The First Linear, Homoleptic Triple-Decker Sandwich Complex of an f-Element: A Molecular Model for Organolanthanide Nanowires

The first structurally authenticated linear, homoleptic triple-decker
sandwich complex of an f-element, (η8-COT′′)Nd(μ-η8:η8-COT′′)Nd(η8-COT′′) (2; COT′′ = [C8H6(SiMe3)2-1,4]2−) has become available through a rather unexpected synthetic pathway.
Treatment of [Li(THF)4][Nd(COT′′)2] (1) with anhydrous cobalt(II) chloride (molar ratio
ca. 2:1) in a toluene suspension afforded 2 in 72% isolated
yield. The most notable structural feature of 2 is the
near-linear arrangement of the COT′′ rings with (ring
centroid)−Nd−(ring centroid) angles of 176.1 and 175.6°,
respectively, and a Nd−(ring centroid)−Nd angle of 177.9°,
making the title compound the first true molecular model for lanthanide-based
nanowires.