Organometallic compounds of the lanthanides. 42. Bis(dimethoxyethane)lithium bis(cyclopentadienyl)bis(trimethylsilyl)lanthanide complexes

Article abstract of DOI:10.1021/om00099a016

The trichlorides of Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu react with NaC₅H₅ in tetrahydrofuran in the presence of dimethoxyethane (dme) with formation of bis(cyclopentadienyl)lanthanide chloride complexes of the types (C₅H₅)₂Ln(μ-Cl)₂Na(dme). The reactions of these organolanthanide halide complexes with (trimethylsilyl)lithium in dme yield compounds of the type [Li(dme)₂][(C₆H₅)₂Ln(SiMe ₃)₂] (Ln = Sm, Dy, Ho, Er, Tm, Lu). (C₅H₅)₂Sm(μ-Cl)₂Na(dme) reacts with (trimethylgermyl)lithium in dme/pentane with formation of [Li(dme)₃][(C₅H₅)₃SmClSin(C ₅H₅)₃] (7a). The new compounds have been characterized by elemental analyses and IR and NMR spectra. The structure of [Li(dme)₃][(C₅H₅)₃SmClSm(C ₅H₅)₃] (7a) has been elucidated through complete X-ray analysis. The crystals are monoclinic with a = 14.00 (1) A?, b = 13.38 (2) A?, c = 23.49 (3) A?, β = 93.37 (9)°, space group P2₁/n, Z = 4, and R = 0.0411 for 4671 reflections. The [Cp₃SmClSmCp₃]^- anion consists of two Cp₃Sm unite bridged by a chlorine atom with Sm-Cl distances of 2.827 (2) and 2.798 (2) A?.