Materials for electronic devices

A material comprising a compound A of a formula (A)

• where the variables that occur are:
• Z is CR1;
• Ar1 is the same or different at each instance and is an aromatic ring system which has 6 to 30 aromatic ring atoms and is optionally substituted by one or more R1 radicals, or a heteroaromatic ring system which has 5 to 30 aromatic ring atoms and is optionally substituted by one or more R1 radicals;
• Ar1 groups here is optionally bonded to one another via R1 radicals;
• R1 is the same or different at each instance and is selected from H, D, F, C(═O)R2, CN, Si(R2)3, P(═O)(R2)2, OR2, S(═O)R2, S(═O)2R2, 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 30 aromatic ring atoms, and heteroaromatic ring systems having 5 to 30 aromatic ring atoms;
• where two or more R1 radicals is optionally 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 R2 radicals;
• and where one or more CH2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups mentioned is optionally replaced by —R2C═CR2—, —C≡C—, Si(R2)2, C═O, C═NR2, —C(═O)O—, —C(═O)NR2—, P(═O)(R2), —O—, —S—, SO or SO2;
• R2 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 30 aromatic ring atoms and heteroaromatic ring systems having 5 to 30 aromatic ring atoms;
• where two or more R2 radicals is optionally joined to one another and may form a ring;
• and where the alkyl groups, aromatic ring systems and heteroaromatic ring systems mentioned is optionally substituted by F or CN;
• and a compound P which is a complex of bismuth.