Synthesis and reactivity of a μ-1,2-dinitrogen dinickel(ii) complex with a C–H activated silaamidinate pincer ligand

Abstract

Reaction of the silaamidinate nickel bromide LSi(NAr)₂NiBr₂Li(thf)(OEt₂) (L = PhC(NtBu)₂, Ar = 2,6-iPr₂C₆H₃, 1) with NaHBEt₃ led to intramolecular C–H activation with the formation of the μ-1,2-dinitrogen dinickel pincer complex [LSi(NAr)(NAr)Ni]₂(μ-1,2-N₂) (Ar = 2-C(CH₃)₂-6-iPrC₆H₃, 2). Single-crystal X-ray diffraction analysis of 2 disclosed a square planar Ni(II) atom bridged by N₂. Reaction of 2 with carbon monoxide and 2,6-dimethylphenyl isocyanide yielded square planar carbonyl and isocyanide complexes 3 and 4 with release of N₂. These results provide new approaches for the coordination of N₂ with nickel(II) species.