Studies on organolanthanide complexes: III. The stabilization of early lanthanocene chlorides by using a ring-bridged dicyclopentadiene ligand

Abstract

THF-solvated early lanthanocene chlorides containing ring-bridged dicyclopentadiene as a ligand [C 5H 4(CH 2) 3C 5H 4]LnCl · THF (Ln = Nd, Pr) were synthesized. The disproportionation of dicyclopentadienyl lanthanide chlorides is thus successfully prevented and the stabilization of early lanthanocene chloride achieved. In order to further demonstrate that the products obtained are tetrahydrofuran-solvated, similar complexes of Gd, Dy, Ho, Er, Yb and Lu were also synthesized and characterized. The products obtained are without exception coordinated with one molecular tetrahydrofuran. When the tetrahydrofuran coordinated lanthanocene chlorides were allowed to react with 2,2′-bipyridyl, the coordinated tetrahydrofuran was replaced by 2,2′-bipyridyl in each case to form the 2,2′-bipyridyl complex. The latter are more stable towards air and moisture than the former ones. Fifteen new complexes were synthesized and their structures were verified by elemental analyses, infrared spectra, mass spectra and 31H NMR. Moreover, the variable temperature (77–291 K) magnetic susceptibilities were also measured.