X-ray crystal structures of two (ethylidyne)tricobalt clusters. Thermolysis of Cp*Co(H2
-H), not Cp*3
The structures of the μ3-ethylidyne tricobalt clusters Cp*3Co3(μ3-CCH3)2 (2) and Cp*3Co3(μ3-CCH3)-(μ3-H) (3) were determined by X-ray crystallography. The 48-electron cluster 2 consists of an equilateral triangle of cobalt atoms (Co-Co = 2.437(1) A) symmetrically capped on each face by a μ3-CCH3 ligand. Cluster 3 was necessarily disordered by the crystallographic site symmetry (3/m) and was therefore refined by employing a mirror-disordered model (3a) which assigned half-weight to the disordered μ3-CCH3 ligand. The 46-electron cluster 3a consists of an equilateral triangle of cobalt atoms (Co-Co = 2.378(1) A) symmetrically capped on a single face by a μ3-CCH3 ligand.