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

Abstract

The trichlorides of Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu react with NaC/sub 5/H/sub 5/ in tetrahydrofuran in the presence of dimethoxyethane (dme) with formation of bis(cyclopentadienyl)lanthanide chloride complexes of the types (C/sub 5/H/sub 5/)/sub 2/Ln(/mu/-Cl)/sub 2/Na(dme). The reactions of these organolanthanide halide complexes with (trimethylsilyl)lithium in dme yield compounds of the type (Li(dme)/sub 2/)((C/sub 5/H/sub 5/)/sub 2/Ln(SiMe/sub 3/)/sub 2/) (Ln = Sm, Dy, Ho, Er, Tm, Lu). C/sub 5/H/sub 5//sub 2/Sm(/mu/-Cl)/sub 2/Na(dme) reacts with (trimethylgermyl)lithium in dme/pentane with formation of (Li(dme)/sub 3/)((C/sub 5/H/sub 5/)/sub 3/SmClSm(C/sub 5/H/sub 5/)/sub 3/) (7a.). The new compounds have been characterized by elemental analyses and IR and NMR spectra. The structure of (Li(dme)/sub 3/)(C/sub 5/H/sub 5/)/sub 3/SmClSm(C/sub 5/H/sub 5/)/sub 3/ (7a) has been elucidated through complete X-ray analysis. The crystals are monoclinic with a = 14.00 (1) /angstrom/, b = 13.38 (2) /angstrom/, c = 23.49 (3) /angstrom/, /beta/ = 93.37 (9)/degree/, space group P2/sub 1//n,Z = 4, and R = 0.0411 for 4671 reflections. The (Cp/sub 3/SmClSmCp/sub 3/)/sup /minus// anion consists of two Cp/sub 3/Sm units bridged by a chlorine atom with Sm-Cl distances of 2.827 (2) and 2.798 (2) /angstrom/.