Co6H8(P iPr3)6: A Cobalt Octahedron with Face-Capping Hydrides.

Authors :: Ohki, Yasuhiro
Shimizu, Yuki
Araake, Ryoichi
Tada, Mizuki
Sameera, W. M. C.
Ito, Jun-Ichi
Nishiyama, Hisao
Source :: Angewandte Chemie International Edition; 12/19/2016, Vol. 55 Issue 51, p15821-15825, 5p
Publication Year :: 2016
Abstract: A square-planar Co<subscript>4</subscript> amide cluster, Co<subscript>4</subscript>{N(SiMe<subscript>3</subscript>)<subscript>2</subscript>}<subscript>4</subscript> ( 2), and an octahedral Co<subscript>6</subscript> hydride cluster, Co<subscript>6</subscript>H<subscript>8</subscript>(P<superscript> i</superscript>Pr<subscript>3</subscript>)<subscript>6</subscript> ( 4), were obtained from metathesis-type amide to hydride exchange reactions of a Co<superscript>II</superscript> amide complex with pinacolborane (HBpin) in the absence/presence of P<superscript> i</superscript>Pr<subscript>3</subscript>. The crystal structure of 4 revealed face-capping hydrides on each triangular [Co<subscript>3</subscript>] face, while the formal Co<superscript>II</superscript><subscript>2</subscript>Co<superscript>I</superscript><subscript>4</subscript> 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. [ABSTRACT FROM AUTHOR]