Crystal structure of bis-(η²-ethyl-ene)(η⁵-penta-methyl-cyclo-penta-dien-yl)cobalt

The title compound, [Co(C₁₀H₁₅)(C₂H₄)₂], was prepared by Na/Hg reduction of [Co₂(C₁₀H₁₅)₂(μ-Cl)₂] in THF under an ethyl-ene atmosphere and crystallized from pentane at 193 K. The Co-C(olefin) bonds have an average length of 2.022 (2) Å, while the Co-C(penta-dien-yl) bonds average 2.103 (19) Å. The olefin C=C bonds are 1.410 (1) Å. The dihedral angle between the planes defined by the cyclo-penta-dienyl ligand and the two olefin ligands is 0.25 (12)°. In the crystal, mol-ecules are linked into chains by C-H⋯π inter-actions.