Versatile behavior of hydrido monometallic or heterobimetallic carbonyl anions toward dichlorophosphines and 1,1-dichlorodiphosphines

Abstract

No. 64) and the noncentrosymmetric space group C2cb (standard setting Aba2, C\l, No. 41). With Z = 8 (Table I) the space group Cmca demands that the formula unit possesses a mirror plane and that the Ru, O, C(l), C(4), C(5), C(6) atoms lie at x = 0 and V j. In C2cb no symmetry demands are placed on the formula unit. Cmca was initially assumed, and this space group was subsequently verified by the unambiguous, refined structure. Interpretation of the three-dimensional Patterson function gave the Ru coordinates. The carbon and oxygen atoms were found from a Fourier synthesis phased on Ru. Following several cycles of anisotropic least-squares refinement, the thermal ellipsoid of the cyclopentadienyl carbon lying on the mirror plane, C(6), was found to be abnormally extended in the direction perpendicular to the mirror plane. This was taken to indicate some disorder in the cyclopentadienyl ring, with a fraction of the cyclopentadienyls occupying a position rotated by 180°about the ring axis. By trial, the occupany of this rotated position was found to be 0.3. Refinement of the major component, with occupany 0.7, gave well-behaved thermal ellipsoids and improved bond distances. The hydrogen atoms of the Cp and 2-methylallyl ligands were then placed at calculated positions [C-H = 0.95 A, B(H) = B(C) + 1.0] during refinement, with the positional and thermal parameters fixed. Full-matrix refinement with weights w = [ 2]/) + (bF02)2]1/2 and k = 0.08 gave a final R value of 0.041, fiw = 0.055, for 1013 observed reflections. An extinction correction was included in the structure factor calculation and was refined during final least-squares refinement, giving g = 4.87 X 6.Both structure factor calculations used atomic scattering factors for C, O, and Ru, with anomalous dispersion from Cromer and Liberman,13 and for bonded H from Stewart, Davidson and Simpson.14