N-heterocyclic carbenes (NHCs) are highly versatile ligands with unique features that are able to engage into robust metal-ligand bonds, owing to their strong electron σ-donating and relatively weak π-accepting abilities. Aiming at efficient and stable emitters, coordination features of NHCs have been successfully employed for modulating both optical and redox properties yielding outstanding Ir III complexes. In addition, NHCs are an unparalleled tool that helps to suppressing nonradiative pathways and shift emission into the blue region. As [a] A

Two novel neutral rhenium(i) tricarbonyl complexes bearing a pyridoannelated N-heterocyclic carbene are synthetized and fully characterized, which display red photoluminescence arising from a triplet excited state with ligand centered character.