Metal center dependent coordination modes of a tricarbene ligand.

The reaction of the benzene derived trisimidazolium salt [1](PF(6))(3) with [PdCl(allyl)](2) gave complex [2](PF(6))(3) featuring three Pd(allyl) moieties sandwiched between two tricarbene ligands, whereas the reaction of [1](PF(6))(3) with [M(Cp*)(Cl)(2)](2) (M = Ir, Rh) resulted in the formation of dinuclear M(III) complexes [3]PF(6) (M = Ir) and [4]PF(6) (M = Rh) where each metal center is coordinated by an NHC donor and orthometallates the central phenyl ring. The remaining imidazolium group in [4]PF(6) can be metallated with [Rh(Cp*)(Cl)(2)](2) to give the trinuclear triply orthometallated complex [5].