Materials for electronic devices

A compound of the formula (I-1)

• where the compounds may each be substituted by an R3 or R6 radical at the unoccupied positions on the aromatic rings, and where the variables that occur are as follows:
• Z1 is the same or different at each instance and is selected from CR1 and CR3;
• X1 is the same or different at each instance and is a divalent group selected from —C(R4)2—, —C(R4)2—C(R4)2—, —CR4—CR4— and —Si(R4)2—;
• R1 is the same or different at each instance and is a group of the formula (N)
• ArL is selected from aromatic ring systems which have 6 to 40 aromatic ring atoms and may be substituted by one or more R5 radicals, and heteroaromatic ring systems which have 5 to 40 aromatic ring atoms and may be substituted by one or more R5 radicals;
• Ar2 is the same or different at each instance and is selected from aromatic ring systems which have 6 to 40 aromatic ring atoms and may be substituted by one or more R5 radicals, and heteroaromatic ring systems which have 5 to 40 aromatic ring atoms and may be substituted by one or more R5 radicals;
• E is a single bond or a divalent group selected from the group consisting of C(R5)2, Si(R5)2, N(R5), O, and S;
• R2 is selected from H, and D;
• R3 is the same or different at each instance and is selected from H, D, F, CN, Si(R7)3, straight-chain alkyl groups having 1 to 20 carbon atoms, branched or cyclic alkyl groups having 3 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms, where said alkyl groups, said aromatic ring systems and said heteroaromatic ring systems may each be substituted by one or more R7 radicals;
• R5 is the same or different at each instance and is selected from H, D, F, C(═O)R7, CN, Si(R7)3, N(R7)2, P(═O)(R7)2, OR7, S(═O)R7, S(═O)2R7, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• where the alkyl, alkoxy, alkenyl and alkynyl groups mentioned and the aromatic ring systems and heteroaromatic ring systems mentioned may each be substituted by one or more R7 radicals;
• and where one or more CH2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be replaced by —R7C═CR7—, —C═C—, Si(R7)2, C═O, C═NR7, —C(═O)O—, —C(═O)NR7—, NR7, P(═O)(R7), —O—, —S—, SO or SO2;
• R4 is the same or different at each instance and is selected from H, D, F, CN, straight-chain alkyl groups having 1 to 20 carbon atoms, branched or cyclic alkyl groups having 3 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• where said alkyl groups, said aromatic ring systems and said heteroaromatic ring systems may each be substituted by one or more R7 radicals;
• R6 is the same or different at each instance and is selected from H, D, F, CN, Si(R7)3, straight-chain alkyl groups having 1 to 20 carbon atoms, branched or cyclic alkyl groups having 3 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• where said alkyl groups, said aromatic ring systems and said heteroaromatic ring systems may each be substituted by one or more R7 radicals;
• R7 is the same or different at each instance and is selected from H, D, F, CN, Si(R8)3, straight-chain alkyl groups having 1 to 20 carbon atoms, branched or cyclic alkyl groups having 3 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms, where said alkyl groups, said aromatic ring systems and said heteroaromatic ring systems may each be substituted by one or more R8 radicals;
• R8 is the same or different at each instance and is selected from H, D, F, CN, alkyl groups having 1 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• where the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems mentioned may be substituted by F or CN;
• k is 0 or 1, where, in the case that k=0, the ArL group is absent and the nitrogen atom of the group of the formula (N) constitutes the attachment position;
• m is 0 or 1, where, in the case that m=0, the E group is absent and the Ar2 groups are not bonded to one another;
• i is 0, which means that the R1 group marked with index i is absent;
• and
• where there is at least one Z1 group that is CR1.