X-RAY CRYSTALLOGRAPHIC AND SPECTROSCOPIC STRUCTURAL STUDIES OF UBR(PO2H2)3-2H2O

The synthesis, crystal structure and spectroscopic studies of UBr(PO2H 2)3.2H2O are reported. This compound crystallizes in the orthorhombic space group P bcm with four molecules per unit cell of dimensions: a = 7.488(5) angstrom, b = 10. 1 92(2) angstrom and c = 15.203(5) angstro m. The structural determination converges to R = 0.043 and R(w) = 0.03 3 for 1906 independent reflections having 2-degrees<2theta (Mo K alpha )<100-degrees and / >3nu (/). The structure analysis reveals that the tetravalent uranium is surrounded by eight oxygen atoms as a distorted tetragonal antiprism and the Br atom is surrounded by six hydrogen at oms forming a distorted octahedron. There are two kinds of tetrahedral (H2PO2)- anions. The visible absorption spectrum indicates that the o xidation state of uranium is 4+ and the interpretation of the infrared spectra confirms the crystallographic results.