Synthesis and crystal structures of tris(2-methoxyethylcyclopentadienyl)lanthanide complexes

Abstract

The tris(2-methoxyethylcyclopentadienyl)lanthanide complexes [Ln(C5H4CH2CH2OMe)3](Ln = La, Pr, Nd, Gd or Y) were synthesized by the reaction of sodium 2-methoxyethylcyclopentadienide with the corresponding LnCl3 and the products were characterized by elemental analyses, mass, IR and 1H NMR spectroscopy. Crystal structure determinations revealed the complexes to be unsolvated monomeric metallocenes with lanthanide centres co-ordinated by three cyclopentadienyl rings and two oxygen atoms of the three 2-methoxyethyl moieties present; the third oxygen is not co-ordinated. The distances Ln–C (η5) and Ln–O(1)(co-ordinated oxygen) decrease as the ionic radius decreases; however, Ln–O(3)(co-ordinated oxygen) increases.