Synthesis of anhydrous lanthanide chloride complexes from oxides and the crystal structure of [GdCl3(thf)(2)(tmeda)]

Complexes of [LnCl(3)(dme)(2)] (Ln = Sm, Gd; dme = dimethoxyethane) were pr epared in dimethoxyethane solution from the lanthanide oxides and hydrogen chloride, which was formed in situ from chlorotrimethylsilane and water. Th e recrystallization of [LnCl(3)(dme)(2)] from tetrahydrofuran in the presen ce of tetramethylethylenediamine (tmeda) resulted in [LnCl(3)(thf)(2)(tmeda )] (Ln = Sm, Gd). The samarium and gadolinium complexes were found to be is omorphous by unit cell determination. Each seven-coordinated gadolinium ato m adopts a distorted pentagonal bipyramidal geometry with chlorine atoms in axial positions. The thermal decomposition of the compounds in argon resul ted in LnOCl. (C) 1998 Elsevier Science Ltd. All rights reserved.