Co₆H₈(PⁱPr₃)₆: A Cobalt Octahedron with Face‐Capping Hydrides

Abstract

A square‐planar Co4 amide cluster, Co4{N(SiMe3)2}4 (2), and an octahedral Co6 hydride cluster, Co6H8(PiPr3)6 (4), were obtained from metathesis‐type amide to hydride exchange reactions of a CoII amide complex with pinacolborane (HBpin) in the absence/presence of PiPr3. The crystal structure of 4 revealed face‐capping hydrides on each triangular [Co3] face, while the formal CoII2CoI4 oxidation state of 4 indicated a reduction of the cobalt centers during the assembly process. Cluster 4 catalyzes the hydrosilylation of 2‐cyclohexen‐1‐one favoring the conjugate reduction. Generation of the catalytically reactive Co cluster species was indicated by a trapping experiment with a chiral chelating agent.