A new bimetallic complex containing Ce and Al: η 8-cyclooctatetraenylcerium-di-μ-isopropoxydiethylaluminum

Abstract

The reduction of Ce(O-i-C 3H 7) 4·B, where B=i-C 3H 7OH or pyridine, by (C 2H 5) 3Al in the presence of cyclooctatetraene yields a new crystalline complex, η 8-C 8H 8)Ce(O-i-C 3H 7) 2Al(C 2H 5) 2 (I) which can coordinate one mol of acetonitrile forming a crystalline adduct (II). The base can be easily removed under reduced pressure from (II) which converts into (I). The structure of complexes (I) and (II) has been investigated through mass spectrometry, alcoholysis, deuterolysis, IR and 1H NMR. Both (I) and (II) are paramagnetic and show in the presence of polar molecules, e.g. pyridine or acetonitrile, NMR spectra noticeably dependent on the temperature. The experimental results have been interpreted on the basis of an asymmetric bridge between Ce and Al formed at T > 45 °C.