Crystal and molecular structure of bis(diisopropylphenylphosphine)hexahydridoosmium, [OsH6(PC12H19)2]: single-crystal neutron diffraction study at 20 K

The crystal and molecular structure of the hexahydridoosmium complex (OsH/sub 6/(PC/sub 12/H/sub 19/)/sub 2/), determined from a low-temperature X-ray diffraction analysis, has been refined on the basis of neutron diffraction data obtained at 20 K. The dodecahedral ML/sub 2/H/sub 6/ core has approximate mm symmetry with the phosphines in equivalent B (five-neighbor) sites and a P-Os-P angle of 155.2 (1)/sup 0/. The Os-H distances range from 1.637 (4) to 1.668 (4) A, with a mean value of 1.649 (5) A. Crystal data at 20.0 (5) K: a = 17.016 (3) A, b = 13.762 (3) A, c = 10.857 (3) A, ..beta.. = 98.91 (2)/sup 0/, V = 2512 (1) A/sup 3/, monoclinic, P2/sub 1//n, Z = 4, M/sub r/ 584.8. 29 references, 2 figures, 3 tables.