Cyclopentadienylcobalt sulfide and selenide cluster compounds: synthesis and structural characterizations

The reaction of CpCo(CO)2 with elemental sulfur yielded the new sulfur-rich compound Cp4Co4(μ3-S)(μ3-S2)3 (1). The structure of 1 contains a Co4S7 core composed of three μ3-disulfido ligands and one μ3-sulfido ligand. PEt3 abstracts sulfur from 1 to yield the new compound Cp4Co4(μ3-S)3(μ3-S2) (2). Compound 2 is also a cage compound, but it contains three μ3-sulfido ligands and only one μ3-disulfido ligand. Compound 2 is converted back to 1 by reaction with elemental sulfur. The selenium homologue Cp4Co4(μ3-Se)3(μ3-Se2) (3) was obtained from the reaction of CpCo(CO)2 with elemental selenium. The structures of 1, 2 and 3 were determined by single-crystal X-ray diffraction analyses.