Organic electroluminescent device

An organic electroluminescent device comprising an oligomer

• wherein the oligomer is
• a double-complex salt comprising at least one positively charged metal complex K1 and at least one negatively charged metal complex K2,
• where K1 has one of the following formulae (85), (86), (87), (90), (94), (122), (130), (132), (134), (136):
• and
• K2 is selected from formula (158)
• where
• R1 to R16 are, identically or differently on each occurrence, one of the following groups:
• H, deuterium, F, Cl, Br, I, N(R21)2, CN, NO2, Si(R21)3, B(OR21)2, C(═O)R21, P(═O)(R21)2, S(═O)R21, S(═O)2R21, OSO2R21, a straight chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a straight-chain alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R21, where one or more adjacent CH2 groups may be replaced by R21C=CR21, C≡C, Si(R21)2, Ge(R21)2, Sn(R21)2, C═O, C═S, C═Se, C═NR21, P(═O)(R21), SO, SO2, NR21, O, S or CONR21 and where one or more H atoms may be replaced by F, Cl, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R21, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R21, or a diarylamino group, diheteroarylamino group or arylheteroarylamino group having 10 to 40 aromatic ring atoms, which may be substituted by one or more radicals R21, or a combination of these systems;
• two or more of these substituents may also form a mono- or polycyclic, aliphatic, aromatic and/or benzo-fused ring system with one another;
• R21 is on each occurrence, identically or differently, H, F or an aliphatic, aromatic and/or heteroaromatic radical having 1 to 20 C atoms, in which, in addition, one or more H atoms may be replaced by F;
• two or more substituents R21 here may also form a mono- or polycyclic, aliphatic or aromatic ring system with one another;
• AL1, AL2, AL3, AL4 are each, identically or differently on each occurrence, an anionic ligand selected from hydride, deuteride, the halides F, Cl, Br and I, alkylacetylides, arylacetylides, aryl groups, alkyl groups, alkenyl groups, borates, cyanide, cyanate, isocyanate, thiocyanate, isothiocyanate, aliphatic or aromatic alcoholates, aliphatic or aromatic thioalcoholates, amides, carboxylates and anionic, nitrogen-containing heterocycles;
• wherein the device is hermetically screened from the environment.