Group 5 transition metal imido complexes with dianionic guanidinate ligands displaying extended interactions

Abstract

N,N′ ,N″–tri(isopropyl)guanidinate complexes of M(V) (M = Nb, Ta) bearing imido ligands represent unique examples of monoanionic and dianionic guanidinate complexes of these metals; single crystal X-ray analyses for two of the latter species, {[µ-(NPrⁱ)₃C]₂TaMe(NPrⁱ)}(Mg₂Cl₂)·4C₆D₆ and {(µ-η²:η² (PrⁱN)₃C)Ta(NPrⁱ)Cl}₂, exhibit unusual bonding modes involving all of the nitrogen centers of the ligand.