Syntheses and crystal structures of two ytterbocene complexes [Yb(η-Cp′′)2I(THF)] and [Yb(η-Cp′′)2(μ-Cl)2Li(THF)2] (Cp′′=C5H3(SiMe3)2-1,3)

The ytterbocene(III) iodide [Yb(η-Cp′′)2I(THF)] (1) (Cp′′=C5H3(SiMe3)2-1,3) was synthesized by the reaction of two equivalents of Na(Cp′′) with YbI3(THF)2 (obtained from Yb and an excess of (ICH2)2 in THF). The heterobimetallic complex [Yb(η-Cp′′)2(μ-Cl)2Li(THF)2] (2) was prepared from two equivalents of Li(Cp′′) with YbCl3. The crystal structures of 1 and 2 have been determined. The formation of the ytterbium(II) complex [Yb(η-Cp′′)(OAr)(THF)x] (3) (OAr=OC6H2But2-2,6-Me-4) was observed (1H- and 171Yb-NMR spectroscopy) during the reaction of either Na(Cp′′) or [Yb(η-Cp′′)2(THF)] with [Yb(OAr)2(THF)3].