Syntheses and crystal structures of anhydrous Ln(hfac)3(monoglyme). Ln = La, Ce, Pr, Sm, Eu, Gd, Tb, Dy, Er, Tm

Abstract

The crystal structures of a broad series of anhydrous Ln(hfac)₃(monoglyme) complexes, prepared in moderate to high yield, are presented: hfac = 1,1,1,5,5,5-hexafluoroacetylacetonato-; Ln = La, Ce, Pr, Sm, Eu, Gd, Tb, Dy, Er, Tm. This study contradicts the general assumption that monoglyme is too small a polyether to act as a partitioning agent displacing coordinated water on the larger lanthanide(III) ions. The structures of an intermediate La(hfac)₃(monoglyme)₂ species and the hydrated Ce(hfac)₃(monoglyme)(H₂O) species are also included. The crystallographic evidence presented herein is supplemented by other characterization techniques (melting point, IR, etc.) and trends are delineated.