Linear, Trinuclear Cobalt Complexes with o-Phenylene-bis-Silylamido Ligands

Chemistry. 2017 May 11;23(27):6504-6508. doi: 10.1002/chem.201700496. Epub 2017 Apr 19.

Abstract

Transamination of [Co{N(SiMe3 )2 }2 ]2 with C6 H4 (NHSiiPr3 )2 gave the centrosymmetric trinuclear [{Coter N(SiMe3 )2 (μ-η-[o-C6 H4 (κNSiiPr3 )2 ])}2 Coint ] (1) (Coter , Coint =terminal, internal Co, respectively), with 3-coordinate Coter , and Coint "sandwiched" between the o-phenylenes of the two ligands; experimental and computational data support CoII centres and ditopic o-amido-imino-cyclohexen-allyl ligands; magnetic studies reveal intermetallic ferromagnetic interactions and single-molecule magnet (SMM) character. One-electron reduction of 1 yielded the salt [K(18-crown-6)(THF)2 ][{Coter N(SiMe3 )2 (μ-η-[o-C6 H4 (κNSiiPr3 )2 ])}2 Coint ] (4) with the anion isostructural to 1. The centrosymmetric Fe complex [{Feter N(SiMe3 )2 (μ-η-[o-C6 H4 (κNSiiPr3 )2 ])}2 Feint ] (5), analogous to 1, was also obtained.

Keywords: bridging ligands; cobalt; iron; magnetochemistry; o-phenylene; transamination.