The structure of disulfurbis(bis(diphenylphosphino)ethane)iridium(I) chlorideacetonitrile, [Ir(S2)-((C6H5)2PCH2CH2P(C6H5)2)2]Cl·CH3CN, has been determined from three-dimensional X-ray data collected by counter methods. This compound crystallizes in space group D2d4-P421c of the tetragonal system with four formula weights per cell (a = 22.064 (9), c = 20.747 (9) A). The observed and calculated densities are 1.51 (2) and 1.486 g/cm3, respectively. Full-matrix least-squares refinement of the structure has yielded a final conventional R factor of 0.050 (on F) for the 3041 independent reflections with F2 > 3tr(F2). The ions and solvate molecule occupy general positions in the cell. The [Ir(S2)((C6H5)2PCH2CH2P(C6H5)2)2]+ cation displays approximately trigonal-bipyramidal coordination and is nearly isostructural with the previously reported oxygen carriers, [M(O2)((C6H5)2-PCH2CH2P(C6H))2)2]+= (M = Ir, Rh). The disulfur molecule is ir bonded at an equatorial site, with an average Ir-S distance of 2.41 (2) A. The four phosphorus atoms complete the coordination sphere at 2.33-2.37 A from the metal. While the S-S linkage of 2.066 (6) A is similar to that reported for octasulfur (2.060 (3) A), it is significantly longer than the 1.889-Å S-S bond in free disulfur. The Ir-S2 bonding is easily rationalized in terms of the π-bonding model previously advanced for the d8 oxygen carriers.
ASJC Scopus subject areas
- Colloid and Surface Chemistry