Materials for organic electroluminescent devices

A compound of formula (1):

• wherein
• Ar1 is on each occurrence, identically or differently, an aryl or heteroaryl group having 6 to 18 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R1, wherein at least one Ar1 has 10 or more aromatic ring atoms;
• Ar2 is on each occurrence, identically or differently, an aryl or heteroaryl group having 6 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R1;
• Ar3 and Ar4
• are on each occurrence, identically or differently, an aromatic or heteroaromatic ring systems having 5 to 25 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R1;
• wherein at least one Ar3 is a group of formula (Ar3-2) and/or at least one Ar4 is a group of formula (Ar4-2):
• wherein
• the dashed bonds in the group of formula (Ar3-2) indicate the bonding to Ar1 and to a group Ar3 or Ar4;
• the dashed bond in the group of formula (Ar4-2) indicates the bonding to Ar3;
• E1 stands for —C(R0)2;
• and
• the groups of formulae (Ar3-2) and (Ar4-2) are optionally substituted at each free position by a group R1;
• E is identically or differently on each occurrence, selected from the group consisting of —BR0—, —C(R0)2—, —C(R0)2—C(R0)2—, —C(R0)2—O—, C(R0)2—S—, —R0C═CR0—, —R0C═N—, —Si(R0)2—, —Si(R0)2—Si(R0)2—, —C(═O)—, —C(═NR0)—, —C(═C(R0)2—, —O—, —S—, —S(═O)—, —SO2—, —N(R0)—, —P(R0)—, and —P((═O)R0)—, wherein two groups E are optionally in a cis or trans position relative to each other;
• R0 and R1
• are on each occurrence, identically or differently, H, D, F, Cl, Br, I, CHO, CN, N(Ar5)2, C(═O)Ar5, P(═O)(Ar5)2, S(═O)Ar5, S(═O)2Ar5, NO2, Si(R2)3, B(OR2)2, OSO2R2, a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R2, wherein in each case one or more non-adjacent CH2 groups are optionally replaced by R2C═CR2, C≡C, Si(R2)2, Ge(R2)2, Sn(R2)2, C═O, C═S, C═Se, P(═O)(R2), SO, SO2, O, S, or CONR2 and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, I, CN, or NO2, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R2, or an aryloxy group having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R2, and wherein two adjacent substituents R0 and/or two adjacent substituents R1 optionally define a mono- or polycyclic, aliphatic ring system or aromatic ring system, which is optionally substituted by one or more radicals R2;
• R2 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, CHO, CN, N(Ar5)2, C(═O)Ar5, P(═O)(Ar5)2, S(═O)Ar5, S(═O)2Ar5, NO2, Si(R3)3, B(OR3)2, OSO2R3, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R3, wherein in each case one or more non adjacent CH2 groups is optionally replaced by R3C═CR3, C≡C, Si(R3)2, Ge(R3)2, Sn(R3)2, C═O, C═S, C═Se, P(═O)(R3), SO, SO2, O, S, or CONR3 and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, I, CN, or NO2, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R3, or an aryloxy group having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R3, and where two adjacent substituents R2 optionally define a mono- or polycyclic, aliphatic ring system or aromatic ring system, which is optionally substituted by one or more radicals R3;
• R3 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, CN, a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 20 C atoms, wherein in each case one or more non adjacent CH2 groups is optionally replaced by SO, SO2, O, or S and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, or I, or an aromatic or heteroaromatic ring system having 5 to 24 C atoms;
• Ar5 is an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R3;
• n is an integer from 2 to 20.