Sandwich and Half-Sandwich Ln(II) (Ln = Sm, Yb) Complexes with Bulky Fluorenyl Ligands. Competitive Abstraction of H or SiMe3 from 2,7-tBu2-9-SiMe3-Fluorene by an Amido Anion

The half-sandwich fluorenyl-amido complex [2,7-tBu(2)-9-SiMe3C13H6]Yb[N(SiMe3)2](DME) was synthesized by the reaction of [(Me3Si)(2)N](2)Yb(THF)(2) with 2,7-tBu(2)-9-SiMe3C13H7 (1:1 molar ratio) in 83% yield. The analogous reaction of [(Me3Si)(2)N](2)Sm(THF)(2) affords a mixture of equimolar amounts of the half-sandwich complexes [2,7-tBu(2)-9-SiMe3C13H6]Sm[N(SiMe3)(2)](DME) (2a) and heteroligand sandwich [2,7-tBu(2)-9SiMe(3)C(13)H(6)]Sm[2,7-tBu(2)C(13)H(7)](DME) (2b). The heteroligand sandwich complex [2,7-tBu(2)-9-SiMe3C13H6]Sm[2,7-tBu(2)-C13H7](THF) 2 (3) was synthesized in 60% yield by reacting [(Me3Si)(2)N](2)Sm(THF)(2) with 2 equiv of 2,7-tBu(2)-9-SiMe3C13H7. Complexes 2b and 3 result from competitive abstraction of H or SiMe3 from 2,7-tBu2-9-SiMe3-fluorene by an amido group. In contrast, the homoligand sandwich complex [2,7-tBu(2)-9-SiMe3C13H6](2)Sm(DME) (5) could be synthesized in 80% yield when [(p-tBuC(6)H(4)) 2 CH]2Sm(DME) 2 was used as a precursor. The complex (2,7-tBu(2)C(13)H(7))2Sm(THF) 2 (6) was synthesized by the reaction of 2,7-tBu(2)C(13)H(8) with [(Me3Si)(2)N](2)Sm(THF) 2 (2:1) in 65% yields. The crystal structures of complexes 1, 2a,b, 3, 5, and 6 were established by X-ray analyses.

Automated summary

Various half-sandwich complexes were synthesized under different reaction conditions, indicating the versatility of the reactions towards ligand substitution and complex formation.