Mono-cyclononatetraenyl lanthanide complexes

Abstract

The synthesis of the first half-sandwich complexes based on the cyclononatetraenyl (Cnt = C₉H₉⁻) ligand ([Ln^III(η⁹-Cnt)(η³-BH₄)₂(thf)] (Ln = La, Ce)) is reported. The title compounds were obtained from the reaction of [Ln(BH₄)₃(thf)₃] and [K(Cnt)]. Further solvation of [Ln^III(η⁹-Cnt)(η³-BH₄)₂(thf)] with tetrahydrofuran (THF) resulted in a reversible decoordination of the Cnt ring and the formation of the ionic species [Ln^III(η³-BH₄)₂(thf)₅][Cnt]. Removal of THF from [La^III(η⁹-Cnt)(η³-BH₄)₂(thf)] gave the polymeric compound [La^III(μ-η²:η²-BH₄)₂(η³-BH₄)(η⁹-Cnt)]_n.