Oxydiacetato Complexes of Thorium(IV), the Crystal Structures of Tetra-aquo Bis(oxydiacetato) thorium(IV) Hexahydrate and Di(sodium nitrate) Disodium Tris(oxydiacetato) thorium(IV)

The crystal and molecular structures of Th(oda)2(H2O)4·6H2O (1) and Na2[Th(oda)3]·2NaNO3 (2) (oda = oxydiacetate) have been determined from three-dimensional X-ray diffraction data and refined by least squares to R = 0.049 and Rw = 0.049 for 2265 independent reflections for (1) and to R = 0.024 and Rw = 0.023 for 2196 independent reflections for (2). Crystal parameters are as follows: (1), tetragonal, space group P41212, a = 10.335(2), c = 20.709(5) A and Z = 4; (2), monoclinic, space group C2/c, a = 17.096(5), b = 9.451(2), c = 16.245(4) A, β = 107.8(1) and Z = 4. In both compounds the thorium atom lies on a crystallographic two-fold axis. The co-ordination number for thorium in (1) is 10 (bicapped square antiprism geometry), the compound is monomeric, the two oda ligands are tridentate to the metal, and four water molecules complete the coordination sphere; in thorium (2) the coordination number is 9 (tricapped trigonal prism geometry) with three oda ligands tridentate to the metal, the [Th(oda)3]2− and NO3− anions are held together through the sodium ions which are coordinated both to the oda carboxylic oxygens and to the nitrate oxygens. The ThO coordination distances are: in (1) 2.411(8), 2.414(9) for the carboxylic oxygens, 2.479(10) and 2.486(8) for water molecules and 2.697(9) for the etheric oxygen and in (2) 2.384(3), 2.402(4) and 2.402(4) for the carboxylic oxygens, 2.559(5) and 2.562(4) A for the etheric oxygens.