Crystal structure of [μ-1κ,:2(1,2,3,4-η)-1,2,3,4-tetra-phenyl-buta-1,3-diene-1,4-di-yl]bis-(tri-carbonyl-osmium)(-).

In the title complex CHOOs or (μ-η-CPh)Os(CO), one Os atom is part of a metalla-cyclo-penta-diene ring, while the second Os atom is π-bonded to the organic portion of this ring. The distance of 2.7494 (2) Å between the two Os atoms is typical of an Os-Os single bond.