Materials for organic electroluminescent devices

A compound of the following formula (1):

• where the following applies to the symbols and indices used:
• Ar1 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 6 to 60 C atoms, selected from the group consisting of fluorene, spirobifluorene, biphenyl, terphenyl, quaterphenyl, carbazole, dibenzofuran and dibenzothiophene, each of which optionally is substituted by one or more radicals R5;
• Ar2 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 6 to 60 C atoms, which optionally in each case is substituted by one or more radicals R5;
• ArS is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 6 to 60 C atoms, which optionally in each case also is substituted by one or more radicals R5;
• R1, R2, R3, R4 are selected on each occurrence, identically or differently, from the group consisting of H, D, F, Cl, Br, I, CN, Si(R6)3, 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 optionally is substituted by one or more radicals R6, where in each case one or more non-adjacent CH2 groups optionally is replaced by Si(R6)2, C═NR6, P(═O)(R6), SO, SO2, NR6, O, S or CONR6 and where one or more H atoms optionally is replaced by D, F, Cl, Br or I, an aromatic or heteroaromatic ring system having 6 to 60 C atoms, which may in each case be substituted by one or more radicals R6, an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which optionally is substituted by one or more radicals R6, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R6, where two or more adjacent substituents R1 or R2 or R3 or R4 may optionally form a mono- or polycyclic, aliphatic ring system, which optionally is substituted by one or more radicals R6;
• R5 is selected on each occurrence, identically or differently, from the group consisting of H, D, F, Cl, Br, I, CN, Si(R6)3, 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 optionally is substituted by one or more radicals R6, where in each case one or more non-adjacent CH2 groups optionally is replaced by Si(R6)2, C═NR6, P(═O)(R6), SO, SO2, NR6, O, S or CONR6 and where one or more H atoms optionally is replaced by D, F, Cl, Br or I, an aromatic or heteroaromatic ring system having 6 to 60 C atoms, which may in each case be substituted by one or more radicals R6, an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which optionally is substituted by one or more radicals R6, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R6, where two or more adjacent substituents R5 optionally forms a mono- or polycyclic, aliphatic ring system, which optionally is substituted by one or more radicals R6;
• R6 is selected from the group consisting of H, D, F, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic or heteroaromatic ring system having 5 to 30 C atoms, in which one or more H atoms optionally is replaced by D or F, where two or more adjacent substituents R6 may form a mono- or polycyclic, aliphatic ring system with one another;
• is 1;
• m is 0, 1 or 2;
• n is on each occurrence, identically or differently, 0, 1, 2, 3 or 4;
• p, q are each 0;
• r, s are on each occurrence, identically or differently, 0, 1, 2, 3 or 4, where p+r<4 and q+s≦.