Hexacyclic heteroaromatic compounds for electronic devices

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

• where the symbols used are as follows:
• Y is the same or different at each instance and is a bond or NR1, NAr, O, S, C(R1)2, CArR1, C(Ar)2, Si(Ar)2, SiArR1 or Si(R1)2, where at least one Y group is selected from NR1, NAr, O, S, C(R1)2, CArR1, C(Ar)2, Si(Ar)2, SiArR1 or Si(R1)2;
• X is the same or different at each instance and is N or CR1,
• Ar is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and may be substituted by one or more R1 radicals;
• at the same time, two Ar radicals bonded to the same carbon atom or silicon atom may also be joined to one another by a single bond or a bridge selected from B(R1), C(R1)2, Si(R1)2, C═O, C═NR1, C═C(R1)2, O, S, S═O, SO2, N(R1), P(R1) and P(═O)R1;
• R1 is the same or different at each instance and is H, D, OH, OR2, F, Cl, Br, I, CN, NO2, N(Ar1)2, N(R2)2, C(═O)Ar1, C(═O)R2, P(═O)(Ar1)2, P(Ar1)2, B(Ar1)2, B(OR2)2, Si(Ar1)3, Si(R2)3, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms, each of which may be substituted by one or more R2 radicals, where one or more nonadjacent CH2 groups may be replaced by —R2C═CR2—, —C≡C—, Si(R2)2, Ge(R2)2, Sn(R2)2, C═O, C═S, C═Se, C═NR2, —C(═O)O—, —C(═O)NR2—, NR2, P(═O)(R2), —O—, —S—, SO or SO2 and where one or more hydrogen atoms may be replaced by D, F, Cl, Br, I, CN or NO2, 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, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and may be substituted by one or more R2 radicals, or an aralkyl or heteroaralkyl group which has 5 to 40 aromatic ring atoms and may be substituted by one or more R2 radicals, or a combination of these systems, at the same time, two or more radicals may form a ring system with one another;
• Ar1 is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and may be substituted by one or more nonaromatic R2 radicals;
• at the same time, it is possible for two Ar1 radicals bonded to the same silicon atom, nitrogen atom, phosphorus atom or boron atom also to be joined to one another by a single bond or a bridge selected from B(R2), C(R2)2, Si(R2)2, C═O, C═NR2, C═C(R2)2, O, S, S═O, SO2, N(R2), P(R2) and P(═O)R2;
• R2 is the same or different at each instance and is H, D, F, Cl, Br, I, CN, B(OR3)2, NO2, C(═O)R3, CR3═C(R3)2, C(═O)OR3, C(═O)N(R3)2, Si(R3)3, P(R3)2, B(R3)2, N(R3)2, NO2, P(═O)(R3)2, OSO2R3, OR3, S(═O)R3, S(═O)2R3, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms, each of which may be substituted by one or more R3 radicals, where one or more nonadjacent CH2 groups may be replaced by —R3C═CR3—, —C≡C—, Si(R1)2, Ge(R3)2, Sn(R3)2, C═O, C═S, C═NR3, —C(═O)O—, —C(═O)NR3—, NR3, P(═O)(R3), —O—, —S—, SO or SO2 and where one or more hydrogen atoms may be replaced by D, F, Cl, Br, I, CN or NO2, 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 R3 radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and may be substituted by one or more R3 radicals, or a combination of these systems;
• at the same time, two or more substituents may also form a ring system with one another;
• R3 is the same or different at each instance and is selected from the group consisting of H, D, F, CN, an aliphatic hydrocarbyl radical having 1 to 20 carbon atoms or an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and in which one or more hydrogen atoms may be replaced by D, F, Cl, Br, I or CN and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms;
• at the same time, it is also possible for two or more substituents to form a ring system with one another.