Tetramethylcyclopentadienyl vs Cyclopentadienyl Substituents. Synthesis and Structural Characterization of Organolanthanide Compounds Derived from the Versatile Ligand Me2Si(C5Me4H)(C2B10H11)

Reaction of Me2Si(C5Me4H)Cl with 1 equiv of Li2C2B10H10 in toluene/Et2O gave the monoanionic salt [Me2Si(C5Me4)(C2B10H11)]Li(OEt2)0.5 (1), which could be conveniently converted into the dianionic salt [{[(μ-η5):σ-Me2Si(C5Me4)(C2B10H10)]Li(THF)}2Li][Li(THF)4]·THF (2) by treatment with 1 equiv of n-BuLi. 1 reacted with 1 equiv of LnCl3 in THF to give [η5-Me2Si(C5Me4)(C2B10H11)]LnCl3Li(THF)3 (Ln = Nd (3), Sm (4)). 3 could further react with 1 equiv of 1 to afford [η5-Me2Si(C5Me4)(C2B10H11)]2Nd(μ-Cl)2Li(OEt2)(THF) (6), which could also be prepared from the reaction of NdCl3 with 2 equiv of 1. Partial hydrolysis of 4 resulted in the isolation of the novel cluster [{[η5-Me2Si(C5Me4)(C2B10H11)]Sm}2(μ2-Cl)3(μ3-Cl)4Li(OEt2)2Li(THF)2Sm(μ4-O)]2 (5). Treatment of 1 with 4 equiv of NaNH2 in THF, followed by reaction with 1 equiv of YbCl3, produced (η5-C5Me4H)2Yb(μ-Cl)2Li(THF)2 (7). An equimolar reaction between 2 and NdCl3 yielded the anionic compound [{η5: σ-Me2Si(C5Me4)(C2B10H10)}2Nd][Li(DME)3] (11). Interaction of ...