Materials for electronic devices

A compound of a formula (I)

• where the variables that occur are as follows:
• Z1 is the same or different at each instance and is selected from N and CR1;
• where the unit
• may be replaced by a unit selected from units of the following formulae:
• where the dotted bonds in the units each correspond to the bonds in the unit
• and where
• the variables Z1 in the unit in these cases are C;
• Ar0 is phenylene substituted by R2 radicals;
• Ar1 and Ar2 are the same or different at each instance and are selected from aromatic ring systems which have 6 to 40 aromatic ring atoms and are substituted by R4 radicals, and from heteroaromatic ring systems which have 5 to 40 aromatic ring atoms and are substituted by R4 radicals;
• Ar3 and Ar4 are the same or different at each instance and are selected from aromatic ring systems which have 6 to 40 aromatic ring atoms and are substituted by R5 radicals, and from heteroaromatic ring systems which have 5 to 40 aromatic ring atoms and are substituted by R5 radicals;
• where at least one of Ar3 and Ar4 is selected from aryl groups which have 10 to 20 aromatic ring atoms and are substituted by R5 radicals;
• ArL is selected from aromatic ring systems which have 6 to 40 aromatic ring atoms and are substituted by R3 radicals and from heteroaromatic ring systems which have 5 to 40 aromatic ring atoms and are substituted by R3 radicals;
• R1 is the same or different at each instance and is selected from H, D, F, Cl, Br, I, C(═O)R6, CN, 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, where said alkyl, alkoxy, alkenyl and alkynyl groups are each substituted by R6 radicals;
• and where one or more CH2 groups in said alkyl, alkoxy, alkenyl and alkynyl groups 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;
• R4 is the same or different at each instance and is selected from H, D, F, Cl, Br, I, C(═O)R6, CN, Si(R6)3, 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 radicals may be joined to one another and may form a ring;
• where said alkyl, alkoxy, alkenyl and alkynyl groups and said aromatic ring systems and heteroaromatic ring systems are each substituted by R6 radicals;
• and where one or more CH2 groups in said alkyl, alkoxy, alkenyl and alkynyl groups may be replaced by —RC≡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;
• R2, R3 and R5 are the same or different at each instance and are selected from H, D, F, Cl, Br, I, C(═O)R6, CN, 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 radicals selected from the R2, R3 and R5 radicals may be joined to one another and may form a ring;
• where said alkyl, alkoxy, alkenyl and alkynyl groups and said aromatic ring systems and heteroaromatic ring systems are each substituted by R6 radicals;
• and where one or more CH2 groups in said alkyl, alkoxy, alkenyl and alkynyl groups 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;
• R6 is the same or different at each instance and is selected from H, D, F, Cl, Br, I, C(═O)R7, CN, Si(R7)7, 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 are each substituted by R3 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, Cl, Br, I, CN, 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 said alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems may be substituted by one or more radicals selected from F and CN;
• m is 0, 1, 2 or 3;
• n is 0, 1, 2 or 3;
• k is 0 or 1.