Synthesis and Characterization of an Iron(IV) Ketimide Complex

Addition of 4 equiv of LiN═C(t)Bu(2) to FeCl(2) in Et(2)O/THF results in the formation of [Li(THF)](2)[Fe(N═C(t)Bu(2))(4)] (1). Oxidation of 1 with 0.5 equiv of I(2) in Et(2)O/DME yields [Li(DME)][Fe(N═C(t)Bu(2))(4)] (2) in moderate yield. Both 1 and 2 are high spin and exhibit tetrahedral geometries in the solid state. Oxidation of 1 with 1 equiv of I(2) in Et(2)O yields Fe(N═C(t)Bu(2))(4) (3) in good yield. Surprisingly, complex 3 exhibits a diamagnetic ground state and a nearly square planar geometry about the Fe center.