Synthesis, Structure, and Reactivity of the Ethyl Yttrium Metallocene, (C5Me5)2Y(CH2CH3), Including Activation of Methane

(C5Me5)2Y­(μ-Ph)2BPh2, 1, reacted with ethyllithium at −15 °C to make (C5Me5)2Y­(CH2CH3), 2, which is thermally unstable at room temperature and formed the C–H bond activation product, (C5Me5)2­Y­(μ-H)­(μ-η1:η5-CH2C5Me4)­Y­(C5Me5), 3, containing a metalated (C5Me5)1– ligand. Spectroscopic evidence for 2 was obtained at low temperature, and trapping experiments with iPrNCNiPr and CO2 gave the Y–CH2CH3 insertion products, (C5Me5)2Y­[iPrNC­(Et)­NiPr-κ2N,N′], 4, and [(C5Me5)2Y­(μ-O2CEt)]2, 5. Although 2 is highly reactive, low temperature isolation methods allowed the isolation of single crystals which revealed an 82.6(2)° Y–CH2–CH3 bond angle consistent with an agostic structure in the solid state. Complex 2 reacted with benzene and toluene to make (C5Me5)2YPh, 7, and (C5Me5)2YCH2Ph, 8, respectively. The reaction of 2 with [(C5Me5)2YCl]2 formed (C5Me5)2Y­(μ-Cl)­(μ-η1:η5-CH2C5Me4)­Y­(C5Me5) in which a (C5Me5)1– ligand was metalated. C–H bond activation also occurred with methane which reacted with 2 to make [(C5Me5)2YMe]2, 9.