Synthesis and structural characterization of the [NiRh6(CO)16]2− dianion: a new mixed heptanuclear carbonyl cluster. Evidence for other NiRh mixed carbonyl cluster anions

The first heptanuclear mixed carbonyl cluster, the anion [NiRh6(CO)16]2- has been prepared by redox condensation of [Rh6(CO)15]2- with [Ni6(CO)12]2- or Ni(CO)4. The structure of the metallic framework is based on a distorted octahedron of Rh atoms capped on one face by a nickel atom and is closely related to that previously observed in the isoelectronic [Rh7(CO)16]3- anion. Evidence is also reported for the existence of [NiRh5(CO)15]- and [NiRh4-(CO)12]2-.