R2 here optionally forms a mono- or polycyclic aliphatic or aromatic ring system with one another;
• a, b, c and d are on each occurrence, identically or differently, 0 or 1, with the proviso that a+b=1 or 2 and c+d=1 or 2, where a=0 and b=0 and c=0 and d=0 in each case means that the corresponding bridge X is not present;
• with the exception of the following compounds: