CRYSTAL AND MOLECULAR STRUCTURE OF TRICARBONYLBIS(TRIPHENYLPHOSPHINE)OSMIUM(O) OS(CO)3(P(C6H5)3)2

The crystal and molecular structure of tricarbonylbis (tripheny lphosphine )osmium (0), Os(CO)3(P(C6H5)3)2, has been determined from three-dimensional X-ray data collected by multiple-film methods. The structure has been refined by leastsquares techniques down to a final R factor on F of 9.1%. The material crystallizes in space group D3d-P3cl of the trigonal system, with six molecules in a cell of dimensions a = 15.80 (2) Å and c = 23.20 (3) Å. The observed and calculated densities are 1.60 ± 0.02 and 1.59 g/cm3, respectively. The crystal structure is made up of well-separated monomeric molecular units. Threefold crystallographic symmetry is imposed upon four of the molecules in the unit cell; the remaining two molecules are crystallographically required to possess D3-32 point symmetry. Thus the inner coordination about the two independent Os atoms is trigonal bipyramidal with the phosphine ligands at the pices and the three carbonyls in the equatorial plane. The average Os-P and Os-C distances are 2.36 (3) and 1.92 (5) Å. The Os-C-O linkage islinear. © 1969, American Chemical Society. All rights reserved.