Method for the separation of enantiomeric mixtures from metal complexes

A process for separating mixtures containing enantiomers of metal complexes with aromatic and/or heteroaromatic ligands, comprising the steps of:

• A) providing a mixture of reactive metal complexes, wherein the mixture comprises at least two enantiomers of the reactive metal complexes;
• B) reacting the mixture provided in step A) with an optically active boron compound to obtain a diastereomer mixture;
• and
• C) separating the diastereomer mixture obtained in step B).

A metal complex of formula (1b)

• Ir(L)n(L′)m (1b)
• wherein
• L is the same or different in each instance and is a bidentate ligand;
• L′ is the same or different in each instance and is a ligand;
• n is 1, 2, or 3;
• and
• m is 0, 1, 2, 3, or 4;
• and wherein two or more ligands L are optionally joined together or L is optionally joined to L′ via a single bond or a bivalent or trivalent bridge so as to define a tridentate, tetradentate, pentadentate, or hexadentate ligand system;
• and
• wherein at least one of the ligands L and/or L′ comprises a boron-containing substituent having a chiral center.