First example of a neutral homoleptic uranium alkyl. Synthesis, properties, and structure of U[CH(SiMe3)2]3

Article abstract of DOI:10.1021/om00105a051

The reaction of U(O-2,6-Bu^t₂C₆H₃)₃ with 3 equiv of LiCH(SiMe₃)₂ in hexane at ambient temperature provides royal blue U[CH(SiMe₃)₂]₃ (1) in ca. 40% isolated yield. In the solid state, 1 is pyramidal with crystallographically imposed C₃ symmetry, a U(1)-C(4) (i.e., U-C_α) bond length of 2.48 (2) A?, and a C(4)-U(1)-C(4′) bond angle of 107.7 (4)°. The molecular structure also features a γ-agostic interaction with three symmetry-related silyl methyl groups [U(1)-C(7) = 3.09 (2) A?]. 1 is thermally stable as a solid at room temperature but decomposes with loss of H₂C(SiMe₃)₂ at ca. 60°C. Solutions of 1 in hexane or THF slowly decompose over the course of several hours. Reaction of UCl₃(THF)_x with 3 equiv of LiCH(SiMe₃)₂ in THF does not produce U[CH-(SiMe₃)₂]₃ but rather a green ionic complex of formula [Li(THF)₃] [UCl{CH(SiMe₃)₂}₃].