Organic electroluminescent device comprising anode, cathode and at least one emitting layer, characterised in that at least one compound of the formula, or is employed in an emitting layer as a mixture with at least one fluorescent or phosphorescent dopant, where the following applies to the symbols and indices used: Y is selected on each occurrence, identically or differently, from CH and CR 1, where at most two groups R 1 may be present per aromatic six-membered ring; R 1 is on each occurrence, identically or differently, H, F, Cl, Br, I, N(Ar) 2, C(=O)Ar, P(=O)(Ar) 2, S(=O)Ar, S(=O) 2 Ar, CR 2 =CR 2 Ar, CN, NO 2, Si(R 2) 3, B(OR 2) 2, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, which may in each case be substituted by one or more radicals R 2, where one or more radicals R 2 may be substituted, where one or more non-adjacent CH 2 groups may be replaced by -R 2 C=CR 2 -, -C≡C-, Si(R 2) 2, Ge(R 2) 2, Sn(R 2) 2, C=O, C=S, C=Se, C=NR 2, P(=O)(R 2), SO, SO 2, -NR 2 -, -O-, -S- or -CONR 2 - and where one or more H atoms may be replaced by F, Cl, Br, I, CN or NO 2, or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may in each case be substituted by one or more radicals R 2, or an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R 2, or a combination of these systems; Ar is on each occurrence an aromatic or heteroaromatic ring system having 5-30 aromatic ring atoms, which may be substituted by one or more non-aromatic radicals R 1; two radicals Ar on the same nitrogen atom may also be linked to one another by a single bond or a bridge X; R 2 is on each occurrence, identically or differently, H or an aliphatic, aromatic or heteroaromatic hydrocarbon radical having 1 to 20 C atoms; two or more adjacent substituents R 2 may also form a mono- or polycyclic aliphatic or aromatic ring system with one another; X is on each occurrence, identically or differently, a divalent bridge selected from C(R 1) 2, C=O, C=NR 1, O, S, S=O, SO 2, N(R 1), P(R 1), P(=O)R 1, C(R 1) 2 -C(R 1) 2, C(R 1) 2 -C(R 1) 2 -C(R 1) 2, C(R 1) 2 -O and C(R 1) 2 -O-C(R 1) 2; where the naphthalene group may be substituted by one or more radicals R 1, characterised in that at least one substituent R 1 that contains at least one aryl or heteroaryl group is present. Y is selected on each occurrence, identically or differently, from CH and CR 1, where at most two groups R 1 may be present per aromatic six-membered ring; R 1 is on each occurrence, identically or differently, H, F, Cl, Br, I, N(Ar) 2, C(=O)Ar, P(=O)(Ar) 2, S(=O)Ar, S(=O) 2 Ar, CR 2 =CR 2 Ar, CN, NO 2, Si(R 2) 3, B(OR 2) 2, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, which may in each case be substituted by one or more radicals R 2, where one or more radicals R 2 may be substituted, where one or more non-adjacent CH 2 groups may be replaced by -R 2 C=CR 2 -, -C≡C-, Si(R 2) 2, Ge(R 2) 2, Sn(R 2) 2, C=O, C=S, C=Se, C=NR 2, P(=O)(R 2), SO, SO 2, -NR 2 -, -O-, -S- or -CONR 2 - and where one or more H atoms may be replaced by F, Cl, Br, I, CN or NO 2, or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may in each case be substituted by one or more radicals R 2, or an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R 2, or a combination of these systems; Ar is on each occurrence an aromatic or heteroaromatic ring system having 5-30 aromatic ring atoms, which may be substituted by one or more non-aromatic radicals R 1; two radicals Ar on the same nitrogen atom may also be linked to one another by a single bond or a bridge X; R 2 is on each occurrence, identically or differently, H or an aliphatic, aromatic or heteroaromatic hydrocarbon radical having 1 to 20 C atoms; two or more adjacent substituents R 2 may also form a mono- or polycyclic aliphatic or aromatic ring system with one another; X is on each occurrence, identically or differently, a divalent bridge selected from C(R 1) 2, C=O, C=NR 1, O, S, S=O, SO 2, N(R 1), P(R 1), P(=O)R 1, C(R 1) 2 -C(R 1) 2, C(R 1) 2 -C(R 1) 2 -C(R 1) 2, C(R 1) 2 -O and C(R 1) 2 -O-C(R 1) 2;