Bright orange/red-emitting rhodium(III) and iridium(III) complexes: tridentate N∧C∧N-cyclometallating ligands lead to high luminescence efficiencies

Rhodium(III) complexes rarely display strong phosphorescence, in contrast to well-known iridium(III) complexes with cyclometallating ligands. This study shows how 1,3-bis(1-isoquinolyl) benzene cyclometallates to Rh(III) through (NCN)-C-boolean AND-N-boolean AND-coordination to give complexes with unprecedented phosphorescence quantum yields at room temperature. Their highly emissive Ir(III) analogues are also described.