Crystal and molecular structure of tetracarbonyliodo-[o-phenylenebis(dimethylarsino)] tungsten(II) triiodide

Abstract Crystals of the title compound are monoclinic, spacegroup P 2 1 / m ; a = 14.43(1), b = 10.86(1), c = 8.01(1) A β = 93.51(8)°; Z = 2. The structure was solved from diffractometer data by Patterson and Fourier methods and refined by least squares to R 0.07 for 1544 independent reflections. The cations have crystallographic m symmetry with the metal and iodine atoms on the mirror plane. The metal atom has a capped trigonal prismatic environment with the iodine atom in the unique capping position [2.842(3) A], two arsenic atoms [2.636(2) A] and two carbonyl groups [2.067(24) A] in the capped quadrilateral face and two carbonyl groups [1.988(25) A] in the remaining edge. The distortions of the geometry from the ideal are very small despite the variations in ligand type in the quadrilateral face. The triiodide anion is asymmetrical with dimensions [2.895(3), 2.957(4) A, 178.6(1)°].