Materials for organic electroluminescent devices

A compound of formula (1)

• where the symbols and indices used are as follows:
• X is the same or different at each instance and is CR or N, with the proviso that not more than two X groups per cycle are N, and also with the proviso that two adjacent X groups that are part of the same six-membered ring are CR, where the adjacent R radicals form an aromatic or heteroaromatic ring system which has 4 to 8 ring atoms, is fused onto the cycle and may be substituted by one or more R radicals;
• Y is the same or different at each instance and is a BR, C(R)2, C═O, Si(R)2, NR, NAr1, O, S, Se, SO, SO2, PR or P(═O)R, where, in the case that m or n is 0, the carbon atoms that bind to Y are each X;
• m and n are 0 or 1, where m+n is 1;
• Ari is an aromatic ring system which has 6 to 40 aromatic ring atoms and may be substituted by one or more R1 radicals, or a heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted by one or more R1 radicals;
• R is the same or different at each instance and is H, D, F, Cl, Br, I, N(Ar′)2, N(R1)2, OAr, SAr, B(OR1)2, CHO, C(═O)R1, CR1═C(R1)2, CN, C(═O)OR1, C(═O)NR1, Si(R1)3, NO2, P(═O)(R1)2, OSO2R1, OR′, S(═O)R1, S(═O)2R1, SR1, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may be substituted in each case by one or more R1 radicals, where one or more nonadjacent CH2 groups may be replaced by —R1C═CR1—, —C≡C—, Si(R1)2, NR1, CONR1, C═O, C═S, —C(═O)O—, P(═O)(R′), —O—, —S—, SO or SO2, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms, and may be substituted in each case by one or more R1 radicals, where two or more R radicals bonded to the same cycle may together form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system which may be substituted by one or more R1 radicals, and where two R radicals bonded to the same carbon or silicon atom may together form a monocyclic or polycyclic, aliphatic, aromatic or heteroaromatic ring system which may be substituted by one or more R1 radicals;
• Ar′ is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted by one or more R1 radicals;
• R1 is the same or different at each instance and is H, D, F, I, B(OR2)2, N(R2)2, CHO, C(═O)R2, CR2═C(R2)2, CN, C(═O)OR2, Si(R2)3, NO2, P(═O)(R2)2, OSO2R2, SR2, OR2, S(═O)R2, S(═O)2R2, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R2 radicals and where one or more CH2 groups in the abovementioned groups may be replaced by —R2C═CR2—, —C≡C—, Si(R2)2, C═O, C═S, —C(═O)O—, NR2, CONR2, P(═O)(R2), —O—, —S—, SO or SO2, and where one or more hydrogen atoms in the abovementioned groups may be replaced by D, F, Cl, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and may be substituted in each case by one or more R2 radicals, where two or more R1 radicals together may form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system;
• R2 is the same or different at each instance and is H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by D or F;
• at the same time, two or more R2 substituents may be joined to one another and may form a ring.