No abstract

No abstract

In this report, we present intricate pathways for the synthesis of linear nickel­(I) silylamide K­{m}­[Ni­(NR2)2] (NR2 = −N­(SiMe3)2). This is achieved first via the reduction of nickel­(II) trisamide Li­(donor)4[Ni­(NR2)3] (Li­(thf) x [1]) with KC8 in the presence of 18-crown-6 or crypt.222. In due course, the behavior of Li­(donor)4[Ni­(NR2)3] as a source of masked two-coordinate nickel­(II) hexamethyldisilazanide is explored, leading to the formation of nickel­(I) and nickel­(II) N-donor adducts, as well as metal–metal-bonded dinickel­(I) trisamide K­(toluene)­[Ni2(NR2)3] (K­(toluene)­[5]). Finally, a convenient and reliable synthesis of K­{m}­[Ni­(NR2)2] by ligand exchange of phosphines in [Ni­(NR2)­(PPh3)2] with K­{m}­(NR2) is presented. This allows for the comprehensive analysis of its electronic properties which reveals a fluxional behavior in solution with tight anion/cation interactions.

A pair of trigonal imido iron complexes ([Fe(NMes)L2]0,−) in two oxidation states is reported. The anionic complex K{crypt.222}[Fe(NMes)L2] is best described as an iron(ii) imide.

We report on the synthesis of a variety of trigonal imido cobalt complexes [Co(NAryl)L 2 ] À , (L= N-(Dipp)SiMe 3 ), Dipp = 2,6-diisopropylphenyl) with very long CoÀN Aryl bonds of around 1.75 . Their electronic structure was interrogated using a variety of physical and spectroscopic methods such as EPR or X-Ray absorption spectroscopy which leads to their description as highly unusual imidyl cobalt complexes. Computational analyses corroborate these findings and further reveal that the high-spin state is responsible for the imidyl character. Exchange of the Dipp substituent on the imide by the smaller mesityl function (2,4,6-trimethylphenyl) effectuates the unexpected Me 3 Si shift from the ancillary ligand set to the imidyl nitrogen, revealing a highly reactive, nucleophilic character of the imidyl unit.