Crystal structure of bis-(η(2)-ethyl-ene)(η(5)-penta-methyl-cyclo-penta-dien-yl)cobalt.

The title compound, [Co(C(10)H(15))(C(2)H(4))(2)], was prepared by Na/Hg reduction of [Co(2)(C(10)H(15))(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)†à , while the Co-C(penta-dien-yl) bonds average 2.103†(19)†à . The olefin C=C bonds are 1.410†(1)†à . 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.