| dc.description |
The cluster anion [Os4(CO)1 2H3]<sup>â </sup> reacts with commercial [NO][PF6] in acetonitrile via the in situ formation of orthophosphoric acid to give the neutral cluster species, [Os4(CO)1 2H4], [Os4(CO)1 2H3(µ-OPO3H2)], and [Os4(CO)1 2H3(µ-OH)]. The latter two products crystallise together in a 2 : 1 ratio in the monoclinic space group P21/c with unit-cell dimensions a= 14.315(3), b= 30.732(4), c= 15.314(3)à , β= 101.48(2)°, and Z= 4. The structure was solved by a combination of direct methods and Fourier-difference techniques and refined by blocked full-matrix least squares to R= 0.051 for 5 091 observed reflections. In each of the µ-OPO3H2 and µ-OH compounds the four osmium atoms define a â butterflyâ configuration with two triangles sharing a common edge but which are not coplanar, supported by the bridging oxygen linkage. The three hydrido-ligands were not located but the Osâ Os bond lengths suggest that they bridge in the same arrangement as that found previously in [Os4(CO)1 2H3I] by neutron diffraction. |
