The structure of a dinuclear complex of osmium(I) with a metal-to-metal single bond: bis(μ-acetato)hexacarbonyldiosmium

Abstract

The crystal and molecular structure of bis-(μ-acetato)hexacarbonyldiosmium, (CH 3CO 2) 2(CO) 6, has been determined from the intensities of 3919 independent reflections measured with a counter diffractometer. The compound crystallizes in the monoclinic space group P2 1/c with eight molecules in a unit cell of dimensions a=7.767(6), b=28.347(14)c, c=14.600 (6) A and β=103.16(2); ϱ obs=2.83 and ϱ calcd=2.816 g/ml. The structure was solved by Patterson and Fourier methods and refined by least squares to a conventional R factor of 9.2% and a weighted R of 8.9%. The crystal structure is composed of dinuclear molecular units with no cyrstallographically imposed symmetry. The two independent molecules are identical within their estimated standard deviations and each has approximately C 2v symmetry with cisoid bridging acetate groups. The coordination about each osmium atom is roughly octahedral and the Os-Os distance is 2.731(2) A.