Metal complexes

A compound of formula (1)

• containing a substructure M (L), of the formula (2):
• where the symbols and indices used are as follows:
• M is iridium;
• D is Cor N, where one D is C and the other D is N;
• X is the same or different at each instance and is CR or N;
• R is the same or different at each instance and is H, D, F, Cl, Br, I, N(R1)2, CN, NO2, OR′, SR1, COOR1, C(═O)N(R1)2, Si(R1)3, B(OR1)2, C(═O) R′, P(═O)(R1)2, S(═O) R′, S(═O) 2R′, OSO2R1, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R1 radicals, where one or more nonadjacent CH2 groups may be replaced by Si(R1)2, C═O, NR′, O, S or CONR1, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms, and may be substituted in each case by one or more R1 radicals;
• optionally, two R radicals together may also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system;
• R1 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R2)2, CN, NO2, OR2, SR2, Si(R2)3, B(OR2)2, C(═O)R2, P(═O) (R2)2, S(═O) R2, S(═O)2R2, OSO2R2, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may each be substituted by one or more R2 radicals, where one or more nonadjacent CH2 groups may be replaced by Si(R2)2, C—O, NR2, O, S or CONR2 and where one or more hydrogen atoms in the alkyl, alkenyl or alkynyl group may be replaced by D, F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R2 radicals;
• optionally, two or more R1 radicals together may form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system;
• R2 is the same or different at each instance and is H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical, having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F;
• L′ is the same or different at each instance and is a ligand;
• n is 1, 2 or 3;
• m is 0, 1, 2, 3 or 4;
• optionally, two or more ligands L may be joined together, or L may be joined to L′, by a single bond or a bivalent or trivalent bridge, thus forming a tridentate, tetradentate, pentadentate or hexadentate ligand system.