Materials for electronic devices

A compound of the following formula (I) or (II):

• where the variables that occur are as follows:
• Z1 is the same or different at each instance and is selected from CR1 and CR3;
• Ar1 is an aryl group which has 6 to 20 aromatic ring atoms and may be substituted by one or more R3 radicals, or a heteroaryl group which has 5 to 20 aromatic ring atoms and may be substituted by one or more R3 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;
• Ar3 is an aryl group which has 6 to 20 aromatic ring atoms and may be substituted by one or more R2 radicals, or a heteroaryl group which has 5 to 20 aromatic ring atoms and may be substituted by one or more R2 radicals;
• 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—, —Si(R4)2—, O and S;
• 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;
• E is a single bond or a divalent group selected from C(R5)2, Si(R5)2, N(R5), O, and S;
• R0 is selected from H, D, aromatic ring systems which have 6 to 40 aromatic ring atoms and may be substituted by one or more R6 radicals, and heteroaromatic ring systems which have 5 to 40 aromatic ring atoms and may be substituted by one or more R6 radicals;
• R1 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 R6 radicals, and heteroaromatic ring systems which have 5 to 40 aromatic ring atoms and may be substituted by one or more R6 radicals, with the proviso that two or more R1 radicals are not joined to one another and form a ring;
• R2 is the same or different at each instance and is selected from H, D, F, Si(R6)3, 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 two or more R0 radicals may be joined to one another and may form a ring;
• 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 R6 radicals;
• and where one or more CH2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be replaced by —R6C═CR6—, —C≡C—, Si(R6)2, C═O, C═NR6, —C(═O)O—, —C(═O)NR6—, NR6, P(═O)(R6), —O—, —S—, SO or SO2;
• R3, R4, R5 are the same or different at each instance and are selected from H, D, F, C(═O)R6, Si(R6)3, N(R6)2, P(═O)(R6)2, OR6, S(═O)R6, S(═O)2R6, 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 two or more R4 or R5 radicals may be joined to one another and may form a ring;
• 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 R6 radicals;
• and where one or more CH2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be replaced by —R6C═CR6—, —C═C—, Si(R6)2, C═O, C═NR6, —C(═O)O—, —C(═O)NR6—, NR6, P(═O)(R6), —O—, —S—, SO or SO2, with the proviso that two or more R3 radicals or two or more R1 and R3 radicals are not joined to one another and form a ring:
• R6 is the same or different at each instance and is selected from H, D, F, C(═O)R7, 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 two or more R6 radicals may be joined to one another and may form a ring;
• 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;
• R7 is the same or different at each instance and is selected from H, D, F, alkyl or alkoxy groups having 1 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 two or more R7 radicals may be joined to one another and may form a ring;
• and 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, 1, 2 or 3, where, in the case that k=0, the Art 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;
• where, in formula (I) and (II), all positions shown as unsubstituted may each be substituted by an R3 radical;
• wherein, in one of the formulae (I) and (II), one or two Z1 groups in each case are CR1, and the other Z1 groups are CR3, and
• where, in formula (I) and in formula (II), there is in each case at least one Z1 group which is CR1.