Preparation of single enantiomers of chiral at metal bis-cyclometallated iridium complexes.

Reaction of [Ir(C^N)2Cl]2 with chiral bidentate N⁁OH ligands provides complexes [Ir(C^N)2(N^O)] as a 1 : 1 mixture of diastereomers which can be separated by crystallisation. A pure diastereomer can be converted to [Ir(C^N)2(bipy)][CF3CO2] with complete retention of stereochemistry at the metal.