New Type of Reaction of Lanthanide Hydrido Complexes with C₆₀: Oxidative Dehydrogenation vs Addition. The Reversible σ-C₆₀−C₆₀ Bond Formation in Complex [{(Me₃Si)₂NC(N<i>Cy</i>)₂}₂Lu(Et₂O)⁺](C₆₀^−•)

A novel type of reaction of lanthanide hydrido complexes with C60 is described. The hydride anion of complex [{(Me3Si)2NC(NCy)2}2Lu(μ-H)]2 reduces C60 (1:2 molar ratio, toluene, 20 °C) to the radical anion, and the reaction results in the formation of ionic complex [{(Me3Si)2NC(NCy)2}2Lu(Et2O)+](C60−•). At low temperature (below ∼120 K) reversible dimerization of radical anions C60−• occurs and affords the complex [{(Me3Si)2NC(NCy)2}2Lu(Et2O)+]2[(C60−)2]·2(C7H8)·(Et2O) with the diamagnetic σ-bonded (C60−)2 dianion.