CRYSTAL AND MOLECULAR-STRUCTURE OF TRIS-(O-ISOPROPYLXANTHATO)-CHROMIUM(III)

The title compound has been synthesized by the reaction of CrCl3 . 6H2O with K{S2COCH(CH3)2} in a 1:3 molar ratio in an aqueous medium. It has been characterized by elemental analysis and IR spectral studies. Crystals of Cr{S2COCH(CH3)2}3 are monoclinic, space group P2(1)/n with a = 10.002(2), b = 10.973(1), c = 18.961(6) angstrom, beta = 91.78(2)-degrees, V = 2079.9 angstrom 3, Z = 4, D(calc) = 1.46 g cm-3, monochromatic radiation (Mo-K-alpha), lambda = 0.71069 angstrom, mu = 11.2 cm-1, F(0 0 0) = 948, T = 295K, final R = 0.0320 for 2641 reflections. The environment of the chromium atom is based on an octahedral geometry having six sulfur donor atoms from three symmetrically chelated ligands with average distances: Cr-S = 2.396(9) angstrom, C-S = 1.690(3) angstrom and C-O = 1.315(3) angstrom. The bond distance between oxygen atom and the carbon atom of the isopropyl group (O-C(av) = 1.478(4) angstrom) suggests that the form -S2(-)C = O(+)CH(CH3)2 contributes significantly to the structure of the isopropyl group.