Introducing Tetrel Zintl Ions to N-Heterocyclic Carbenes - Synthesis of Coinage Metal NHC Complexes of [Ge9{Si(SiMe3)3}3]-

Reaction of the functionalized tetrel cluster [Ge9R3](-){R = Si(SiMe3)(3)} with coinage metal N-heterocyclic carbene (NHC) complexes affords the first Zintl cluster transition metal complexes coordinated by NHC molecules. In [(eta(3)-Ge9R3)M(NHCDipp)], the D-3d-symmetric cluster polyhedron coordinates with a triangular Ge-3 face to the coinage metals M = Cu, Ag, Au, which themselves also bind to the NHC. The role of fine tuning of electronic properties by using an NHC ligand is discussed for the transformation reaction of [(eta(3)-Ge9R3)Ag(NHCDipp)] to yield [Ag(eta(3)-Ge9R3)(2)][Ag(NHC(Dipp)x)(2)]. All complexes are fully characterized including single-crystal X-ray structure analyses.