title: Synthesis and characterization of thorium(IV) sulfates.
abstract: Three Th(IV) sulfates, two new and one previously reported, have been synthesized from aqueous solution. In all of the compounds, the sulfate anions coordinate the Th(4+) metal center(s) in a monodentate manner with Th-S distances of 3.7-3.8 Å. Th(SO(4))(2)(H(2)O)(7)·2(H(2)O) (1; P2(1)/m, a = 7.224(1) Å, b = 12.151(1) Å, c = 7.989(1) Å, ss =98.289(2)°) and Th(4)(SO(4))(7)(H(2)O)(7)(OH)(2)·H(2)O (2; Pnma, a = 18.139(2) Å, b = 11.173(1) Å, c = 14.391(2) Å) each contain 9-coordinate monomeric (1,2) and dimeric (2) Th(IV) cations in monocapped square antiprism geometry. Alternatively, Th(OH)(2)SO(4) (3; Pnma, a = 11.684(1) Å, b = 6.047(1) Å, c = 7.047(1) Å) is built from chains of hydroxo-bridged, 8-coordinate Th(4+) centers. Whereas 1 adopts a molecular structure, 2 and 3 both exhibit 3D architectures. Differences in the dimensionality and the topology of 1-3 are manifested in the local coordination environment about the Th(IV) centers, the formation of oligomeric Th(4+) species, and the extended connectivity of the sulfate ligands. Herein, we report the syntheses and characterization of 1-3 as well as the atomic correlations of 1 in solution, as determined by high-energy X-ray scattering (HEXS).
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Karah E
authors.initials: KE
authors.lastname: Knope
authors.forename: Richard E
authors.initials: RE
authors.lastname: Wilson
authors.forename: S
authors.initials: S
authors.lastname: Skanthakumar
authors.forename: L
authors.initials: L
authors.lastname: Soderholm
mesh_terms: D060326:Chemistry Techniques, Synthetic; D008958:Models, Molecular; D013431:Sulfates / Q000737:chemistry*; D013910:Thorium / Q000737:chemistry*
chemical_list: D013431:Sulfates; D013910:Thorium