The formation of an imidozirconium compound by migration of the imido group from phosphorus to zirconium

Abstract

The η³/η¹-bis(tert-butylamido)cyclodiphosph(III)azane zirconium chloride (η³-L)(η¹-LH)ZrCl [1; L = (PNtBu)₂(NtBu)₂] has been synthesized from the reaction of ZrCl₄ with LH₂ and nBuLi in toluene. Further reaction of 1 with K–Na alloy in toluene leads to the cleavage of two P–N bonds of the η³-L ligand and the migration of the NtBu group from P to Zr, with the formation of the amidoimidozirconium potassium complex [(η¹-LH)ZrNtBu{(NtBu)₂PPNtBu}{K·(η⁶-C₇H₈)}·0.5C₇H₈] (2). The molecular structures of 1 and 2 have been determined by X-ray diffraction. In the crystalline state of 2 an η¹-L ligand, an imido moiety (NtBu) and two amido nitrogen atoms [η²-(NtBu)₂PPNtBu] bind to the zirconium center, and the coordination sphere of K is occupied by three amido nitrogen atoms [η³-(NtBu)₂PPNtBu], an η⁶-C₇H₈ molecule and two Me groups.