Nitrogenous heterocycles for organic electroluminescent devices

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

• Formula (I)
• where the symbols are as follows:
• A is the same or different at each instance and is B(R), B(Ar), P(R)O, P(Ar)O, C(R)2, C(Ar)2, Si(R)2, Si(Ar)2, Ge(R)2, Ge(Ar)2, Ti(R)2, Ti(Ar)2, Zr(R)2, Zr(Ar)2, Hf(R)2, Hf(Ar)2, SO2 or SO;
• Z is the same or different at each instance and is N(Ra), N(Ara), 0 or 5;
• X1 is the same or different at each instance and is N or CRb, with the proviso that not more than two of the X1, X2, X3 groups in one cycle are N, or the X1 group together with an X2 group forms an ortho-bonded aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and may be substituted by one or more Rb radicals;
• X2 is the same or different at each instance and is N or CRb, with the proviso that not more than two of the X1, X2, X3 groups in one cycle are N;
• X3 is the same or different at each instance and is N or CRb, with the proviso that not more than two of the X1, X2, X3 groups in one cycle are N, or the X3 group together with an X2 group forms an ortho-bonded aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and may be substituted by one or more Rb radicals, where the X2 group forms an aromatic or heteroaromatic ring system with not more than one X1 or X3 group in any cycle;
• R is the same or different at each instance and is H, D, OH, F, Cl, Br, I, CN, NO2, N(Ar)2, N(R′)2, C(═O)N(Ar)2, C(═O)N(R′)2, C(Ar)3, C(R′)3, Si(Ar)3, Si(R′)3, Ge(R′)2, Ge(Ar)3, B(Ar)2, B(R′)2, C(═O)Ar, C(═O)Rc, P(=O)(Ar)2, P(=O)(Rc)2, P(Ar)2, P(Rc)2, S(═O)Ar, S(═O)Rc, S(═O)2Ar, S(═O)2Rc, OSO2Ar, OSO2Rc, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 carbon atoms, where the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group may in each case be substituted by one or more Rc radicals, where one or more nonadjacent CH2 groups may be replaced by RcC=CRc, C≡C, Si(Rc)2, Ge(Rc)2, C═O, C=S, C=Se, C=NRc, —C(═O)O—, —C(═O)NRc—, NRc, P(=O)(Rc), —O—, —S—, SO or SO2, 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 Rc radicals, or an aryloxy or heteroaryloxy group which has 5 to 60 aromatic ring atoms and may be substituted by one or more Rc radicals, or an arylthio or heteroarylthio group which has 5 to 60 aromatic ring atoms and may be substituted by one or more Rc radicals, or a diarylamino, arylheteroarylamino, diheteroarylamino group which has 5 to 60 aromatic ring atoms and may be substituted by one or more Rc radicals, or an arylalkyl or heteroarylalkyl group which has 5 to 60 aromatic ring atoms and 1 to 10 carbon atoms in the alkyl radical and may be substituted by one or more Rc radicals;
• at the same time, one R radical may form a ring system together with a further group;
• 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 Rc radicals;
• at the same time, it is possible for two Ar radicals bonded to the same carbon atom, silicon atom, germanium atom, titanium atom, zirconium atom, hafnium atom also to be bridged to one another by a single bond or a bridge selected from B(Rc), C(Rc)2, Si(Rc)2, Ge(Rc)2, C═O, C=NRc, C=C(R′)2, O, S, S═O, SO2, N(Rc), P(Rc) and P(═O)Rc;
• Ara 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 Ra radicals;
• Ra, Rb, Rc is the same or different at each instance and is H, D, OH, F, Cl, Br, I, CN, NO2, N(Ar′)2, N(R1)2, C(═O)N(Ar′)2, C(═O)N(R1)2, C(Ar′)3, C(R1)3, Si(Ar′)3, Si(R1)3, Ge(Ar′)3, Ge(R1)3, B(Ar′)2, B(R1)2, C(═O)Ar′, C(═O)R1, P(=O)(Ar′)2, P(=O)(R1)2, P(Ar′)2, P(R1)2, S(═O)Ar′, S(═O)R1, S(═O)2Ar′, S(═O)2R1, OSO2Ar′, OSO2R1, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 carbon atoms, where the alkyl, alkoxy, thioalkoxy, 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, Ge(R1)2, C═O, C=S, C=Se, C=NR1, —C(═O)O—, —C(═O)NR1—, NR1, P(=O)(R′), —O—, —S—, SO or SO2, 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 R1 radicals, or an aryloxy or heteroaryloxy group which has 5 to 60 aromatic ring atoms and may be substituted by one or more R1 radicals;
• at the same time, two Ra, Rb, Rc radicals may also form a ring system with one another or with a further group;
• 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, where it is possible for two Ar′ radicals bonded to the same carbon atom, silicon atom, germanium atom, nitrogen atom, phosphorus atom or boron atom also to be bridged to one another by a single bond or a bridge selected from B(R′), C(R1)2, Si(R1)2, C═O, C=NR1, C=C(R1)2, O, S, S═O, SO2, N(R1), P(R′) and P(═O)R1;
• R1 is the same or different at each instance and is H, D, F, Cl, Br, I, CN, NO2, N(Ar″)2, N(R2)2, C(═O)Ar″, C(═O)R2, P(=O)(Ar″)2, P(Ar″)2, B(Ar″)2, B(R2)2, C(Ar″)3, C(R2)3, Si(Ar″)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 groups 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, 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 60 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 60 aromatic ring atoms and may be substituted by one or more R2 radicals, or an aralkyl or heteroaralkyl group which has 5 to 60 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 R1 radicals together may form a ring system;
• at the same time, one or more R1 radicals may form a ring system with a further part of the compound;
• Ar″ 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 R2 radicals;
• at the same time, it is possible for two Ar″ radicals bonded to the same carbon atom, silicon atom, nitrogen atom, phosphorus atom or boron atom also to be joined together via a bridge 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 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, where two or more substituents R2 together may form a ring system.