Synthesis and crystal and molecular structure of bis(nitrato)[diisopropyl (N,N-diethylcarbamyl)methylenephosphonate]dioxouranium(VI)

The complex UO2(NO3)2[i-C3H7O)2P(O)CH2C(O)N(C2H5)2] was prepared by the addition of UO2(NO3)2.6H2O to the carbamylmethylenephosphonate ligand in ethanol. The compound has been characterized by infrared, 1H, 13C]1H], and 31P]1H] NMR spectroscopy. A single-crystal X-ray analysis of this compound has been completed at -280C, and the complex crystallizes in the monoclinic space group P21/n with a = 10.520 (4) angstrom, b = 10.963 (4) angstrom, c = 20.033 (8) angstrom, #betta# = 103.79 (3)0, Z = 4, V = 2243.7 angstrom3, and p/sub calcd/ = 1.99g cm-3. The structure was solved with use of heavy-atom techniques, and blocked least-squares refinement converged with R/sub F/ = 4.1% and R/sub wF/ = 3.9% for 4153 independent reflections with F greater than or equal to 4sigma(F). The molecular structure of the compound consists of a linear UO22+ ion surrounded at its equator by four oxygen atoms from two bidentate nitrate ions and the phosphoryl and carbonyl oxygen atoms from a bidentate phosphonate ligand. Several important bond distances include U-O(uranyl)/sub av/ = 1.7.56(6) angstrom, U-O(phosphoryl) = 2.420 (4) angstrom, U-O(carbonyl) = 2.406 (5) angstrom, U-O(nitrate)/sub av/ = 2.512 (5) angstrom, P-O(phosphoryl) = 1.485 (5) angstrom, and C-O(carbonyl) = 1.260 (8) angstrom