Triply cyclometalated trinuclear iridium(III) and trinuclear palladium(II) complexes with a tri-mesoionic carbene ligand

The first example of a triply cyclometalated homopolynuclear tri-Ir-III complex with additional carbene donors is presented. Cooperative catalysis and the interplay between homogenous and heterogeneous catalyses are discussed for the tri-Ir-III complex and a related non-cyclometalated tri-Pd-II complex.