Heterocyclic compounds for organic electroluminescent devices

A compound comprising at least one structure of the formula (I):

• where the symbols and indices used are as follows:
• X is N, CR or, if p=1, C;
• X1 is the same or different at each instance and is N, CAra or CR1, with the proviso that not more than two of the X1 groups in one cycle are N;
• X2 is the same or different at each instance and is N, CArb or CR2, with the proviso that not more than two of the X2 groups in one cycle are N;
• X3 is the same or different at each instance and is N, CArc or CR3, with the proviso that not more than two of the X3 groups in one cycle are N;
• p is 0 or 1, where the aromatic or heteroaromatic 6-membered ring with the X3 radicals is absent if p=0;
• Ara 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;
• Arb 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 R2 radicals;
• Arc 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 R3 radicals;
• R is the same or different at each instance and is H, D, F, Cl, Br, I, N(R4)2, N(Ar′)2, CN, NO2, OR4, OAr′, SR4, SAr′, COOR4, C(═O)N(R4)2, Si(R4)3, B(OR4)2, C(═O)R4, P(═O)(R4)2, S(═O)R4, S(═O)2R4, OSO2R4, 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 R4 radicals, where one or more nonadjacent CH2 groups may be replaced by Si(R4)2, C═O, NR4, O, S or CONR4, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms, and may be substituted in each case by one or more R4 radicals;
• at the same time, two R radicals together or one R radical together with one R2 radical may also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system;
• R1 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R4)2, N(Ar′)2, CN, NO2, OR4, OAr′, SR4, SAr′, COOR4, C(═O)N(R4)2, Si(R4)3, B(OR4)2, C(═O)R4, P(═O)(R4)2, S(═O)R4, S(═O)2R4, OSO2R4, 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 R4 radicals, where one or more nonadjacent CH2 groups may be replaced by Si(R4)2, C═O, NR4, O, S or CONR4, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms, and may be substituted in each case by one or more R4 radicals;
• at the same time, two R1 radicals together or one R1 radical together with one R2 radical may also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system;
• R2 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R4)2, N(Ar′)2, CN, NO2, OR4, OAr′, SR4, SAr′, COOR4, C(═O)N(R4)2, Si(R4)3, B(OR4)2, C(═O)R4, P(═O)(R4)2, S(═O)R4, S(═O)2R4, OSO2R4, 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 R4 radicals, where one or more nonadjacent CH2 groups may be replaced by Si(R4)2, C═O, NR4, O, S or CONR4, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms, and may be substituted in each case by one or more R4 radicals;
• at the same time, two R2 radicals together or one R2 radical together with one R, R1, R3 radical may also form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system;
• R3 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R4)2, N(Ar′)2, CN, NO2, OR4, OAr′, SR4, SAr′, COOR4, C(═O)N(R4)2, Si(R4)3, B(OR4)2, C(═O)R4, P(═O)(R4)2, S(═O)R4, S(═O)2R4, OSO2R4, 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 R4 radicals, where one or more nonadjacent CH2 groups may be replaced by Si(R4)2, C═O, NR4, O, S or CONR4, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms, and may be substituted in each case by one or more R4 radicals;
• at the same time, two R3 radicals together or one R3 radical together with one R2 radical may also form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system;
• 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 R4 radicals;
• R4 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R5)2, CN, NO2, OR5, SR5, Si(R5)3, B(OR5)2, C(═O)R5, P(═O)(R5)2, S(═O)R5, S(═O)2R5, OSO2R5, 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 R5 radicals and where one or more nonadjacent CH2 groups may be replaced by Si(R5)2, C═O, NR5, O, S or CONR5, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R2 radicals;
• at the same time, two or more R4 radicals together may form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system;
• R5 is the same or different at each instance and is H, D, F or an aliphatic, aromatic or heteroaromatic organic radical, in which one or more hydrogen atoms may also be replaced by F;
• characterized in that
• in at least one of the rings having the X1, X2 or X3 groups, two nonadjacent X1, X2 or X3 groups in one ring are N.