Synthesis and characterization of half- and full-sandwich lanthanacarboranes of the C2B9-carborane ligand. X-ray crystal structures of [LnCl2(THF)5][nido-C2B9H12] (Ln=Y, Yb)

Treatment of LnCl3(THF)x with one equivalent of Na2[nido-7,8-C2B9H11] in THF gave the half-sandwich lanthanacarborane chloride compound (η5-C2B9H11)Ln(THF)2(μ-Cl)2Na(THF)2 (Ln=Y (1), Er (2), Yb (3), Lu (4)). Recrystallization of 1 or 3 from a wet THF–toluene solution afforded the ionic compound [LnCl2(THF)5][nido-C2B9H12] (Ln=Y (5), Yb (6)). Reaction of 1 or 3 with Na2[nido-7,8-C2B9H11] in a molar ratio of 1:1 in THF generated the full-sandwich lanthanacarborane {(η5-C2B9H11)2Ln(THF)2}{Na(THF)2} (Ln=Y (7), Yb (8)). All of these new compounds were characterized by 1H-, 13C-, and 11B-NMR spectra and elemental analyses. The solid-state structures of 5 and 6 were further confirmed by single-crystal X-ray analyses.