Method for the production of heteroleptic ortho-metallated organometallic compounds

A process for the preparation of compounds (I)

• wherein
• M is, identically or differently on each occurrence, Rh, Ir, Pd or Pt;
• Z is, identically or differently on each occurrence, N or P;
• A, A′ is, identically or differently on each occurrence, N, C—H or C—R or C—R′;
• or alternatively two adjacent ring atoms A-A or A′-A′ on each occurrence, identically or differently, stand for S, O, Se or N—R1, with the proviso that these units do not occur more than once per ring;
• R, R′ is, identically or differently on each occurrence, F, Cl, Br, NO2, CN, a straight-chain, branched or cyclic alkyl or alkoxy group having 1 to 20 C atoms, where one or more non-adjacent CH2 groups may be replaced by —CR1═CR1—, —C≡C—, —O—, —S—, —NR1—, or —CONR1— and where one or more H atoms may be replaced by F, or an aryl, heteroaryl, aryloxy or arylamino group having 4 to 14 C atoms, which may be substituted by one or more non-aromatic radicals R;
• where a plurality of substituents R on the same ring together may in turn define a further mono- or polycyclic, aliphatic or aromatic ring system;
• R1 is, identically or differently on each occurrence, H or an aliphatic or aromatic hydrocarbon radical having 1 to 20 C atoms;
• n is 1 for M=Pd or Pt and is 2 for M=Rh or Ir;
• which comprises reacting a compound (Ia)
• wherein
• Y is on each occurrence, identically or differently, F, Cl, Br, I, OR1, R1COO, SR1, N(R1)2;
• and the other symbols and indices are as defined for compound (I),
• with an organometallic compound (Ib)
• where Q stands for an alkali metal, an alkaline-earth metal or alkaline-earth metal halide, trialkyltin or zinc or a zinc halide, which may optionally also be substituted by further organic groups, and the other symbols and indices have the meaning given for compound (I).