Synthesis and an X-ray diffraction study of the polynuclear complex Na[(UO2)(2)(OH)(3)(CH3COO)(2)] with bridging acetato and hydroxo groups

Sodium trihydroxodiacetatodiuranylate Na[(UO2)(2)(OH)(3)(CH3COO)(2)] was sy nthesized and studied by X-ray diffraction and IR spectroscopy. The crystal s are orthorhombic, a = 7.166(2) Angstrom, b = 11.983(3) Angstrom, c = 16.3 56 Angstrom, space group Pnc2, Z = 4, d(calcd) = 3.46 g/cm(3). The pentagon al-bipyramidal U(1) and U(2) coordination polyhedra are combined into infin ite chains by two bridging OH groups and a bidentate bridging CH3COO- ions. Acetate ions of the other type are coordinated to the U(1) atoms as bident ate chelating ligands. The fifth coordination site in the equatorial plane of U(2) is occupied by the terminal OH group. Infinite anionic chains are f ormed by alternation of edge- and vertex-sharing uranium coordination polyh edra. The refinement converged to R = 0.034.