A Rising Star: Luminescent Carbene-Metal-Amide Complexes

Coinage metal (gold, silver, and copper) complexes are attractive candidates to substitute the widely studied noble metal complexes, such as, iridium(III) and platinum(II), as luminescent materials in organic light-emitting diodes (OLEDs). However, the development of coinage metal complexes exhibiting high emission quantum yields and short exciton lifetimes is still a formidable challenge. In the past few years, coinage metal complexes featuring a carbene-metal-amide (CMA) motif have emerged as a new class of luminescent materials in OLEDs. Thanks to the coinage metal-bridged linear geometry, coplanar conformation, and the formation of excited states with dominant ligand-to-ligand charge transfer character and reduced metal d-orbital participation, most CMA complexes have high radiative rates via thermally activated delayed fluorescence. Currently, the family of CMA complexes have rapidly evolved and remarkable progresses in CMA-based OLEDs have been made. Here, a Concept article on CMA complexes is presented, with a focus on molecular design principles, the correlation between molecular structure/conformation and optoelectronic properties, as well as OLED performance. The future prospects of CMA complexes are also discussed. This concept article on luminescent carbene-metal-amide (CMA) complexes is presented in terms of molecular design strategies, structure-property correlations and their applications in organic light-emitting diodes (OLEDs). The future directions and opportunities for advancing the development of CMA complexes and the related OLEDs are proposed as well.image

Automated summary

In recent years, coinage metal complexes, such as gold, silver, and copper, have been studied as luminescent materials in OLEDs, showing potential to replace noble metal complexes like iridium(III) and platinum(II). The use of carbene-metal-amide (CMA) complexes in OLEDs has emerged as a new class of luminescent materials with high radiative rates and reduced metal d-orbital participation. This concept article discusses the molecular design principles, structure-property correlations, and future prospects of CMA complexes in OLEDs.