Trialkylboron/Lanthanide Metallocene Hydride Chemistry: Polydentate Bridging of (HBEt₃)^- to Lanthanum

The reaction of [(C5Me5)2LaH]x with BEt3 is reported, and the solid-state structures of the lanthanum product (C5Me5)2La[(μ-H)(μ-Et)2BEt], 1, and its THF adduct (C5Me5)2La(THF)[(μ-H)(μ-Et)BEt2], 2, are compared with that of the hydride-bridged “tuckover” complex (C5Me5)2La(μ-H)(μ-η1:η5-CH2C5Me4)La(C5Me5), 3.