Synthesis, reactivity and structural characterization of linked bis(amidinate) ytterbium complexes

Reaction of the dilithium salt of a linked bis(amidinate) dianionic ligand LLi2 [L=Me3SiNC(Ph)N(CH2)3NC(Ph)NSiMe3] with anhydrous YbCl3 in THF in 1:1 molar ratio, after crystallized from hexane, afforded the linked bis(amidinate) ytterbium chloride LYb(μ-Cl)2YbL(THF) (1). The chloro bridges in complex 1 can be easily broken by donor solvent. Recrystallization of complex 1 from hexane in the presence of THF formed the monomeric ytterbium chloride LYbCl(THF)2 (2). Reaction of complex 2 with 1 equiv. of CpNa, after workup, gave the desired ytterbium complex LYbCp(DME) (3) in high yield. All the complexes were characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction.