New ionic half-metallocenes of early lanthanides

Marc Visseaux (1) , Philippe Zinck (1) , Michael Terrier (1) , André Mortreux (1) , Pascal Roussel (1)

1 UCCS - Unité de Catalyse et Chimie du Solide - UMR 8181

We present in this study a new and one-step method allowing the preparation of an unprecedented family of stable half-lanthanidocenes. X-ray analysis shows that the isolated compounds all display the same ionic Ln–Mg bimetallic structure consisting of two anionic (CpR)Ln(BH4)3 species and one cationic Mg(THF)6 (CpR =C5Me5, Ln = Nd, 1a, Ln = La, 1b; CpR =C5H5, Ln = Nd, 2a; CpR =C5H2Ph3, Ln = Nd, 3a). Such complexes display high stability with respect to disproportionation in solution. Combined with dialkylmagnesium, neodymium complexes provide powerful catalysts for stereospecific isoprene polymerisation.

Mots clés: Polymers; elastomers; and plastics; Chemical synthesis; Catalysis; Crystal structure; X-ray diffraction

Domaines: Catalyse; Chimie de coordination; Polymères

Marc Visseaux, Philippe Zinck, Michael Terrier, André Mortreux, Pascal Roussel. New ionic half-metallocenes of early lanthanides. Journal of Alloys and Compounds, 2008, 451, pp.352. ⟨10.1016/j.jallcom.2007.04.140⟩. ⟨hal-00264451⟩