title: Unexpected formal [1+3] cycloadditions between azides and alpha-zirconated phosphanes: a route to unprecedented phosphazide and iminophosphorane complexes.
abstract: Polycyclic zwitterionic complexes that incorporate one or two phosphonium unit(s) as cationic center(s) and zirconocene-ate moiety(ies) as the anionic counterpart(s) can be easily prepared by either [1+3] or [1+3] and [2+3] cycloadditions which involve bi- or tricyclic alpha-zirconated phosphanes 3 or 4 and various azides. Some of these species exhibit unprecedented phosphazide chelation with bonding between the zirconium and a nitrogen atom in the alpha position relative to phosphorus. When heated, the phosphazide complexes lose dinitrogen to form stable polycyclic zwitterionic phosphonium mono- or dinuclear complexes. The solid-state structure of the two zwitterionic complexes 5 and 8 was determined by X-ray crystallography.
authors.affiliation: Laboratoire de Chimie de Coordination du CNRS, Toulouse, France.
authors.forename: V
authors.initials: V
authors.lastname: Cadierno
authors.forename: M
authors.initials: M
authors.lastname: Zablocka
authors.forename: B
authors.initials: B
authors.lastname: Donnadieu
authors.forename: A
authors.initials: A
authors.lastname: Igau
authors.forename: J P
authors.initials: JP
authors.lastname: Majoral
authors.forename: A
authors.initials: A
authors.lastname: Skowronska