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.