Conceptual advances in the preparation and excited-state properties of neutral luminescent (C^N) and (C^C*) monocyclometalated gold(III) complexes

Abstract

Luminescent cyclometalated complexes are indispensable in today’s technologies and are applied as emitters in organic light-emitting diode (OLED) devices, photocatalysts, photodynamic therapy and sensing. Compared to the extensively investigated triplet-based emitters containing platinum(II) and iridium(III) metal centers, research on gold(III) containing metal complexes remain limited. The most prominent cyclometalated gold(III) complexes are based on a (C^N^C) or (C^C^N) pincer framework and have been previously summarized in numerous publications and reviews. More recently, the research on emissive (C^N) and (C^C*) gold(III) complexes is gaining increasing attention due to the greater possibility to tune the electronic and photophysical properties. This review presents recent advances made in the preparation methods and the intriguing excited-state properties of (C^N) and (C^C*) monocyclometalated gold(III) complexes. In addition, this review aims to correlate experimental findings with computational calculations, to identify current challenges and provide future perspectives on this interesting topic.