Organic electroluminescent devices comprising azomethine-metal complexes

An organic electroluminescent device comprising, in the emitting layer, at least one phosphorescent compound and at least one compound of formula (I)

• wherein
• M is on each occurrence, identically or differently, a metal ion in the oxidation state +II, selected from Be, Mg, Ca, Sr, Ba, Fe, Ru, Os, Co, Cu, Zn, Cd, Hg, Sn and Pb;
• X is on each occurrence, identically or differently, O, S or CO—O;
• Ar1 is an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R and in which individual aromatic groups may be linked to one another via alkylene groups having 1 to 10 C atoms, in which, in addition, one or more non-adjacent C atoms is optionally replaced by O or S;
• Ar2 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R;
• Y is on each occurrence, identically or differently, a single bond or an alkylene group having 1 to 10 C atoms, in which, in addition, one or more non-adjacent C atoms which are not bonded to the nitrogen is optionally replaced by O and which is optionally substituted by one or more radicals R;
• R is on each occurrence, identically or differently, H, F, Cl, Br, I, N(R2)2, CN, NO2, Si(R2)3, B(OR2)2, C(═O)R2, P(═O)(R2)2, S(═O)R2, S(═O)2R2, OSO2R2, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R2, where one or more non-adjacent CH2 groups is optionally replaced by R2C═CR2, C≡C, Si(R2)2, Ge(R2)2, Sn(R2)2, C═O, C═S, C═Se, C═NR2, P(═O)(R2), SO, SO2, NR2, O, S or CONR2 and where one or more H atoms is optionally replaced by F, Cl, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, each of which is optionally substituted by one or more radicals R2, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R2, or a combination of these systems;
• two or more substituents R here optionally forms a mono- or polycyclic aliphatic or aromatic ring system with one another;
• R1 is on each occurrence, identically or differently, H, F, CF3, a straight-chain alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R2, where one or more non-adjacent CH2 groups is optionally replaced by R2C═CR2, C≡C, Si(R2)2, Ge(R2)2, Sn(R2)2 and where one or more H atoms is optionally replaced by F, Cl, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, each of which is optionally substituted by one or more radicals R2, or a combination of these systems;
• R1 here optionally forms a mono- or polycyclic aliphatic or aromatic ring system with one or more substituents R;
• R2 is on each occurrence, identically or differently, H, F or an aliphatic, aromatic or heteroaromatic hydrocarbon radical having 1 to 20 C atoms, in which, in addition, one or more H atoms is optionally replaced by F;
• two or more substituents R2 here optionally forms a mono- or polycyclic aliphatic or aromatic ring system with one another;
• n is on each occurrence, identically or differently, 0, 1 or 2.