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

Abstract

Transamination of [Co{N(SiMe3 )2 }2 ]2 with C6 H4 (NHSiiPr3 )2 gave the centrosymmetric trinuclear [{Co(ter) N(SiMe3 )2 (μ-η-[o-C6 H4 (κNSiiPr3 )2 ])}2 Co(int) ] (1) (Co(ter) , Co(int) =terminal, internal Co, respectively), with 3-coordinate Co(ter) , and Co(int) "sandwiched" between the o-phenylenes of the two ligands; experimental and computational data support Co(II) 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 ][{Co(ter) N(SiMe3 )2 (μ-η-[o-C6 H4 (κNSiiPr3 )2 ])}2 Co(int) ] (4) with the anion isostructural to 1. The centrosymmetric Fe complex [{Fe(ter) N(SiMe3 )2 (μ-η-[o-C6 H4 (κNSiiPr3 )2 ])}2 Fe(int) ] (5), analogous to 1, was also obtained.