Materials for organic electroluminescent devices

An organic electroluminescent device (OLED) comprising a compound of the formula (2A),

• where the following applies to the symbols and indices used:
• R1 stands on each occurrence, identically or differently, for H, D, F, CN, a straight-chain alkyl groups having 1 to 10 C, where one or more H atoms may be replaced by D or F;
• R2 stands on each occurrence, identically or differently, from the group consisting of F, CN, a straight-chain alkyl, alkoxy or thioalkyl groups having 1 to 20 C atoms or a branched or a cyclic alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, each of which may be substituted by one or more radicals R3, where in each case one or more non-adjacent CH2 groups may be replaced by R3C═CR3, C═C, C═O, P(═O)(R3), SO, SO2, O, S or CONR3 and where one or more H atoms may be replaced by D or F, an aromatic or heteroaromatic ring systems having 5 to 30 aromatic ring atoms, which may in each case be substituted by one or more radicals R3, or an aryloxy groups having 5 to 30 aromatic ring atoms, which may be substituted by one or more radicals R3;
• R3 stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(Ar)2, C(═O)Ar, P(═O)(Ar)2, S(═O)Ar, S(═O)2Ar, NO2, Si(R4)3, B(OR4)2, OSO2R4, a straight-chain alkyl, alkoxy or thioalkyl groups having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 40 C atoms, each of which may be substituted by one or more radicals R4, where in each case one or more non-adjacent CH2 groups may be replaced by R4C═CR4, C≡C, Si(R4)2, Ge(R4)2, Sn(R4)2, C═O, C═S, C═Se, P(═O)(R4), SO, SO2, O, S or CONR4 and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO2, an aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R4, or an aryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R4, where two adjacent substituents R3 may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R4;
• R4 stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CN, a straight-chain alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, where in each case one or more non-adjacent CH2 groups may be replaced by SO, SO2, O, S and where one or more H atoms may be replaced by D, F, Cl, Br or I, or an aromatic or heteroaromatic ring system having 5 to 24 C atoms;
• Ar is on each occurrence, identically or differently, and aromatic of heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may in each case also be substituted by one or more radicals R4;
• n is on each occurrence equal to 1 and
• wherein the OLED comprising the compound of the formula (2A), is employed as an electron-acceptor material in a hole-injection layer.