Materials for organic electroluminescent devices

A compound of the formula (1) or (2),

• where the following applies to the symbols and indices used:
• X is O or S;
• ArS is an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which may in each case also be substituted by one or more radicals R3;
• Ar is a condensed aryl group having 10 to 40 aromatic ring atoms,
• which may in each case be substituted by one or more radicals R3
• or Ar is a group of formula (Ar-1),
• with the proviso that Ar is not a fluoranthene;
• and where the dashed line represents the bond to ArS or, if ArS is absent, to the phenyl group of the heterocycle comprising X as depicted in formula (1) or (2);
• E is O, S, C(R0)2;
• wherein when t is 0 then the divalent bridge E is absent;
• R0, R1, R2, R3 are on each occurrence, identically or differently, H, D, F, Cl, Br, I, CHO, C(═O)Ar1, P(═O)(Ar1)2, S(═O)Ar1, S(═O)2Ar1, (R4)C═C(R4)Ar1, CN, NO2, N(R4)2, Si(R4)3, B(OR4)2, B(R4)2, B(N(R4)2)2, OSO2R4, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a straight-chain alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R4, where one or more, CH2 groups is optionally replaced by (R4)C═C(R4), C≡C, Si(R4)2, Ge(R4)2, Sn(R4)2, C═O, C═S, C═Se, P(═O)(R4), SO, SO2, N(R4), O, S or CON(R4) and where one or more H atoms is optionally replaced by D, F, Cl, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R4, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R4;
• two adjacent substituents R0, two or more adjacent substituents R1, two or more adjacent substituents R2 and/or two or more adjacent substituents R3 may also form a mono- or polycyclic, aliphatic or aromatic or heteroaromatic ring system with one another;
• Ar1 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which may in each case be substituted by one or more radicals R4;
• R4 is on each occurrence, identically or differently selected from the group consisting of H, D, F, Cl, Br, I, CN, Si(R5)3, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl with 3-40 C-atoms which is optionally substituted by one or more radicals R5, wherein each one or more non-adjacent CH2 groups by is optionally replaced C(R5)═C(R5), Si(R5)2, C═NR5, P(═O)(R5), SO, SO2, NR5, O, S or CONR5 and where one or more H atoms is optionally replaced by D, F, Cl, Br or I, an aromatic or heteroaromatic ring system having 6 to 40 carbon atoms which is optionally substituted by one or more radicals R5, an aryloxy group having 5 to 40 aromatic ring atoms which is optionally substituted by one or more radicals R5, or an aralkyl group having 5 to 40 aromatic ring atoms which is optionally substituted by one or more radicals R5, where optionally two or more adjacent substituents R4 can form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system with one another;
• R5 is selected from the group consisting of H, D, F, an aliphatic hydrocarbon radical having 1 to 20 carbon atoms or an aromatic or heteroaromatic ring system having 5 to 30 C atoms, wherein two or more adjacent substituents R5 can form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system with one another;
• m, n, r, u are each, identically or differently, 0, 1, 2 or 3;
• p, t are each, identically or differently, 0 or 1;
• q, v are each, identically or differently, 0, 1, 2, 3 or 4;
• s is 0, 1 or 2.