Fluorenyl andansa-Dimethylsilylbis(fluorenyl) Derivatives of Divalent Ytterbium and Samarium − Synthesis and Structure of the First Mixed-Ligand LnII Classic Sandwich Complex (C13H9)(C5Me5)Yb(DME)

Novel fluorenyl complexes of divalent ytterbium (C13H9)2Yb(L)n [L = THF, n = 2 (1); L = DME, n = 1 (2)] have been prepared by reaction of YbI2(THF)2 with 2 equiv. of C13H9K as well as by reaction of (C10H8)Yb(THF)2 with fluorene in THF. Oxidation of 1 by tBuN=CHCH=NtBu (DAD) resulted in the formation of (C13H9)2Yb(DAD) (3). The reaction of {YbI(DME)2]2(µ-C10H8)} (4) with fluorene did not give (C13H9)YbI(DME) (5), but the redistribution products YbI2(DME) and 2. The first mixed-ligand sandwich complex of a divalent lanthanide metal (C13H9)(C5Me5)Yb(DME) (6) was prepared in a one-pot reaction of 4 with C5Me5H and C13H9K in DME. ansa-Me2Si(C13H8)2Yb(THF) (7) and ansa-Me2Si(C13H8)2Sm(THF)4 (8) were obtained by treatment of the appropriate LnII iodides with ansa-Me2Si(C13H9)2K2 in THF. The molecular structures of 1 and 6 were determined by single-crystal X-ray diffraction.