Co6 H8 (Pi Pr3 )6 : A Cobalt Octahedron with Face-Capping Hydrides

Yasuhiro Ohki; Yuki Shimizu; Ryoichi Araake; Mizuki Tada; W M C Sameera; Jun-Ichi Ito; Hisao Nishiyama

doi:10.1002/anie.201608262

Co₆ H₈ (Pⁱ Pr₃ )₆ : A Cobalt Octahedron with Face-Capping Hydrides

Angew Chem Int Ed Engl. 2016 Dec 19;55(51):15821-15825. doi: 10.1002/anie.201608262. Epub 2016 Nov 16.

Authors

Yasuhiro Ohki^{1

2}, Yuki Shimizu¹, Ryoichi Araake¹, Mizuki Tada^{1

3}, W M C Sameera⁴, Jun-Ichi Ito⁵, Hisao Nishiyama⁵

Affiliations

¹ Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan.
² PRESTO, Japan, Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
³ Research Center for Materials Science (RCMS) & Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Japan.
⁴ Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, 060-0810, Japan.
⁵ Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Japan.

PMID: 27862749
DOI: 10.1002/anie.201608262

Abstract

A square-planar Co₄ amide cluster, Co₄ {N(SiMe₃ )₂ }₄ (2), and an octahedral Co₆ hydride cluster, Co₆ H₈ (Pⁱ Pr₃ )₆ (4), were obtained from metathesis-type amide to hydride exchange reactions of a Co^II amide complex with pinacolborane (HBpin) in the absence/presence of Pⁱ Pr₃ . The crystal structure of 4 revealed face-capping hydrides on each triangular [Co₃ ] face, while the formal Co^II₂ Co^I₄ 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.

Keywords: clusters; cobalt; hydride; hydrosilylation.

Publication types

Research Support, Non-U.S. Gov't