Compound of the formula where the following applies to the symbols and indices occurring: Z is on each occurrence, identically or differently, CR 1 or N, where Z is equal to C if a group Ar 1 or Ar 2 is bonded; W is equal to CH or N; Ar 1 is on each occurrence, identically or differently, an aromatic ring system having 6 to 30 aromatic ring atoms, which may be substituted by one or more radicals R 1; Ar 2 is on each occurrence, identically or differently, an aromatic ring system having 6 to 24 aromatic ring atoms, which may be substituted by one or more radicals R 1; R 1 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, C(=O)R 2, CN, Si(R 2) 3, NO 2, P(=O)(R 2) 2, S(=O)R 2, S(=O) 2 R 2, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, where the above-mentioned groups may in each case be substituted by one or more radicals R 2 and where one or more CH 2 groups in the above-mentioned groups may be replaced by -R 2 C=CR 2 -, -C≡C-, Si(R 2) 2, C=O, C=S, C=NR 2, -C(=O)O-, -C(=O)NR 2 -, NR 2, P(=O)(R 2), -O-, -S-, SO or SO 2 and where one or more H atoms in the above-mentioned groups may be replaced by D, F, Cl, Br, I, CN or NO 2, or an aromatic ring system having 6 to 30 aromatic ring atoms, which may in each case be substituted by one or more radicals R 2; R 2 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, C(=O)R 3, CN, Si(R 3) 3, NO 2, P(=O)(R 3) 2, S(=O)R 3, S(=O) 2 R 3, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, where the above-mentioned groups may in each case be substituted by one or more radicals R 3 and where one or more CH 2 groups in the above-mentioned groups may be replaced by -R 3 C=CR 3 -, -C≡C-, Si(R 3) 2, C=O, C=S, C=NR 3, -C(=O)O-, -C(=O)NR 3 -, NR 3, P(=O)(R 3), -O-, -S-, SO or SO 2 and where one or more H atoms in the above-mentioned groups may be replaced by D, F, Cl, Br, I, CN or NO 2, or an aromatic ring system having 6 to 30 aromatic ring atoms, which may in each case be substituted by one or more radicals R 3; R 3 is on each occurrence, identically or differently, H, D, F or an aliphatic or aromatic organic radical having 1 to 20 C atoms, in which, in addition, one or more H atoms may be replaced by D or F; n is on each occurrence, identically or differently, 0, 1, 2, 3, 4 or 5; m is on each occurrence, identically or differently, 0, 1, 2 or 3; where the three groups which are bonded to the central nitrogen atom, regarded as a whole, are not all identical, where the sum of the indices n is at least equal to 2, and where the following compounds are excluded from the claim scope: Z is on each occurrence, identically or differently, CR 1 or N, where Z is equal to C if a group Ar 1 or Ar 2 is bonded; W is equal to CH or N; Ar 1 is on each occurrence, identically or differently, an aromatic ring system having 6 to 30 aromatic ring atoms, which may be substituted by one or more radicals R 1; Ar 2 is on each occurrence, identically or differently, an aromatic ring system having 6 to 24 aromatic ring atoms, which may be substituted by one or more radicals R 1; R 1 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, C(=O)R 2, CN, Si(R 2) 3, NO 2, P(=O)(R 2) 2, S(=O)R 2, S(=O) 2 R 2, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, where the above-mentioned groups may in each case be substituted by one or more radicals R 2 and where one or more CH 2 groups in the above-mentioned groups may be replaced by -R 2 C=CR 2 -, -C≡C-, Si(R 2) 2, C=O, C=S, C=NR 2, -C(=O)O-, -C(=O)NR 2 -, NR 2, P(=O)(R 2), -O-, -S-, SO or SO 2 and where one or more H atoms in the above-mentioned groups may be replaced by D, F, Cl, Br, I, CN or NO 2, or an aromatic ring system having 6 to 30 aromatic ring atoms, which may in each case be substituted by one or more radicals R 2; R 2 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, C(=O)R 3, CN, Si(R 3) 3, NO 2, P(=O)(R 3) 2, S(=O)R 3, S(=O) 2 R 3, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, where the above-mentioned groups may in each case be substituted by one or more radicals R 3 and where one or more CH 2 groups in the above-mentioned groups may be replaced by -R 3 C=CR 3 -, -C≡C-, Si(R 3) 2, C=O, C=S, C=NR 3, -C(=O)O-, -C(=O)NR 3 -, NR 3, P(=O)(R 3), -O-, -S-, SO or SO 2 and where one or more H atoms in the above-mentioned groups may be replaced by D, F, Cl, Br, I, CN or NO 2, or an aromatic ring system having 6 to 30 aromatic ring atoms, which may in each case be substituted by one or more radicals R 3; R 3 is on each occurrence, identically or differently, H, D, F or an aliphatic or aromatic organic radical having 1 to 20 C atoms, in which, in addition, one or more H atoms may be replaced by D or F; n is on each occurrence, identically or differently, 0, 1, 2, 3, 4 or 5; m is on each occurrence, identically or differently, 0, 1, 2 or 3;