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

Abstract

The complex UO/sub 2/(NO/sub 3/)/sub 2/(i-C/sub 3/H/sub 7/O)/sub 2/P(O)CH/sub 2/C(O)N(C/sub 2/H/sub 5/)/sub 2/) was prepared by the addition of UO/sub 2/(NO/sub 3/)/sub 2/.6H/sub 2/O to the carbamylmethylenephosphonate ligand in ethanol. The compound has been characterized by infrared, /sup 1/H, /sup 13/C)/sup 1/H), and /sup 31/P)/sup 1/H) NMR spectroscopy. A single-crystal X-ray analysis of this compound has been completed at -28/sup 0/C, and the complex crystallizes in the monoclinic space group P2/sub 1//n with a = 10.520 (4) angstrom, b = 10.963 (4) angstrom, c = 20.033 (8) angstrom, ..beta.. = 103.79 (3)/sup 0/, Z = 4, V = 2243.7 angstrom/sup 3/, and p/sub calcd/ = 1.99g cm/sup -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 UO/sub 2//sup 2 +/ 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)more » = 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.« less