Sandwich-type Uranium-Substituted of Bismuthotungstate: Synthesis and Structure Determination of [Na(UO2)2(H2O)4(BiW9O33)2]

The sandwich-type [Na(UO2)2(H2O)4(BiW9O33)2]uranium (VI) has been synthesized by reacting the trivacant species of B-alpha-[BiW9O33]with {expression} and investigated by IR and UV-Vis spectroscopy, and elemental analysis. The X-ray single crystal analysis was carried out on Na13[Na(UO2)2(H2O)4(BiW9O33)2] * 33H2O (I) which crystallizes in the orthorhombic system, space group Pna21 with a = 33.8454(19) A, b = 21.1484(12) A, c = 13.2403(7) A, alpha = 90 deg , beta = 90 deg , gamma = 90 deg , and Z = 4. The polyanion consists of two lacunary B-alpha-[BiW9O33]groups which sandwich two uranyl cations and one sodium cation. The uranium atoms adopt distorted pentagonal-bipyramidal coordination, achieved by two equatorial bonds to each BiW9O33 unit and one external water ligand. The coordination of each uranium atom is evident by the shift of nuas(W-Ob-W) and nuas(Bi-O) stretching vibrational bonds.